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CT 01-05; CALAVERA HILLS, VILLAGE K; GEOTECHNICAL; 1990-05-15
miERIH REPCWT OF (XC7EECHNICAL INVESTIGKriGN CAEAVERA. HEIGHTS VHiAGES W-X-Y TAMARACK AND COUSGE BOUEJEVTVRD CARLSBAD, CALIFORNIA PREPARED FOR: Lyon Ccnnunities, Incorporated 4330 La Jolla Village Drive, Suite 130 Scin Diego, Califomia 92122 PREPARED BY: Southem Califomia Soil & Testing, Inc. Post Office Box 20627 6280 Riverdale Street San Diego, Califomia 92120 SOUTHERN CAUiraRNIA SOIL 6280 RIVERDALE ST. SAN OIEGO, CALIF. 92120 • TELE 280-4321 e, -7 » ENTERPRISe ST. ESCONOIOO. CALIF. 92025 TtLC AND TESTING, INC. P.O. BOX 20627 SAN OIEGO, CALIF. 92120 May 15, 1990 Lyon Conminities, Incorporated 4330 La Jolla Village Drive Suite 130 San Diego, Califomia 92122 SCS&T 9021049 Report No. 1 AITENriON: Mr. George Haviar SUBJECT: Interim Report of Geotechnical Investigation, Calavera Heights Villages W-X-Y, Tamarack and College Boulevard, Carlsbad, Califomia. Gentlemen: In accordance with your request, we have conpleted an interim geotechnical investigation for the subject project. We are presenting herewith our findings and reconroendations. In general, we found the site suitable for the proposed development provided the recommendations presented in the attached report are followed. If you have any questions after reviewing the contents contained in the attached report, please do not hesitate to contact this office. This of^rtunity to be of professional service is sirxrerely appreciated. Resp^tfully submitted, rFDRNIA^SQ] '.A —-A^ Daniel B. AlJler, R.C.E. #36037 :NG, INC. DBA:JRH:KAR:nw cc: (2) Subnitted (4) Hunsaker and Associates (1) SCS&T, Escondido SOUTHERN CALIFORNIA bhn R. High, C.E.G AND TESTING TAH[£ OF OOWIEMrS Introduction and Project Description 1 Project Scope 2 Findings 3 Site Description 3 General Geology and Subsurface Conditions 3 Geologic Setting and Soil Description 3 1) Basement Ccntiplex-Jurassic Metavolcanics and Cretaceous Granitics (Jmv/Kgr) 4 2) Santiago Formation (Es) 5 3) Older Quaternary (Pleistocene) Alluvium (Qoal) 5 4) Younger Quatemary (Holocene) Allvivium (Qyal) 5 Tectonic Setting 7 Geologic Hazards 7 Groundshaking 8 Seismic Survey and Rippability Characteristics 8 General 8 Rippability Characteristic of Granodioritic Rock 12 Rijpable Condition (0-4,500 Ft./Sec.) 12 Marginally Rippable Condition (4,500 Ft./Sec.-5,500 Ft./Sec) 13 NOnrifpable Condition (5,500 Ft./Sec. & Greater) 13 Rifpability Characteristics of Metavolcanics and Associated Hypabyssal Rocks and Tonalitic Rocks 13 Rippable Condition (0-4,500 Ft ./Sec.) 13 Itorginally Rippable Condition (4,500-5,500 Ft./Sec.) 14 Nonrippable Condition (5,500 Ft. Sec. & Greater) 14 Seismic Traverse Limitations 14 Groundwater 15 Conclusions and Recommendations 16 General 16 Grading 17 Site Preparation 17 Select Grading 17 Cut/Fill Transition 17 Imported Fill 18 Rippability 18 Oversized Rock 18 Slope Construction 18 Surface Drainage 18 Subdrains 19 Earthwork 19 Slope Stability 19 Foundations 19 General 19 Reinforcenent 20 Interior Concrete Slabs-on-Grade 20 Exterior Concrete Slabs-on-Grade 21 Special Lots 21 Expansive Characteristics 21 Settlatent Characteristics 21 Earth Retaining Walls 22 Passive Pressure 22 Active Pressure 22 TABE£ OF COIWEMTS (continued) PACT Backfill 22 Factor of Safety 22 Limitations 23 Review, Cft>servation and Testing 23 Uniformity of Conditions 23 Change in Scope 23 Time Limitations 24 Professional Standard 24 Client's Responsibility 24 Field Ejqjlorations 25 Laboratory Testing 25 ATTACHMENTS TABLES Table I Table II Table III Gaieralized Engineering Characteristics of Geologic Units, Page 6 The !4axirnLim Bedrock Accelerations, Page 8 Seismic Traverse Sumnnary, Pages 9 tiirough 12 FIGURE Figure 1 Site Vicinity Map, Follows Page 1 FLKEES Plate Plate Plates Plate Plate Plate Plate Plate Plate Plate Plate Plates Plates 1 Plot Plan 2 Unified Soil Classification Chart 3-9 Trench Logs 10 Grain Size Distribution 11 Compaction Test Results Expansion Test Results 12 Direct Shear Sumtary 13 Oversize Rock Disposal 14 Caiiyon Subdrain Detail 15 Slope Stability Calculations 16 Weakened Plane Joint Detail 17 Retaining Wall Subdrain Detail 18-20 Seismic Line Traverses 21-23 Catepillar Rippability Charts APPEicrx Reconmended (Srading Specification and Special Provisions SOUTHERN CALIFORNIA SOIL AND TESTING, INC. 6280 RIVERDALE ST. SAN OIEGO. CALIF. 92120 • TELE 280-4321 • P.O. 80X 20627 SAN OIEGO. CALIF. 92120 f, T B ENTERPRISE ST. CSCOMDIOO. CALIF. 92029 • TELE -J » A - » % « A nnSRIH REPCWT OF GBCTTBCHNICAL INVESnGMION CALAVERA HEIOflS VILLAffiS W-X-Y TAMARACK AND COLLEGE BOULEVARD CARLSBAD, CALIFCM^IA mrRODUcnoN AND FRDJBCT EESCRIPTIGN This report presents the results of our interim report of geotechnical investigation for Calavera Heights Subdivision, Villages W-X-Y, Tamarack and College Boulevard, in the City of Carlsbad, Califomia. The site location is illustirated on the following Figure Number 1. It is our understanding that the site will be developed to receive a residential svidivision with associated paved streets. It is anticipated that the structures will l^e one and/or twD stories high and of wood frame construction. Shallow foundations and conventional slab-on-grade floor systems are proposed. Grading will consist of cuts and fills up to approximately 40 feet and 35 feet deep, respectively. Cut and fill slopes up to approxinately 35 feet high at a 2:1 (horizontal to vertical) are also anticipated. To assist with the pr^jaration of this report, ware provided with a grading plan prepared by Hunsaker and Associates dated December 6, 1989. In addition v« revievred our "Supplemental Soil Investigation, Calavera Hills Subdivision," dated October 6, 1988, "Report of Geotechnical Investigation, Village Q and T, Calavera Hills Subdivision, " dated January 10, 1984, and SOUTHERN CALIFORNIA SOIL AND TESTING, INC ;/ -"••.-•\ SITE i -i^ .i ,11.-.. ... ; . fl ; ; Vl SOUTMIRII CALIFORNIA SOIL ATB«TIMO,IIIC. BY: CALAVERAS HEIGHTS-VILLAGE KAR/EM JOBNUMBcii: 9021054 DATI: 5-15-90 FIGURE #1 SCS&T 9021049 May 15, 1990 Page 2 our "Sumnary of Geotechnical Investigation, Lake Calavera Hills," dated August 6, 1984. The site configuration, topography and approximate locations of the subsvirface explorations are shown on Plate Nuntier 1. PRDOBCT SCOPE This interim report is based on the review of the aforementioned preliminary report for the Calavera Hills Subdivision. A site specific report will be prepared at a later date v*ien further field investigation and analysis of laboratory data has been completed. For the purpose of this report appropriate field investigation and laboratory test data was extracted from the previously mentioned report. More specifically, the intent of this study was to: a) Describe the subsurface conditions to the depths influenced by the proposed construction. b) The laboratory testing performed in the referenced report was used to evaluate the pertinent engineering properties, including laearing capacities, expansive characteristics and settlement potential, of the anticipated materials which will influence the development of the proposed subject site. c) Describe the rippability characteristics of the existing rock. d) Define the general geology at the site including possible geologic tiazards vAiich could have an effect on the site development. e) Develop soil engineering criteria for site grading and provide recaiinendations regarding the stability of proposed cut and fill slopes. f) Address potential construction difficulties and provide recomnendations conceming these problems. SCS&T 9021049 May 15, 1990 Page 3 g) Recommend an appropriate foundation system for the type of structures anticipated and develop soil engineering design criteria for the reconmiended foundation design. FINDINGS SnE EESCRimCK The subject site is an irregular shaped parcel of land, designated as Villages W, X and Y within the Calavera Heights development in Carlsbad, California- The subject site covers approximately one hundred acres and is bounded on the south, east and north by undeveloped land and by residential housing and undeveloped land on the west. Topographically, the site is located in hilly terrain with well developed, large, drainage courses with steep-sided slopes. Elevations range from approximately 325 feet (MSL) at the central northem property boundary to 90 feet (MSL) at the eastem boundary. The inclinations of the nattiral slopes ajce generally on the order of 1.5 to 1, horizontal to vertical, or flatter. Drainage is accomplished via sheetflow and the well developed drainage courses in southerly, easterly and northeasterly directions. Vegetation is ccnprised of sparse to very dense chaparral on the hillsides and dense native shrubs and small trees within the large drainage courses. Overhead pov«r lines traverse the site in a southwest to northeast direction. The site is undeveloped, with the exception of the power lines. OTERAL GEOLOGY AID SUBSURFACE CCWDITIGNS GBOLOGIC SEEEIMG AI© SOIL EESCRIPTION: The subject site is located near the boundary between the Foothills Physiographic Province and the Coastal Plains Physiographic Province of San Diego County and is underlain by materials of igneous and sedimentary origin and siorficial residuum. The site is underlain by the basement complex rocks consisting of Jurassic-age metavolcanic rocks, Cretaceous-age granitic rocks, as well as Tertiary-age Santiago Formation and Quatemaiy-age alluvium. A brief description of the materials on-site, in general decreasing order of age, is presented below. SCS&T 9021049 May 15, 1990 Page 4 1) BASEMENT CQMPIBX - JURASSIC MBEAVOLCANICS AND CREIACBQUS OWNITICS {JaxiryEgpc) z The oldest rocks exposed at the site are the Jurassic metavolcanic and associated hypabyssal rocks. The metavolcanic rocks are generally andesite or dacite in composition and the associated hypabyssal rocks are their porphyritic equivalents (ie: diorite porphyry to granodiorite porphyry). The fine grained hypabyssal rocks are considered to be about the same age as the nBtavolcanics and are consequently older than the other intrusive rtxrks found at tJie site. Both the metavolcanics and the associated hypabyssal rocks weather to dark, smooth hills or jagged, angular outcrops with a clayey, rocky topsoil. The metavolcanic and hypabyssal rocks are generally rippable with conventional earth-moving equipment to depths of only a few feet. The other rocks in the basement conplex are the granitic rocks of the Cretaceous Southem Califomia Batholith which have intruded the older rocks and are, to a large degree, mixed with them. The granitic rocks at the project site appear to be both tonalitic and granodioritic in composition. The tonalitic roc)cs are usually dark gray, fine to medium grained rocks v*iereas the granodioritic rocks cire usually yellowish brown to grayish brown, medium to coarse grained rocks. The weathering and rippability characteristics of the tonalitic rocks appear to be somev^iat similar to those of the mstavolcanic/hypabyssal rocks. The tonalitic rocks may be rippable to greater depths than the netavolcanic rocks but ripping nay be difficult and time consuming. In addition, it should be noted that the material generated from the tonalitic rocks will have the appearance of the metavolcanic rocks rather than that of good quality "decomposed granite". In contrast to the weathering characteristics of the metavolcanic/hypabyssal rock and the tonalitic rocks, the granodioritic rocks commonly weather to rounded outcrops or boulders in a matrix of grus ("decomposed granite"). The granodioritic rocks are variable in their ejoravation characteristics but commonly contain areas which are rippable to SCSST 9021049 r^v 15, 1990 Page 5 depths of several feet or several tens of feet, yet include localized areas of boulders or unweathered rock which are not rippable with conventional heavy equipment. The areas underlain by the respective rock types in the basement complex are intermixed and are not differentiated on the accompanying geologic map. It should be noted that since the different rock types are mixed, the areas on the map v*iere given a dual classification. The boundaries between the basement rock types are very irregular, therefore they ware not differentiated on Plate Nuniaer 1. 2) SANTIAGO FORMATION (Es): The Eocene sediments at the project site are represented by the sandstones, siltstones, and claystones of the Santiago Formation. The Santiago Formation at the site appears to be characterized largely by the grayish white sandstones and siltstones with lesser amounts of the dark greenish brown claystone. A well-developed, clayey topsoil is present on most of the Santiago Formation. 3) OUKR QUZSTERNARY (PLEISTOCENE) AEJjUVIUM (Qoal): Older alluvial deposits consisting of grayish brown to yellowish brown and greenish brown, medium dense, silty sands, clayey sands, and sandy silts were encountered at the southeastem portion of the project site. These deposits range in thickness from only a few feet to in excess of ten feet. Smaller, un-mapped areas may be encountered at other scattered locations. 4) YOlllGER QUKEERNARY (HOLOCENE) ATUUVIIM (Qyal): Younger alluvial deposits consisting of unconsolidated, loose to medium dense deposits of clay, silt, sand, and gravel are present in the modem drainage courses. These deposits range in thickness from less than a foot to over ten feet. Due to their ubiquitous occurrence, the younger alltivial deposits are not delineated on the geologic map except in the larger channels. SCS&T 9021049 May 15, 1990 Page 6 A relatively thin layer of loose topsoils and subsoils should be anticipated overlying the entire site. These deposits consist of varying mixtures of silts, sands and clays. It is estimated that these deposits do not exceed 3.5 feet in conbined thickness. Table I presents sone of the pertinent engineering characteristics of the mterials at the site. TABUS I QUERALIZED ENGINEERING CHARACTERISTICS OF MAIN GB0OX3IC UNITS Unit Name and Symbol Rippability Amount of Oversize Material Slope Stability/ Erosion Compressibility Expansive Potential Granitic Rocks- Kgr (Granodiorite) Granitic Rocks- Kgr (Tonalite) Metavolcanic and Hypabyssal Rocks-Jmv Santiago Formation-Es (Mudstone) Santiago Fomation-Es (Sandstone and Siltstone) Generally Rippable to + 15 Feet Marginally Rippable to Nonrippable Marginally Rifpable to Nonrippable Rif^jable Rippable Low to Moderate Moderate to High Moderate to High Nominal Nominal Good Good Nominal Nominal Good Nominal Generally Poor Generally Good Low Low Nominal Nominal Nominal Moderate to High Low to Moderate Older Alluvium-Qoal Rifpable Nominal Moderately Erodible Moderate to High Low to High SCS&T 9021049 May 15, 1990 Page 7 TECTONIC SETTING: A few small, apparently inactive faults have been mapped previously within the vicinity of the site. No evidence of faulting was noted in our exploratory trenches for the referenced reports but it is possible that future grading operations at the site may reveal some of these faults. Due to their status of activity and geometry, these small faults should be only of minor consequence to the project. It should also be noted that several prominent fractures and joints which are probably related, at least in part, to the strong tectonic forces that dominate the Southem Califomia region are present within the vicinity of the site. These features are usually near-vertical and stri)« in both a general northwesterly direction (subparallel to the regional structural trend) and in a general northeasterly direction (subperpendicular to the regional structural trend). All cut slopes should be inspected by a qualified geologist to assess the presence of adverse jointing conditions in the final slopes. In addition, it should be recognized that much of Southem Califomia, is ageracterized by major, active fault zones that could possibly affect the subject site. The nearest of these is the Elsinore Fault Zone, located approximately 20 miles to the northeast. It should also be noted that the possible off-shore extension of the Rose Canyon Fault Zone is located approximately eight miles west of the site. The Rose Canyon Fault Zone conprises a series of northwest trending faults that could possibly be classified as active based on recent geologic studies. It is anticipated that the Rose Canyon Fault will be classified as active in the near future. Recent seismic events along a small portion of the Rose Canyon Fault Zone have generated earthquakes of 4.0 or less magnitude. Other active fault zones in the region that could possibly affect the site include the Coronado Banks and San Clemente Fault Zones to the west, the Agua Blanca and San Miguel Fault Zones to the south, and the Elsinore and San Jacinto Fault Zones to the northeast. GESOLDGLC HAZARDS: The site is located in an area vMch is relatively free of potential geologic hazards. Hazards such as tsunamis, seiches, liquefaction, and landsliding should be considered negligible or nonexistent. SCS&T 9021049 May 15, 1990 Page 8 GROUNDSHRECCNG: One of the most likely geologic hazards to affect the site is groundshaking as a result of movement along one of the major, active fault zones mentioned above. The maximum bedrock accelerations that would be attributed to a maximum probable earthquake occurring along the nearest portion of selected fault zones that could affect the site are sumnarized in the following Table II. TABE£ II Maximum Probable Distance Bedrock Design Acceleration Acceleration Rose Canyon 8 miles 6.5 nagnitude 0 36 g 0.23 g Elsinore 20 miles 7.3 nagnitude 0 25 g 0.17 g Coronado Banks 24 miles 7.0 nagnitude 0 18 g 0.12 g Scin Jacinto 43 miles 7.8 nagnitude 0 14 g 0.10 g Earthquakes on the Rose Canyon Fault Zone are e^qjected to be relatively minor. Itejor seismic events are likely to be the result of movement along the Coronado Banks, San Jacinto, or Elsinore Fault Zones. Experience has shown that stiructures that are constructed in accordance with the Uniform Building Code are fairly resistant to seismic related liazards. It is, therefore, our opinion that structural damage is unlikely if such buildings are designed and constructed in accordance with the minimum Standards of the most recent edition of the Uniform Building Code. SEISMIC SURVEY AND RIPPABILITy CHARACTERISTICS GENERAL: The results of our seismic survey and exploratory trenches performed for the referenced reports indicate that blasting will be required to obtain proposed cuts. In addition, isolated boulders are anticipated within cut areas that may require special handling during grading operations. A sunnary of each seismic traverse is presented in Table III SCS&T 902104S May 15, 191 0 IB Page 9 below, and P .ates Number 18 through 20. )ur interpretation is ba^> on the rifpability ( haracteristics of granitic ind metavolcanic rock as^escribed in Pages 12 through 15. TABE£ III Seismic Travcorse No. S73-14 Proposed Cut: 48 Feet Geologic Unit: Metavolcanic Interprr ?tation: 0' -15' Nonripp ible Seismic Tcavinrse No. SW-10 Propose 1 Cut: 50 Feet Geologic Unit: Metavolcanic Interpr<Jtation: 0'- 3' Rippabl 3 3'-17' RippabJs with Hardrock Floaters 17'-30' Nonripp able Seismic Tranrase Nb. SW-IOR Propose! Cut: 50 Feet Geologi- Unit: Metavolcanic Interpretation: 0'- 3' RippabJe 3'-17' RifpabJe with Hardrock Floaters 17'-30' Nonripiable Seifairic Tcavazse No. Sff-ll Proposed Cut: None Geologic Unit: Metavolcanic Interpretation: 0'- 6' Rippab. e 6'-27' Nonripj able Seismic Tcavscse No. Sff-llR Proposed Cut: None Geologic Unit: Metavolcanic Interpietation; 0'- 6' Rippab e 6' -27' Nonrip able SCS&T 9021049 May 15, 1990 Page 10 TAHt£ III (continued) Seijsmic Traverse No. SW-12 Proposed Cut: Geologic Unit: Interpretation: 29 Feet Metavolcanic C- 6' Rippable 6'-21' Marginally Rippable with Hardrock Floaters -t- 21' Nonrippable Seismic Traverse No. SW-12R Prcposed Cut: 29 Feet Geologic Unit: Metavolcanic Interpretation: 0'- 5' Rippable 5'- 26' Rippable with Hardrock Floaters -t- 26' Nonrippable Seismic Travecse No. SW-13 Proposed Cut: Geologic Unit: Interpretation: 13 Feet Metavolcanic 0'- 4' Rippable 4'-15' Rippable with Hardrock Floaters + 15' Nonrippable Seismic Traverse No. SW-14 Proposed Cut: 38 Feet Geologic Unit: Metavolcanic Interpretation: 0'- 4' Rippable 4'-21' Rippable with Hardrock Floaters -»- 21' Nonrippable Seismic Tcawetse No. SH-14R Proposed Cut: Geologic Unit: Interpretation: 38 Feet Metavolcanic 0'- 3' Rippable 3'-14' Rippable with Hardrock Floaters 14'-30' Marginally Rippable with Hardrock Floaters SCS&T 9021049 May 15, 1990 Page 11 TABLE III (continued) Seismic Traverse No. SX-15 Proposed Cut: Geologic Unit: Interpretation: Unknown Metavolcanic 0'- 6' Rippable 6'-15' Rippable with Hardrock Floaters + 15' Nonrippable Seismic Ttaverse No. SX-I5R Proposed Cut: Geologic Unit: Interpretation: Unknown Metavolcanic O'-ll' Rippable -I- 11' Nonrippable Seismic Tcaverse No. SZl-16 Proposed Cut: Geologic Unit: Interpretation: None Granitic 0'-16' Rippable 16'-27' Rippable with Hardrock Floaters + 27' Nonrippable Seismic Travecse No. SZ1-16R Proposed Cut: None Geologic Unit: Metavolcanic/Granitic Interpretation: 0'-20' Rippable with Hardrock Floaters -I- 20' Nonrippable Seismic Traverse No. SZ2-17 Proposed Cut: Unknown Geologic Unit: Metavolcanic/Granitic Interpretation: 0'- 5' Rippable + 5' Nonrijpable SCS&T 9021049 May 15, 1990 Page 12 TaPTF. Ill (ccmtinxied) Seismic Tcaverse No. SZ2-17R Proposed Cut: UnJoiown Geologic Unit: Metavolcanic/Granitic Interpretation: 0'-20' Rippable with Hardrock Floaters + 20' Nonrippable In general, our seismic survey indicated that areas underlain by granitic rock present rippable material to depths ranging up to approximately 27 feet, with nonrippable material below this depth. In areas underlain by metavolcanic and associated hypabyssal rock, nonrippable materials appear to be encountered at depths of approximately 0 feet to 21 feet. In addition, a variable zone of marginally rippable rock usually exists between the rippable and nonrippable rock. The generation of fine material during blasting and mining operations is essential due to the characteristics of the on-^site rock material. Therefore, "pre-shooting" of nonrippable material before removing the overlying soils and rippable rock is suggested. This procedure often helps to generate nr>re fine material and to facilitate the mixing of soil and rock to be used as fill. RTppARTT.mr CHARACTERISTIC OF GRMIODIC»OTIC ROCK RIFPABlf OONDinCN (0-4,500 FT./SBC.): This velocity range indicates rippable materials which may consist of decomposed granitic rock possessing random hardrock floaters. These materials will break down into slightly silty, well graded saixi, whereas the floaters will require disposal in an area of nonstructural fill. Some areas containing numerous hardrock floaters may present utility trench prc*)lems. Further, large floaters e^qposed at or near finish grade may present additional problems of removal and disposal. SCS&T 9021049 May 15, 1990 Page 13 Materials within the velocity range of from 3,500 to 4,000 fps are rippable with difficulty by backhoes and other light trenching equipment. MAKHHALLY RJEPABLE CONDITION (4,500 FT./SBC.-5,500 FT./SBC.): This range is rippable with effort by a D-9 in only slightly weathered granitics. This velocity range nay also include numerous floaters with the possibility of extensive areas of fractured granitics. Excavations may produce material that will partially break down into a coarse, slightly silty to clean sand, but containing a high percentage of + 1/4" material. Less fractured or weathered materials may be found in this velocity range that would require blasting to facilitate removal. Materials within this velocity range are beyond the capability of backhoes and lighter trenching equipment. Difficulty of excavation would also be realized by gradalls and other heavy trenching equipment. NONRIFPABLE COOITION (5,500 FT./SBC. & GREATER): This velocity range includes nonrippable material consisting primarily of fractured granitics at lower velocities with increasing hardness at higher velocities- In its natural state, it is not desirable for building pad subgrade. Blasting will produce oversize material requiring disposal in areas of nonstructural fill. This upper limit has been based on the Rippability Chart shown on Plates Nunfcer 18 through 20 utilized for this report. However, as noted in the Caterpillar Chart on Plates Nuntoer 21 through 23, this upper limit of rippability may sometimes be increased to 7,000 to 8,000 fps material using the D-9 mounted #9 Series D Ripper. RtpPARTT.TW CHARACIERISnCS OF MEraiVaLCANICS AND ASSOCIflaH) HYPABYSSAL ROCKS AM) TONALITIC ROCKS R£PEAEI£ GCMDmCN (0-4,500 FT./SBC.): This velocity range indicates rippable materials which nay vary from decomposed metavolcanics at SCS&T 9021049 May 15, 1990 Page 14 lower velocities to only slightly decomposed, fractured rock at the higher velocities. Although rippable, materials may be produced by excavation that will not be useable in stmctural fills due to a lack of fines. Experience has shown that material within the range of 4,000 to 4,500 fps most often consists of severely to moderately fractured angular rock with little or no fines and sizeable quantities of + 1/4" material. For velocities between 3,500 to 4,500 fps, rippability will be difficult for backhoes and light trenching equipment. MAWSINAEiY RIPPABtJE CONDITION (4,500-5,500 FT./SBC.): Excavations in this velocity range would be extremely time consuming and vrouid produce fractured rock with little or no fines. The higher velocities could require blasting. Trenching equipment would not function. NONRIPPAHL£ CONDITION (5,500 FT./SBC. & O^EAaER): This velocity range may include noderately to slightly fractured rock which vrould require blasting for removal. Material produced would consist of a high percentage of oversize eind angular rock. Rippability of metavolcanics may be acconplished for higher velocities using the Caterpillar D-9 with the #9 D Series Ripper. Due to the fractured nature of sone metavolcanics, ripping might be acconplished in as high as 8,000 fps material. SEISMIC TRAVERSE LIMITZVnONS The results of the seismic survey for this investigation reflect rippability conditions only for the areas of the traverses. However, the conditions of the various soil-rock units afpear to be similar for the remainder of the site and may be assumed to possess similar characteristics. SCS&T 9021049 lay 15, 1990 Page 15 Our reporting is presently limited in that refraction seismic surve:'S do not allow for prediction of a percentage of expectable oversize or hardrock floaters. Subsurface varia ions in the degree of weathered rock to fractured rock are not accurately predictable. The seismic refraction nethod requires that materials become incrreasingly dense with depth. In areas denser, higher velocity materials are underlain by lower velocity n^JPSals, the lower velocity materials would not be indicated by our survey All of the velocities used as upper limits for rippability are s object to fluctuation depending upon sucl local variations in rock conditions as: a) Fractures, Faults anc Planes of Weakness of Any Kind b) Weathering and Degrei of Decomposition c) Brittleness and Crys alline Nature d) Grain Size Further, the range of rippcbility using Caterpillar equipment may be increased using different ecTiipment. However, it should be noted that ripping of higher velocity ma terials may become totally dependeit on the tiite available and the economi:s of the project. Ripping of higher velocity materials can be achieved but it may become economically infeasible. GROUNDKAXERs No groundwater was encountered during our sobsurface explorations for the referenced reports. Even though no major groundwater problems are anticipated eithe r during or after constmction of the proposed development, seasonal grou idwater from precipitation runoff may be encountered within the larcer drainage swales during grading for the developmsnt. It is suggested that canyon subdrains be installed within drainage swales which are to receive fill. It should be realized that groundwater problems may occur after development of a site even vhere none were present before developmeit. These are usually nunor phenome \a and are often the result of an altera^ ion of the permeability characterist ics of the SCS&T 9021049 May 15, 1990 Page 16 soil, an alteration in drainage pattems and an increase in irrigation water. Based on the permeability characteristics of the soil and the anticipated usage of the development, it is our opinion that any seepage problems which nay occur will be minor in extent. It is further ovir opinion that these problems can be most effectively corrected on an individual basis if and v*ien they develop. CONCLUSIONS AM) RBO0MMEM)AnONS GENERAL In general, no geotechnical conditions were encountered which would preclude the development of the site as tentatively planned, provided the recommendations presented herein are followed. The main geotechnical condition that will affect the proposed site developnent include hard granitic, metavolcanic, and hypabyssal rock, which will require heavy ripping and blasting in order to make the proposed excavations. It is anticipated that the material generated from the cuts of the granitic, metavolcanic and hypabyssal rock will contain relatively low amounts of fine soils and large amounts of oversized material. Since rock fills require a percentage of fine soil, mining of the site, importing of fine materials or exporting excess rock may be necessary. Existing loose surficial dqposits such as topsoils, subsoils, younger alluvium, and any weathered formational materials encountered are considered unsuitable for the support of settlement sensitive improvements, and will require removal and/or replacement as compacted fill. Expansive soils were also present within the svibject area. Where possible, select grading is recommended to keep nondetrimentally expansive soils within four feet from finish pad grade. In areas vi^iere this is not feasible, special foundation consideration will be necessary. However, it is anticipated that only miinor amounts of expansive soils will be encountered. SCS&T 9021049 May 15, 1990 Page 17 GRADING SITE PREPARmai: Site preparation should begin with the removal of any existing vegetation and deleterious matter from proposed improvaient areas. Removal of trees should include their root system. Any existing loose surficial depos. ts such as topsoils, subsoils, younger alluvium and any weathered formational materials, in areas to be graded should be removed to firm natural ground. The extent of the topsoils and subsoils will be approxinately ore to three and one half feet. Firm natural ground is defined as soil having en in-place density of at least 90 percent. Soils exposed in the bottom of »!Xcavations should be scarified to a depth of 12 inches, noisture conditioned and reconpacted to at least 90 percent as determined in accordance with ASTM D 1557-78, Method A or C. The minimum horizontal limits of removal should include at least five feet beyond the perimeter of the stmctures, anl all areas to receive fill and/or settlement-sensitive improvements. SELECT (auU)ING: Expansive soils should not be allowed within four feet from finish pad gracU . In addition, expansive soils should not be placed within a distance from tne face of fill slopes equal to ten feet or half the slope height, v*d.chevi;r is more. Select material should consist of granular soil with an expansic n index of less than 50. It is reccamended that select soils have relatively low permeability characteristics. In areas undercut for select grading purposes, the bottom of the excavation should be sloped at a minimum of thne percent away from the center of the stmcture. Minimum lateral extent • f select grading should be five feet away from the perimeter of settlanent-S(?nsitive improvements. COT/FILL nWNSinON: It is anticipated that a transition line between cut and fill soils may run through sone of the proposed building pads. Due to the different s Jttlement characteristics of cut and fill soils, construction of a stmcture partially on cut and partially on fill is not reccmnended. Based on this, we recomnend that the cut portion of the building pads be undercut to a depth of at least three feet below finish grade, and the SCS&T 9021049 May 15, 1990 Page 18 materials so excavated replaced as xiniformly compacted fill. The minimum horizontal limits of these recomnendations should extend at least five feet outside of the proposed inprovenents. IMPCaOED FILL: All fill soil imported to the site should be granular and should have an e^qansion index of less that 50. Further, import fill should be free of rock and lumps of soil larger than six inches in diameter and should be at least 40 percent finer than 1/4-inch. Any soil to be imported should be approved by a representative of this office prior to importing. RIFPABIIJTY: It is anticipated that the proposed cuts will require heavy ripping and blasting. Plates Numter 18 through 20 contain the results of our seismiic traverses. The results are summarized within this report. This condition will be further evaluated during the preparation of the geotechnical investigation report. Additional seismdc traverses will be performed in areas v^*lere deep cuts are proposed. OVERSIZQ) R0(3C: Oversized rock is defined as material exceeding six inches in maximum dimension. It is anticipated that oversized material will be generated from proposed cuts. Oversized material may be placed in stmctural fills as described in Plate Numtaer 13. SLOPE CONSIRUCnCN: The face of all fill slopes should be compacted by backrolling with a sheepsfoot compactor at vertical intervals no greater than four feet and should be track walked when completed. Select grading should be performed to limit expansive soils within ten feet from face of fill slope or one half the slope height, whichever is greater. Recommendations contained within this report reflect a select grading condition. All cut slopes should be observed by our engineering geologist to verify stable geologic conditions. Should any unstable conditions be found, miitigating measures could be required. SURFACE DRAINBGE: It is recommended that all surface drainage be directed away from the stmctures and the top of slopes. Ponding of water should not be allowed adjacent to the foundations. SCS&T 9021049 May 15, 1990 Page -9 SUBEKAINS: A subdrain should be installed in canyon areas to receive fill ai excess of ten feet. A subdrain detail is provided in Plate Numiber 14. EARHWCWK: All earthwork and grading contaiplated for site preparati on should be accomplished in accordance with the attached Recornmended Gradi ng Specifications and Special Provisions. All special site preparation recomnendations presented in the sections above will supersede those in tie Standard Recomrended Grading Specifications. All embankments, stmctm al fill and fill should be compacted to at least 90% relative compaction at or slightly over optimum moistvure content. Utility trench backfill within fi ^e feet of the proposed stmctiires and beneatJi asj^ialt pavements should be conpacted to minimum of 90% of its maximum dry density. The upper t>e. ve inches of subgrade beneath paved areas should be conpacted to 95% of ts maximum dry density. This compaction should be obtained by the paviag contractor just prior to placing the aggregate base material and should i ot be part of the mass grading requirements. The maxinum dry density of e ch soil type should be determined in accordance with ASTM Test Metl od D-1557-78, Method A or C. SLOPE STABILITY Proposed cut and fill slopes should be constmcted at a 2:1 (horizontal to vertical) or flatter inclination. It is estimated that cut and fill slo es will extend to a maximum height of about 35 feet. It is our opinion t lat said slopes will possess an adequate factor of safety with respect to d sep seated rot:ational failure and surficial failure (see Plate Number 15). "he engineering geologist should observe all cut slopes during grading to ascertain that no adverse conditions are encountered. FOUOOTONS fJJjRRAT.i If the lots are capped with nondetrimentally e^qansive soi LS, conventional shallow foundations nay be utilized for the support of -he proposed structures. The footings should have a minimum dept± of 12 inc les SCS&T 9021049 May 15, 1990 Page 20 and 18 inches below lowest adjacent finish pad grade for one-and-tvro-story constmction, respectively. A minimum width of 12 inches and 18 inches is recommended for continuous and isolated footings, respectively. A bearing capacity of 2000 psf may be assumed for said footings. This bearing capacity may be increased by one-third when considering wind and/or seismdc forces. Footings located adjacent to or within slopes should be extended to a depth such that a minimtum distance of six feet and seven feet exist between the footing and the face of cut slopes or fill slopes, respectively. Retaining walls in similar conditions should be individually reviewed by this office. If it is found to be unfeasible to cap the lots with nondetrimentally expansive soils as recommended, special foundation and slab design will be necessary. This generally consists of deepened and more heavily reinforced footings, thicker, more heavily reinforced slabs. Reconrendations for expansive soil conditions will be provided after site grading when the expansion index and depth of the prevailing foundation soils are known. REXMPORCEMEKT: Both exterior and interior continuous footings should be reinforced with at least one No. 4 bar positioned near the bottom of the footing and one No. 4 bar positioned near the top of the footing. This reinforcenent is based on soil characteristics and is not intended to be in lieu of reinforcenent necessary to satisfy stmctural considerations. If expansive soils exist within four feet of finish grade, additional reinforcing will be necessary. INTERIOR CONCRETE ON-GRADE SLABS: If the pads are capped with nondetrimentally ejqansive soils, concrete on-grade slabs should have a thickness of four inches and be reinforced with at least No. 3 reinforcing bars placed at 36 inches on center each way. Slab reinforcement should be placed near the miiddle of the slab. As an altemative, the slab reinforcing may consist of 6"x6"-W1.4;iW1.4 (6"x6"-10/10) welded wire mesh. However, it should be realized that it is difficult to maintain the proper position of wire mesh during placement of the concrete. A four-inch-thick layer of clean, coarse sand or crushed rock should be placed under the slab. This SCS&T 9021049 May 15, 1990 Page 21 layer should consist of material having 100 percent passing the one-half-inch screen; no more than ten percent passing sie^^ #100 and no more than five percent passing sieve #200. Where moisture-sensitive floor coverings are planned, the sand or rock should be overlain by a visqueen moisture barrier and a two-inch-thick layer of sand or silty sand should be provided above the visqueen to allow proper concrete curing. EXTERIOR SL»BS-CK-a»DE: For nonexpansive soil conditions, exterior slabs should have a munimum thickness of four inches. Walks or slabs five feet in width should be reinforced with 6"x6"-W1.4xW1.4 (6"x6"-10/l0) welded wire mesh and provided with weakened plane joints. Any slabs betv^n five and ten feet should be provided with longitudinal weakened plane joints at the center lines. Slabs exceeding ten feet in width should be provided with a weakened plane joint located three feet inside the exterior perimeter as indicated on attached Plate Numiber 16. Both traverse and longitudinal weakened plane joints should be constmcted as detailed in Hate Numiaer 16. Exterior slabs adjacent to doors and garage openings should be connected to the footings by dowels consisting of No. 3 reinforcing bars placed at 24-inch intervals extending 18 inches into the footing and the slab. SPECIAL LOTS: Special lots are defined as lots underlain by fill with differential thickness in excess of ten feet. The follcwing increased foundation recommendations should be utilized for said lots. Footings should be reinforced with two No. 4 bars positioned near the bottom of the footing and tvjo No. 4 hairs positioned near the top of the footing. Concrete on grade slabs should be reinforced with at least Nb. 3 reinforcing bars placed at 18 inches on center each way. Lots with fill differentials in excess of thirty feet should be evaluated on an individual basis. EXPANSIVE CHARAClERISnCS: Metavolcanic rock generally weathers to a clayey subsoil, and its presence within four feet of finish pad grade will require special site preparation and/or foundation consideration. SETZLEMENT CHARACTERISTICS: T!he anticipated total and/or differential settlements for the proposed stmctures may be considerexi to be within SCS&T 9021049 May 15, 1990 Page 22 tolerable limiits provided the recommendations prese tted in this report are followed. It should be recognized that miinor hairlim. cracks on concrete due to shrinkage of constmction materials or redistribution of stresses are normal and nay be anticipated. EARSH RE^MNING WALLS PASSIVE PRESSURE: The passive pressure for the prevailing soil conditions may be considered to be 450 pounds per square foot pjr foot of depth up to a maximum of 2000 psf. This pressure may be increased one-third for seismic loading. The coefficient of friction for concrete tJ soil may be assumed to be 0.35 for the resistance to lateral movement. Wlien combining frictional and passive resistance, the former should be reduced by one-third. The upper 12 inches of exterior retaining wall footings should not be included in passive pressure calculations v*ien landscaping abuts the bottom of the wall. ACTIVE PRESSURE: The active soil pressure for the design of uru?estrained earth retaining stmctures with level backfills may be assumed to be equivalent to the pressure of a fluid weighing 35 pounds per cubic foot. For 2:1 (horizontal to vertical) sloping backfills, 14 pcf should be added to the preceding values. These pressures do not considjr any surcharge. If any are anticipated, this office should be contacted for the necessary increase in soil pressure. This value assumes a drained backfill condition. Waterproofing details should be provided by the project architect. A subdrain detail is provided on the attached Plate Nu.tiber 17. BACKFni^: All backfill soils should be compacted to at least 90% relative compaction. Expansive or clayey soils should net be used for backfill material. The wall should not be backfilled until the masonry has reached an adequate strength. FACTOR OF SAFETY: The above values, with the exception of the allowable soil bearing pressure, do not include a factor of safety. Appropriate factors of safety should be incorporated into thj design to prevent the walls from overturning and sliding. SCS&T 9021049 May 15, 1990 Page 23 UHETKTICNS REVIEW, OBSERVKTIGN AND TESTING The recomnendations presented in this report are contingent upon our review of final plans and specifications. Such plans and specifications should be made available to the geotechnical engineer and engineering geologist so that they nay review and verify t±eir ccmpliance with this report and wit:h Chapter 70 of the Uniform Building Code. It is recornmended that Southem Califomia Soil & Testing, Inc. be retained to provide continuous soil engineering services during the earthwork operations. This is to verify compliance with the design concepts, specifications or recommendations and to allow design changes in the event that subsurface conditions differ from those anticipated prior to start of constmction. UNUtUKHlTY OF GCrDITICtB The recommendations and opinions e:q)ressed in this report reflect our best estimate of the project requirements based on an evaluation of the subsurface soil conditions encountered at the subsurface exploration locations and on the assimption that the soil conditions do not deviate appreciably from those encountered. It should be recognized that the performance of the foundations and/or cut and fill slopes may be influenced by undisclosed or unforeseen variations in ths soil conditions that may occur in the intermediate and unexplored areas. Any unusual conditions not covered in tliis report that nay be encountered during site developnent should be brought to ths attention of the geotechnical engineer so that he may make modifications if necessary. CSHNGE IN SCOPE This office should be advised of any changes in the project scope or proposed site grading so that we may determine if the recommendations cont:ained herein are appropriate. This should be verified in writing or modified by a written addendum. SCS&T 9021049 May 15, 1990 Page 24 TIME LDOTATIONS The findings of this report are valid as of this date. Changes in the condition of a property can, however, occur with the passage of time, whether they be due to natural processes or the work of nan on this or adjacent properties. In addition, changes in the Standards-of-Practice and/or Govemment Codes nay occur. Due to such changes, the findings of this report nay be invalidated v^holly or in part by changes beyond our control. Therefore, this report should not be relied upon after a period of two years without a review by us verifying the suitability of the conclusions and recommendations. PROFESSICMAL STAM3ARD In the performance of our professional services, we comply witih that level of care and skill ordinarily exercised by members of our profession currently practicing under similar conditions and in the sane locality. The client recognizes that subsurface conditions may vary from those encountered at the locations v*iere our trenches, surveys, and explorations are made, and tJiat o\xc data, interpretations, and recommendations are based solely on ths information obtained by us. We will be responsible for those data, interpretations, and recommendations, but shall not be responsible for the interpretations by others of the information developed. Our services consist of professional consultation and observation only, and no warranty of any kind whatsoever, express or implied, is made or intended in connection with the work performed or to be performed by us, or by our proposal for consulting or other services, or by our furnishing of oral or written reports or findings. CLIENT'S RESPONSIBILITr It is the responsibility of lyon Comnunities Incorporated, or their representatives to ensure that the information and recommendations contained herein are brought to the attention of ths stmctural engineer and architect SCS&T 9021049 May 15, 1990 Page 25 for the project and incorporated into the project's plans and specifications. It is further their responsibility to take the necessary measures to insure that the contractor and his subcontractors carry out such recommendations during constmction. FIELD EXPLORATIONS Three subsurface trench explorations were made at the locations indicated on the attached Plate Nuirber 1 on December 21, 1982, and three on July 7, 1983, adjacent to or witJiin the subject site (see Plates Number 3 through 6). In addition, Plates Number 7 through 9 from the referenced reports contain additional trench excavations made in Decentoer 15, 1982, of similar soils within the subject subdivision. These explorations consisted of trenches dug by the means of a backhoe. One seismic traverse was performed on April 14, 1973 and eight were performed on January 11, 1983. The field work was conducted under the observation of our engineering geology personnel. The results are shown on Plates Number 18 through 20. The soils are described in accordance with the Unified Soils Classification System as illust:rated on the attached simplified chart on Plate 2. In addition, a verbal textural description, the wet color, the apparent moisture and the density or consistency are provided. The density of granular soils is given as eitJier very loose, loose, medium dense, dense or very dense. The consistency of silts or clays is given as either very soft, soft, medium stiff, stiff, very stiff, or hard. LABORATORY TESTING Laboratory tests were performed in accordance with the generally accepted American Society for Testing and Materials (ASTM) test methods or suggested procedures. A brief description of the tests performed is presented below: a) CLASSIFICATION: Field classifications were verified in the laboratory by visual examination. The final soil classifications are in accordance with the Unified Soil Classification System. SCS&T 9021049 May 15, 1990 Page 26 b) MDISTURE-OTNSITY: In-p .ace noisture contents and dry densities were detemdned for representative soil samples. This information was an aid to classification and permitted recognition of variations in material consistency with depth. The dry unit weight is detemdned ii pounds per cubic foot, and the in-place moisture content is determdned as a percentage of the soil's dry weight. The results ara summarized in the trench logs. c) (SIAIN SIZE DISTKimfi'lJi: The grain size distribution was determdned for representative samples of the native soils in accordance with ASTM D422. The results of these tests are presented on Plate Numter 10. d) GCMPACnON TEST: The naximum dry density and optimum moisture content of typical so: Is were determdned in the laboratory in accordance with ASTM Standard Tfest D-1557-78, Method A. The results of these tests are presented on the attached Plate Numiber 11. e) EXPANSION TEST: The ejqpansive potential of clayey soils was determdned in accordarre with the following test procedure and the results of these te sts appear on Plate Number 11. Allow the trirrned, undisturbed or remolded sample to air dry tc a constant mDistiare content, at a temperature of 100 degrees F. Place the dried sample in the consolidoneter and allow to compress under a load o: 150 psf. Allow moisture to contact the sample anti measure its expansion from an air dried to saturated condition. f) DIRECT SHEAR TESTS: Direct shear tests v«re performed to determine the failure envelope based on yield shear strength. The shear box was designed to accomnnodate a sample having a SCS&T 9021049 May 15, 1990 Page 27 diameter of 2.375 inches or 2.50 inches and a height of 1.0 inch. Samples were tested at different vertical loads and a saturated noisture content. The shear stress was applied at a constant rate of strain of approximately 0.05 inches per mdnute. The average shear strength values for granitic and netavolcanic rock are presented on attached Plate Number 12. SUBSURFACE EXPLORATION LEGEND UNIFIED SOIL CLASSIFICATION CHART SOIL DESCRIPTION GROUP SYMBOL TYP!:AL NAMES I. COARSE GRAINED, more than half of material is larger than No. 200 sieve size. Well graded gravels, gravel-GRAVELS CLEAN GRAVELS GW Well graded gravels, gravel- More tnan half of sand mixtures, little or no coarse fraction is fines. larger than No. 4 GP Poorly graced gravels, gravel sieve size but sand mixtures, little or no smaller than 3". fines. GRAVELS WITH FINES GM Silty gravels, poorly graded (Appreciable amount gravel-sand-sllt mixtures. of fines) GC Clayey gravels, poorly graded gravel-sand, clay mixtures. SANDS CLEAN SANDS SW Well graded sand, gravelly More than half of sands, little or no fines. coarse fraction is SP Poorly graded sands, gravelly smaller than No. 4 sands, little or no fines. sieve size. SANDS WITH FINES SM Silty sands, poorly graded (Appreciable amount sand and silty mixtures. of fines) SC Clayey sands, poorly graded sand and clay mixtures. II. FINE GRAINED, more than half of material is smaller than No. 200 sieve size. SILTS ANO CLAYS ML Inorganic silts and very fine sands, rock flour, sandy silt or clayey-silt-sand mixtures with slight plas- ticity. Liquid Limit CL Inorganic clays of low to less than 50 medium plasticity, gravelly clays, sandy clays, silty clays, lean clays. OL Organic silts and organic silty clays or low plasticity. SILTS AND CLAYS MH Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, elastic Silts. Liquid Limit CH Inorganic clays of high greater than 50 plasticity, fat clays. OH Organic clays of medium to high plasticity. HIGHLY ORGANIC SOILS PT Peat and other highly organic soils. — Water level at time of excavation or as indicated US — Undisturbed, driven ring sample or tube sample CK — Undisturbed chunk sample BG — Bulk sample SP — Standard penetration sample yV SOUTHBRN CALIFORNIA SOIL A TESTING, INC. CALAVERA HEIGHTS-VILLAGE W-X-Y yV SOUTHBRN CALIFORNIA SOIL A TESTING, INC. BY: KAR/EM DATE: 5-03-90 yV SOUTHBRN CALIFORNIA SOIL A TESTING, INC. JOB NUMBER: 9021049 Plate No. 2 I I Class TRENCH ::0. IT-50 Descriotior. SM Gray-brown, Moist, Dense to Very Dense, Siltv Sand (Decomposed Granite^ Trench Ended ac 4 Feet y\ SOUTHERN CALIFORNIA ^15LN soil- * TESTING, INC. ^^^^ BAN oiaao, cAuranNiA ••^•o CALAVERA HEIGHTS-VILLAGE W-X-Y BY CRB DATE 12-21-82 JOB NO. 9021049 Plate Mo. 3 i.SS 10 3rown i. F.ed-brov.Ti. Clavev Hilcv ^;inc ...:isc, ..eaium jense. 3 o i i •' Vellov/-broTO, S.^^j-broim, Jray-orc^vTi. Moist, Medium Dense. Clavev biltv Sand. Porous (Older Alluvium") Sandy Clay/Clavev Sand Urench Ended ac 10 Feet 113.2 3.0 10/.8 15.5 SOUTHERN CALIFORNIA SOU- A TESTINQ, INC. CALAVERA HEIGHTS-VILLAGE W-X-Y BY CRB DATE 12-21-82 JOB NO. 9021049 Plate 'Jo. 4 •y / ass SM/ escr: SM --.ec-orown. ..cist. ...Baium uense, _ ^ayey S;.lrv S;inc I ."..'Dsoii) Vellcw and C-rav-bro^vTi. M.;ist, Dense Co Verv Dense. Siltv Sand fCec:omposed Granite) rrench Ended ac J Feet SOUTHERN CALIFORNIA X3LgS SOIL. & TESTING , INC. 1 SAM eiaao. CAUIKHMIA ••^•a CALAVERA HEIGHTS-VILLAGE W-X-Y 1 12-21-82 1 9021049 Plate No. 5 z UJ o a. TV -1 ICA LE o u. a. tn S tn < < CO -1 CO u TRENCH NUMBER TX-77 ELEVATION DESCRIPTION DC H < M S: 5 < z >-NT ON ITY Ui oc z < (0 UJ a. tn o AP ON OR u V) z _ Ul > oc o u 25 oc s o u UJ o I- o < < -i a. Ui 2 = o u GM BROWN SANDY GRAVEL (TOPSOIL) HUMID/ MOIST MEDIUM DENSE GM GRAY BROWN SANDY GRAVEL (METAVOLCANIC ROCK) HUMID VERY DENSE REFUSAL AT 2.5' TX-78 CL BROWN SILTY CLAY (TOPSOIL) MOIST STIFF GM GRAY BROWN SANDY GRAVEL (METAVOLCANIC ROCK) HUMID VERY DENSE REFUSAL AT 3' TRENCH NUMBER X-79 CL BROWN SILTY CLAY (TOPSOIL) MOIST STIFF GM GRAY BROWN SANDY GRAVEL (METAVOLCANIC ROCK) HUMID VERY DENSE REFUSAL AT 3' SUBSURFACE EXPLORATION LOG LOGGED BY: DATE LOGGED:, ,^ 7-18-83 JOB NUMBER: 9021049 Plate No. 6 SOUTHERN CALIFORNIA SOIL A TESTING.INC. : 1 5 ' TRENCH NUMBER - ; < I , _i <£ I ! 5 1 E'_E'-'AT;Z N z. ~ ' < I < I .0 1 - I 7) 75 U I SM/Sa RED iROWN, CLAYEY SILTY SAND (TOPSOIL) DESCFIIPTICN — ijj ts. UJ 3 X t-< to a. — i O < Z z Ui < a. 0. < z iii •Ji tn z o tn z Ui o c o in z _ Ui — > ~ X Q iU X 3 >- m 5 s z z o u Ui > z o a S o u UJ K MOIST TO WET RED, BROWN. GRAY, SANDY CLAY (WEATHERED DECOMPOSED GRANITE) YELL3W BROWN, SILTY GRAVELY SANE (DECOMPOSED GRANITE) WET MOIST MEDIUM DENSE MEDIUM STIFF DENSE TO VERY DENSE r 4- t- BG REFL3AL AT 3' TRE^CH NUMBER TQ-Z SM/SL BG CK ML BROIAN CLAYEY SILTY SAND (TOFSOIL) MOIST GREEN BROWN, SANDY SILT MOIST :SM/ML SM YELIOW, RED, BROWN. SILTY SAN! (WEATHERED DECOMPOSED GRAf ITE) MOIST YEL! OW BROWN, SILTY SAND (DEf OMPOSED GRANITE) MOIST TRE) CH ENDED AT 8' MEDIUM DENSE STIFF MEDIUM DENSE MEDIUM DENSE TO DENSE VERY DENSE 121.9 12.1 SOUTHERN CALIFORNIA SOI . A TESTING,INC. SUBSURFACE EXPLORATION LOG LOGGED BY: CRB DATE LOGGED: •,2-15-82 JOB NUMBER: 9021049 Plate No. 7 I I ^ a. UJ c < 15 I I f I TRENCH NUMBER < I u. ( E L E A T; C Or-l DESO~IPTIC:N — « .a — X ^ < OT a. — at O < S X < a. 0. < >-> > z e— jj Ol tn OT X f" Z _ OT Ui a Ui — OT Ui a Q u a. OT Z X >-5 CO O X Q 2 Ui Z O z UJ o > — — H- H O < < a. o u . 3. BAGSM/SC CK I RED BROWN. CLAYEY SILTY SAND (TOPSOIL) MOIST MEDIUM DENSE ;SM CK 4_ 6_ 7 CK 8 YELLOW BROWN, SILTY SAND (DECOMPOSED GRANITE) MOIST DENSE TO VERY DENSE 118.2 10.8 0- 1 - 2- TRENCH ENDED AT 8' TRENCH NUMBER '3-7 ;SM CK I : SM RED BROWN. (TOPSOIL) ILTY SAND .MOIST DARK GRAY, GRAVELY SILTY SAND (DECOMPOSED GRANITE) MOIST MEDIUM DENSE DENSE TO VERY DENSE TRENCH ENDED AT 2 SOUTHERN CALIFORNIA SUBSURFACE EXPLORATION LOG SOIL A TESTING,INC. LOGGED BY: DATE LOGGED: 12-15-82 SOIL A TESTING,INC. JOB NUMBER: 9021049 Plate No. 8 < I - ,0 t TRENCH NUMBER ELEV AT;" N; 2 I 'J) I < ! •3 i — 'il — X UJ -. X ^ < OT o. — a. O < S Ui K < O. OESCRIF TICN OT Z o 'J OT z Ui K O OT Z _ Ui — ° 1 >• X a OJ X ^ z OT Ul O s z o u Ui o > — * *— K o < < -J a. s o UJ X SM/ I RED BROWN. CL; YEY SILTY SC I SAND (TOPSOIL MOIST GM T BAGl GRAY, SANDY G AVEL (METAVOLCANIC ROCK) MOIST MEDIUM DENSE DENSE TO VERY DENSE TRENCH ENDED ^T 5' TRENCH NUMBER TQ-9 SM/ SC CL SM CK t- BAGi RED BROWN, CLAYEY SILTY SAND (TOPSOIL) MOIST GRAY BROWN, SANDY CLAY (WEATHERED DECOMPOSED GRANITE) YELLOW BROWN SILTY SAND (DECOMPOSED (RANITE) TRENCH ENDED AT 6' MOIST MOIST MEDIUM DENSE STIFF DENSE TO VERY DENSE 128.1 10.1 SOUTHERN CALIFORNIA SOIL ATESriNG,INC. SUBSURFACE EXPLORATION LOG LOGGED BY: DATE LOGGED: i 2.:) 5.32 JOB NUMBER: 9021049 Plate No<. 9 i 9 36 lOOn-T 90 ao 70 so S 40 u i 30 18- U.S Slondard Sieves 2' f Ki" •IO *ZQ ^iU 20 10 0 1000 24' 12: 6' 4 1 2 100 2: .. .lil — ic Ji IU Hydrometer (Minutas) •3U - »bQ "190 .*^0Q. IS* W lOO < S 4 I S 4 S Grain Sue (mm) »l7t $ « 1 i I lOu ;)(! eo 70 Ul 9a I s & « s 2 40' h 10 -« PARTICLE SIZE LIMITS 1 " BOULDER!COBBLES 1 GRAVEL SAND SILT OR CLAY 1 " BOULDER!COBBLES 1 Coon* 1 Fina Coort* 1 Madiuin | FInt SILT OR CLAY (12 in.) 3 in. 3/4 in. No.4 N0.IO U. S. STANDARD — - — — TQ-2 1? 3' — TQ-2 (3 4'-5' — . ..— TQ-8 0 4'-5' No.40 No. 200 SIEVt SIZE I i I 1 c \IAXIMUy DENSITY & OPTIMUM MOISTURE CONTENT A .—^ S7M D1557-7S METHOD A MP DESCRIPTION Maximum | Density (pet) Optimum 1 Moisture 1 ContC/.) 1 3 2 -3' Yellow Brown, Silty Gravelly Sand 114.8 13.8 1 TC-2 •3 2 -3' Green Brown, Sandy Silty Clay 114.0 15.0 1 n J- c (3 4 r, - 3 Yellow/Reddish Brown, Silty Sand 112.6 14.8 1 '0-3 9 3 -4' Grey, Silty Sandy Gravel 128.4 11.7 1 EXPANSION TEST RESULTS SAMPLE TQ-: LJ 2'-3' TQ-2 @ 3'-4' CONDITION Remolded ' Remolded j 1 'NITIAL M.C. (•/.) 1 1 ' 1 14.8 i ' 1 . .NITIAL ZENSITY (PCF] 101.3 101.8 ! ' i 1 FINAL M.C. (•/.) 30.5 26.0 1 NORMAL STRESS (PSF) 150 150 1 EXPANSION % lE.C 0 SOUTHERN CALIFORNIA CALAVERA HEIGHTS-VILLAGE W-X-Y | * SOIL A TESTING, INC. BY: KAR O*TE: 1-10-84 1 \^ * SOIL A TESTING, INC. JOB NUMBER: 9021049 Plate No. 11 1 I I I I I I UL (0 cn <n UJ O) < UJ z (A DIRECT SHEAR SUMMARY 1 2 3 2M L 2L NORMAL STRESS, KSF SAMPLE DESCRIPTION ANGLE OP INTERNAL FRICTION (•) COHESION INTERCEPT (pBf) TQ-8@3'-4' Remolded to 90% 38 200 ^1 SOUTHERN CALIFORNIA I^X^ SOIL A TESTING,INC. CALAVERA HEIGH BT: KAR JOB NUMBER: 9021049 S-VILLAGE W-X-Y DATE: 5-01-90 Plate No. 12 o r H ill 01 H (A O c -I z m o r iS a o • z c B • KAR o KAR > KAR r— •« AVI m o ?o ro J» 1—• o m VO »—t VO CD sc —1 o tn -o > I < Ot m 1—* rt-i— at LA z tn o cn m O 1—' OJ 1 1 VO X 1 o -< J3V£flSl2£_BQ£K_DIS RQSAL ( blructurol Soil - RocK Till) pa 4 min- Ki^Qk—LJiJ^^^ *w ZONE D I • • R 1^?' . 'min. * •ons 1. Coivacitd tall fill IMII coMttlM it litii 40 ptrccnt (•II iliM Mtttoi IM-lacli iltia, (b| •tl«)it), ««4 toa$tttm4 la (Cc«r«Mtt MIU MMirictiloni for •trHCt.ral fill. 2. iKki Mar 4 faat In MIIM <I««IIOA not p*r.ut«d la fill. I(»N0 lOK A: Coa|iKl«l toll rill. No rock frtgmcnti o»(r i Inctiet In ifrttttH aiMAtlon. lUttC I: llo<tl 2 lo 4 feet In B^IIIKJII dlwflllon pUccd In ciM^iKled toll rill conlumlnf lo tONf A. lONi C: latki i liKhft lo 2 feci In MIIIM 4lMntlon unlferalir dlvlrlbu- i«d «n4 M«ll (p«<cd In cai>^*c(*d toll fill conforatn, (a I(M 4. lONC D: Ntqulrtd Itr «ll cilillnf ilopei (;l 4nd lltcpcr. Mt alnlMia coiipKllon. lOM A, I, or C Mitcrlil aty ba uiM far ZOW D. NATURAL /'^/ GROUND l^/^ BENCHING^ REMOVE UN8U ITABLE MATE HAL SUBDRAIN TRENCH: SBE DETAIL A a B DETAIL A FILTER MATERIAL '6 CUBIC FEET/FOOT FILTER MATERIAL SHALL BE CLASS 2 PERMEABLE MATERIAL PER STATE OF CALIFORNIA STANDARD SPECIFICATIONS, AND APPROVED ALTERNATE. CLASS 2 FILTER MATERIiL SHOULD COMPLY WITH THE FOLLOWINQ LIMITS PERFORATED PIPE 4 0 MINIMUM PERFORATED PIPE SURROUNDED WITH FILTER MATERIAL SIEVE SIZE 1 3/4 3/8 No. 4 No. 8 N«. 30 No. 60 Mo. 200 % PASSIN3 100 00-100 40-1OO 2S-40 18-83 S-1S 0-7 0-8 DETAIL B « MIN OVERLAP FILTER FABRIC MIRAFI 140 OR APPROVED EQUIVALENT) DETAIL \ B-1 1 1/2"MAX GRAVEL OR APPROVED EQUIVALENT 6 CUBIC FEET/FOOT DETAIL B-2 1 1/2"QRAVEL WRAPPED IN FILTER FABRIC DETAIL OF CANYON SUBDRAIN TERMINAL DESIGN FINISH GRADE ^1 20 MIN NON PERFORATED 4'MIN PERFORATED 4'MIN PIPE SUBDRAIN INSTALLATION:SUBDRAiN PIPE SHALL BE INSTALLED wiTt^ PERFORATIONS DOWN SUBDRAIN PIPE:6UBDRAIN PIPE SHALL BE PVC OR ABS. TYPE SDR 35 FOR FILLS UP TO 35 FEET DEEP, OR, TYPE SDR 21 FOR FILLS UP TO 100 FEET DEEP y\ SOUTHERN CALIFORNIA SOIL A TESTING, INC. CALAVERA HEIGHTS-VILLAGE W-X-Y y\ SOUTHERN CALIFORNIA SOIL A TESTING, INC. BY: KAR DATE: 5-03-30 y\ SOUTHERN CALIFORNIA SOIL A TESTING, INC. JOB NUMBER: 9021049 Plate No. H SLOPE STABILI'Y CALCULATIONS Janbu's SimDlified Slooe Stability Method \C(?) = WH Tcn(^ FS = Ncf(-WH Assume Homogeneous Strenqth Parameters rhrouahout the siooe ^ (°) C(psf) W.(pcf^ Incl H (ft) -S 38 200 130 2:1 35 2.2 Metavolcanic & Granitic Rock * Cut & Fill Slopes Average Shear Strength Values Where; .ef c w s H FS .Angle of Internal Friction Cohesion (psf) Unit weight of Soil (pcf) Height of Slope (ft) Factor of Safety SOUTHERN CALIFORNIA N;^F^ SOIL A TESTING,INC. CALAVERA HEIGHTS - VILLAGE W-X-Y SOUTHERN CALIFORNIA N;^F^ SOIL A TESTING,INC. BV: KAR DATE: 5-03-90 SOUTHERN CALIFORNIA N;^F^ SOIL A TESTING,INC. Plate No. 15 TRANSVERSE WEAKENED PLANE JOINTS Q' ON CENTER (MAXIMUM) w w/2 w/2 ! ^ 1 —. i 1 ^^^^^^^^^^^^^^^^^^^^^ \ SLABS IN EXCESS OF 10 FEET IN WIDTH SLABS' 6 TO 10 FEET IN WIDTH PLAN NO SCALE n TOOLED JOINT FT 1-1/4 T/2 5 -10/10) WELDED MESH 1 v WEAKENED PLANE JOINT DETAIL NO SCALE SOUTHERN CALIFORNIA >^/^ SOIL L TESTINQ, INC. CALAVERA HEIGHTS-VILLAGE W-X-Y SOUTHERN CALIFORNIA >^/^ SOIL L TESTINQ, INC. BYi KAR OATEi.. 5-03-90 SOUTHERN CALIFORNIA >^/^ SOIL L TESTINQ, INC. JOB NUMBBIt 9021049 Plate No. 16 — WATERPROOF BACK OF WALL PER ARCHITECTS SPECIFICATIONS 3/4 INCH CRUSHED ROCK OR MARIDRAIN MOO OR EQUIVALENT QEOFABRIC BETWEEN ROCK AND SOIL 4" DIAMETER PERFORATED PIPE •HOUSE ON GRADE SLAB i MOUSE RETAINING WALL SUBDRAIN DETAIL NO SCALE ^/V SOUTHERN CALIFORNIA ! SOIL A TESTING,INC. CALAVERA HEIGHTS-VILLAGE W-X-Y BY: KAR JOB NUMBER . 9021049 DATE: 5-03-90 Plate No. 17 RIPPABILITY INDEX NO RIPPING SOFT MEDIUM HARD BLASTING 1000 2000 3000 4000 5000 VEUDCITY, FT/SEC. I ^ I 6000 7000 8000 9000 ^oooo RESULTS TRAVERSE NO. -5 S73-6 S73-8 S73-9 S73-lds73-llS73-l4s73-i: S73-l( a lb ,a,, & 71 r a lb g,|t? ± / / / I I OTE: THE ABOVE RESULTS ATTEMPT TO SHOW DEPTHS TO HORIZONS OF VARYING DENSITY IN DIFFERENT LOCATIONS OVER THE STUOf AREA. SEISMIC TRAVERSE NUMBERS REFER TO LOCATIONS PIDTED ON ATTACHED PLANS. THE*RIPRABIUTY INDEX*IS A MODIFICATION OF CHARTS BY THE CATERPILLAR CO. AND ARTICLE IN *ROA0S AND STREETS' SEPT. 1967. SOUTHERN CAUFORNIA TESTING LABORATORY, INC. 8280 RIVERDALE STREET SAN OlEad CAUFORNU 82120 714-0834134 CALAVERA HEIGHTS-VILLAGE W-X-Y SEISMIC RESULTS BY DBA JOB NO. on9in/io DATE ^-U-73 P1 -It-O Hry 1 Q RIPPABiLiTY NDEX NO RIPPING SOFT MEDIUM HARD BLASTING / —i X \ p-1 1 y p-^ p-i '."I - T 'I' 1000 2000 3000 4000 5000 6000 7000 8000 9000 1(XXX) PI / VELOCITY, FT/SEC. RESULTS TRAVERSE NO. 3PH^ , OTE- THE ABOVE RESULTS ATTEMPT TO SHOW DEPTHS TO HORIZONS OF VARYING DENSITY IN DIFFERENT LOCATIONS OVER THE STUDT AREA. SEISMIC TRAVERSE NUMBERS^ REFER TD LOCATIONS PiDTED ON ATTACHED PUNS. ^« AL*? .'SS^^'^^X 'NOEX'lS A MODIFICATION OF CHARTS BY THE CATERPILLAR CO. ANO ARTICLE IN 'ROADS AND STREETS; SEPT^ 1967. SOUTHERN CALIFOniMIA SOIL & TESTIIMB LAB, IIMC. •••a niVBROAi.a arnnT SEISMIC RESULTS CALAVERA HEIGHTS-VILLAGE W-X-Y BV DBA JOB NO. qn?indQ DATE 1-11-83 »^ _ - _ ». _ in RIPPABILITY INDEX NO RIPPING SOFT MEDIUM HARD BLASTING 0 1000 2000 3000 4000 5000 6000 70QO BQOO 9000 10000 VELOCITY, FT/SEC. RESULTS TRAVERSE NO. GBOPH^ u. z I-0. UJ o alb aJJ^ fl I& NOTE: THE ABOVE RESULTS ATTEMPT TO SHOW DEPTHS TO HORIZONS OF VARYING DENSITY IN DIFFERENT LOCATIONS OVER THE STUCV AREA. SEISMIC TRAVERSE NUMBERS REFER TO LOCATIONS PIDTED ON ATTACHED PLANS. THE*RIPPABIUTY INDEX'IS A MODIFICATION OF CHARTS BY THE CATERPILLAR CO. AND ARTICLE IN 'ROADS AND STREETS' SEPT^ 1967. y^V SOUTHERN CALIFORNIA \ ^^^^ &n\l. & TESTING LAB. INC. ^^^r^ BAN Diaaa, CALIPOnNIA aBiso CALAVERA HEIGHTS-VILLAGE W-X-Y 1 SEISMIC RESULTS BV DBA DATE 1-11-83 1 SEISMIC RESULTS JOB Na 0091 n/iQ Plate No. 20 DSL CATERPILLAR PERFORMANCE HANDBOOK Edition 17 October 1986 Salamic Velocity ^••1 Par ••a— • looo DSL Ripper Performance • Multi or Single Shank No. 8 Ripper • Estimated by Seismic Wave Velocities SOUTHERN CALIFORNIA SOIL L TESTING, INC. CALAVERA HEIGHTS-VILLAGE W-X-Y BY: KAR JOB NUMBER: 9021049 DATE: 5-03-90 Plate No. 21 DSL CATERPILLAR PERFORMANCE HANDBOOK Edition 17 October 1986 Salamic Velocity ••M Par BaaMa • loOO TOPSOIL CLAY IGNEOUS ROCKS GRANITE SABALT SEDIMENTARY ROCKS 3HALE SAND8TONE SILTSTONE CLAYSTONE CONOLOUERATE MET AMORPHIC ROCKS SCHIST SLATE RIPPABLE '0 11 12 13 14 15 D9L Ripper Performance a Multi or Single Shank No. 9 Ripper • Estimated by Seismic Wave Velocities SOUTHERN CALIFORNIA SOIL & TESTING. INC. CALAVERA HEIGHTS-VILLAGEW-X-Y BY: KAR JOB NUMBER: 9021049 DATE: 5-03-90 Plate No. 22 Seismic Velocity ••at Par • tooo Dl 1N CATERPILLAR PERFORMANCE HANDBOOK Edition 17 October 1986 •15 8 9 10 11 12 13 14 15 TOPSOIL CLAY IGNEOUS ROCKS QRAMTE 3ASALT SEDIMENTARY ROCKS SHALE SANDSTONE 3K.TST0NE CLAYSTONE CONQLOMERATE METAMORPHIC ROCKS SCMST SLATE T2ZZZZZZZZIZZZZL \VyyyyyyyyZ7T77 Vy(y^/X//\ YSZZ2ZZ2ZZ. TZZZZZZ2ZZZZZ: RIPPABLE MARQINAL NON-R(PPABLE // //^ D1 1 N Ripper Performance a Muiti or Single Shank No. 9 Ripper • Estimated by Seismic Wave Velocities SOUTHERN CALIFORNIA SOIL & . TESTING, INC. CALAVERA HEIGHTS-VILLAGE W-X-Y BY: KAR JOB NUMBER: 9021049 DATE: 5-03-90 Plate No. 23 CMAVERA HEIOnS VHMGES W-X-Y, TAMARACK AND OJLLBGE BG0I£V7VRD, CARE5BAD RBOCMMENOED C3»DING SPBCIFICATICNS - GEHE31AL PRDVISICNS GE2ERAL ZOTHfT The intent of these specifications is to establish procedures for clearing, conpacting natural ground, preparing areas to be filled, and placing and conpacting fill soils to the lines and grades shown on the accepted plans. The recoitmendations contained in the preliminary geotechnical investigation report and/or the attached Special Provisions are a part of the Recontnended Grading Specifications and shall supersede the provisions contained hereinafter in the case of conflict. These specifications shall only be used in conjunction with the geotechnical report for which they are a part. No deviation from these specifications will be allowed, except vthere specified in the geotechnical report or in other written ccjtminication signed by the Geotechnical Engineer. CBSERVATICN AIO TESTING Southern California Soil and Testing, Inc., shall be retained as the Geotechnical Engineer to observe and test the earthwork in accordance with these specifications. It will be necessary that the Geotechnical Engineer or his representative provide adequate observation so that he may provide his opinion as to whether or not the work was acconplished as specified. It shall be the responsibility of the contractor to assist the Geotechnical Engineer and to keep him appraised of work schedules, changes and new information and data so that he my provide these opinions. In the event that any unusual conditions not covered by the special provisions or preliminary geotechnical report are encountered during the grading operations, the Geotechnical Engineer shall be contacted for further recomnendations. (R-9/89) SCS&T 9021049 May 15, 1990 Appendix, Page 2 If, in the opinion of the Geotechnical Engineer, substandard conditions are encountered, such as questionable or unsuitable soil, unacceptable moisture content, inadequate conpaction, adverse vveather, etc.; construction should be stopped until the conditions are remedied or corrected or he shall recommend rejection of this vjork. Tests used to determine the degree of conpaction should be performed in accordance with the following American Society for Testing and Materials test methods: Maximum Density & Optimum Moisture Content - ASTM D-1557-78. Density of Soil In-Place - ASTM D-1556-64 or ASTM D-2922. All densities shall be expressed in terms of Relative Compaction as determined by the foregoing ASTM testing procedures. PREPARATIGN OF AREAS TO RECEIVE FILL All vegetation, bnish and debris derived from clearing operations shall be reriDved, and legally disposed of. All areas disturbed by site grading should be left in a neat and finished appearance, free from unsightly debris. After clearing or benching the natural ground, the areas to be filled shall be scarified to a depth of 6 inches, brought to the proper noisture content, conpacted and tested for the specified minimum degree of conpaction. All loose soils in excess of 6 inches thick should be removed to firm natural ground vrtiich is defined as natxiral soils v*iich possesses an in-situ density of at least 90% of its maxinum dry density. (R-9/89) SCS&T 9021049 May 15, 1990 Appendix, Page 3 When the slope of the natural ground receiving fill exceeds 20% (5 horizontal units to 1 vertical unit), the original ground shall be stepped or benched. Benches shall be cut to a firm conpetent formational soils. The lower bench shall be at least 10 feet wide or 1-1/2 times the the equipment width whichever is greater and shall be sloped back into the hillside at a gradient of not less than two (2) percent. All other benches should be at least 6 feet wide. The horizontal portion of each bench shall be conpacted prior to receiving fill as specified herein for conpacted natural ground. Ground slopes flatter than 20% shall be benched v»^n considered necessary by the Geotechnical Engineer. Any abandoned buried structures encountered during grading operations must be totally removed. All underground utilities to be abandoned beneath any proposed stmcture should be removed from within 10 feet of the structure and properly capped off. The resulting depressions from the above described procedures should be backfilled with acceptable soil that is conpacted to the requirements of the Geotechnical Engineer. This includes, but is not limited to, septic tanks, fuel tanks, sev«r lines or leach lines, storm drains and water lines. Any buried structures or utilities not to be abandoned should be brought to the attention of the Geotechnical Engineer so that he nay determine if any special recomnendation will be necessary. All water wells v^ich will be abandoned should be backfilled and capped in accordance to the requirements set forth by the Geotechnical Engineer. The top of the cap should be at least 4 feet below finish grade or 3 feet below the bottom of footing v^iichever is greater. The type of cap will depend on the diameter of the well and should be determined by the Geotechnical Engineer and/or a qualified Structural Engineer. (R-9/89) SCS&T 9021049 May 15, 1990 Appendix, Page 4 FILL MATERIAL Materials to be placed in the fill shall be approved by the Geotechnical Engineer and shall be free of vegetable matter and other deleterious substances. Granular soil shall contain sufficient fine material to fill the voids. The definition and disposition of oversized rocks and expansive or detrinental soils are covei-ed in the geotechnical report or Special Provisions. Expansive soils, soils of poor gradation, or soils with low strength characteristics may be thoroughly mixed with other soils to provide satisfactory fill material, bat only with the explicit consent of the Geotechnical Engineer. Any .mport material shall be approved by the Geotechnical Engineer before being brought to the site. PLACING AND GOMPACTION OF FHI* i^roved fill matierial shall be placed in areas prepared to receive fill in layers not to exceed 6 inches in conpacted thickness. Each layer shall have a uniform moisture content in the range that will allow the conpaction effort to be efficiently applied to achieve the specified degree of conpaction. Each layer shali be uniformly compacted to the specified minimum degree of compaction with equipment of adequate size to economically conpact the layer. Conpaction equipment should either be specifically designed for soil conpaction or of proven reliability. The minimum degree of conpaction to be achieved is specified in either the Special Provisions or the recomnendations contained in the preliminary geotechnical investigation repoi-t. When the structural fill maters al includes roclcs, no rocks will be alloved to nest and all voids must be carefully filled with soil such that the minimum degree of compaction recommended in the Special Provisions is achieved. The naximum size aiid spacing of rock permitted in structural fills and in non-structural fiMs is discussed in the geotechnical report, when applicable. (R-9/89) SCS&T 9021049 May 15, 1990 Appendix, Page 5 Field observation and compaction tests to estimate the degree of conpaction of the fill will be taken by the Geotechnical Engineer or his representative. The location and frequency of the tests shall be at the Geotechnical Engineer's discretion. When the conpaction test indicates that a particular layer is at less than the required degree of conpaction, the layer shall be reworked to the satisfaction of the Geotechnical Engineer and until the desired relative conpaction has been obtained. Fill slopes shall be conpacted by means of sheepsfoot rollers or other suitable equipment. Conpaction by sheepsfoot rollers shall be at vertical intervals of not greater than four feet. In addition, fill slopes at a ratio of two horizontal to one vertical or flatter, should be trackrolled. Steeper fill slopes shall be over-built and cut-back to finish contours after the slope has been constructed. Slope conpaction operations shall result in all fill material six or more inches inward from the finished face of the slope having a relative conpaction of at least 90% of maximmi dry- density or the degree of conpaction specified in the Special Provisions section of this specification. The conpaction operation on the slopes shall be continued until the Geotechnical Engineer is of the opinion that the slopes will be stable surficially stable. Density tests in the slopes will be made by the Geotechnical Engineer during construction of the slopes to determine if the required conpaction is being achieved. Where failing tests occur or other field problems arise, the Contractor will be notified that day of such conditions by written connRjnication from the Geotechnical Engineer or his representative in the form of a daily field report. If the nethod of achieving the required slope conpaction selected by the Contractor fails to produce the necessary results, the Contractor shall rework or rebuild such slopes until the required degree of conpaction is obtained, at no cost to the Owner or Geotechnical Engineer. (R-9/89) SCS&T 9021049 May 15, 1990 Appendix, Page 6 COT SLOPES The Engineering Geologist shall inspect cut slopes excavated in rock or lithified formational material during the grading operations at intervals determined at his discretion. If any conditions not anticipated in the preliminary report such as perched water, seepage, lenticular or confined strata of a potentially adverse nature, unfavorably inclined bedding, joints or fault planes are encountered during grading, these conditions shall be analyzed by the Engineering Geologist and Soil Engineer to determine if mitigating measures are necessary. Unless otherwise specified in the geotechnical report, no cut slopes shall be ejKavated higher or steeper than that allowed by the ordinances of the controlling govemnental agency. BHGINCERING OBSEKVATICN Field observation by the Geotechnical Engineer or his representative shall be made during the filling and conpacting operations so that he can e^qjress his opinion regarding the conformance of the grading with acceptable standards of practice. Neither the presence of the Geotechnical Engineer or his representiative or the observation and testing shall not release the Grading Contractor from his duty to compact all fill material to the specified degree of conpaction. SEASON LDCnS Fill shall not be placed during unfavorable wsather conditions. When vrork is interrupted by heavy rain, filling operations shall not be resumed until the proper moisture content and density of the fill materials can be achieved. Danaged site conditions resulting from vreather or acts of God shall be r^jaired before acceptance of work. (R-9/89) 9 r f I I I I I I I I I I I I SCS&T 9021049 May 15, 1990 i^pendix, Page 7 RECXWMENDED GRADING SPECIFICATIONS - SPECIAL PROVISIOB .RELKEIVE 0CMPJOn:GN: The minimum degree of conpaction to be obtained in conpacted natural ground, conpacted fill, and conpacted backfill shall be at least 90 percent. For street and parking lot subgrade, the upper six inches should be conpacted to at least 95% relative conpaction. EXPAIGIVE SOUS: Detrinentally expansive soil is defined as clayey soil v*u.ch has an expansion index of 50 or greater when tested in accordance with the Uniform Building Code Standard 29-C. OVERSIZED MKEERIAL: Oversized fill material is generally defined herein as rocks or lunps of soil over 6 inches in diameter. Oversize materials should not be placed in fill unless recomnendations of placement of such material is provided by the geotechnical engineer. At least 40 percent of the fill soils shall pass through a No. 4 U.S. Standard Sieve. nuacmON LOTS: where transitions between cut and fill occ\ar within the proposed building pad, the cut portion should be undercut a mininum of one foot below the base of the proposed footings and reccnpacted as structural backfill. In certain cases that would be addressed in the geotechnical report, special footing reinforcenent or a combination of special footing reinforcement and undercutting may be required. (R-9/89)