Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Home
My WebLink
About
CT 04-18; OCEAN MIST CONDOMINIUMS; PRELIMINARY GEOTECHNICAL EVALUATION; 2004-06-21
.. S Geotechnical .Geologic- Environmental I i I 1: 5741 Palmer Way • Catisbad, California 92008 • (760) 438-3155 • FAX(760)931-0915 HI.. RDA Designs I Carlsbad, California 92008 I Attention: Mr. Ron Alvarez June 21, 2004 W.O. .4369-A-SC Subject: Preliminary Geotechnical Evaluation, Proposed Ocean Mist Condominiums, 325-347 Oak Avenue, City of Carlsbad, San Diego County, California Dear Mr. Alvarez: In accordance with your request, GeoSoils, Inc. (GSl) has performed a preliminary geotechnical evaluation of the subject site. . The purpose of the study was to evaluate the onsite soils and geologic conditions and their effects on the proposed site development from a geotechnical viewpoint. . . . . .5 EXECUTIVE SUMMARY .1 Based on our review of the available data (see Appendix A),. field exploration, laboratory testing, and geologic analysis, residential development of the property appears to be feasible from a gOotechnical viewpoint, provided the recommendations presented in the text of this report are properly incorporated into the design and construction of the project. The most significant elements of this study are summarized below: . The proposed development will consist of a condominium structure. With basement/garage sub-floors and two additional stories above the sub-floor, as well as. underground utility improvements.. . . . . Excavation into Quaternary-age terrace deposits will be necessary prior to foundation construction, of the basement sub-floor. In general, unsuitable soils are on the order of ±1 to ±2 feet across a majority of the site. However, localized deeper removals cannot be precluded, should settlement-sensitive improvements be proposed within their influence. It is anticipated that the removal of unsuitable bearing materials will generally be performed by default during excavation for the garage/basement todesign grades, and thus, should not adversely affect proposed superjacent improvements. ... I I ": •' The expansion -potential of tested onsite soils is generally'ver y l o w . C o n v e n t i o n a l foundations may likely be utilized for these soil c o n d i t i o n s ; h o w e v e r , b a s e d o n f i e l d I . mapping in' the vicinity of. the site, the pres e n c e o f n u m e r o u s . p a l e o l i q u e f a c t i o n features ("sand blows," liquefaction craters, s a n d f i l l e d f i s s u r e s a n d i n j e c t i o n . d i k e s , sand vents, etc.), may exist within the site. Po t e n t i a l l i q u e f a c t i o n o f s u c h a r e a s i n . . the future that may impact surface, improveme n t s i s c o n s i d e r e d v e r y l o w , p r o v i d e d . . that the recommendations presented in this r e p o r t a r e i n c o r p o r a t e d i n t o t h e d e s i g n and construction .of the project. Mitigation f o r s t r u c t u r e s m a y b e p r o v i d e d , b y t h e , . use of post-tensioned stabs. Mitigation in ot h e r a r e a s m a y b e a c c o m p l i s h e d b y overexcavation and/or geotextiles, as evalu a t e d i n t h e f i é l d . d u r i n g g r a d i n g , b a s e d S. on proposed development and use . . . '". . . . . If paleoliquefaction' feat exist, post-tensioned foundations would b e m o s t . suitable for this project. However, this r e c o m m e n d a t i o n w o u l d b e b a s e d . o n conditions disclosed during grading. . . .. ... S •. .. At the time of this report, corrosion testing r e s u l t s . h a d n o t b e e n r e c e i v e d , f o r t h e S I subject site. An addendum report, presenti n g t h o s e r e s u l t s , w i l l b e p r o v i d e d w h e n • . lab testing is complete.'. '. . . . . . I' Our evaluation indicates that proposed tempor a r y c o n s t r u c t i o n s l o p e s o n s i t e .may generally be considered .surficially' un s t a b l e , a n d m a y r e q u i r e s h o r i n g . I Recommendations for shoring are provided h e r e i n In general, and based upon the available dat a t o d a t e , g r o u n d w a t e r i s n o t e x p e c t e d to be a major factor in development of the s i t e ; h o w e v e r , p e r c h e d w a t e r m a y o c c u r during construction and/or after site develop m e n t , a n d s h o u l d b e a n t i c i p a t e d . T o . - . mitigate the potential for water vapor proble m s o w i n g t o t h e p o s s i b i l i t y o f p e r c h e d .I. ' water, the use of 4,500 psi óoncrete, with a n a l t e r e d w a t e r - c e m e n t r a t i o ( 0 . 4 5 ) i s . additionally recommended.. . ... .. . .' . I • Our evaluation indicates there are no know n a c t i v e f a u l t s c r o s s i n g t h e s i t e ' The seismic acceleration values and design p a r a m e t e r s p r o v i d e d h e r e i n s h o u l d b e 1 considered during the design of the proposed d e v e l o p m e n t . , I , ' • Adverse geologic . features that would preclude project, fe a s i b i l i t y w e r e n o t encountered. The recommendations presented in this rep o r t s h o u l d b e i n c o r p o r a t e d i n t o t h e , design and construction considerations of th e p r o j e c t . , I RDA Designs S ' ' '.. . . . . W.O. 4369-A-SC Fiie:e:\wp9\4300\4369a.pge . " S Page Two 'GeoSoils, Inc. S. TABLE OF CONTENTS I SCOPE OF SERVICES 1 I SITE CONDITIONS/PROPOSED DEVELOPMENT FIELD STUDIES 1 1 1 REGIONAL GEOLOGY 3 EARTH MATERIALS 3 Topsoil/Colluvium ......................................................3 Terrace Deposits ........................................... .......... ... 3 I. MASS WASTING .............................................. .• ................ 5 I FAULTING AND REGIONAL SEISMICITY 5 Faulting ............. . ........5 I . Seismicity .. . ............................... . . . . . . . . . . . . . . . . . . . . . . Seismic. Shaking Parameters . .. .............................. . . . . . . . . . . 7 8 Seismic Hazards 8 I . GROUNDWATER ...............................................................9 LIQUEFACTION POTENTIAL ...................................................9 -, LABORATORY TESTING ......................................... ................ 10 General ....................................... . . . . . . . . . . . . . . . . . . . . . 10 Moisture-Density Relations . ...........................................10 Shear Testing ........, ........................................ . . . . . . .10. .I . Expansion Potential ....................................................11 - Corrosion Testing 11 I PRELIMINARY CONCLUSIONS 11 EARTHWORK CONSTRUCTION RECOMMENDATIONS General.................................................................11 11 Site Preparation ......................................................... . 12 * . Removals (Unsuitable Surficial Materials) ................................ Fill Placement ............................................................12 12 Transitions/Overexcavation ............................................12 Subdrains....................................................................13 Temporary Construction Slopes .........................................13. Preliminary Shoring Recommendations .................................. 13: I General ............................................................13 I Lateral Pressures ..........................................................14 I . . . . . GeoSoils, Inc. . I: .• . . S •.' •. .: . .. Design of Soldier Piles S 14 Lagging 14 , Internal Bracing ............................................................. •. 14 Deflection 15 Monitoring 15 I RECOMMENDATIONS - FOUNDATIONS 15 Preliminary Foundation Design 15 Value ............................................................ .. .16 .. S SI Bearing Lateral Pressure................................................................ . 16 ... Foundation Settlement ..................................................16. I .Footing Setbacks.... .................................................... 16 Construction ...............................................................17 Very Low Expansion Potential (E I 0 to 20) 17 POST-TENSIONED SLAB SYSTEMS 18 -Tensioning Institute Method 19 I Post UTILITIES 20 I WALL DESIGN PARAMETERS 20 Conventional Retaining Walls ............................................20 S S Restrained Walls ............................................................ Cantilevered Walls ...................................................21 20 Retaining Wall Backfill and Drainage ....................................... . 21 1 5 Wall/Retaining Wall Footing Transitions ................................ 25 TOP-OF-SLOPE WALLS/FENCES/IMPROVEMENTS 25 I Slope Creep ..........................5 . 25 Top of Slope Walls/Fences 26 I DRIVEWAY, FLATWORK, AND OTHER IMPROVEMENTS 27 DEVELOPMENT CRITERIA 29 Slope Deformation ........................................ S ..........29 Slope Maintenance and Planting ............................................30.. I . Drainage ..............................................................30 S Toe of Slope Drains/Toe Drains.. * ........................................ 31 . S Erosion Control ..........................................................34 5 'S . S Landscape Maintenance . S .....34 55 Gutters and Downspouts ..................................................34 S Subsurface and Surface Water ......................................... 34 I Site Improvements .....................................................35 Tile Flooring ...........................................................35. S Additional Grading ............................ S ..35 RDA Designs 5 •S 5 5 . S Appendix A FiIe:e:\wp9\4300\4369a.pge S Page ii S 1 5 5 GeoSoils, Inc. S I S Footing Trench Excavation 35 Trenching 36 Utility Trench Backfill 36 I SUMMARY OF RECOMMENDATIONS REGARDING GEOTECHNICAL OBSERVATION AND TESTING 36 I OTHER DESIGN PROFESSIONALS/CONSULTANTS 37 I PLAN REVIEW 37 i LIMITATIONS 38 FIGURES I Figure l'-'site Location Map 2 Figure 2 - Boring Location Map 4 Figure 3 - California Fault Map 6 I . . Détaill - Typical Retaining Wall Backfill and Drainage Detail .............. . :22 Detail 2 - Retaining Wall Backfill and Subdrain Detail Geotextile Drain 23 Detail 3 . Retaining Wall and 'Subdrain Detail Clean Sand Backfill ............ . 24, I Detail 4 - Schematic Toe Drain Detail 32 Detail 5 - Subdrain Along Retaining Wall Detail ... . . ................... . .. 33. I ATTACHMENTS: .. . :. . ". Appendix A - References ...........................................Rear, of Text I . Appendix .B - Test Pit and Boring Logs .............. .............Rear Appendix C EQFAULT, EQSEARCH, and FRISKSP' ............:. of Text , Rear of Text Appendix D.-.General Earthwork 'and Grading Guidelines . '. . Rear of Text'.. I I I I I I . . , RDA Designs . .. Appendix A . : Fi1e:e:\wp9\4300\4369a.pge ' , ' . 'Page iii ' I GeoSoils, Inc. PRELIMINARY GEOTECHNIcAL EVALUATION PROPOSED OCEAN MIST CONDOMINIUMS, 325-347. OAK AVENUE Cu? OF CARLSBAD, SAN DIEGO COUNTY, *CALIFORNIA SCOPE OF SERVICES . . The scope of our services has included the following: 1. Review of the available geologic literature for the site and vicinity (see Appendix A). 2. Subsurface exploration consisting of excavation of one exploratory hand auger boring and three exploratory test pits with arubber tired backhoe for geotechnical logging and sampling (see Appendix B). a Laboratory testing of representative soil samples collected during our subsurface exploration program. . 4 General areal seismicity evaluation (see Appendix C). 5. Appropriate engineering and geologic analysis of data collected and preparation of this report. . . . . . SITE CONDITIONS/PROPOSED DEVELOPMENT The site consists of a roughly rectangular, lot located on the south side of Oak Avenue in the City of Carlsbad, California (see Figure 1, Site Location Map). The site is surrounded on the remaining sides by residential property. Topographically, the site slopes very gently to the west and elevation at the site is approximately 50 feet Mean Sea Level (MSL). Drainage appears to be directed westward. Proposed site development is anticipated to consist of demolition of the existing structures and construction of a condominium structure with basement/garage sub-floor and two additional stories above the sub-floor, as well as underground utility improvements. It is anticipated that the planned buildings will use continuous footings and slab-on-grade floors or post-tension foundations, with wood-frame and/or masonry block construction. Building loads are assumed to be typical for this type of relatively Iightstructure. It is also our understanding that sewage disposal is proposed to be accommodated by tying into the regional municipal system., .. FIELD STUDIES Field studies conducted by GSl consisted of geologic mapping of the site, and the excavation of one exploratory hand auger boring and three exploratory test pits with a rubber tired backhoe for evaluation of near-surface soil and geologic conditions. The GeoSoils, Inc. I 'I I I 1 I. I I I. I I. I I 1 o 1/2 TL— - 4 N Scale Miles * Rsproduc.d with permission granted by Thomas Bros. Maps. This map Is 'copyrighted by Thomas Bros. Maps. It Is unlawful to copy or reproduce all or any part thereof, whether for personal use or resale, without permission. All rights reserved. W.O. GèOS4•llS,ft*Jc. 4369ASC SITE LOCATION MAP Figure 1 Base Map: The Thomas Guide, San Diego County Street Guide and Directory, 2004 Edition, by F Thomas Bros. Maps, page 1106, 1:1/2 mile LEGEND S Base Map Provided by Client B-i TD:4 Approximate location of exploratory . hand auger boring with total, depth in feet S TP-3• Approximate location of exploratory TD:3' test pit with total depth in feet : I Based on our site exploration, terrace deposits appear relatively massive. Elsewhere in the vicinity, it has been our experience that bedding structures within terrace deposits are relatively flat lying and therefore adverse bedding conditions are not anticipated. MASS WASTING No evidence of any significant pre-existing mass wasting features were indicated or observed during field exploration or during a review of available publications. FAULTING AND REGIONAL SEISMICITY Faulting The site is situated in a region of active as well as potentially-active faults. Our review indicates that there are no known active faults crossing the site within the areas proposed for development (Jennings, 1994), and the site is not within an Earthquake Fault Zone (Hart and Bryant, 1997). There are a number of faults in the southern California area that are considered active and would have an effect on the site in the form of ground shaking should they be the source of an earthquake. These faults include, but are not limited to: the San Andreas fault; the San Jacinto fault; the Elsinore fault; the Coronado Bank fault zone; and the Newport-Inglewood - Rose Canyon fault zone. The location of these, and other major faults relative to the site, are indicated on Figure 3 (California Fault Map). The possibility of ground acceleration or shaking at the site may be considered as approximately similar to the southern California region as a whole. The following table lists themajor faults and fault zones in southern California that should have a significant effect on the site should they experience significant activity. rARiAtE biTANcE ._., .. ...- .- n. . MILES(KM) - J Rose Canyon . 5.4 (8.7) Newport-Inglewood-Offshore 5.1 (8.7) Coronado Bank-Agua Blanca 21.3 (34.3)- Elsinore-Temecula 23.9 (38.5) San Jacinto-Anza - 46.4 (74.7) RDA Designs W.O. 4369-A-SC 325-347 Oak Avenue . . June 21, 2004 Fi1e:e:\wp9\4300\4369a.pge - . Page 5 GeoSoils, Inc. I I I I 1 I I [1 I I 1 I LI I I I I I : ':. '.:boring and test pits were logged 'by 'a geologist from our firm, who collected representative bulk and undisturbed samples from the test pits for appropriate laboratory testing The I logs of the boring and test pits are presented in Appehdix B.. The locations of the boring and test pits are presented on Figure 2 REGIONAL GEOLOGY I The subject. property is located within 'a prominent natural geomorphic province in southwestern California known as the Peninsular Ranges. It is characterized by steep, elongated mountain ranges and valleys that trend northwesterly. The mountain ranges are I '. 'underlain by basement, rocks consisting of pre-Cretaceous metasedimentary rocks, Jurassic metavolcanic rocks, 'and Cretàceous plutonic rocks of the southern California 0 I batholith In the San Diego region, deposition occurred during the Cretaceous Period and Cenozoic 1 .. . Era in the continental margin of a forearc basin. Sediments, derived from Cretaceous-age plutonic rocks and Jurassic-age volcanic rocks, were deposited into, the narrow, steep, coastal plain and continental margin of the basin These rocks have been uplifted, eroded, and deeply incised. During early Pleistocene time, a broad coastal plain was developed :from the deposition of, marine and terrestrial terrace deposits. During mid to late' Pleistocene time, this plain was uplifted, 'eroded, and incised. Alluvial deposits have since. filled the lower valleys, and young marine sediments are-currently being deposited/eroded within coastal and beach areas. The site is generally: underlain'by terrace deposits. EARTH MATERIALS I Earth materials onsite consist of topsoil/colluvium and Pleistocene-age terrace deposits A description of each material type is presented in the following discussion Topsoil/CollUvium I.. Topsoil/colluvium underlies the site'to'a depth of approximately 1/2 foot below the existing ground surface. The topsoil/colluvial soils encountered onsite generally consist of light brown, silty sand. The materials, generally were dry, loose, and porous. These materials I are considered unsuitable for the support -of settlement-sensitive improvements in .their existing state. 'Terrace Deposits' Pleistocene-age terrace deposits underlie the site at shallow depth. Where encOuntered, I ' :these materials are typically red brown, 'dry to moist, and medium dense to dense. Unweathered dense terrace deposits are considered suitable for structural support. RDA Designs ' . 0 , , W.O. 4369-A-SC 325-347 Oak Avenue ' ' , June 21, 2004 R ' Fi1e:e:\wp9\4300\4369a.pge ' ' . . ' Page 3 GeoSöils,, Inc. ' 0 i.: :'. ..: . .: :1 ,.• ::.. .... I I . ' The acc'elération-attënuation relations of Sadigh, et al. (1997) Horizontal Soil, Bozorgnia,. Campbell, and Niazi (1999) Horizontal-Soil-Correlation, and Campbell and Bozorgnia (1997 Rev.).'Soft Rock have been incorporated into .EQFAULT (Blake, 2000a). . For this study, I peak horizontal ground accelerations anticipated at.the site were determined based on the random mean plus 1 - sigma attenuation cUrve and mean attenuation curve developed by Joyner and Booré . (1981, 1,982a, 1982b; 1988, 1990), Bozorgnia, Campbell, and Mazj (1999); and Campbell and Bozorgnia (1997). EQFAULT is a computer program by Thomas F. Blake. (20O0a) which performs deterministic seismic hazard analyses using up to 150 digitized California faults as earthquake sources.. . The, program estimates the closest'distance between each fault and a given site. If a fault. is found to'be within a user-selected radius, the program estimates peak horizontal ground I ' ' acceleration that may occur at the site from an upper bound ("maximum credible") earthquake on that fault. Site acceleration (g) is computed by one of many user-selected I acceleration-attenuation relations that are contained in EQFAULT. Based on the EQFAULT program, peak horizontal ground accelerations from an upper bound event at the site may be on the order of 0.57g to 0.65g. I' ' 'Historical site seismicity was evaluated with the acceleration-attenuation relations of . Campbell. and Bozorgnia (1997 Rev.) Soft Rock and the computer program EQ'SEARCH I' :.(Blake, 2000b) .This program performs a search of the historical earthquake records for magnitude 5.0 'to' 90' seismic events within: a 100-mile radius, between the years 1800 through 'December 2003. Based on the selected acceleration-attenuation I' relationship, a peak horizontal ground acceleration is estimated, which may have effected the.site during the specific event listed. Based on the available data and the attenuation relationship. used, the, estimated maximum (peak) site acceleration during the period 1800 through 2003 was 0.25g.., Site specific probability of exceeding various peak' horizontal ' ground accelerations and a seismic recurrence curve are also estimated/generated from the historical data. Computer printouts of pertinent portions of ,the EQSEARCH program are presented in Appendix C. A probabilistic seismic hazards analyses was performed using FRISKSP (Blake, 2000c, which models' earthquake sources as three-dimensional planes and evaluates the site .:specific probabilities 'of exceedance for given peak acceleration levels or pseudo-relative I . ' velocity levels. ,Based on a review-of these data, and considering the relative seismic 'activity of the southern California region, a peak horizontal ground acceleration of 0.33g. was calculated'. This value was chosen 'as it corresponds to a 10 percent probability of '.exceedänce in '50 years (or a 475-year return period). I '.RDA Designs ' . ' ' W.O. 4369-A-SC 325-3470ak'Avenue' . June 21, 2004 FiIe:e:\wp9\4300\4369a.pge . ' ' ' . ' ' . Page 7 GàoSoils Inc... 100 200 300 400 500 600 CALIFORNIA FAULT MAP RDA. I 1100- 1000 H 'I 900-- 800 1 700 I 500H I: 300 1 .200 1 db 100 1 0 1 100 )II I IIII I IIII I III I I -400 -300 -200 -100 0 1' . W.O. 4369-A-SC Figure 3 I . . . GeoSoils, Inc. Seismic zone (per Figure 162*) : . "s .41, Seismic Zone Factor (per Table 161*) 0.40 Soil Profile Type (per Table 16J*) . . , ' .; S0 Seismic Coefficient Ca (per Table 16-Q*) 0.44 Na " Seismic Coefficient C,, (per Table 16-R*) . . . .. 0.64 N,, Near Source Factor Na' (per Table 16S*) .• 1.0 Near Source Factor N,, (per Table 16T*)'S ' 1.1 .• Seismic Source Type (per Table 1 6U*). ' . B Distance to Seismic Source . . '5.1mi(8.2km) Upper Bound Earthquake(Newport-Inglewood) .'•M 6.9 *Figure and table references from Chapter 16of the UBC_(iCBO,1997).' I . Seismic_Hazards The following list Includes other seismic related hazards that have been considered during our evaluation of the site. The hazards I listed are considered negligible and/or completely' . mitigated as a result of site location, soil* characteristics,' and typiôal site development procedures I Tsunami ' Dynamic Settlement Surface Fault Rupture Ground Lurching' or Shallow Ground Rupture It is important-to keep in perspective that in the event of a maximum probable or credible, 'earthquake occurring on any of the nearby major faults, strong ground shaking would' occur in the subject sites general area. Potential damage to anystructure(s) would likely be greatest from the vibrations and impelling force caused by the inertia of a structure's mass than from those induced. by the hazards considered above. This potential' would be no greater than that' for other existing structures and improvements in the immediate' I vicinity. I RDA Designs . ' W.O. 4369-A-SC I . 325-347 Oak Avenue ' . ' S. ' , ' June 21, 2004 FiIe:e:\wp9\4300\4369a.pge' ' . S , , ' Page 8' GeoSOiJs, Inc. I I GROUNDWATER I Subsurface water was not eh countered- within the property during field work performed in : preparation of this report.' : Subsurface water is not anticipated to adversely affect site I development, provided that the recommendations contained in this report are incorporated I into final design and construction These observations reflect site conditions at the time of our investigation and do not preclude future.. changes in local groundwater conditions . from excessive irrigation, precipitation, or that were not obvious, at the time of our I investigation Regional groundwater is estimated to be at least 50 feet in depth, below the site. . . Seeps springs, or other indications of a high groundwater level were not .noted.on the subject property during the time of our field investigation . However, seepage may occur locally (as the result of heavy precipitation or irrigation) in areas where any fill soils overlie terrace deposits or impermeable soils. Such conditions may occur during grading or after. the site is developed, and should be anticipated. Sump pumps may be necessary in the i blow-grade parking I LIQUEFACTION POTENTIAL :Seismically-induced liquefaction is a phenomenon in which cyclic stresses, produced by I . • earthquake-induced ground motion, create, excess pore pressures in soils. The soils may. ' thereby acquire a high degree of mobility, and lead to lateral movement, sliding, sand boils, consolidation and settlement of loose sediments, and'other damaging deformations. This phenomenon occurs only below the water table; but after liquefaction' has developed, it can propagate upward into overlying, non-saturated soil as excess pore water dissipates; Typically, liquefaction has a relatively low potential at depths greater than 45 feet and is I ' ' ' •... virtually unknown below a depth of 60 feet. ' . . The condition of liquefaction has two principaFeffects One is the consolidation of. loose sediments with resultant settlement of the ground surface; The other effect is, lateral sliding. Signifiôant permanent lateral movement generally' occurs only when there is significant differential loading, such as fill or natural ground slopes., No such loading 1 conditions exist onsite I. Uquefaôtion susceptibility is related to numerous factors and, the f011owing conditions should be concurrently present for liquefaction to occur: 1).sediments must be relatively, 'young in .age and not have developed a large amount of cementation; 2) sediments I.. generally consist of medium to fine grained relatively Oohesionless sands; 3) the sediments must have low relative density; 4) free groundwater must be present in the sediment; and, 5) the site must experience a seismic event of a sufficient duration and magnitude, to I ' , induce straining of soil particles. RDA Designs ' ' , , ' . W.O. 4369-A-SC 325-347 Oak Avenue . . . June 21, 2004 F1e:e:\wp9\4300\4369a.pge . . , , . . . ,. Page 9 I • ' . , , . GeoSoils, Inc. . .' . . Since at least one or two of the five required concurrent conditions discussed above do not have the potential to affect the site, and evidence of paleoliquefaction features was not observed, our evaluation indicates that the potential for liquefaction and associated adverse effects within the site is low, even with a future rise in groundwater levels. The site conditions will also be improved by removal and recompaction of low density near-surface soils, and if evidence for paleoliquefaction is encountered during grading, the use of post-tension slabs. LABORATORY TESTING I General Laboratory tests were performed on a representative sample of the onsite earth materials in order to evaluate their physical and engineering charaôteristics; The test procedures used and results obtained are presented below. I Moisture-Density Relations ' The laboratory maximum dry density and optimum moisture content for representative site soils was determined according to test method ASTM D-1 557. A maximum dry density of 127.5 pcf at an optimum moisture content of 10.5 percent was determined for a bulk I composite sample obtained from the site. Field moisture and density determinations were also performed. The results of these determinations are presented on the Boring Logs in Appendix B. I Shear Testing Shear testing was performed on a representative, remolded sample of site soil, in general accordance with ASTM Test Method D-3080, in a Direct Shear Machine of the strain control type. The shear test results are summarized below: LOCATIQN . PRIARV RESIDUAL.................. COHESION FRICTIONANGLE COHESION FRIcTION.ANGLE (PSF (DEGREES) (PSF) (DEGREES) . TP-1 @ 2 feet I 122 I 32 I 105 I 32 I I I 11 Li I I I 1 I I I 1 I RDA Designs 325-347 Oak Avenue FiIe:e:\wp9\4300\4369a.pge GeoSoils, Inc. W.O. 4369-A-SC June 21, 2004 Page 10 00 . I' TP-1 @ 6 feet I . U Very Low I Corrosion Testing. Laboratory test results for soluble'sulfates, pH, andcorrosionto metals have not -been received as. of the date of this report. Testing will be presented as an addendum Upon receipt of the results. Additional testing of site materials is recommended when proposed grading is complete, to further evaluate the findings. PRELIMINARY CONCLUSIONS I .Based upon our site reconnaissance test results, it is 'our opinion that the subject site appears suitable for the proposed residential development. The following recommendations should be incorporated into the construction details. i... . . EARTHWORK CONSTRUCTION RECOMMENDATIONS I General All grading should conform'to the guidelines presented in Appendix Chapter A33 of the UBC, the requirements of the City, and the Grading Guidelines presented in Appendix 0,': except where specifically ,superceded in the text of this report Prior to grading, a GSI I 'representative should be 'present' at the preconstruction meeting to provide additional 'grading guidelines, if needed, -and review the earthwork schedule. I During earthwork construction, all site preparation and the general grading procedures of the contractor should be observed and the fill selectively tested by a representative (s) of I GSI. If unusual or unexpected conditions are exposed in the field, they should be reviewed by this office and, if warranted, modified and/or additional recommendations will; be offered. All applicable requirements of local and national construction and general industry I safety orders, the Occupational Safety and Health Act, and the 'Construction 'Safety Act, should be, met. RDA Designs ' ' W.O. 4369-A-SC 325-347 Oak Avenue S ' ' June 21, 2004 FiIe:e:\wp9\4300\4369a.pge S ' ' ' , Page 11 GeoSoils, Inc. u I I I :Debris, Vegetation existing structures, and other deleterioUs material should be removed from the building area prior to the start of construction. Sloping areas to receive fill should. be properly benched in accordance with current industry standards of practice and I guidelines specified in the UBC I Removals (Unsuitable Surficial Materials) Due to the relatively. loose condition of topsoil and weathered terrace deposits, these materials should be removed and recompacted in areas proposed for settlement-sensitive . I structures or areas to receive compacted fill. At this time, removal depths on the order of 1 foot (including topsoil and weathered terrace deposits) below existing grade should be I.. anticipated throughout a majority-of-the site; however, locally deépér• removals cannot be precluded. Due to the relatively loose and porous condition of the topsoil/colluvial, these materials should be removed, moisture conditioned, and recompacted and/or processed I: .in place Removals should be completed below a 1:1 projection down and away from the edge of any settlement-sensitive improvements and/or limits of proposed fill. Once removals are completed, the exposed bottom should be reprocessed and compacted to I .. 90 percent relative compaction. . . Fill Placement . . . . I Subsequent to ground preparation, Onsite soils may be placed in thin (±-6-inch) lifts, cleaned of vegetation and debris; brought to a least optimum moisture content, and compacted to achieve a minimum relative compaction of 90 percent. If soil importation is planned, a sample of the soil import should be evaluated by this office prior to importing, in order to assure compatibility with the onsite site soils and the recommendations I presented in this report. Import soils for a fill cap should be very low expansive (Expansion Index [E.l.] less than 20). The use of subdrainsat the bottom of the fill cap may be necessary, and subsequently recommended based on compatibility with onsité soils and I proximity and/or suitability of an outlet I Transituons/Overexcavation . . Cut portions of cUt/fill transition pads should be overexcavated a minimum 3 feet below I . pad grade. Areas with planned fills less than 3 feet should be overexcavated in order to. Provide a minimum fill thickness of 3 feet, or 2 feet below the foundation, whichever is. greater. Where the ratio of maximum to minimum fill thickness below a given structure I •:• exceeds 3:1, overexcavation should be completed to reduce this ratio to 3:1, or less: . I I RDA Designs .. . . W.O. 4369-A-SC. 325-347 Oak Avenue June 21, 2004 I . Fiie:e:\wp9\4300\4369a.pge .. . . . Page 12 GeoSoils, Inc. . I I I . In 'general, and based upon the available data to date, groundwater is not anticipated to be a factor in development of the site However, due to the nature of the site materials, seepage may be, encountered throughout the site, along with seasonal perched .water I ,within .any drainage areas. Seepage may. also be encountered in "daylighted" joint' systems within the terrace deposits. Thus, subdrain systems are recommended within shallow groundwater areas..,In addition,: subdrainage systems for the control of localized I .groundwater seepage should be. anticipated', should such conditions develop during'or after grading. Should such conditions develop, this office. should be cntacted for, 1 .'mitigative recommendations. Local seepage along the contact between the terrace deposits/bedrock and overburden, materials, or along jointing- patterns of the bedrock, will likely require a subdrain system. I ' 'Where removals are below the subdrain flowline, the, removal materials may be reused as compacted fill provided they are granular, and at a moisture content of at least 2 percent over optimum moisture content (or 1.2 times optimum moisture content, whichever is greater). I Temporary Construction Slopes Proposed site development consists of excavation for garage/basement sub-floors. I . Temporary cuts for wall construction should be constructed at a gradient of 1:1, or flatter, .for slopes exposing terrace deposit materials to a maximum -height of 15 feet, per. CAL-OSHA for Type B soils. Construction materials and/or stockpiled soil should not be I stored within 5 feet of the top of any temporary slope. Temporary/permanent provisions should be made to direct any potential runoff away from the top of temporary slopes. I Shoring will likely be required, if friable conditions are encountered in the terrace deposits Preliminary. Shoring Recommendations I , General I., Should insufficient space for constructing 'portions of the' proposed residence be encountered, shoring may be required. Shoring should consist of cantilever steel soldier beams placed at a maximum of 6-foot on centers, with a minimum embedment below the I ,bottom of the cut, équivalentto half the height of the. cut. The ultimate embedment depth should be provided by the project structural engineer and/or shoring designer, based on the geotechnical parameters provided herein. Wood lagging should be installed as the cut . progresses to, its ultimate configuration. RDA Designs . . . ' ' ' W.O. 4369-A-SC 325-347 Oak Avenue ' ' ' . June 21, 2004 File:e:\wp9\4300\4369a.pgé ' ' , ' Page 13 ' ' GeoSoils, Inc. ' I I Lateral Pressures I . ' For design on cantilevered shoring,' 'a triangular distribution of lateral earth pressure may be used. It may be assumed that the retained soils with a level surface behind.the'shoring Will. exert a lateral pressure, equal to that developed by. a fluid. with a,'density of. 40 pcf.., I Retained soils with a 2:1 back slope ratio will exert a lateral pressure equal to a fluid with adensity of 60 pcf. I If street traffic is located within 10 feet of shorings, the upper 10 feet of shoring adjacent 'to the traffic should be designed to resist 'a uniform lateral pressure of 100 pounds per square foot,(psf), which is a result of an assumed 300 psf surcharge behind the shoring ,due to normal street traffic. I Design of Soldier Piles For the design of soldier piles spaced at least? diameters on centers,'the'alloWable lateral I ' bearing value (passive value) of the soils below the level of excavation may be assumed to be 500 psf per foot of depth, up to a maximum of 5,000 psf. To develop the full lateral value, provisions should be taken to assure firm contact between the soldier piles and the undisturbed soils. The soldier piles below the excavated levels may be used to resist downward loads, if any. The downward frictional, résistance between the' soldier piles and the soils below the excavated level. may be taken as equal to 300 psf. Lagging Continuous wood lagging will be required between the soldier piles. The soldier piles. I ' should be designed for the full anticipated lateral pressure. However, the pressure on the lagging will be less due to arching in the soils. We recommend that the lagging be . ' designed for the recommended earth pressure, but limited to a maximum value of 500 psf. Internal Bracing 1 ' Rakers may be required to internally brace the soldier piles. The raker bracing could be supported lateral ly.by temporary concrete footings (deadmen) or by the permanent interior footings. For design of temporary footings, or deadmen, poured with the bearing surface normal to rakers inclined at 45 degrees, a. bearing value of 2500 ,psf may. be' used, provided the shallowest point of the footing is at least 1 foot below the lowest adjacent grade. I I' RDA Designs, .' ' ' ' W.O. 4369-A-SE 325-347 Oak Avenue ' . June 21, 2004 Fi1e:e:\wp9\4300\4369a.pge .' ' ' ' ' ' ' . '. Page 14 GeoSoils, Inc. . I I Deflection I ..It isdifficultto accurately predict the amount of deflection of a shored profile-. 'It should be: realized, however, that some deflection will occur. We anticipate that this deflection would be on the order of 1/2 inch at the top of the planned 10- to 12-foot shoring If greater I deflection occurs during construction, additional bracing may be necessary to minimize . . deflection. If desired to reduce the deflection of the shoring, a greater active pressure leading to a more stiffer section could be used I Monitoring I '... Some means of.monitoring the performance of the shoring system is recommended'. The . monitoring should consist of periodic surveying of the, lateral and vertical- locations. ofthe . I .tops of all the soldier piles and the lateral movement along the entire lengths of selected' soldier piles. We suggest that photographs of the adjacent improvements be made prior to excavation." 0 ' . RECOMMENDATIONS - FOUNDATIONS Preliminary Foundation Desiañ In the event that the information concerning the proposed 'development plans are not correct, or any changes in the design, location, or loading conditions of the proposed structures are made, the conclusions and recommendations contained in this report are for the subject site only and shall not be considered valid unless the changes are reviewed and conclusions of this report are modified or approved in writing,by this office. The information and recommendations presented in this section are considered minimums and are not meant to supercede design(s) by the project structural engineer or civil -e ngineer specializing in structural design. Upon'request, GSI could provide additional consultation regarding. soil parameters, as related to foundation design. 'They .are considered preliminary recommendations for'proposed construction, 'in consideration of. our field investigation, and laboratory testing and engineering analysis Our review, field work, and recent and previous laboratory testing indicates that onsite soils have a very low expansion potential range (E.l. 0 to 20). Preliminary recommendations for foundation design and construction . are presented below. Final foundation recommendations should be provided at the conclusion of grading based on laboratory testing of fill materials exposed at finish grade RDA Designs W.O. 4369-A-SC 325-347 Oak Avenue . 'June 21, 2004 Fi1e:e:\wp9\4300\4369a.pge Page 15 GeoSoils, Inc. Bearing Value 1. .'The' foundation systems should be designed and constructed in accOrdance with guidelines presented in the latest edition of the UBC 2 An allowable bearing value of 1,500 pounds per square foot (psf) may be used for design of continuous footings 12 inches wide and 12 inches deep and for design of isolated pad foOtings. 24 inches square and 18 inches deep founded entirely, into compacted fill or competent formational material and connected by grade beam or -. tie beam in at least one -direction. ..This value may be increased by 20 percent for each additional 12 inches in depth to, a maximum 'value of 2,500 psf. The above values may be increased by one-third when considering short duration seismic or wind loads No increase in bearing for footing width is recommended Lateral Pressure 1. ' 'For' lateral sliding resistance, a 0.35 coefficient of friction may be. utilized for a concrete to soil contact when multiplied by the dead load. .2. ' Passive earth pressure may be computed as an equivalent fluid having a density of 250 pounds per cubic foot (pcf), with a maximum earth pressure of 2,500 psf., I 3. When combining passive pressure and frictional resistance, the passive pressure: component should be'reduced by one-third. ' ' ' Foundation Settlement 'Foundations systems should be designed to .accommodate a worst case differential settlement of 1 inch in a 40-foot span.. ' .' ' '. • : Footing Setbacks ' ' ' ' ' ,• . ' ' All. footings should maintain a minimum 7-foot horizontal 'setback from the base of the footing to any descending slope. This distance is measured from the footing face at the bearing elevation. Footings should maintain 'a minimum horizontal setback of H/3 (H=slope height) from the base of the footing to the descending slope face, and no. less ,than 7 feet nor need to be greater than 40 feet. Footings adjacent to unlined drainage ,swales should be deepened to a minimum of 6 inches below the invert of the.adjacent unlined swale. Footings for structures adjacent to retaining walls shoUld be deepened so as to extend below a 1:1 projection from the heel of the ,wall. Alternatively, walls may be '.designed to accommodate structural loads from buildings or appurtenances as described in the Retaining Wall section ,of this report. • • .' ' ' ' . RDA Designs ' ' '. ' ' W.O. 4369-A-SC 325-347 Oak Avenue ' . ' ' ' June 21, 2004 File:e:\wp9\4300\4369a.pge , ' '' ' . ' . Page 16. GeoSoils, Inc. • Construction The. following foundation construction recommendations are presented. as a minimum criteria, from a soils engineering standpoint. The onsite soils expansion potentials are generally very low (E.l.Oto 20).: Recommendations for verylow expansive soil conditions are presented herein. . . . . .. . . .. .. Recommendations by the project's'designstructural engineer or architect, which may exceed the soils engineér1s recommendations, should take precedence over the following minimum requirements. Final foundation design will be provided based on the expansion. potential of the near surface soils encountered during grading. . . Very Low Expansion Potential (E.l. 0 to-20) . . . . 1. . . Exterior and interior footings should be founded at a minimum depth of 12 inches for-one-story floor loads, 18 inches for two-story floor loads, and 24 inches for three-story floor loads:below the lowest adjacent ground surface. Isolated column and panel pads, or wall footings, should be founded at a minimum depth of .' 24 inches. All footings should be reinforced with two No. 4 reinforcing bars,, one. placed near the top and one placed near the bottom of the footing. Footing widths should be as indicated in the UBC (ICBO, 1997); width of 12 inches for one-story loads, 15 inches for two-story loads, and 18 inches for three-story loads. 2. A grade beam, reinforced as above, and at least 12 inches wide should be provided across large (e.g, doorways) entrances. The base of the grade beam, should be at the same elevation as the bottom of adjoining footings. Isolated, exterior square footings should be tied within the main foundation in at least one direction with a grade beam. 3.' Residential concrete slabs, where moisture condensátiôn is undesirable, including garage slabs, should be underlain with a vapor barrier consisting of a minimum of 10 mil polyvinyl 'chloride or equivalent membrane with all laps sealed, per the UBC/CBC. This membrane should be covered above and below With a minimum of 2 inches of sand (total of 4 inches) to aid in uniform curing of the concrete and to protect the membrane from puncture. . . . I .4. To further mitigate the potential for water vapor problems owing to the possibility' of perched water, the use of'4,500 psi concrete, with an altered water-cement ratio ' ' ... (0.45) is additionally recommended. . . . . . . . 5 Residential and garage concrete slabs should be a minimum of.5 inches thick, and should be reinforced, with No. 3 reinforcing bar at 18 inches on center in both I ......... . directions. All slab reinforcement should be supported to ensure placement near RDA Designs " . • ' . . W.O. 4369-A-SC 325-347 Oak Avenue .. . ' S June 21, 2004 Fi1e:e:\wp9\4300\4369a.pge. . . . • ' . . . Page 17 GeoSoils, Inc. ' ' I I.' I an. acceptable method of positioning the reinforcement. .. S Garage slabs should be a minimum of 5 inches thick and should be reinforced as above and poured separately from the structural, footings and quartered with expansion joints or saw cuts.. A'positiVe separation from. the footings should be maintained with expansion Joint material to permit relative movement 7 •. Specific. presaturation As.. not 'required for these soil conditions; however, GSI recommends that the moisture content of the'subgrade soils should be equal' to or .greater than optimum moisture content to a depth of 12 inches in the slab areas prior to the placement of visqueen. POST-TENSIONED SLAB SYSTEMS Post-tension foundations are specifically recommended if paleoliquefaction features ("sand .blows," liquefaction craters, sand filled fissures and, injection dikes, sand vents, etc.) are encountered during grading. The recommendations presented below should be followed in addition to those contained in the previous sections, as appropriate. The information and recommendations 'presented below in this section are not meant to supercede design by a registered structural engineer or civil engineer familiar with post-tensioned slab design Post-tensioned slabs should be designed using sound engineering practice and. be in accordance with local and/or'national'code requirements. Upon reqUest,'GSI can, provide additional data/consultation regarding soil parameters as related to post-tensioned'' slab design. From a soil expansion/shrinkage standpoint, a common contributing factor to distress of. 'structures using post-tensioned slabs is fluctuation of moisture in soils underlying the perimeter of the slab, compared to the center, causing a"dishing" or"arching" of the slabs; To mitigate this possibility; a combination of soil presaturation and. construction of a perimeter cut off wall should be employed. To further mitigate the potential for water vapor problems owing to the possibility of perched water, the use of 4,500 psi concrete, with an 'altered water-cement ratio (0.45) is additionally recommended. Perimeter cut-off walls should be a minimum of (18 inches deep for medium expansive soils. The cut-off walls may ,be integrated into the slab design or independent of the slab. The concrete slab should be a minimum of 6 inches thick. Slab underlayment should consist of 4 inches of washed sand with a vapor barrier consisting of 10-mil polyvinyl chloride or equivalent placed. rnid-depth'within the sand. RDA 'Designs' , , ' . ' ' W.O. 4369-A-SC 325-347 Oak Avenue . , , ' ' S June 21, 2004 File:e:\wp9\4300\4369a.pge S ' . , . S Page 18 GeoSoils, Inc. I Li Thornthwaite Moisture Index -20 inches/year Correction Factor for Irrigation 20 inches/year Depth to Constant Soil Suction 7 feet Constant soil Suction (pf)' 3.6 Modulus of Subgrade Reaction (pci) 75 Moisture Velocity 0.7 inches/month I I a I Post-Tensioning Institute Method. I Post-tensioned slabs should have sufficient stiffness to resist excessive bending due to non-uniform swell and shrinkage of subgrade soils. The differential movement can occur at the corner, edge, or center of the slab. The potential for differential uplift can be I . evaluated using the 1997 UBC, Section 1816, based on design specifications of the Post-Tensioning Institute. The following table presents suggested minimum coefficients to be used in the Post-Tensioning Institute design method. I .. The coefficients are considered minimums and may not be adequate to represent worst case conditions such as adverse drainage and/or improper landscaping and maintenance. The above parameters are applicable provided structures have positive drainage that is maintained away from structures. Therefore, it is important that information regarding drainage, site maintenance, settlements, and effects of expansive soils be passed onto future owners. Based on the above parameters, the following values were obtained from figures or tables of the 1997 UBC Section, 1816. The values may not be appropriate to account for possible differential settlement of the slab due to other factors. If a stiffer slab is desired, higher values of ym may be warranted. S . 14SI k~Qi ON'. t. INDEX.OF.' I •.- -. .. SOIUSUBGRADE ": 'vERW - XPANSlON -... IL. :(Ej em center lift 5.0 feet em edge lift 2.5 feet Ym center lift 1.0 inch y edge lift . 0.3 inch I - I RDA Designs 325-347 Oak Avenue FiIe:e:\wp9\4300\4369a.pge W.O. 4369-A-SC June 21, 2004 Page 19 I GeoSoils, Inc. L I I I I I 1 I I I I Deepened footings/edges around the slab perimeter must be used to minimize non-uniform surface moisture migration (from an outside source) beneath the slab An I: edge depth of 12 inches should be considered a minimum. The bottom-of the deepened footing/edge should be designed to resist tension, using cable or reinforcement per the structural engineer. Other applicable recommendations presented under conventional I foundation and the California Foundation Slab Method should be adhered to during the design and construction phase 'of the project. . . . . . . . I UTILITIES Utilities should be enclosed within a closed utilidor (vault) or designed with flexible connections. to accommodate differential settlement and any potentially expansive soil conditions. Due to the potential for differential settlement, air conditioning (A/C) units I . should be supported by. slabs that are incorporated into the building foundation or constructed on a rigid slab with flexible couplings for plumbing and electrical lines. NC : . waste waterlines should be drained to a suitable outlet. S . WALL DESIGN PARAMETERS I; . Conventional Retaining Walls The design parameters provided, below assume that either non expansive soils (Class 2 permeable filter material or Class 3 aggregate base) pr native materials (up to and. I.. including an E.J. of 65) are used to backfill any retaining walls. The type of. backfill (i.e., selector native), should be specified by the wall designer, and clearly shown on the plans Building walls, below grade, should be water-proofed or damp-proofed, depending on the I . degree of moisture protection desired. The foundation system for the proposed retaining walls should .be designed in accordance with the recommendations presented in this and I .preceding sections of this report, as appropriate. Footings should. be embedded a minimum of 18 inches below adjacent grade (excluding landscape layer, 6 inches) and should be 24 inches in width. There should be no increase in bearing for footing width. I . •.Recommendations for specialty walls (i.e., crib, earthstone, geogrid,.etc.) can .be provided upon request, and would be based on site specific conditions. . . Restrained Walls Any- retaining walls that will berestrained prior to placing and compacting. backfill material I .. . or that have re-entrant or male corners, should be designed for an at-rest equivalent fluid pressure (EFP) of 65 pcf, plus any applicable surcharge loading. For areas of male or re-entrant corners, the restrained wall design should extend a minim' um distance of twice I the height of the wall (2H) laterally from the corner. I ..RDA Designs S W.O. 4369-A-SC 325-347 Oak Avenue . . 5 June 21, 2004 Fiie:e:\wp943004369a.pge S S Page 20 I . • S • • . . . .• GeoSoils, .7• S . I__ I I Cantilevered Walls The recommendations presented below are for cantilevered retaining walls.up to 10 feet. high. •Design parameters for walls less than 3 feet in height may be superseded by City and/or County standard design.. Active earth press r6 may be used for retaining wall . design, provided the top of the wail is not restrained frOm minor defleOtibns. Anequivalent. .5 fluid pressure approach may be used to compute the horizontal pressure against the wall. Appropriate fluid unit weights are given below for specific slope gradients of the retained S material. These do not include other superimposed loading conditions due to traffic, . . structures, seismic events or adverse geologic conditions. When wall configurations are finalized, the.appropriate loading conditions for sUperimposed loads can be provided upon request '1-RETAlNED MATERIAl! - t (HORlZONTAL:VERTlCAL)., t.EQUIVALENT: FLUID WEIGHT P C F iS .(sELEcT;BACKFlLL) FLUID WEIGHT P C F S.tj P F1 _IA, Level* . 35 5 45 2to1 50. . 60 * Level backfill behind a retaining wall is defined as compacted earth materials, properly drained, without a slope for a distance of 2H behind the wall. Retaining Wall Backfill and Drainage I. . . Positive drainage must be provided behind all retaining walls in the form of gravel wrapped. 'in geofabric and outlets. A backdrain system is considered necessary for retaining walls. . that are 2 feet or greater in height. Details 1, 2, and 3, present the back drainage Options discussed below. Backdrains should consist of a 4-inch diameter perforated PVC or ABS. pipe encased in either Class? permeable filter material or 1/2-iflCh tO 3/4-inch gravel wrapped .. . in 'approvedfilter fabric (Mirafi 1140 or equivalent). For lOw expansive backfill, the filter. material should extend a minimum of 1 horizontal footbehind the base of the walls and . . upward at least 1 foot. For native backfill that has up to medium expansion potential, continuous Class 2 permeable drain materials should be used behind the wall. •This ' material should be continuous (i.e., full, height) behind the, wall, and it should be . . constructed in accordance with the enclosed Detail 1 (Typical Retaining Wall Backfill and. Drainage Detail) For limited access and confined areas, (panel) drainage behind the wall may becOnstructed'in accordance with Detail 2 (Retaining Wall Backfill and Subdrain Detail Geotextile Drain) Materials with an E I potential of greater than 65 should not be used as backfill for retaining walls. For more onerous expansive situations,' backfill and drainage behind the retaining Wall should conform with Detail 3 (Retaining Wall' And Subdrain Detail Clean Sand Backfill) RDA Designs S . . . . . W.O. 4369-A-SC 325-347 Oak Avenue June 21, 2004 File:e:\wp9\4300\4369a.pge Page 21 GeoSoils, Inc. .,. 1' 00 II11JJjIIIIIit p" ' 4 - Membrane (option.al) 00 1 or Flatter Weep Hole 000 Finished.Surface : 170 - A. ' y/,,1'J. •.. 0 ® WATERPROOFING MEMBRANE (optional): Liquid boot or approved equivalent. ROCK 3/4 to 1-1/2" (inches) rock. FILTER FABRIC: ' S , , S •, Mirafi 140N or, approved equivalent; place fabric flap behind core. ' S • PIPE: •. 4" (inches) diameter perforated PVC. schedule 40 or approved alternative with minimum of 1% gradient to proper outlet point. WEEP HOLE: Minimum 2" (Inches) diameter placed at 20' (feet).on centers along the wall, and 3" (inches) above finished surface. (No weep holes for basement walls.) 5 TYPICAL RETAINING WALL BACKFILL AND DRAINAGE DETAIL S DETAIL 1 Geotechnical • Geologic • Environmental Provide (i)Waterproofing :Membrane (oi ®Weepl Finished DETAILS N. .1'. S. WATERPROOFING MEMBRANE (optional): Uquld boot or approved equivalent. . © DRAIN: . Miradrain 6000 or 3-draIn 200 or equivalent for non-waterproofed walls. Miradrain 6200 or 37drain 200 or equivalent for waterproofed walls. ® FILTER FABRIC: . .. . Mirafi 140N or approved equivalent; place fabric flap behind care. '®PIPE: .. . 4" (inches) diameter perforated PVC. schedule 40 or approved alternative with minimum of 1% gradient to proper outlet point. WEEP HOLE.'. . Minimum 2" (inches) diameter placed at 20' (feet) on centers along the wall, and 3" (inches) above finished surface. (No weep holes for basement walls.) • . RETAINING WALL BACKFILL t<) g' . . AND SUBDRAIN DETAIL GEOTEXTILE DRAIN Geotechnical • Geologic • Environmental DETAIL 2: DETAILS N. T. S. 2 Native Backfill Slope or Level H mm. ~D waterproofing Membrane (optional) 1 I or Flatter © Clean / () Filter Fabric : Sand Backfill .I Heel Width . WATERPROOFING MEMBRANE (optional): Liquid boot or approved equivalent. S ' CLEAN SAND BACKFILL: , ' Must have sand dequivalent value' of 30 or greater; can be densified by water jetting. FILTER FABRIC: Mirafi 140N or approved equivalent. ROCK: 1 cubic foot per linear feet of pipe or 3/4 to 1-1/2" (inches) rock. PIPE:' " ' ' '• 4" (inches) diameter perforated PVC. schedule 40' or approved alternative with minimum of 1% gradient to proper outlet point. ' ©WEEP HOLE: Minimum 2" (inches) diameter placed at 20' (feet) on centers along the wall, and 3" (inches) 'above finished surface. (No, weep holes for basement walls.) RETAINING WALL AND'SUBDRAIN DETAIL CLEAN SAND BACKFILL S DETAIL 3 Geotechniéal 9 Geologic • Environmental I Outlets should consist of a 4-inch diameter solid PVC or ABS pipe spaced no greater than ±100 feet apart, with a minimum of two outlets, one on each end. The use of weep.holes in walls higher than 2 feet should not be considered. The surface of the backfill should be sealed by pavement Or the top 18 inches compacted with native soil.(E.l. .<.90). Proper surface drainage should also be provided For additional mitigation, consideration should be.given to applying a water-proof membrane to the back of all retaining structures. The.. use of a waterstop should be considered for all concrete and masonry Joints 1 Wall/Retaining Wall Footing Transitions . . . I .. Site walls are anticipated to be founded on footings designed in accordance with the recommendations in this report. Should wall footings transition from cut to fill, the civil . designer may specify either: a) A minimum of A-2-foot overexcavation and recompaction of cut materials for a distance of 2H, from the point of transition . . b). '.Increase of the amount of reinforcing steel and wall detailing (i.e., expansion joints or crack control joints) such that a angular distortion of 1/360 for a distance of 2H .• I on either side of the transition may be accommodated Expansion Joints should be sealed with a flexible, non-shrink grout I c) Embed the footings entirely into native formational. 'material . (i.e., deepened .•. footings). ... . . S If transitions from cut to fill transect the wall footing alignment at an angle of less than 45 degrees (plan. view), then the designer should follow recommendation "a" (above) and until such transition is between 45 and 90 degrees to the wall alignment. .' . •' • I TOP-OF-SLOPE WALLS/FENCES/IMPROVEMENTS Slope Creep I. . .. Soils at the site may be expansive and therefore, may become desiccated when allowed to dry. Such soils are susceptible to surficial slope creep, especially with seasonal I . changes in moisture content. Typically in southern California, during the hot and dry' summer period, these soils become desiccated and shrink, thereby developing surface cracks. The extent and depth of these shrinkage cracks depend on many. factors such as • I.. the nature and expansivity of the 'soils, temperature and humidity, and extraction of '..' moisture .from surface soils by plants and roots. When seasonal rains occur, water percolates into the cracks and fissures, causing slope surfaces to .expand,. with a I . corresponding loss in soil density and shear strength near. the slope surface. With the 'I 'RDA Designs . . . . . W.O. 4369-A-SC '• 325-347 Oak Avenue . . June 21, 2004 Fde:e:\wp9\4300\4369a.pge '•. . . . Page 25 •• I . . . . GeoSoils, Inc. S i .:..... '• I passage of time and several moisture cycles, the outer 3 to '5 feet of slope materials experience a very slow, but progressive, outward and downward movement, known as I :slope creep. For slope heights greater-than 10 .feet, this creep related soil movement will. typically impact all rear yard flatwork and other secondary improvements that are located within about 15 feet from the top of slopes, such as swimming pools, concrete flatwork, I.. etc., and in: particular top of slope fences/walls. This influence is normally in the form, of.: detrimental settlement, and tilting of the proposed improvements The dessication/swelling and creep discussed above continues over the life of the improvements, and generally I ,becomes progressively Worse. Accordingly, the developer should provide this information to any homeownersand homeowners association. ' •0 Top of Slope Walls/Fences •0 0 • 0 .• ... 0 Due to the. potential for slope creep for slopes higher than about 10 feet, some settlement. . and tilting of the walls/fence with the corresponding distresses, should be expected.. To mitigate the tilting of top of slope walls/fences, we recommend that the walls/fences be 0 constructed on-deepened foundations without anyconsideration for creep.forces, where the E.I. of the materials comprising the outer 15 feet of the slope is less than 50, or a O combination of grade beam and caisson foundations, for expansion indices greater than 50 comprising the slope, with creep forces taken into account. The grade beam should. be at a minimum of 12 inches by 12 inches in cross section; supported by drilled caissons, O 12 inches minimum in diameter; placed at a maximum spacing of 6 feet on center, and with O a minimum embedment length of 7 feet below thebottOrn of the grade beam. The strength of the concrete and grout should be evaluated by the structural engineer of record. The O proper ASTM tests for the concrete and mortar should be provided along with the slump quantities. The concrete used should be appropriate to mitigate sulfate corrosion, as warranted. The design of the grade beam and caissons should be in accordance with the O recommendations of the project structural engineer, and include the utilization of the* . following geotechnical parameters: O Creep Zone: 0 5-foot vertical zone bèlowthe slope faceand projected upward parallel to the slope face Creep Load:. •. The. creep load projected on the area of the grade beam should be taken as an equivalent fluid approach, having a density of 60 pcf. For the caisson, it should be taken as a 0 ,• 0 '' , uniform 900 pounds per linear foot of caisson's depth, located above the creep. zone. . • 0 • 0 • • Point of Fixity: • Located a distance of 1.5 times the caisson's diameter, below the creep zone. • • 0 0 RDA Designs 0 • : . W.O. 4369-A-SC 325-347 Oak Avenue 0 0 June 21, 2004 File:e:\wp9\4300\4369a.pge 0 , ,, 0 , . Page 26 GeoSoils, Inc. Passive Resistance: •Passive éärth pressure of 300: psf per footofdepth per. foot of caisson diameter, to a maximum value of 4,500 psf may be used to determine caisson depth and spacing, provided that —. 0 0 •' 0 0 they meet or exceed the minimum requirements stated above. . To determine the total lateral resistance, the contribution of the creep prone zone above the point of .fixity, to passive: : resistance, should be disregarded I Allowable Axial Capacity Shaft capacity: 0 350 psf applied below the point of fixity over the surface area of the shaft. Tip capacity 4,500 psf. 'O DRIVEWAY. FLATWORK, AND OTHER IMPROVEMENTS' •o0 ' 0 The soil materials on site may be expansive: The effects of expansive soils are cumulative and typically occur over the lifetime of any improvements. On relatively levelareas, when 0 the soils are allowed to dry, the dessication and swelling process tends to cause. heaving 0 .and distress to flatwork and other improvements The resulting potential for distress to I: improvements may be reduced, but not totally eliminated. To that end, it is recommended 0 - . . that the developer should notify any homeowners or homeowners association of this long- term potential for, distress. To reduce the likelihood of distress,' the following. 0 1 recommendations are presented for all exterior flatwork: : 0 .1. The subgrade area for concrete slabs should be compacted to achieve a minimum 90 percent relative compaction, and then be presoaked to 2 to 3 percentage points 0 . above. (or 125 percent . of) the soils' optimum moisture content, to a depth of . 11.8 inches below subgrade elevation. If very low expansive soils are present, only O 0 optimum moisture content, or greater,.is required and specific presoaking is not 0 0 'warranted. The moisture content of the subgrade should 'be verified within 72. hours prior to pouring concrete.. 2. Concrete slabs should be cast over a non-yielding surface, consisting of a 4-inch ' 0 ' layer of crushed rock, gravel, or cleah sand, that should be compacted and level prior to pouring concrete. If very low expansive soils are present, the rock or gravel 0 ' ' or sand may be deleted. The layer or subgrade should be wet-down. completely 0 • prior to pouring concrete, to minimize loss of concrete moisture to the surrounding 0 earth materials. I I . - RDA Designs .. ' W.O. 4369-A-SC 325-347 Oak Avenue .. . June 21, 2004 . O File:e:\wp9\4300\4369a.pge ' Page 27 1 0 - GeoSoils, Inc. 0 I $ 3 Exterior slabs should be a minimum of 4 inches thick Driveway slabs and approaches should additionally have a thickened edge (12 inches) adjacent to all I landscape areas, to help impede infiltration of landscape water under the slab A. The use of transverse and longitudinal control Joints are recommended to help ..'• '.control slab cracking due to concrete shrinkage or expansion Two ways to I, . mitigate such cracking. are: a) add a sufficient amount of reinforcing steel, increasing tensile'.strength of the slab; and,, b) provide an adequate amount of .J . . control and/or expansion joints to accommodate anticipated concrete shrinkage .. and expansion. . '. I , In order to reduce the potential for unsightly cracks, slabs should. be reinforced at 0 mid-height with a' minimum of No. 3 bars placed at 18 inches on center, in each direction. The exterior slabs should be scored or saw cut, 1/2 to 3/h inches deep, I .often enough so that no section is greater than 10 feet by,10 feet. For sidewalks or ...often narrow slabs, control joints should be provided at intervals of every 6 feet. The slabs should be separated from the.foundations and sidewalks with expansion joint .' .. . . . . . filler material. 5. . No traffic should be allowed upon thenewly poured concrete slabs until they have been properly cured to within 75 percent of design strength.. Concrete compression strength should bea minimum of 2,500 psi. I 6.' Driveways, sidewalks, and patio slabs adjacent to the hoUse should be separated from the house with thick expansion joint filler material. In areas directly adjacent I . to a continuous source of moisture (i.e., irrigation, planters, etc.), all joints should be additionally sealed with flexible mastic. 1 7. Planters and walls should not be tied to the house 8 Overhang structures should be supported on the slabs, or structurally designed • with continuous footings tied in at least two directions. If very low expansion sOils are present, footings need only belied in one direction 9 Any masonry landscape walls that are to be constructed throughout the property should be grouted and articulated in segments no more than. 20 feet long. These I' ' segments should be keyed or doweled together.' 10. Utilities should be enclosed within a closed utilidor (vault) or designed with flexible 4 0 , • .connections to accommodate differential settlement and expansive soil conditions. 11. Positive site drainage should be maintained at all times. Fihish grade on the lots. should provide a minimum of 1 to 2 percent fall to the street, as indicated herein I ." 'RDA Designs 325-347 -Oak Avenue 'FiIe:e:\wp9\4300\4369a.pge W.O. 4369-A-SC June 21, 2004 Page 28 GeoSoils, Inc. It should be kept in mind that drainage reversals could occur, including post-construction settlement.,if ..relatively flat-yard drainage gradients are not periodically maintained by the homeowner or homeowners association 12. Air conditioning (A/C) units should be suppôited by slabs that are incorporated into the building foundation or constructed on a rigid slab with flexible couplings for '.. plumbing and eletrical lines; NC waste Water lines should be drained to a suitable non-erosive outlet 13. Shrinkage cracks could become excessiveif proper 'flnishing and Wring practices. are not -followed. Finishing and. 'cu ring practices should be performed per the , Portland Cement Association Guidelines Mix design should incorporate rate of curing for climate and time of year, sulfate content of soils, corrosion potential of soils, and fertilizers used on site DEVELOPMENT CRITERIA SloDe Deformation I .. Compacted fill slopes designed using customary factors Of safety-for-gross'-or surficial stability and constructed in general accordance with the design specifications should be 'expected to undergo some differential vertical heave or settlement in combination with differential lateral movement in . the out-of-slope direction,'. after 'grading. This post-construction movement occurs in two forms: slope creep, and lateral fill extension (LFE). Slope creep is caused by alternate wetting and drying of the fill soils which results. in slow.downslope movement. This type of movement is expected to occur throughout the life of the slope, and is anticipated to potentially affect improvements or structures (i.e., separations and/or cracking), placed near the top-of-slope, up to a maximum distance of approximately 15 feet from the top-Of-slope, depending, on the slope height. . This movement generally results in' rotation and differential, settlement of improvements located within the creep zone. ,LFE occurs due to deep wetting from irrigation and,rainfall on. slopes comprised of expansive materials. Although some movement shOuld be expected, long-term movement from this source may be minimized, but not eliminated, by placing the fill throughout the slope tegion, wet of the fill's optimum moisture content. It is generally not practical to attempt to eliminate the effects of either slope creep or LFE. Suitable mitigative measures to reduce the potential of lateral deformation typically include: setback of improvements from the slope' faces (per the 19.97.UBC and/or California Building Code), positive structural separations (i.e., joints) between improvements, and stiffening and deepening of foundations. All of these measures are recommended for 'design of structures and improveñients: The ramifications of the above cohditions,, and' recommendations for mitigation, should be provided, to each homeowner and/or any homeowners association. RDA Designs , ' ' ' ' ' .. ' W.O. 4369-A-SC 325-347 Oak Avenue ' •' ' , '' . ' ' ' June 21, 2004 F11e:e:\wp9\4300\4369a.pge . " " ' •: ', .' ' . Page 29 GeoSoils, Inc J Slope Maintenance and Planting I . Water has. been shown to"weakén the inherent, strength of all earth materials. Slope stability is significantly reduced by overly wet conditions..Positive surface drainage away .:.from slopes should be maintained and only the amount of irrigation necessary to sustain plant life should be provided for planted slopes Over-watering should be avoided as it can adversely affect site improvements, and cause perched groundwater conditions. Graded slopes constructed utilizing onsite materials.would be erosive. . Eroded debris may be I. •• minimized and surficial slope stability enhanced by establishing and maintaining a suitable - - , .. • 'vegetation cover soon after construction. Compaction to the,face of fill slopeswould tend. to minimize short-term erosion' until vegetation' is' 'established. Plants selected for 1' •.. . .. landscaping should be light weight, deep rooted types that require little water and are capable of surviving the prevailing climate. Jute-type matting or other fibrous covers may aid in allowing the establishment of a sparse plant cover. Utilizing plants other than those . recommended above will increase the potential for perched water, staining, mold, etc., to develop. A rodent control program to prevent burrowing should be implemented. Irrigation of natural '(ungraded) slope areas is' generally not recommended. These recommendations regarding plant type, irrigation practices, and rodent control should be provided to each homeowner. Over-steepening of slopes should be avoided during I building construction activities and landscaping Drainage'. Adequate lot surface drainage is a very important factor in reducing the likelihood of. adverse performance of foundations, hardscape, and slopes. Surface drainage should be sufficient to prevent ponding of water anywhere on a lot, and especially near structures and lops of slopes. Lot surface. drainage, should be carefully taken,jnto consideration during fine grading, landscaping, and building construction. Therefore, care should be taken that future landscaping or construction activities, do not create adverse drainage' conditions. Positive site drainage within lots and common areas should be provided and maintained at all times. Drainage should not flow uncontrolled down 'any descending slope.' Water should be directed away from foundations and not allowed to pond and/or seep into the. ground. In general, the area within 5 feet around a structure should slope away from the structure. We recommend that unpaved lawn and landscape areas have a minimum gradient of 1 percent sloping away from structures, 'and whenever possible, should be above adjacent paved areas. Consideration should be given to avoiding construction of planters adjacent to structures (buildings, pools, spas, etc.). Pad drainage should be directed toward the street or other approved area(s).. Although not a geotechnical' requirement, roof gutters, down spouts, or .other appropriate means may be utilized. to control roof drainage. Down spouts, or drainage devices should outlet a minimum of 5 feet from structures or into a subsurface drainage system. Areas of seepage may develop due to, irrigation or heavy rainfall, and should be anticipated.. Minimizing irrigation will lessen this potential. If areas of seepage develop,' recommendations for minimizing this effect 'could be provided upon request. I, I 'RDA Designs . . ' ' . . ' W.O. 4369-A-SC 325-347 Oak Avenue . S ' . '. .' . June 21, 2004 Fiie:e:\wp9\4300\4369a.pge ' . , . '' . " ' Page 30 GeoSoils, Inc. ' . I Toe of Slope Drains/Toe Drains I ; . Where significant slopes intersect pad areas; surface drainage down the slope allows for. some seepage into the subsurface materials, sometimes creating conditions causing or ........."contributing to perched and/or ponded water. Toe of slope/toe drains may be beneficial I . . in the, mitigation of this condition due to surface 'dráinage. The general criteria to be utilized by the design engineer for evaluating the need for this type of drain is as follows Is there a,source of irrigation above or on the slope that could contribute to saturation of soil at the: base of the slope? I. Are the slopes hard rock and/or impermeable,, or relatively permeable, or; do the. slopes already have or are they proposed to have subdrains (i.e., stabilization fills, etc.)? Was the lot at the base àf the slope overexcavated or is it proposed to be overexcavated? Overexcavated lots located . at the 'base of a slope could accumulate subsurface water along the base of the fill cap. Are the slopes north facing? North facing slopes tend to receive less sunlight (less evaporation) relative to soUth facing slopes and are more exposed to the currently prevailing seasonal storm tracks. I ' ' What is the slope height? It has been our experience that slopes with heights in ,excess of approximately 10 feet tend to have more problems due to storm runoff and irrigation than slopes of a lesser height. ' .' Do the slopes "toe out" into a residential lot or 9 lot where perched or ponded water I may adversely impact its proposed use? Based on these general criteria, the construction .of toe drains maybe considered by the design engineer along the toe of slopes, or-at retaining walls in slopes ''descending to the ''rear of such' lots. Following ,are Detail '4 (Schematic Toe Drain Detail) and Detail 5 .(Subdrain Along Retaining Wall Detail). Other drains may be warranted due to unforeseen conditions, homeowner irrigation, or other circumstances. Where drains-are constructed 'during grading, including subdrains, the locations/elevations of such drains should be surveyed, and. recorded on the 'final as-built grading plans by the design engineer. It is 'recommended that the above be disclosed to all interested parties, including homeowners and any homeowners association. RDA Designs ' ' . , W.O. 4369-A-SC 325347 Oak Avenue June 21, 2004 F1Ee:e:\wp9\4300\4369a.pge ' . ' ' Page 31 GeoSoils, Inc. DETAILS SCHEMATIC TOE DRAIN DETAIL Drain May Be Constructed into, -. .. or at, the Toe of Slope I Pad Grade NOTES ci S 1) Soil Cap Compacted to 90 Percent Relative Compaction 12" Minimum 2.) Permeable Material May Be Gravel Wrapped in Filter Fabric (Mirafi 140N or Equivalent). S. 3) 4-Inch Diameter Perforated Pipe (SDR 35 or Equivalent) with Perforations Down . . . . - 4.) Pipe to Maintain a Minimum .1 Percent Fall. 5.) Concrete Cutoff Wall to be Provided at Transition •. Pe rmeable to Solid Outlet Pipe. S Material .6.) Solid Outlet Pipe to Drain to Approved Area. . . S S . 7.) Cleanouts are Recomended at Each Property 24" . . • Une. Minimum- Drain Pipe 12" H SCHEMATIC TOE DRAIN DETAIL DETAIL 4 S S Geotechnical s Coastal 9 Geologic • Environmental I DETAILS 1 N T S 1 2:1 SLOPE (TYPICAL) TOP.OF WALL : S I BACKFILL WITH COMPATED NOTES NATIVE SOILS . .: I • &- --- Soil Cap Compacted to 90 Percent 1 •. I Relative Compaction. 112" RETAINING WALL MIN Permeable Material May Be Gravel Wrapped in Filter Fabric (Mirafi 140N or Equivalent). j . . •. _____ I 4-Inch Diameter Perforated Pipe I (SDR 35 of Equivalent) with . ••. MIRAFI 140 FILTERFABRIC Perforations Down. FINISHED. GRADE -v OR EQUAL . . . . . :•' . . Pipe to Maintain a Minimum 1 1 Percent Fall. - -I . . ... . 3/4" CRUSHED GRAVEL . I I - . J7. • . Concrete Cutoff Wall to be Provided WALL FOOTING—JJ at Transition to Solid Outlet Pipe. I ?W1 Fi . . Solid Outlet. Pipe to Drain to. Approved Area. 124" . •• •. Cleanouts are Recommended at'' I 9-" DRAIN . . Each Property Line. I . . . . Compacted Effort Should Be • . . . Applied to Drain .Rock. 1"T02" 1 • •. .. . 12—i . . . . . . S. I .1 • . . . S. S I SUBDRAIN ALONG RETAINING WALL DETAIL ... . . . . S I NOTTOSCALE DETAIL 414j . SUBDRAIN ALONG RETAINING WALL DETAIL Geotechnical • Coastal • Geologic • Environmental Erosion Control Cut and fill slopes will be subject to surficial erosion during and after grading.., Onsite earth materials have a moderate to. high erosion potential. Consideration should be given to providing hay bales and silt fences for the temporary, control of surface water, from a geotechnical viewpoint Landscape Maintenance Only the. amount of irrigation necessary to sustain' plant'.life should be provided. 'Over-watering the landscape areas will adversely. affect proposed site improvements. We would ',recommend that any proposed open-bottom planters adjacent to proposed: structures be eliminated for a minimum distance of 10 feet. As an alternative,' closed-bottom type planters could be utilized An outlet placed in the bottom of the planter, could be installed to direct drainage away from, structures or any exterior concrete 'flàtwork. If planters are constructed adjacent to structures, the sides and bottom of the ' "planter should be provided with a moisture barrier to prevent penetration of irrigation water into the subgrade. Provisions should be made to drain the excess irrigation water from the planters without saturating the subgrade below or adjacent to the planters. Graded slope 1 areas should be planted with. droughtr9sistantvegetation. Consideration should be given' to the type of vegetation chosen and their potential effect upon surface improvements (i.e;, some trees will have an effect on concrete flatwork with their extensive root systems). From., a geotechnical' standpOint leaching is not recommended for:, establishing landsOáping. If the surface soils are processed for the purpose of adding amendments, they should be recompacted to 90 percent minimum relative compaction Gutters 'and Downsoouts As previously discussed in the drainage section, the installation of gutters and downspouts should be considered to collect roof water that may otherwise infiltrate the soils adjacent to the structures If utilizedi the downspouts should be drained into PVC collector pipes or non-erosive devices that will carry the water away from the house; Downspouts and 'gutters are not'a requirement; however, from a geotechnical viewpoint,' provided that, positive drainage' is incorporated into project design (as discussed previously). Subsurface and Surface Water Subsurface and surface water are not anticipated to affect site development, provided that ,the recommendations contained in this report are incorporated' into final design and construction and that prudent surface and subsurface drainage practices are incorporated into the construction plans. Perched groundwater conditions along zones of ,contrasting permeabilities may not be precluded from occurring in the future due to site irrigation, poor drainage conditions, or damaged utilities, and should be anticipated. Should perched groundwater conditions develop, this office could assess the affected area(s) and provide RDA Designs - • ' 0 , " W.O. 4369-A-SC 325-347 Oak Avenue , • , June 21, 2004 -' F11e:e:\w09\4300\4369a.pge ' '. ,. • Page 34 GeoSoils, Inc. ' ••' 0 the 'appropriate recommendations to mitigate the observed groundwater conditions. Groundwater conditions may change with the introduction of irrigation; rainfall, or other factors. .: Site ImDrovements Recommendations for exterior concrete flatwork design and construction can be provided upon request. If in the future, any additional improvements (eg.,poóls; spas, etc.) are planned for-the site, recommendations concerning the geological or geotechnical aspects of design and construction of said improvements could be provided upon request This offlce.should be notified in advance of any fill placement, grading of the site, or trench backfilling after rough grading has been completed. This includes any grading, utility trench, and retaining wall backfihls. S ' Tile Flooring 'Tile flooring can crack, reflecting cracks in the concrete slab below the tile, although small cracks in a conventional slab may not be significant. Therefore, the designer should consider additional steel reinforcement for concrete slabs-on-grade where tile will be placed. The tile installer should consider installation methods that 'reduce possible cracking of the tile, such as slipsheets. Slipsheets or a' vinyl crack isolation membrane '(approved by the Tile' Council of AmericaJCeramic Tile Institute) are recommended between tile and concrete slabs on grade. Additional Gradin This office should be notified in advance of any fill placement, supplemental regrading of the site, or trench backfihling after rough grading has been completed. This includes completion of grading in the street and parking areas and utility trench and retaining wall backfills. I Footing Trench Excavation All footing excavations should be observed by a representative of this firm subsequent to trenching and prior to concrete form and reinforcement placement. The purpose of the observations is to verify that the excavations are made into the recommended bearing material and to the minimum widths and depths recommended for construction. If loose or compressible materials are exposed within the footing excavation, a deeper footing or removal and recompaction of the subgrade materials would be recommended at that time. I Footing trench spoil and any excess soils generated from utility trench excavations should be compacted to a minimum relative compaction of 90 percent, if not removed from the site. . . I J. • RDA Designs . S W.O. 4369-A-SE : • 325-3470akAvenue S • • S June21, 2004 5' .File:e:wp9\4300\4369a.pge S . . S Page 35 5 ., •. GeoSoils, Inc. . S • I I Trenching Considering the nature of the onsite soils, it should be anticipated that caving or sloughing I could be a factor in subsurface excavations and trenching. Shoring or excavating the trench walls at the angle of repose (typically 25 to 45 degrees) may be necessary and should be anticipated. All excavations should be observed by one of our representatives and minimally conform to CAL-OSHA and local safety codes I Utility Trench Backfill All interior utility. trench backfill should be brought to at least .2 percent above I : optimum moisture content and then compacted to obtain a minimum relative compaction of 90 percent of the laboratory standard; As an alternative for shallow. (12-inch .to 18-inch) under-slab trenches, sand having a sand equivalent value of I •• . . . .30 or greater may be utilized and jetted or flooded into-place. Observation, probing• and testing should be provided.toverify the desired results.. . . . 2. Exterior trenches adjacent to, and within areas extending below a 1:1 plane... projected from the outside bottom edge of the footing, and all trenches beneath t hardscape features and in slopes, should be compacted to at least 90 percent of • the laboratory standard.: Sand backfill, unless excavated from the trench, should not be used in these backfill areas: Compaction testing and observations, along I with probing, should be accomplished to verify the desired results 3 All trench excavations should conform to CAL-OSHA and local safety codes I .. . .. . Utilities crossing grade beams, perimeter beams, or footings should either pass below the footing or grade beam utilizing a hardened collar or foam spacer, or pass... I. through the footing or grade beam in accordance with the recommendations of the .. structural engineer. . . . . . . SUMMARY OF RECOMMENDATIONS REGARDING : I .. GEOTECHNICAL OBSERVATION AND TESTING We recommend . that observation and/or testing be performed by GSI at each of the following construction stages: ,. . . During grading/recertification I • During significant excavation (i e , higher than 4 feet) I. . : • •... During placement of subdrains, toe drains, or other subdrainage devices, priorto placing fill and/or backfill.. . . . . .. . . . RDA Designs ,. . . . . . • . W.O. 4369-A-SC 325-347OakAvèniie . . June 21, 2004 . . • Fiie:e:\wp9\4300\4369a.pge . . . . . . . Page 36 GeoSoils, Inc. . . I,,... I '. •. After excavation of building footings, retaining wall footings, and free standing walls . footings, prior to the placement of reinforcing steel or concrete I • Prior to pouring any slabs or flatwork, after presoaking/presaturation of building pads and other flatwork subgrade, before the placement of concrete, reinforcing I steel, capillary break (i.e., sand, pea-gravel, etc), or vapor barriers (i.e.,, visqueen, etc) I • During retaining wall subdrain installation, prior to backfill placement . During placement of backfill for area drain, -interior pluriibing utility line trenches, I and retaining wall backfill During slope construction/repair. When any unusual soil conditions are encountered during any construction I .. operations, subsequent to the issuance of this report.: •. . When any developer or homeowner improvements, such as flatwork, spas, pools, I walls, etc.., are constructed I • A report. of geotechnical bbservatión and .testing should be..provided at the conclusion of each of the above stages, in order to provide concise and clear • . . documentation of site work, and/or to comply with code requirements. I OTHER DESIGN PROFESSIONALS/CONSULTANTS I •• The design civil engineer, structural engineer, post-tension designer, architect, landscape.• architect, wall ,. designer, etc., should review the recommendations provided herein, . incorporate those recommendations into all their respective plans, and: by explicit reference, make this report part of their projedt plans. In order to mitigate potential distress, the foundation and/or, improvement's designer should confirm to GSI and the * •' • governing agency, in writing, that the proposed foundations and/or improvements can tolerate the amount of differential settlement and/or expansion characteristics and design • • '. criteriaspecifled herein. : • • • • .. : • •• • . • • PLAN REVIEW I Final project plans should be reviewed by this office prior to..construction, so that , • . construction is in accordance with the conclusions and recommendations of this report. • Based on our review, supplemental recommendations and/or further geotechnical studies may be warranted I RDA Designs • • . •. . , • . 325-347 Oak Avenue • • . ''. . • June 21, 2004 • • • • File:e:\wp9\4300\4369a.pge . • . • . . Page 37 • . . • . . . • . • GeoSoils, Inc. •. •. * . I I LIMITATIONS The materials :encôurltered on the' project: site'and utilized for our analysis are -believed representative of the area; however, soil and bedrock materials, vary in character 'between excavations and natural outcrops or conditions exposed during mass grading.,Site I conditions may vary due to seasonal changes or other factors •" Inasmuch as our study is based upon our review andengineering analyses and laboratory I data, the conclusions and recommendations are professional opinions These opinions have been derived in accordance with current standards of practice, and ho warranty 'is :. expressed or implied. Standards of practice -are subject to change with time.' GSI assumes'' I no responsibility or liability for work or testing performed by others, or their inaction, or work performed when GSI is not requested to be onsite, to evaluate if our recommendations have been properly implemented Use of this report constitutes an I ' agreement and consent by the user to all the limitations outlined above, notwithstanding'' •' ' any other agreements that may be in place In addition, this report may be subject to '"review by the controlling authorities. Thus, this report brings to completion our scope of I services for this project I I I I I I I I I ' , RDA Designs" • ' ' '' ' , ', '' ' W.O. 4269-A-SC 325-347 Oak Avenue ' ' • ' ' ' ' ' '• , , June 21; 2004 FiIe:e:\wp9\4300\4369a.pge ' ' ' ' ' ' ' ' ' ' ' ' Page 38 ' GeoSoils, Inc. • ' '' ' 0 .: % J ; ' - u . i~ ~ I . . , , .. ~ . : . ~.. . ~ ~~ .. .1 . , ... . - . - ,.. , : -.:. ~:' ... : , - . . . , " I F.- I.` F 171. - - _ 1 ¼ APPENDIX A .-- REFERENCES I i -J - I- I 'i_ - / '-- 4 - 11/ .11 . I , , - , ~l .. . ,~.. . ~, v - 4 t I I 'Blake, T.F., 2000a, EQFAULT, A computer program for the estimation of peak horizontal acceleration from 3-D, fault sources; Windows 95/98 version. ' ..-,..2000b, EQSEARCH, A computer program for the estimation of peak horizóntal acceleration from California historical earthquake catalogs; Windows 95/98 version. 2000c, FRISKSP, A computer program for the probabilistic estimation, of peak acceleration and uniform hazard spectra using 3D. faults as earthquake sources; Windows 95/98 version Bozorgnia, Y, Campbell, KW, and Niazi,. M, 1999, Vertical ground motion Characteristics, relationship with horizontal', component,' and 1 building-code implications; Proceedings of the SM1P99 seminar on utilization of strong-motion 'data, September, 15, Oakland, pp 23-49. Campbell, K.W. and Bozorgnia Y. 1997, Attenuation relations for soft rook Oonditions; in EQFAULT, A computer program for the estimation of peak horizontal acceleration' from 3-D fault sources; Windows, 95/98 version, Blake, 2000a..'' 1994, Near-source attenuation of peak horizontal acceleration from worldwide accelrograms recorded from 1957 'to 1993; Proceedings, Fifth US. National Conference on Earthquake Engineering, Volume Ill, Earthquake Engineering Research Institute, pp. 292-293. Hart, E.W. and Bryant, W.A. 1997,' Fault-rupture hazard zones in California, Alquist-Priolo earthquake fault zoning act with Index to Earthquake Fault Maps; CaliforniaDivision ,of Mines and Geology Special Publication 42: ' •, ' ' ' ': International Conference of Building Officials, 1997, Uniform building code:: Whittier, California, vol. 1, 2, and 3. ', ' ' • ' ' Jennings, C.W., 1994,. Fault' activity map of California and adjacent areas:. California 'Division of Mines and Geology, Map Sheet No. 6, scale 1:750,000. Joyner, W.B, and Boore, D.M'., 1982a, Estimation of responsespectral values as functions of magnitude, distance and site conditions, in eds., Johnson, J.A.,'Carnpbell, K.W.,• and Blake,T.F.: AEG Short Course, SeismicHazard Analysis, June 18, 1994. • 1982b, Prediction of earthquake response spectra, U.S. Geological Survey Open'- File Report 82-977,16p. L I I GeoSoils, Inc. I :; . •..• I Parker, Claude B , Geotechnical Consultant, Preliminary geotechnical report for proposed residential structure, 5480 Carlsbad Boulevard, Carlsbad, County of San Diego, i California, Job no 82-471 P, dated August 22',A 982 Sadigh, K, Chang, C -Y, Egan, J A, Makdisi, F, and Youngs, R R, 1997, Attenuation relations for shallow crustal earthquakes based on'.California strong motion data, Seismological Research Letters, Vol 68, No...1, pp 180-189 I Treiman, J A, 1993, The Rose Canyon fault zone, southern California California Division of Mines and Geology, Open File report OFR 93-02 1 , 1991, Rose Canyon fault zone, San Diego county, California California division of Mines and Geology, fault Evaluation Report FER-216, July 10, revised I January 25, 1991, 14p Weber, F H, 1982, Geologic map of north-central coastal area of San Diego County, California showing recent slope failures and pre-development landslides California I Department of Conservation, Division of Mines and Geology, OFR 82-12 LA I . Wilson, K.L., 1972, Eocene and related geology of a portion of the San Luis Rëy and Encinitas quadrangles, San Diego County, California unpublished masters thesis, University of California, Riverside I .... ...... S... I I I I I I I RDA Designs .. . . . S S . •. Appendix A I Flie e \wp9\4300\4369a pge Page 2 GeoSoils, Inc.. . . S . .. ';'' T'::. ..r'r: : I S '2 : - , I I- 2 2 il, / S t ; ~ ~ ..., - 1, I - .", .. 1. "4 . . , , . . . . I . .* . t S I - , , , , . . I ),: . , . - ~ . . .. ~ .. I .. : : . . ~~ - " ~ , 21 - , .. . .. .. ~ ~ , - . , . . - I . .. ~ .. . . ..I;- - % - - : ~ -1 , - , ,,,, I ~ I - p - I S APPENDIX B f. - I - S TEST PIT AND BORING LOGS I I i I V S S I , , i, "' ~ . I . I . ; .. - . ~ ~ , , . , ; I , . . , I i , , . . . . -/ , . I., ~ . I :., -, '. - , `~ .-S, - -.,~ . ~ " ~ ": . : ~ t~ '. " ! - - ¶11 - ¶ C " t, I ~, , ~~ , ., , " 2 I I p I S - I I - - - - - mm - - - . - - - MM - - W.O. 4369-A-SC RDA Design Ocean Mist Condominiums June 11, 2004 LOG OF EXPLORATORY TEST PITS TEST PIT NO i•.L DEPTH GROUPE DEPTH MOISTUREi frbRY DENSITY :::.• ' DESCRIPTION Ø)1 ypj130 (cf) TP-1 0-/2 SM TOPSOIL: SILTY SAND, light brown, dry, loose. 1/2-2 SM Ring @ 2 108.7 5.2 WEATHERED TERRACE DEPOSITS: SILTY SAND, red Bag @ 6 brown, moist, medium dense; fine grained. 2-6 SM TERRACED DEPOSITS: SILTY SAND, red brown, dense; fine grained. Becomes semi-indurated. Total Depth 6' No Groundwater Encountered Backfilled 6-11-2004 PLATE B-i — — — — — — — — — — — — — — — — () GéoSIWJht W.O. 4369-A-SC RDA Design Ocean Mist Condominiums June 11, 2004 LOG OF EXPLORATORY TEST PITS TEST SIMPLEtu FJELD DRY 4 :PITNo DEpm.: GROUP -1.,'0E 'Y .: DESCRIPTION. SYMOL t5J B (%)4 (pcf) .4 TP-2 0h/2 SM TOPSOIL: SILTY SAND, light brown, dry, loose. 1/2 2 SM WEATHERED TERRACE DEPOSITS: SILTY SAND, red brown, moist, medium dense. 2-4 SM TERRACE DEPOSITS: SILTY SAND, red brown, dense; fine grained. Self-indurated. Total Depth = 4' No Groundwater Encountered Backfilled 6-11-2004 PLATE 8-2 — - - • — — — : :... W.U. 4369-A-SC (7éoSo.11s;Inc. : RDA Design. / ' I Ocean Mist Condominiums June 11, 2004 LOG OF EXPLORATORY TEST PITS TEST SAMP[E FIELD DRY PIT NO. DEPTH GROUP DEPTH MOISTURE DENSITY DESCRIPTION 1 (r SYMBOL :1 ft; (pcf), . .1 . ,... •. TP-3 O-½ SM TOPSOIL: SILTY SAND, light brown, dry, loose. 1/2 SM WEATHERED TERRACE DEPOSITS: SILTY SAND, red brown, moist, medium dense. 2-3 SM TERRACE DEPOSITS: SILTY SAND, red brown, dense; fine grained. Becomes indurated @3'. Total Depth = 3' No Groundwater Encountered Backfilled 6-11-2004 PLATE B-3. BORING LOG .GeoSoils, Inc. . •' : : wo. 4369-A-SC PROJECT: RDA Design S BORING B1 SHEET1 0F1 Ocean Mist Condominiums S S DATE EXCAVATED 6-11-04 Sample - SAMPLE METHOD HAND AUGER Standard Penetration Test S Groundwater 'El Undisturbed Ring Sample - : . S ' • Description of Material SM : TOPSOIL: •• • • • • : . 5-. 0' SILTY SAND, light brown, dry, loose. SM • : TERRACE DEPOSITS: S • • . _,'.• © 1' SILTY SAND, red brown, damp, medium dense to dense. • • S S S • S. - . • • S • • • Total Depth 4' • 5 5 S S • • 5 •• No Groundwater Encountered 5 S •• • Backfilled 6-1-2004 . S • 5 5- 5 5 5 5 S S GeoSoils . •• Inc. . • , Ocean Mist Condominiums PLATE B I. : 0,• H I I • EARTHQUAKE RECURRENCE CURVE I RDA:__ •' ____•' • • ••100-• __ ••__ __ •• __• ___ • • __ 1' • • _ • io____••___ co I • .1-. • _ _ •• .•• ___ _ • __ ____ __ __ __ __ __ __ 75 I • ' • • .001- __ _• __ __ __ __ __ __ I ' __ __ __ __ __ __ __ __ __ __ __ I.: 3.5. .4.0 • 4.5 5.0 .5.5 6.0 6.5 '7.0 7.5 8.0 8.5 9.0 . . . '• .. • • Magnitude .(M) I 1 ' W.O. 4369-A-SC • : • • Plate C-2 co > . — 1: — — — . — . — — — •0 RETURN PERIOD vs. ACCELERATION..','.- CAMP. & BOZ. (1997.Rev.) SR 1 1 1000000 yft,1 100000 1000 (OIO 0.00. 025 0.50 0.75 '1.00 Acceleration (q)- I I PROBABILITY OF EXCEEDANCE I CAMP. & BOZ. (1997 Rev) SR 1 1 1.1 Al 25yrs 50yrs 1.1 lvi i 100 - ____ 75 yrs.. 100 yrs - 90 80 > 70- 60.-I °' 0 0• , ' ____ , Co • 2.'50-T I • 0 40-7- CU,30-I - 1.1 20 -I 0.00 0.25. 0.'50 -.0.75 . 1700 1.25 1.50. .1 • , 0, • 0 'Acceleration (g) . 0 , • , 0 • 0 W.O. 4369-A-SC 0 Plate C4 0 • 0 • 0 • • 0 ' '. I - 4, I -. ±' '"••'-.'. - .'.,. ) - - I'1'll; 4 - t ,- 4. 2 '1. .4 44. - Z f'._ 2 I - 4. - -,... " '4 r ' 2 .1 I ..::..,;. 1:, '.) - - 4 , 4 . I f' 2' - - \ -' - ... -'- 4 I f I -. .' I - - ... -'-I 2 -. I I :• ..:y ':' I 4 1 ' " 4. -4- 4 A ''-' 4 - ., .- / 1 I .1 -' 11 I .4- " '1' .4.. .. - I .4 .4 -- I 4- .4 ? I -4 4 -4 4- 4' *PPENDI)( D - 1 - 44 j I '- A I - -. 4 WORK ,11 TT T1 T 11 N I I I - - 4) - -4 4 4 -44. / ' : : '- - -'. 4 1 I 4/ 1 4 " I r 2 4 4 " - .4 44 ,'. .4.1 4, 4." 4' 4) 4 ,_. - -' 4, 4 4- 1 4 % .4 )'j .4 '.. ;. ' - •,.S' 4 I 4. 4-' i-.' '4 -'4 4 4. - '-4- 4 1 ,. 4. 'I I '' 4 4 4 -4- 4, - I 44_4 2 .. ' 4 4 I... 1 4. I' _ F ., 'A -' '. - 4 -, 4 4. 4 - .. -' ' ".4 4 '14 " ,, .'- I 111. U '4 * 1 - -.4-,, 4-'-, ':' .4.44.4 , 4- '4 .*,. ..,.,. 44 1 - -. '1 4. .44. .4 - ':- I 4- _. '.li 2 - 4 /4 4 ..' " .4 ".) -4 - '4 II' '.4 y' t' ? '4 - .4 -. 144 1 - - .4 4 I " 1 '4 -4 4'4. '4 - '-I 'r I - 4 -;.f ,4 ' -' 21 '4 .' - ' (s - 4, 4 -4 1' 4. "' " ' - - •" .4, 4 ,, -'.4- . "t •. . '--' - : - 1.:'' - , -••.,' ' '. - 4-..: -- ".'.•-S'. -, 4-.'.:'.-.-" -, 2 4- 1. I 1. I -. '4 -4 4, 4 4. 4 4 f .*-_ 4 4 -ç I 4. 4. 4- '4 - , 4 1 - -. 47,, 42 I .4 1 .4 p1-4. 4.4 Y,. -':--' , -:-.' .:.-'-. /'•.':- •', ":' -'--.::: - - A " ' 4. - '4 '4 4 4 1 4, 4 A " A I. I '4 '4 ". ' - 4 U '4. 7 4, 44 4.4 I : I GENERAL EARTHWORK AND GRADING GUIDELINES I General These guidelines present general procedures and requirements for earthwork and grading I as shown on the approved grading plans, including preparation of areas to filled, placement of fill, installation of subdrains and excavations The recommendations contained in the geotechnical report are part of the earthwork and grading guidelines and I would supercede the provisions contained hereafter in the case of conflict Evaluations :performed by the consultant. during the course of grading may result in. new recommendations which could supersede thésé guidelines or the recommendations I . contained in the geotechnical report. The contractor is responsible for the satisfactory completion of all earthwork in accordance I .': .• .with provisions of the project plans and specifications. The project-soil engineer and engineering geologist (geotechnical consultant) or their representatives should provide observation and testing services, and geotechnical consultation during the duration of the . I project I EARTHWORK OBSERVATIONS AND TESTING I Geotechnical Consultant Priorto the commencement of grading, a qualified geotechnical consultant (soil engineer S I. and engineering geologist) should be employed for the purpose of observing earthwork procedures and testing the, fills for conformance with the recommendations of the geotechnical report, the approved grading plans, and applicable grading codes and i ordinances The geotechnical consultant should provide testing and observation so that determination 1........... may be made that the work is being accomplished as specified. lt.is the responsibility of the contractor to assist the, consultants and keep. them apprised of anticipated workS 'schedules and changes, so that they'may'schedule'their personnel.accordingly. ' All clean-outs, prepared ground to receive fill, key excavations, and subdrains should be observed and documented by the project engineering geologist and/or soil engineer prior I ' , to placing and fill. It is the contractors's responsibility to notify the engineering geologist and soil engineer when such areas are ready for observation I Laboratory and Field Tests 'Maximum dry density.tests to determine the degree of compaction should be performed. in.aôcordance with American Standard Testing'Materials test method ASTM designation D-1 557-78. Random field compaction tests should. be performed in accordance with test method ASTM designation D-1 556-82, . D-2937. or D-2922 and D-3017, at intervals of apprOximately 2 feet of fill height or every 1.00 cubic yards of fill placed. These criteria I GeoSoils, Inc. 'I'' •'.".'.. 0 ..... .' H'.. '.H .. I would vary depending on the soil conditions and the size of the project The location and frequency of testing would be at the discretion of the geotechnical consultant Contractor's Responsibility .I All clearing, site preparation, and earthwork performed on the project should be conducted:. by 'the contractor, with observation by geotechnical consultants and staged approval by the governing agencies, as applicable It is the contractor's responsibility to prepare the I ground surface to receive the fihl,.to the satisfaction of the soil engineer, and to place, spread, moisture condition, mix and compact. the fill, in . accordanóe' with the recommen-dations of the soil engineer. The contractor should also remove all major non- earth material considered unsatisfactory by the soil engineer It is the sole responsibility of the contractor to provide adequate equipment and methods I........: to accomplish the earthwork in accordance with applicable grading guidelines, codes or agency ordinances, and approved grading plans'. .*Sufficient watering apparatus and compaction equipment should be provided by the, contractor with due consideration for the fill material, rate of placement, and climatic conditions If, in the, opinion of the geotechnical consultant, unsatisfactory conditions, such as questionable weather, excessive oversized rock., or deleterious material, insufficient support equipment, are resulting in a quality of work that is not acceptable, the consultant will inform the contractor, and the contractor is expected to rectify the conditions, and if necessary, stop I work until conditions are satisfactory. .1, During construction, the contractor shall properly grade all surfaces to maintain good I .drainage.and prevent ponding of water. The contractor shall take remedial measures to control surface water and to prevent erosion of graded areas until such time as permanent.., drainage and erosion control measures. have been installed.' ' .. I .1 .., .. . SITE PREPARATION. All major vegetation, including brush, trees, thick grasses organiO debris, and other 'deleterious material -should be removed and disposed of off-site. These removals must be concluded prior to placing fill. Existing fill, soil, alluvium, colluvium, or rock materials determined by the soil engineer or engineering "geologist as being unsuitable in'-place ' should be removed prior to fill placement: Depending upon the soil conditions, these materials may be reused. as compacted fills. Any materials incorporated as part 'of'the compacted fills should be approved by the soil engineer. I . Any underground structures 'such as cesspools, cisterns, mining shafts, tunnels, septic tanks, wells, pipelines, or other structures not located prior to grading are to be removed I " .or treated in' a manner recommended' by the soil engineer Soft, dry, spongy,'. highly fractured, or otherwise unsuitable ground 'extending to such a depth that surface ' ,processing cannot adequately improve the: condition should be .overexcavated down to' I . RDA Designs ' . ' ' ... ' . ' Appendix D File:e:\wp9\4300\4369a.pge . ' ' . ' ' Page 2, I GeoSouls, Inc. I Ifirm ground and approved by'the soil engineer before compaction and filling operations' continue Overexcavated and processed soils which have been properly mixed and moisture conditioned should be re-compacted to the minimum relative compaction as I specified in these guidelines I Existing ground which is determined to be satisfactory for support of the fills should be scarified to a minimum depth of 6 inches or as directed by the soil engineer. After the scarified ground is brought to optimum moisture content or greater and mixed, the I . materials should be bornpacted.as specified herein:' If the scarified zone is ,grater that .6 inches in depth, it may be necessary to 'remove the excess and place-the material in lifts -restricted to about 6 inches in compacted thickness. I Existing ground which is not satisfactory to support compacted fill should be overexcavated as required in, the geotechnical 'report or by the on-site soils engineer. I and/or engineering geologist Scarification, disc harrowing, or other acceptable form of mixing should' continue until thésoils are broken.down and free of large lumps or clods, " until the working surface is reasonably uniform and free from ruts, hollow, hummocks, or 1 other uneven features which would inhibit compaction as described previously. ...Where fills are to be placed o ground with1 slopes steeper than 5:1 (horizontal to vertical)', the ground should be stepped or benched The lowest bench, which will act as a key, 'should be a minimum of 15 feet wide and should be'at least 2 feet deep into firm material, I ..and approved by the soil engineer and/or engineering geologist:. In fill 'over cut slope' conditions, the recommended minimum Width of the lowest bench or key is also 15 feet with the key founded on firm' material, as designated by the Geotéchnical Consultant. As I " a general rule, unless specifically recommended otherwise by the. Soil Engineer, the minimum width of fill keys should be approximately equal to 1/2 the height of the slope I 'Standard benching is, generally 4 feet (minimum) vertically, exposing firm,' acceptable material. Benching may be used to remove unsuitable materials, although it is understood that the vertical height of the bench may exceed 4 feet.'. Pre-stripping may be considered I for unsuitable materials in excess of 4 feet in thickness All areas to receive fill, including processed areas, removal areas, and the toe of fill benches should be observed and approved by the soil engineer and/or engineering' 'geologist prior to placement. of fill. Fills may then be properly placed and compacted until design grades (elevations) are attained. ' I COMPACTED FILLS Any earth materials' imported, or excavated on the property may be utilized , in the fill provided 'that each material has been determined to be suitable by the soil engineer. These materials should be, free of roots, tree branches, 'other organic matter or other RDA Designs .' ' ' " ' ' , . Appendix D Fi1e:e:\wp9\4300\4369a.pge ' . '' ., , Page 3 I GeoSoils, Inc. I I' I deleterious -materials. All unsuitable materials should be removed from the fill as directed by the., soil engineer.. Soils .of poor gradation, undesirable expansion potential, or substandard strength characteristics may be designated by the consultant as, unsuitable and may reqUire blending with other soils to serve as a satisfactory fill'rnaterial. Fill materials derived.from'benching.operations should be. dispersed throughout the fill area and blended with other bedrock derived material. Benching operations should not result in the benched material being placed:Only within..a single equipment width away from the fill/bedrock contact.. I I I Oversized materials, defined as 'rock or other 'irreducible materials 'with a maximum dimension greater than 12 inches should not be buried or placed in fills unless the location of materials and disposal methods are'' specifically approved by the soil engineer; 'Oversized material should betaken off-site or placed in accordance with recommendations of the soil engineer in areas designated 'as' suitable for rock disposal. Oversized material should not be placed within 10 feet vertically of finish grade (elevation) or within 20 feet :horizontally of slope faces. To facilitate future:trenching, rock should not. be placed within the range of foundation "excavations, future *utilities, or' underground construction unless specifically approved by the soil engineer and/or the developers representative If import material is 'required.for grading, representative 'samples' of the materials to be I ' utilized as compacted fill should be. analyzed in the laboratory by the' 'soil engineer to determine its physical properties. If any material other than' that previously tested is encountered during grading, an appropriate analysis of this material should be conducted 'by the soil engineer as soon as pOssib!e. Approved' fill material should be placed, in areas. prepared 'to receive fill in near horizontal layers that when compacted' should 'not exceed 6 inches. in thickness. .The-soil engineer may approve thick lifts if testing indicates the grading procedures are such that adequate I ' , compaction is being achieved with lifts of greater thickness. Each layer should be spread evenly and blended to attain uniformity of material and moisture suitable for compaction 'Fill layers at a moisture content less than optimum should be watered and mixed and wet ,fill layers should be aerated by scarification or should .be- blended with drier material. Moisture condition, blending, and 'mixing of the fill 'layer should continue until the fill materials have a uniform moisture content at or above optimum moisture After each layer has. been evenly spread, moisture' conditioned and mixed, it should'be uniformly compacted to a minimum of 90 percent of maximum density as determined by ASTM,test designation, D-1'557-78,' or as otherwise -recommended by the soil engineer. I ' Compaction equipment should be adequately sized and should be specifically designed for soil compaction or of proven reliability to'efflciently'achieve the specified degree of, compaction 'RDA Designs ' ' ' ' ' '' ' Appendix D' File:e:\wp9\4300\4369a.pge " ' ' ' ' '. ' ' Page 4 GeoSoils, Inc. I I Where tests indicate that the density of any layer of fill, or portion thereof, is below the required relative compaction, or improper moisture is in evidence, the particular layer or. portion shall be re-worked until the required density and/or moisture content has been. I attained:.. No additional fill shall be placed in an area until the last placed lift of fill has been tested and found to meet the density and moisture requirements, and is approved by the I soil engineer. Compaction of slopes should be accomplished, by over-building a'minimum of 3 feet I . horizontally, and subsequently trimming back to the design slope configuration. Testing shall be performed as the fill is elevated to evaluate compaction as the fill core is being developed. 'Special efforts maybe necessary to attain the specified compaction in the fill. I . slope zone Final slope shaping should be performed by trimming and removing !oose . materials with appropriate equipment. A final determination of fill slope compaction should be based on observation' and/or testing of the finished slope face. Where compacted fill I . .: slopes are designed steeper than 2:1 '(horizontal to vertical), specific material types, a higher minimum relative compaction, and special grading procedures, may be I recommended If an alternative to Over-building and cutting back the compacted fill slopes is selected, then special effort should be made to achieve the required compaction in the outer 10 feet I of each lift of fill by undertaking the following I . . . 1. An extra piece of equipment consisting of a heavy short shanked sheepsfoot should be used to roll (horizontal) parallel to the.slopes continuously as fill is placed. The sheepsfoot roller-should also be used to roll perpendicular to the slopes, and i. . . . .. extend out over the slope to provide adequate compaction to the face of the slope: -. . . . . . 2. Loose fill should not be spilled out over the face of the slope as each lift is compacted.: Any loose fill spilled over a previously completed slope face should be trimmed off or be subject to re-rolling Field compaction tests Will be made in the outer (horizontal) 2 to8 feet of the slope at appropriate vertical intervals, subsequent to compaction operations. . I . After completion Of the slope, the slope face shouldbe shaped with a small tractor and then re-rolled with a.sheepsfoot to achieve compaction to near the slope face. Subsequent to testing to verify compaction, the slopes should be grid-rolled to achieve compaction to: the slope face. Final testing should be used to confirm compaction after grid rolling I". Where testing indicates less than adequate' compaction, the contractor will be responsible to rip, water, mix and re-compact the slope material as necessary to achieve compaction. Additional testing should be performed to verify compaction. RDA Designs . .. . . Appendix D . File e \wp9\4300\4369a pge Page 5 GeoSoits, Inc. . . . I 6 Erosion control and drainage devices should be designed by the project civil engineer in compliance with ordinances of the controlling governmental agencies, and/or in accordance with the recommendation of the soil engineer Or engineering 0 geologist I SUBDRAIN INSTALLATION I Subdrains should be installed in approved ground in accordance with the approximate alignment and details indicated by the geotechnical consultant Subdrain locations or materials should not be changed or modified without approval of the geotechnical I consultant..The soil engineer and/or engineering geologist may recommend and direct changes in 'subdrain line, 'grade and drain material in the field, pending exposed conditions The location of constructed subdrains should be recorded by the project civil I engineer 1 EXCAVATIONS ' , •,: Excavations and cut slopes should be examined during grading by the engineering geologist. If direóted by. the engineering geologist, further excavations or overexcavation ' . and re-filling of cut areas should be performed' and/or remedial grading of cut slopes should be performed. When fill over cut slopes are to, b.e graded, unless otherwise approved, the cut portion of the slope should be observed by the engineering geOlogist prior to placement of materials for construction of the fill portion of the slope. The engineering geblogist should observe all cut slopes and should be notified by the contractor when cut slopes are started. If, during the course' of grading, unforeseen. adverse or potential adverse geologic conditions are encountered, the engineering geologist and soil engineer should investigate, evaluate and make recommendations to, 'treatthese problems. The need for cut slope buttressing Or 'stabilizing should be based on in-grading evaluation by the engineering geologist, whether anticipated or not. , Unless otherwise specified in soil and geological reports, no cut slopes should be excavated higher' or' steeper than that allowed by the ordinances 'of controlling governmental agencies: 'Additionally, short-term stability of temporary cut slopes is the I contractors responsibility. , Erosion' control and drainage devices should be designed bythe projectcivil engineer and I :, •,' ' should be constructed in compliance with the ordinances of the controlling governmental agencies; 'and/or in 'accordance with the recommendations of the soil engineer or engineering geologist. 0 • , •, 0 • • 0 • I ' RDA Designs ' ' • 0 ' ' ' 0 Appendix D 'Fiie:e:\wp9\4300\4369a.pge ' ' . • " • ' Page 6 • , • 1 • •. 0 , ' •• ' 'GeoSoils, Inc. '• , • ' 0 , I COMPLETION Observation, testing and consultation bythé.geotechnical consultantshould be conducted I during-the grading operations in ordertb state an opinion that all cut'andfilled areas.are graded in accordance with the approved project' specifications.. . . . 1 After completion of grading and after the soil engineer and engineering geologist have finished their observations of the work, final reports should be submitted subject to review a . by the controlling governmental agencies. No further excavation or filling should be. undertaken without prior notification of the soil engineer and/or engineering geologist I ,.All finished cut and fill slopes should be protected from erosion and/or be planted in .accordance with the project speôifications and/or as recommended by a landscape architect. Such protection and/or planning should be undertaken as soon .as practical after p completion of grading I JOB SAFETY I General At GeoSoils, Inc. (GSl) getting the job done safely is of primary concern.. The following is . the . company's safety considerations for use by all employees on multi-employer construction sites., On ground personnel are at highest risk.of injury'and possible fatality on grading and construction projects. GSl recognizes that construction activities will vary .I .on each, site and that site safety is the prime responsibility of the, contractor; however, everyone must be safety conscious and responsible at all times. To achieve our. goal of. - . avoiding accidents, cooperation between the'client, the contractor and GSI personnel must I be maintained In an effort to minimize risks associated with geotechnical testing and. observation, the following precautions are to be implemented for the safety of field. personnel On grading and construction projects I ' Safety Meetings:'GSl field personnel are directed to attend contractors regularly scheduled and documented safety meetings Safety Vests: Safety vests are provided for and, are to be worn .byGSl personnel at all times when they are working in the field Safety Flags: 'Two safety flags are ' provided to GSl field technicians; one is to be affixed to the vehicle when on site, the, other is to be placed atop the spoil pile on all test pits I RDA Designs . ' '. . ' ' . Appendix D File:e:\wp9\4300\4369a.pge . ' . , ' . , Page 7 'GeoSoils,. Inc. 1 I . Flashing Lights: :All vehicles stationary in the grading area shall use rotatingôr'flashing amber beacon, or strobe lights, on the vehicle during all field testing While operating 'a vehicle in the grading area, the emergency, flasher on the vehicle shall be activated. In the event that the contractor's representative observes any of our, personnel not 1 following the above, we request that it be brought to the attention of our office Test Pits' Location. Orientation and Clearance The technician is 'responsible for selecting test pit locations. A primary concern should be the technicians's safety. Efforts will be made to coordinate locations with' the grading contractors authorized representative, and to select locations following 'or behind the established traffic pattern, preferably outside of current traffic. The contractors authorized' 'represéntativè (dump man, operator, supervisor, grade checker, etc.) 'should direct. excavation of the pit and safety during the test period 'Of paramount concern should be,, the soil technicians safety and obtaining enough tests to represent the fill Test pits should be excavated so that the spoil pile is placed away form oncoming traffic, whenever possible. The technician's vehicle, is to be placed next to the test pit, opposite the spoil pile. 'This necessitates the fill be maintained in a: driveable condition.. Alternatively, the contractor may wish to park a piece of. equipment in front of the' test holes', particularly in 'small fill areas or those with limited access. ' 'A zone of non-encroachmeht should be established for all test pits. No grading equipment' should enter this 'zone 'during the testing procedure. The zone should extend approximately 50 feet outward from the center of the test pit. This zone is established for safety and ,to avoid excessive ground vibration which typically decreased test results.. I I I 1 I When taking slope tests the technician should, park the vehicle directly above or below the test location. If this is 'not 'possible, a prominent flag should be placed at the top of thern slope. The contractor's representative should effectively keep all equipment at a safe operation distance (e.g., 50 feet) away from the slope during this testing." ' The technician is directed to withdraw from the active portion of the fill assoon as possible' following testing. The technician's vehicle shoUld be parked at the perimeter of the fill in a highly Visible location,, well away from the equipment *traffic pattern. The contractor should inform our personnel of all changes to haul roads, cut and fill areas or other factors that. may affect site access and site safety. In the event that the technicians safety, is jeopardized or compromised. as a result of the contractors failure to comply 'with any,of the above, the technician is required, by company policy, to immediately withdraw and notify his/her supervisor. The grading contractors representative will eventually be contacted-in an effort to effect a solution. However, in the RDA Designs ' ' ' Appendix D FiIe:e:\wp9\4300\4369a.pge ' ' : •. ' Page 8 I ' ',•, ' 'GeoSoils, Inc. ' interim, no further testing will be perlormed until the situation is rectified Any fill place can be considered unacceptable and subject to reprocessing, recompaction or removal In the event that the soil technician does not comply with the above or other established' ' safety guidelines, we request that-the contractor brings this to his/her'. attention and notify this office Effective communication and coordination between the contractors . representative'. and the soils technician is strongly encouraged in order to implement the above safety plan Trench and Vertical Excavation It is the contractor's responsibility to provide safe access into trenches where compaction testing is needed Our personnel are directed not to enter any-excavation or vertical cut which: 1) is 5 feet or . deeper. unless shored or laid back; 2) displays any evidence of instability, has any loose... . rock or other debris which"could fall into the trench; or 3) displays any other evidence of , any Unsafe conditions regardless of depth. All trench excavations or Vertical cuts in excess of 5 feet deep, Which any person enters, I should be shored or. laid back; Trench access should be provided in 'accordance with CAL-OSHA and/or state and local standards." Our personnel are directed not to enter'any I trench by being lowered or "riding down" on the equipment If the contractor fails to provide safe access to trenches for compaction testing, our 'company policy requires that the soil. technician withdraw and notify his/her supervisor.' The contractors representative will eventually be co'ntacted in an effort to effect a solution. All backfill not tested due to safety .concerns or other reasons could be subject 'to. 1 reprocessing and/or removal If GSI personnel become aware of anyone working 'beneath an unsafe trench wall or. I ' ' • ' vertical excavation, we have a legal obligation to -put the contractor and. owner/developer on notice to' immediately correct the situation. If corrective steps are not taken, GSI then has an obligation to notify CAL-OSHA and/or the proper authorities I I I RDA Designs'•' • • ' ' . .• Appendix 0 F1e:e:\wp9\4300\4369a.pge ' '. ' ' ' Page 9 1 ,. . ' •,, ' ' ' GeoSoils, 'Inc. '. CANYON SUBDRAIN DETAIL 2. --- - TYPE A - - - - - --------- - PROPOSED COMPACTED FILL /' 4 \,-NATURA.L GROUND 1 N -COLLUVIUM AND ALLUVIUM (REMOVE) ,' / /f S 'S - - - - BEDROCK 0 •. S .• SlIz TYPICAL BENCHING '''ZZ SEE ALTERNATIVES Lo s : - -------------- TE B 40 -- - - - PROPOSED COMPACTED FILL 0 \-NATURAL GROUND . Ji,\\\' N :• N COLLUVIUM AND ALLUVIUM (REMOVE) __ S • •i S • 5 0 -- • • - - - - S_ BEDROCK S • TYPICALBENCHING \4: S. • • • SO SEE ALTERNATIVES NOTEt ALTERNATIVES, LOCATION AND EXTENT OF SUBORAINS SHOULD BE DETERMINED I BY THE SOILSENGIHEER AND/OR ENGINEERING GEOLOGISTDURING -GRADING. S • S S .• 01 AT- i :.. .. ... .... I CANYON. SUBORAIN ALERNTATE DETAILS I I ALTERNATE 1 PERFORATED PIPE AND FILTER MATERIAL 12 MINIMUM 6 MINIMW • FILTER:MATERIAL MINIMUM VOLUME OF 9 FT. .'. .. /LINEARFT. 6 ABS OR PVC PIPE OR.APpROVED •::.•.: SUBSTITUTE WITH MINIMUM 8 (114 ) PERFS. MINIMUM LINEAR FT. IN BOTTOM HALF OF PIPE. i• .... ...... 'ASTM 02751. SOR 35 OR ASTM 01527. SCHD, LO . A-I •. . ASTM O3034 SOR 35 OR ASTM 01785 SCHO 40 r3 MINIMUM . • . FOR CONTINUOUS RUN IN EXCESS OF 56.0 FT. •..• - •• 1 USE 8'J( PIPE I FILTER MATERIAL SIEVE SIZE . . PERCENT PASSING •. .. 1INCH . $100 •. . . . .. . . . I. . .314 INCH . . 90100 . . . I . 318 INCH : 1.0-100 . .. : . . . NO.4• • . 25-40 •• .• . . . . NO8 •• . . 18-33 . .• . •, I . ..NO., 30 5-15 NO. 200 •. .5 . 0-3 . . . S. I ALTERNATE 2 PERFORATED PIPE, GRAVEL AND FILTER FABRIC 6.0 MINIMUM OVERLAP 6 MINIMUM OVERLAP -0" MINIMUM I 4~* MINIM UM BEDD ING 40 MINIMUM BEDDING A-2 GRAVEL MATERIAL 9 FWUNEARFT r PERFORATED PIPE: SEE ALTERNATE I. . • . . S 13 S I . GRAVEL CLEAN 311. INCH ROCK OR APPROVED SUBSTITUTE- FILTER FABRIC: MIRAFI 11.0. OR APPROVED SUBSTITUTE .5 I - I II i PLATE EG-2 I i DETAiL FOR FILL SLOPE TOEING OUT i ON FLAT ALLUVIATED CANYON TOE OF SLOPE AS SHOWN ON GRADING PLAN FILL ORIGINAL GROUND SURFACE TO BE I RESTORED WITH COMPACTED FILL NALOUND SURFACE I BACKCUT VARIES FOR DEEP REMOVALS. , BACKtUT5HOULDBE MADE NO • 0ISTEEPER0THAts4:1 OR AS NECESSARY < APITICIPATED ALLUVIAL REMOVAL. I FOR SAFETY CONSiDERATIONS. • : I' / DEPTH PER SOIL ENG1NEER. JL 1 PROVIDE A 1:1 -MINIMUM PROJECTION FROM TOE OF I :.• SLOPE AS SHOWN ON GRADING PLAN TO THE RECOMMENDED REMOVAL DEPTH. SLOPE HEIGHT. SITE CONDITIONS ANDIOR • 0 0 LOCAL CONDITIONS COULD DICTATE FLATTER PROJECTIONS. I REMOVAL ADJACENT TO EXISTING FILL I ADJOINING CANYON FILL - - - I LLIMITS \>PROPOSED ADDITIONAL COMPACTEDFILL COMPACTED FI LINE\I 0 \ TEMPORARY COMPACTED ALL 0 0 • • • • )FOR DRAINAGE ONLY Gal • •23 Oaf /Qat (TO BE REMOVED) • (EXISTING COMPACTED FILL) /T. rll7j 0 LEGEND - - TO BE REMOVED BEFORE Gal ARTIFICIAL FILL Nic 1 . • • •. 0 • • PLACING ADDITIONAL • 0 0 • • • •0 • 00 • • • 0 COMPACTED FILL • • Oaf ALLUVIUM 0 • I I PLATE EG-3 6 MINIMUM 2 MINIMUM PIPE 4' MINIMUM, PIPE 2MINIMUM :...... : 2 MINIMUM I- -1 m m (7) FILTER MATERIAL SHALL BE OF THE FOLLOWING SPECIFICATION . OR AN APPROVED EQUIVALENT: SIEVE SIZE PERCENT PASSING 1INCH I ioo: :. 3/6 !NCH .90--loo.,. . 3/8 INCH .40-100 NO.4 25-40 NO.-8 18-33 NO. 30 . . 5-15 . NO. 50 .. 0-7 NO. 200 0-3 . GRAVEL SHALL BE OF THE FOLLOWING SPECIFICATION OR AN APPROVED EQUIVALENT: SIEVE SIZE PERCENT PASSING 11/2 INCH.. 100' NO.4 50 NO. 200 8. SAND EQUIVALENT: MINIMUM OF 51. - TYPICAL STABILIZATION /'BUTTRESS SUBORAIN DETAIL FILTER MATERIAL MINIMUM OF-FIVE FP/LINEAR Ft OF PIPF OR FOUR FI'ILINEAR Ft OF PIPE WHEN PLACED IN SQUARE CUT TRENCH. . . ALTRNATIVE IN LIEU OF FILTER MATERIAL: GRAVEL MAY BE ENCASED 'IN APPROVED FILTER FABRIC. FILTER FABRIC SHALL BE MIRAFI 140 OR EQUIVALENT. FILTER FABRIC SMALL BE. LAPPED A MINIMUM OF 12m ON ALL JOINTS. MINIMUM 4' DIAMETER PIPE: ABS—ASTM 0-2751, SOR 35 OR ASTM D-1527 SCHEDULE. 40 PVC—ASTM 0-3036, 4DR35 OR ASTM 0-1785 SCHEDULE 40 WITH A CRUSHING STRENGTH OF 1.000 POUNDS MINIMUM, AND A MINIMUM 'OF 8 UNIFORMLY SPACED PERFORATIONS PER FOOT OF PIPE INSTALLED WITH PERFORATIONS OF BOTTOM OF PIPE. PROVIDE CAP AT UPSTREAM END OF PIPE. SLOPE AT 294 TO OUTLET PIPE. OUTLET PIPE TO BE CONNECTED TO SUBORAIN PIPE WITH TEE OR ELBOW . • NOTE:: 1. TRENCH FOR OUTLET PIPES TO BE BACKFILLED WITH ON—SITE SOIL. 2. BACKO RAINS AND LATERAL DRAINS SHALL BE LOCATED AT ELEVATION OF EVERY BENCH DRAIN. . FIRST DRAIN LOCATED A 1 ELEVATION JUST ABOVE LOWER LOT GRADE. ADDITIONAL DRAINS MAYBE REQUIRED AT THE DISCRETION OF THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. fts Will - -.- - FILL OVER NATURAL DETAIL SIDEH1LL FILL COMPACTED FILL PROPOSED GRADE MAINTAIN MINIMUM 15 WIDTH TOE OF SLOPE AS SHOWN ON GRADING PLAN SLOPE TO BENCH/BACKCUT PROVIDE A 11 MINIMUM PROJECTION FROM / DESIGN TOE OF SLOPE TO TOE OF KEY IAN AS SHOWN ON AS BUILT Oft NATU RAL SLOPE TO co MAYAWD BE RESTORED WITH / 71%\W1tV/ft\ COMPACTED FILL / \/ \ \ BENCH WIDTH MAY VARY ACKCUT VARIES . - - - - - - - - S MINIMUM NOTE 1. WHERE THE NATURAL SLOPE APPROACHESOR EXCEEDS THE / 1' MINIMUM KEY WIDTrf DESIGN SLOPE RATIO, SPECIAL RECOMMENDATIONS WOULD BE / 2'X 3MININUM KEY DEPTH PROVIDED BY THE SOILS ENGINEER / 2, THE NEED FOR AND DISPOSITION OF DRAINS WOULD BE DETERMINED 2' MINIMUM IN BEDROCK OR BY THE SOILS ENGINEER BASED UPON EXPOSED CONDITIONS m APPROVED MATERIAL S. S -. .. . '0 • 0 S. . .. 0) 0 0 •0 0 •0• •0 FILL OVER CUT DETAIL CUT/FILL CONTACT MAINTAIN MINIMUM 15' FILL SECTION FROM - 1 AS SHOWN ON GRADING PLAN BACKCUT TO FACE OF FINISH SLOPE - 2. AS SHOWN ON AS BUILT PROPOSED GRADE COMPACTED FILL \\ \\ H 'MINIMUM ORIGINAL TOPOGRAPHY 'MINIMUM / - CUT SLOPE BENCH WIDTH MAY VARY LOWEST BENCH WIDTH / 4 BEDROCK OR.APPROVEO MATERIAL 15' MINIMUM OR H/2 S NOTE. THE CUT PORTION OF THE SLOPE SHOULD BE EXCAVATED AND EVALUATED BY THE SOILS ENGINEERANO/OR ENGINEERING S GEOLOGIST PRIOR TO CONSTRUCTING THE FILL PORTION rn S S S 55 S .'. C) I [.i51 REMOVE. UNSTABLE MATEFIAL NATURAL SLOPE 15'MINIMUH 1 ----~ROPOSED FINISHED GRADE ' UNWEATHERED BEDROCK.• OR APPROVED MATERIAL : H2 REMOVE: UNSTABLE MATERIAL ....' COMPACTED STABILIZATION FILL - - 1@ MINIMUM TILTED BACK I / IF RECOMMENDED BY THE SOILS ENGINEER AND/OR ENGINEERING :2 ' GEOLOGIST, THE REMAINING CUT PORTION OF THE SLOPE MAY - REQUIRE REMOVAL AND REPLACEMENT WITH COMPACTED FILL. NOTE t SUBORAINS ARE NOT REQUIRED UNLESS SPECIFIED BY SOILS ENGINEER A N D / O R E N G I N E E R I N G G E O L O G I S T , 2. W1 SHALL BE EQUIPMENT WIDTH 115') FOR SLOPE HEIGHTS LESS THAN 25 FEET.: FOR S L O P E S G R E A T E R THAN 25 FEET W SHALL BE DETERMINED BY THE PROJECT SOILS ENGINEER AND /OR E N G I N E E R I N G GEOLOGIST AT NO TIME SHALL 1W BE LESS THAN 14/2 156 MIeNIMUM KEY WIDTH -U NOTE: 1. THE NEED AND DISPOSITION OF DRAINS WILL BE DETERMINED! BY THE SO I L S E N G I N E E R A N D / O R ENGINEERING GEOLOGIST BASED ON FIELD CONDITIONS".,• • 2. PAD OVEREXCAVATION AND RECOMPACTION SHOULD BE PERFORMED IF DETERMIN E D T o B E m • NECESSARY BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. • 0 I • • • (0 • •• • - - - - - - - - - - - DAYLIGHT CUT LOT DETAIL NATURAL GRADE RECONSTRUCT COMPACTED FILL SLOPE AT 2 1 OR FLATTER (MAY INCREASE OR DECREASE PAD AREA). OVEREXCAVATE AND RECOMPACT " REPLACEMENT FILL ,~015:~PROPOSED FINISH GRADE AVOID AND/OR CLEAN UP SPILLAGE OF / 3' MINIMUM BLANKET FILL MATERIALS ON THE NATURAL SLOPE 17 V. . . c,O" ' . . BEDROCK OR APPROVED MATERIAL / . . . .•: . . . V .u. ../ ., TYPICAL BENCHING •: 2'MINIMUM r KEY kI2INT ,, V •. •• •..: ... -ii.. DEPTH / \/ V .. . .• V V Ii V V . V •; -o I— .. .. V •. V •V NOTE: 1. SUBORAIN AND KEY WIDTH REQUIREMENTS WILL B E D E T E R M I N E D B A S E D O N E X P O S E D S U B S U R F A C E V CONDITIONS AND THICKNESS OF OVERBURDEN m 2 PAD OVER EXCAVATION AND RECOMPACTION SHOULD BE P E R F O R M E D I F D E T E R M I N E D N E C E S S A R Y B Y 9 ) THE SOILS ENGINEER AND/OR THE ENGINEERING GEOLOGIST V. ... I TRANSITION LOT DETAIL I CUT LOT (MATERIAL TYPE TRANSITION) I NATURAL GRADE I I MIN M PAD GRADE . . S . FILL OVEREXCAVATE AND ROHPAC I ••.•... .. rVf/ W/A\V//\\\ 3MINIMUM* UNWEATHERED BEDROCK OR APPROVED MATERIAL i LBCHNG I . :. •• . CUT-FILL LOT (DAYLIGHT TRANSITION) O I NATURAL GRADE - 1NJMUM I ••. . ••_• . . .... . . PAD GRADE OVER EXCAVATE--* . . . ,.. I • . . COMPACTED FILL >- . . AND RECOMPACT • . •. • 4\" /\ //\\ f/\\ \\Y/\Y' 3 MINIMUM* • . .•• I • • W\ 4' • MATERIAL 1• UNWEATHERED BEDROCK OR APPROVED •• . I • • .' \\\//\\. . TYPICAL BENCHING • . I NOTE: *DEEPER OVEREXCAVATION MAY BE RECOMMENDED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST IN STEEP CUT-FILL TRANSITION AREAS. I PLATE EG-11' I H I SETTLEMENT PLATE.'AND . RISER DETAIL 1 2'X 2'X 114 STEEL PLATE TANOAR,D 314 PIPE NIPPLE WELDED TO TOP DF PLATE. . 1 314X 5' GALVANIZED PIPE. STANDARD PIPE THREADS TOP-AND BOTTOM. EXTENSIONS THREADED ON BOTH ENDS AND ADDED IN 5' INCREMENTS. ' 3 INCH 'SCHEDULE Lb 'PVC PIPE SLEEVE, ADD IN 5INCREMENTS WITH GLUE JOINTS.. I 1. H H I I I H FINAL GRADE MAINTAIN 5' CLEARANCE OF HEAVY EQUIPMENT. _.L.e ...L.AMECHANICALLY HAND COMPACT IN 2VERT1CAL 4— -r"v LIFTS OR ALTERNATIVE SUITABLE TO AND ,ACCEPTED'BY THE SOILS ENGINEER. ''i .5' ' ' I ' ' I, MECHANICALLY HAND COMPACT THE INITIAL 5' VERTICAL WITHIN A 5' RADIUS OF PLATE BASE. Ar BOTTOM OF CLEANOUT PROVIDE A MINIMUM 1' BEDDING OF COMPACTED SAND NOTE: 1. LOCATIONS OF SETTLEMENT PLATES SHOULD BE CLEARLY MARKED AND READILY VISIBLE (RED FLAGGED) TO EQUIPMENT OPERATORS. 2, CONTRACTOR SHOULD MAINTAIN CLEARANCE OF A 5* RADIUS OF PLATE BASE AND WITHIN 5 (VERTICAL) FOR HEAVY EQUIPMENT. ALL WITHIN CLEARANCE AREA SHOULD BE HAND :COMPACTED TO PROJECT SPECIFICATIONS OR COMPACTED, BY ALTERNATIVE APPROVED BY THE SOILS ENGINEER. ' 3. AFTER 5' (VERTICAL) OF FILL-IS IN PLACE, CONTRACTOR SHOULD MAINTAIN'A 5RADIUS EQUIPMENT CLEARANCE FROM RISER. . PLACE AND MECHANICALLY HAND COMPACT INITIAL 2' OF FILL PRIOR TO ESTABLISHING THE INITIAL READING. 5. IN THE EVENT OF DAMAGE TO THE SETTLEMENT PLATE OR EXTENSION RESULTING FROM EQUIPMENT OPERATING WITHIN THE SPECIFIED CLEARANCE AREA, CONTRACTOR SHOULD IMMEDIATELY NOTIFY, THE SOILS ENGINEER AND SHOULD BE RESPONSIBLE FOR RESTORING THE SETTLEMENT PLATES TO WORKING ORDER. 6., AN'ALTERNATE DESIGN AND METHOD OF INSTALLATION MAY BE PROVIDED AT.THE DISCRETION OF THE SOILS ENGINEER. PLATE EG-14 OVERSIZE ROCK DISPOSAL VIEW NORMAL TO SLOPE FACE PROPOSED FINISH GRADE MINIMUM (E) S 15' MINIMUM 20'MINIMUM (B) co -.- ' 5MINIMUM MINIMUM (C) MIMN BEDROCK OR APPROVED MATERIAL VIEW PARALLEL TO SLOPE FACE PROPOSED FINISH GRADE 10 MINIMUM (E) 'lOO MAXIMUM I 150 MINIMUM jMINIMUM 15' MINIMUM FROM- CA /1 WALL..MMUMC) / BEDROCK OR APPROVED MATERIAL NOTE: (A) ONE EQUIPMENT WIDTH OR A MINIMUM 0F15 FEET. HEIGHT AND WIDTH MAY VARY DEPENDING ON ROCK SIZEAND TYPE OF EQUIPMENT. LENGTH OF WINDROW SHALL BE NO GREATER THAN 100' MAXIMUM, IF APPROVED. BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST, WINDROWS MAY BE PLACED DIRECTLY ON COMPETENT MATERIAL OR BEDROCK PROVIDED ADEQUATE SPACE IS AVAILABLE FOR COMPACTION. ORIENTATION OF WINDROWS MAY VARY BUT SHOULD BE AS RECOMMENDED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. STAGGERING OF WINDROWS IS Not NECESSARY UNLESS RECOMMENDED. . S CLEAR AREA FOR UTILITY TRENCHES. FOUNDATIONS AND SWIMMING POOLS. ALL FILL OVER AND AROUND ROCK WINDROW SHALL BE COMPACTED TO 90% RELATIVE COMPACTION OR AS RECOMMENDED. • (01 AFTER FILL BETWEEN WINDROWS IS PLACED AND COMPACTED WITH THE LIFT OF FILL COVERING WINDROW, WINDROW SHOULD BE PROOF ROLLED WITH A 0-9 DOZER OR EQUIVALENT.. VIEWS ARE DIAGRAMMATIC ONLY. ROO< SHOULD NOT TOUCH AND VOIDS SHOULD BE COMPLETELY FILLED IN. PLATE RD-1 I: :.. •:. I ROCK DISPOSAL PITS VIES ARE DIAGRAMMATIC ONLY. ROCK SHOULD NOT TOUCH I AND VOIDS SHOULD BE-COMPLETELY,FILLED. IN. FiLL LIFTS COMPACTED OVER ROCK AFTER EMBEDMENT I [ GRANULAR MATERIAL I "-- -- LARGE ROCK --- - --------I I COMPACTED FILL • SIZE OF EXCAVATION TO BE . . . I . . COMMENSURATE WITH ROCK SIZE r 1 I ROCK DISPOSAL LAYERS I GRANULAR SOIL TO FILL VOIDS, COMPACTED 'FILL 0 ENSIFJED BY FLOODING - - I LAYER ONE ROCK HIGH 113 C1I)(ID~1IXtjs PROPOSED FINISH GRADE. . . . . . SLAYER ~O V E =S I Z ELA Y E FR LOPE S MINIMUM OR BELOW LOWEST UTILI 110 FACE I COMPACTED ALL 13 MINIMUM . IS S 'FILL SLOPE ••• S. • I CLEAR ZONE 2O.MINIMUM . S • S I I• LAYER ONE ROCK HIGH • S • 5 STOP VIEW • 5•5 PLATE R02 S S S .5 •5 5 • .