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Home My WebLink AboutCDP 2016-0006; MFD-01; GEOTECHNICAL PLAN REVIEW UPDATE; 2016-10-24-• .. .. SMS' GEOTECHNICAL SOLUTIONS, INC. Consulting Geotechnical Engineers & Geologists 5931 Sea Lion Place, Suite 109 Carlsbad, California 92010 Office: 760-602-7815 smsgeosol.inc@gmail.com .. Project No. GI-15-12-50 ii -.. -.. 111111 --- 111111 .. ... October 24, 2016 Ohms Collaborative Mr. Hector Aramburo 536 Sears Avenue San Diego, California 92114 RECEIVED DEC 1 9 2016 CITY OF Cr\RLSBAD PLANNING DIV13!0N GEOTECHNICAL PLAN REVIEW UPDATE, PROPOSED ARELLANO 4-UNIT APARTMENTS, 2637 JEFFERSON STREET, CARLSBAD, CALIFORNIA The most current plans for the proposed 4-unit apartment redevelopment at the above-referenced property, prepared by Ohms Collaborative ( dated May 31, 2016), were provided to us for review and comment. A copy of the project Plot Plan/Site Plan is reproduced and attached herein as a Geotechnical Map, Figure 1. As shown, project redevelopment now proposes complete demolition/removal of the existing swimming pool, and backfilling the pool areas to achieve finish pad grades, allowing for construction of the planned new structures and improvements . • Project property was the subject of a geotechnical study completed by this office in connection with the planned redevelopment, which resulted in the following written technical report: .. .. .. • Geotechnical Investigation Proposed 3-Story, 4-Unit Residence 2637 Jefferson Street Carlsbad, California Project No. GI-15-12-20, dated January 11, 2016 The referenced report was review in connection with this effort. A copy of the report is attached with this transmittal as an Appendix. The purpose of this plan review update report was to verify compatibility of the revised development plans, as shown on the attached Figure 1, with the site indicated geotechnical conditions. Modified and/or amended conclusions and recommendations consistent with the attached plan (Figure 1) are also provided in the following sections, and will supplement or superseded those given in the referenced report (Appendix), where applicable. -• - 11111 -• -• -------.. - 11111 ---... -- I I .. Ohms Collaborative Mr. Hector Aramburo October 24, 2016 Page2 Our effort in connection with the preparation of this plan review update report also included a site visit by the undersigned on October 20, 2016. Added subsurface explorations, soil sampling and laboratory testing were not necessary and prior work was considered adequate for the purpose of this effort. Pertinent geotechnical data generated during our original study are summarized in the enclosed Appendix. I. SITE CONDITIONS -PROPOSED REDEVELOPMENT Based on our recent site visit, the property remains unchanged from those conditions described in the referenced report (see Appendix). The proposed new redevelopment scheme is delineated on the enclosed Figure 1. As shown, the general redevelopment scheme remains substantially the same, as used as a basis for our original site geotechnical study. However, the existing swimming pool in the southwest comer of the property is now planned for complete demolition/removal, and backfilling to finish pad grades. Backfilling the pool to finish pad grades will allow the construction of the planned new structures and improvements in that area. Import fill soils are expected to complete the pool backfill work. However, grade elevation changes are not planned in connection with the pool backfilling, and final pad grades will remain very near the existing grades. Associated improvements will include Permeable Interlocking Concrete Pavers (PICP). II. CONCLUSIONS AND RECOMMENDATIONS Project redevelopment scheme, as proposed on the enclosed Figure 1, substantially proposes a similar concept, as originally considered and used as a basis of our prior study, referenced herein. Basedonourreviewofthepriorgeotechnicalstudy(Appendix),andourunderstandingoftheproject revised plans (Figure 1 ), redevelopment of the property for the planned 4-unit apartments, remains feasible and is acceptable from a geotechnical viewpoint Geotechnical conditions presented in our original Geotechnical Investigation report, dated January 11, 2016 (Appendix) stay unchanged, and all conclusions and recommendations provided therein remain valid. The following added and/or amended recommendations are also consistent with the project most current plans and should be considered is the final designs and implemented during the construction phase, where applicable and as appropriate. A. Pool Demolition and Ground Preparation Pool removal should consist of demolition of the existing pool concrete shell and all associated existing perimeter decking, underground piping and structures, with the generated demolitions debris properly removed and properly disposed of from the site. Demolition and construction debris should not be allowed to occur or contaminate new site fills and backfills . .. -.. - 1111 .. ... - ... ---.. -.. -.. ---.. -• • • I .. • 1111 - Ohms Collaborative Mr. Hector Aramburo October 24, 2016 Page3 Bottom of pool ground exposures should be inspected upon the completion of demolition work and approved by the project geotechnical consultant or his designated field representative prior to backfilling operations. Backfilling should only be allowed on firm competent ground exposures (minimum 90% in-place compaction levels). For this purpose some over-excavation of the bottom of pool exposures may be necessary and should be anticipated. Preparation of bottom of pool excavations receiving new fills/backfills shall construct neat, level surfaces free of roots, vegetation, stumps, and unsuitable matter which are adequately benched and keyed-in into the surrounding firm ground, as directed and approved in the field . The existing upper pad grade soils surrounding the pool should be stripped (removed to the depths specified in the referenced report (2½ below the existing grades, or 12 inches below rough finish sub grade, whichever is more), unless otherwise approved or directed in the field. New fills and backfills can only be placed on level surfaces. All grounds steeper than 5: 1 receiving fills/backfills should be properly benched and keyed as directed in the field . B. Pool Areas Backfillin& and Import Soils Import soils will be required to complete pool backfilling and achieve final design pad grades in that area. Import soils should be good quality sandy granular (D.G.), non-corrosive deposits (SM/SW) with very low expansion potential (100% passing I-inch sieve, more than 50% passing #4 sieve and less than 18% passing #200 sieve with expansion index less than 20). Import soils should be inspected, tested as necessary, and approved by the project geotechnical engineer prior to delivery to the site. Import soils should also meet or exceed engineering characteristic and soil design parameters as specified in the referenced report (see Appendix) . New fills and backfills should be adequately processed, thoroughly mixed, moisture conditioned to slightly (2%) above the optimum moisture levels, or as directed in the field, placed in thin (8 inches maximum) uniform horizontal lifts and mechanically compacted with heavy construction equipments to a minimum of 90% of the corresponding laboratory maximum dry density per ASTM D-1557, unless otherwise specified. C. Permeable Interlockin& Concrete Pavers <PICP) We understand Permeable Interlocking Concrete Pavers (PICP) are considered as a part of the project stormwater quality treatment BMP. Project stormwater BMP permeable interlocking pavers should consist of a self-contained system disallowing saturation of adjacent foundation bearing soils, wall backfills and site improvement subgrade. In general, PICP pavements should maintain a minimum clear distance of 5 feet from the building .. • .. ---.. -.. - --------.. -.. ... --- I I Ohms Collaborative Mr. Hector Aramburo October 24, 2016 Page4 foundations with finish subgrade sloped away at a minimum 2% onto a 12 inches wide collector trench along the low edge provided with a 4-inch diameter (Sch. 40 or SDR 35) underdrain pipe surrounded with ¾-inch crushed rocks, as conceptually shown in the enclosed Typical Permeable Paver Detail, Figure 2. In case of nearby wall backfills, a minimum 10 feet clear setback should be considered. The perforated underdrain pipe should discharge collected water into an appropriate storm drainage facility Perimeter cut off walls and curb restraints should be provided, and bottom and sides of the system lined with an impervious liner, as shown. PICP pavements closer than 5 feet to building foundation ( or 10 feet from adjacent retaining walls or top of slope) may also require additional mitigation measures such as construction of a minimum 8 inches wide, 3-sack concrete cutoff wall extending a minimum of 24 inches below bottom of the foundation, as directed in the field. PICP pavement structural section should consist of 31/s-inch, PICP over a minimum of 2 inches of ASTM No. 8 bedding course/choke stone over a minimum 8 inches of ASTM No. 57 stone base course over a minimum of 12 inches of95% compacted subgrade (per ASTM D-1557). Bedding course/choke stone and base course stone should also be well compacted, consolidated and interlocked ( avoid crushing the underdrain pipes) with heavy construction equipments. ASTM No. 8, No. 9 or No. 89 should be used for joint materials depending on the joint size and per manufacturer recommendations . Gradation requirements for ASTM No. 57, No. 8, No. 89 and No. 9 are as follows: l½" 100 l" 95 to 100 ½" 25 to 60 100 100 3/e" 85 to 100 90 to 100 100 No.4 0 to 10 10 to 30 20 to 55 85 to 100 No. 8 0 to 5 0 to 10 5 to 30 10 to 40 No. 16 0 to 5 0 to 10 0 to 10 No. 50 0 to 5 0 to 5 -• -.. -------.. -------• .. L • • I ; Ohms Collaborative Mr. Hector Aramburo October 24, 2016 Page5 D. Trash Enclosure Slab Trash enclosure slab should be a minimum of 6 inches thick reinforced with minimum #4 bars at 16 inches on center maximum. The enclosure slab should also be provided with a minimum 12 inches wide by 12 inches thick thickened edge reinforced with minimum at least 1-#4 bar top and bottom . All remaining geotechnical site development recommendations including grading and earthworks, footings and slab-on-grade foundations and soil design parameters will remain the same as specified (see Appendix). Should any questions arise concerning this report, please do not hesitate to contact this office. Reference to our Project No. GI-5-12-20 will help to expedite our response to your inquiries. We appreciate this opportunity to be of service to you again. SMS Geotechnical Solutions, Inc . Attachments: Geotechnical Map, Figure 1 Typical Permeable Paver Detail, Figure 2 Appendix Distribution: Addressee (3, e-mail) SMS GEOTECHNICAL SOLUTIONS, INC. . . . ·. ~(@:fl:@:r~11 !D'l'©t plan notes: 1) see specifications for general construction requirements. 2) NC units cannot be placed in the front or side yard setbacks, or in the five-foot rear yard (accessoJY building) setback, unless they are under two feet in height compared to tl1e average grade. All machinel}' must conform to tl1e City of Coronado Noise Ordinance. See 2/A1 for NC locations. 3}'AII surface water is to drain away from buildings at a MIN of 5% slopewithin the first 10feet (2% for irilpefVious surfaces). See above arrows for drainage pattern. Contractor to approve all drainage schemes prior to completion of the project. 4) Landscape irrigation to be installed in all landscaped areas including adjoining public property. Landscape· irrigation will have weather or soil based controllers as required by CGC 4.304.1 5) Underground all existing, proposed, and future utilities to the site: see attached plans and specifications. 6) New buildings shall have approved address numbers, building numbers or approved building identification placed in a position that is plainly legible and visible from the street or road fronting the property. These numbers shall contrast in color to background. Numbers shall be min. 4" high with min. stroke width of 1/2" per CFC 505.1. . L""·@i""'l'l'..;1 . "\;.o$:l\':i' \EA Concrete f: -: -: < < { Landscaping · ·, ... , ....... _ .. ,, ··1 _:\/.'·;-:::;°:(_ Tile ~ Pavers fbermeable) GEOTECHNICAL LEGEND ~ ci..l :I· ,:'-c1· ___ , Qt Qs af Approximate Exploratory Boring Location Approximate Cmdact Approximate Location of Existing Pool (fo Be Demolished & Backfilled) Terrace Deposits Topsoil Artificial Fill Project No, GI-15-12-50 15' -0" RYSB It_ 150.0' b r,::===~:::ls===t=====~~l-----------------~~J~(/)~-----------~ ~ u ~ ci 3' -O" 5' -1 3/4" Patio 15'--111/4" F.O.S Trash enclosure ,--- 1 -----------~~--~· --.-"' I ~f'i: 1. ~Com lex% w~ I r-----',...1 --v I 11 I I \-----i.11 I \ I! I I 1 \ 1 111~...___ I I \ / I I \ I I ___ ,.., I I 9x1s 11 I i l parking I· i j I araa .! 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PERM£A8L£ PA \IERS (TRAFFIC RA TED) UPPER 12" AT 95% COMPACTION. (ASTM 01557) Schematic And Conceptual Only No-Scale ....... -·····----.. --··· . ' BM GEOTECHNICAL SOLUTIONS, INC. 5931 Sea Lion Place, Suite 109 Carlsbad, California 92010 (760) 602-7815 smsgeosol.inc(a'gmail.com JECT NO: Gl-15-12-50 TE: J-1/8" THICK CONCRETE PAVfRS, TRAmc LOADING 6" CONCRETE EDGE RESTRAIN -2" BEDDING COURSE (NO. B AGCREGA TE OR PER MANUFACTURER SPECS) 8" THICK OPEN GRADED BASE, ~TH MIN. 5" P€R HOUR INAL TRA TION RA TE {No. 57 STONE -J/4" MAX.) 4" PERFORATED UNDERDRAIN SCH. 40 PVC. CONNECT TO PERFORA TEO PIPES UNDER THE BIORETENTION AREAS. I FIGURE NO: 10-22-2016 2 • -.. ---• -• --.. -.. • • • -• -• .. -.. APPENDIX ---------• .. • ---------• -• -• -• --• • -• -• -- Geotechnical Investigation Proposed 3-Story 4-Unit Residence 2637 Jefferson Street Carlsbad, California January 11, 2016 Prepared For: Ohms Collaborative Mr. Hector Aramburo 536 Sears Avenue San Diego, California 92114 Prepared By: SMS Geotechnical Solutions, Inc. 1645 S. Rancho Santa Fe Road, Suite 208 San Marcos, California 92078 Project No. GI-15-12-50 -.. -• -.. ,. .. -.. -.. - 1111 .... .. • I I I I " • Project No. GI-15-12-50 January 11, 2016 Ohms Collaborative Mr. Hector Aramburo 536 Sears A venue San Diego, California 92114 SMS GEOTECHNICAL SOLUTIONS, INC. Consulting Geotechnical Engineers & Geologists 1645 S. Rancho Santa Fe Road, Suite 208 San Marcos, California 92078 Office: 760-761-0799 smsgeosol. inc@gmail.com GEOTECHNICAL INVESTIGATION, PROPOSED 3-STORY 4-UNIT RESIDENCE 2637 JEFFERSON STREET, CARLSBAD, CALIFORNIA Pursuant to your request, SMS Geotechnical Solutions Inc. has completed the attached Geotechnical Investigation Report for the proposed 3-story 4-unit residential redevelopment at the above- referenced property . The following report summarizes the results of our subsurface exploratory test excavations, field in- situ testing and sampling, laboratory testing, engineering analysis and provides conclusions and recommendations for the proposed redevelopment, as understood. From a geotechnical engineering standpoint, it is our opinion that the planned 3-story 4-unit residential redevelopment at the project property is feasible, provided the recommendations presented in this report are incorporated into the design and construction of the project. The conclusions and recommendations provided in this study are consistent with the site indicated geotechnical conditions and are intended to aid in preparation of final redevelopment plans and allow more accurate estimates of construction costs. We appreciate this opportunity to be of service to you. If you have any questions or need clarification, please do not hesitate to contact this office. Reference to our Project No. GI-15-12-50 will help to expedite our response to your inquiries. SMS Geotechnical Solutions, Inc. ----------------- --- ----- 411111 .. 411111 Ill 1111111 • -• TABLE OF CONTENTS I. INTRODUCTION ...................................................... 1 II. SITE DESCRIPTION ................................................... 1 III. PROPOSED DEVELOPMENT ........................................... 2 IV. SITE INVESTIGATION ................................................. 2 V. GEOTECHNICAL CONDITIONS A. Earth Materials ............ . B. c. D. Groundwater and Surface Drainage Faults/Seismicity ..•••••••.•. Seismic Ground Motion Values D. Geologic Hazards and Slope Stability F. Laboratory Tests and Test Results ... • • 3 • • 3 . .......... 3 . ... 3 . ......... 5 ........ 6 . .......... 6 VI. SITE CORROSION ASSESSMENT ....................................... 9 VII. CONCLUSIONS ...................................................... 10 VIII. RECOMMENDATIONS .... A. Grading and Earthworks B. Footing and Slab-on-Grade Foundations C. Soil Design Parameters .......••..... D. Exterior Concrete Slabs and Flatwork E. Asphalt and PCC Pavement Design ... 12 12 16 17 18 19 F. General Recommendations .....•......•.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 IX. GEOTECHNICAL ENGINEER OF RECORD (GER) •.••••..•...•........•• 23 X. LIMITATIONS ....................................................... 23 REFERENCES Regional Index Map ....• Approximate Site Plan Boring Logs ....... . Fault -Epicenter Map ..... . Typical Isolation Joints and Re-Entrant Comer Reinforcement Typical Retaining Wall Back Drainage Detail ..••...••...•.• APPENDIX FIGURES .... 1 .... 2 3&4 . ... 5 .... 6 . ................ 7 ----------------------------• -.. -• I. GEOTECHNICAL INVESTIGATION PROPOSED 3-STORY 4-UNIT RESIDENCE 2637 JEFFERSON STREET CARLSBAD, CALIFORNIA INTRODUCTION The project property investigated herein consists of an older existing development currently supporting a single-story residence with associated structures and improvements. The property is in a residential neighborhood off Jefferson Street within the City of Carlsbad. The project site is located west of Interstate 5 and north of Carlsbad Village Drive. The approximate property location is shown on a Regional Index Map attached to this report as Figure 1. Approximate site coordinates are 33.1664°N latitude and -117.3487°W longitude. We understand the existing building will be completely demolished and removed to allow for construction of a new 3-story, 4-unit residence. The existing in-ground swimming pool will remain and is not a part of this investigation. Consequently, the purpose of this investigation was to determine soil and geotechnical conditions at the project property and to ascertain their influence upon the planned redevelopment. Subsurface explorations utilizing test borings, in-situ testing and soil sampling, laboratory testing, and engineering analysis were among the activities conducted in conjunction with this effort which has resulted in the remedial grading and foundation recommendations presented herein. The scope of this work is limited to those areas planned for a new building construction as specifically delineated in this report. Other areas of the property including the existing swimming pool and perimeter retaining walls, structures, and improvements were not investigated and are beyond the scope of this work. II. SITE DESCRIPTION An Approximate Site Plan roughly depicting the existing site conditions, and proposed new 3-story 4-unit residence was reproduced from the available base architectural site plan, and is included with this report as Figure 2 (the existing building to be demolished is not shown). The property is characterized by an existing, nearly level building pad near the Jefferson Street grade along the eastern site margin. Developed residential properties neighbor the site to the north and south, with the southerly property roughly at similar grades. The northern adjacent property is elevated above the subject site up to approximately 6 feet maximum. Ground elevation transition along the northern property line is provided with a variable-height CMU retaining wall. An approximate 5 foot high CMU retaining wall marks the western property line and provides ground elevation transition from the project pad grade to the lower neighboring developed property. ------------------------ ----• --• • • Ill • • Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page2 The project existing level building pad was likely developed by minor to modest grading efforts. Large graded or natural slopes are not present on or in immediate vicinity to the site. Engineering and grading records pertinent to the original pad development and existing building construction are not available for review. The project property is landscaped and maintained with site drainage generally considered developed. Surface drainage mostly drains away from the existing building in westerly and easterly directions. Excessively moist to wet ground conditions were not noted at the time of our field investigations. III. PROPOSED DEVELOPMENT The existing building will be demolished and removed to allow for construction of a new 3-story, 4-unit residential building on the northern half of the property. Associated structures and improvements will include exterior stairwells to the upper level units, new underground utilities, paving, and access driveway improvements on the southern half of the property. The existing swimming pool on the southwest comer of the property will remain, and will not be a part of the project redevelopment or this report. Significant ground modifications or the creation oflarge new graded embankments is not anticipated in connection with the planned site redevelopment. However, minor cuts and fills on the order of 2 feet maximum may be expected for reestablishing a level building pad and achieving final design grades. Construction setbacks on the order of 7 feet will be maintained from the northern and southern property lines, while 20 and 15 feet setbacks will be observed from the eastern and western property boundaries, respectively. Detailed foundation and construction plans are not yet available. However, conventional wood- frame with exterior stucco building type construction supported on shallow stiff concrete footings and slab-on-grade floor foundations are anticipated. IV. SITE INVESTIGATION Subsurface conditions at the project site were chiefly determined by the excavation of two exploratory test borings drilled with a limited access tri-pod mounted rotary drill rig. Boring locations were constrained and limited by the existing building, structures, underground utilities, and improvements. At lease one test boring (B-1) was extended a minimum of 10 feet into the underlying formational rocks, or 10 feet below the anticipated final building pad grades, whichever was more. Borings were logged by our project engineer, who also supervised in-situ testing and the collection of representative soil samples at selected intervals for subsequent laboratory testing . Approximate boring locations are shown on the enclosed Figure 2. Logs of the exploratory borings are included as Figures 3 and 4. Laboratory test results and engineering properties of selected representative soil samples are summarized in following sections . ... • .. .. • • -.. -• ----• • • • -• .. • -• -• -----• .. llli -• Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page3 V. GEOTECHNICAL CONDITIONS The project site is underlain at shallow depths by natural Terrace Deposits that are widely exposed along coastal areas of Carlsbad. Instability which could preclude the planned new building construction was not in evidence. The following earth materials were recognized: A. Earth Materials Terrace Deposits (Qt): Pleistocene age Terrace Deposits, typical of local coastal areas, underlay the property at shallow depths. As exposed in our exploratory borings, the Terrace Deposits typically consist of yellow to orange brown-colored fine to medium grained silty sandstone deposits that were found in dense to very dense and tight to cemented conditions overall. Project underlying Terrace Deposits are considered dense and competent deposits that will adequately support new fills, structures, and improvements. Fill/Topsoil (at): A relatively thin section of undifferentiated fill/topsoil deposits mantles site Terrace Deposits. Based on our subsurface explorations, site fill/topsoil deposits are typically on the order of2½ feet thick maximum at the exposed locations, and chiefly consist of dark tan to grey brown silty fine sand that occur in moist to very moist and loose conditions overall. The upper undifferentiated fill/topsoil mantle is expected to thicken in a westerly direction and may be estimated to occur as backfill soil approaching 5-feet thick behind the western property line retaining wall. Site existing surficial undifferentiated fill/topsoil deposits are not suitable for structural support in their present condition and should be regraded, where appropriate, under the new building and improvements as outlined in following sections . B. Groundwater and Surface Drainaee Subsurface water was not encountered in our test borings to the depth explored and is not expected to impact the new construction at the property. However, the proper control of surface drainage is an important factor in the continued stability and future performance of planned new building and graded surfaces. Ponding of surface run-off near foundations should not be allowed and over-watering of site vegetation should be avoided. Pad perimeter surfaces should be fine/ contour graded to direct run-off away from the building foundations and site improvements. Surface run-off should be properly captured and discharged into an approved storm drainage outlet. I I I I I I I I I Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California C. Faults/Seismicity January 11, 2016 Page 4 Faults or significant shear zones are not indicated on or near proximity to the project site. As with most areas of California, the San Diego region lies within a seismically active zone; however, coastal areas of the county are characterized by low levels of seismic activity relative to inland areas to the east. During a 40-year period (1934-1974), 37 earthquakes were recorded in San Diego coastal areas by the California Institute of Technology. None of the recorded events exceeded a Richter magnitude of 3. 7, nor did any of the earthquakes generate more than modest ground shaking or significant damages. Most of the recorded events occurred along various offshore faults which characteristically generate modest earthquakes. Historically, the most significant earthquake events which affect local areas originate along well known, distant fault zones to the east and the Coronado Bank Fault to the west. Based upon available seismic data, compiled from California Earthquake Catalogs, the most significant historical event in the area of the study site occurred in 1800 at an estimated distance of 11.8 miles from the project area. This event, which is thought to have occurred along an offshore fault, reached an estimated magnitude of 6.5 with estimated bedrock acceleration values of 0.115 at the project site. The following list represents the most significant faults which commonly impact the region. Estimated ground acceleration data compiled from Digitized California Faults (Computer Program EQFAULT VERSION 3.00 updated) typically associated with the fault is also tabulated. TABLE 1 MAXIMUM FAULT ZONE DISTANCE FROM SITE PROBABLE ACCELERAffON lR.H.) Newport-Inglewood Fault 4.7 miles 0.252g Rose Canyon Fault 5.0 miles 0.246g Coronado Bank Fault 21.1 miles 0.184g Elsinore-Julian Fault 24.2 miles 0.142g The location of significant faults and earthquake events relative to the study site are depicted on a Fault -Epicenter Map attached to this report as Figure 5. More recently, the number of seismic events which affect the region appears to have heightened somewhat. Nearly 40 earthquakes of magnitude 3 .5 or higher have been recorded in coastal regions between January 1984 and August 1986. Most of the earthquakes are thought to have been generated along offshore faults. For the most part, the recorded events I I I I I I I I I I Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Pages remain moderate shocks which typically resulted in low levels of ground shaking to local areas. A notable exception to this pattern was recorded on July 13, 1986. An earthquake of magnitude 5.3 shook County coastal areas with moderate to locally heavy ground shaking resulting in $700,000 in damages, one death, and injuries to 30 people. The quake occurred along an offshore fault located nearly 30 miles southwest of Oceanside. A series of notable events shook County areas with a (maximum) magnitude 7.4 shock in the early morning of June 28, 1992. These quakes originated along related segments of the San Andreas Fault approximately 90 miles to the north. Locally high levels of ground shaking over an extended period of time resulted; however, significant damages to local structures were not reported. The increase in earthquake frequency in the region remains a subject of speculation among geologists; however, based upon empirical information and the recorded seismic history of County areas, the 1986 and 1992 events are thought to represent the highest levels of ground shaking which can be expected at the study site as a result of seismic activity. In recent years, the Rose Canyon Fault has received added attention from geologists. The fault is a significant structural feature in metropolitan San Diego which includes a series of parallel breaks trending southward from La Jolla Cove through San Diego Bay toward the Mexican border. Test trenching along the fault in Rose Canyon indicated that at that location the fault was last active 6,000 to 9,000 years ago. More recent work suggests that segments of the fault are younger having been last active 1000 -2000 years ago. Consequently, the fault has been classified as active and included within an Alquist-Priolo Special Studies Zone established by the State of California. Fault zones tabulated in the preceding table are considered most likely to impact the region of the study site during the lifetime of the project. The faults are periodically active and capable of generating moderate to locally high levels of ground shaking at the site. Ground separation as a result of seismic activity is not expected at the property. D. Seismic Ground Motion Values Seismic ground motion values were determined as part of this investigation in accordance with Chapter 16, Section 1613 ofthe2013 California Building Code (CBC) and ASCE 7-10 Standard using the web-based United States Geological Survey (USGS) ground motion calculator. Generated results including the Mapped (Ss, S1), Risk-Targeted Maximum Considered Earthquake (MCER) adjusted for Site Class effects (SMs, SM1) and Design (S0s, SDI) Spectral Acceleration Parameters as well as Site Coefficients (Fa, Fv) for short periods (0.20 second) and 1-second period, Site Class (based on average field SPT penetration resistance), Design and Risk-Targeted Maximum Considered Earthquake (MCER) Response Spectrums, Mapped Maximum Considered Geometric Mean (MCEo) Peak Ground I I I I I I I I I I I I Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page 6 Acceleration adjusted for Site Class effects (PG.AM) and Seismic Design Category based on Risk Category and the severity of the design earthquake ground motion at the site are summarized in the enclosed Appendix. E. Geolo&ic Hazards and Slope Stability Geologic hazards are not presently indicated at the project site. Significant slopes are not present at or in close proximity to the project property, nor are any are planned in conjunction with the proposed redevelopment. The most significant geologic hazards at the property will be those associated with ground shaking in the event of a major seismic event. Liquefaction or related ground rupture failures are not anticipated. F. Field and Laboratory Tests and Test Results Earth deposits encountered in our exploratory test excavation were closely examined and sampled for laboratory testing. Based upon our test borings and field exposures site soils have been grouped into the following soil type: TABLE2 Soil Tvue Descriodon 1 Dark tan to grey-brown silty fine sand (FilVfopsoil) 2 Yellow to orange-brown silty sandstone (Terrace Deoosits) The following tests were conducted in support of this investigation: 1. Standard Penetration Tests: Standard penetration tests (SPT) were performed at the time of borehole drilling in accordance with ASTM standard procedure D-1586 using rope and cathead. The procedure consisted of a standard 51 MM outside diameter sampler without liner, 457 MM in length and 35 MM in inside diameter driven with a 140-pound hammer, dropped 30 inches using 5-foot long AW drill rods. The bore hole was 150 MM ( 6 inches) in diameter and water was used at highly cemented depths to aid drilling. The test results are indicated at the corresponding locations on the attached Boring Logs. 2. Grain Size Analysis: Grain size analysis was performed on a representative sample of Soil Type 2. The test results are presented in Table 3. I I I I I I I I I I I I I I Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page 7 I I I I I TABLE3 Sieve Size II l" I ¾" I #4 I #10 I #20 I #40 I #200 I Location I Soil Type II Percent Passing I B-1 @ 2' I 2 II 100 I 100 I 100 I 100 I 99 I 85 I 25 I 3. Maximum Dry Density and Optimum Moisture Content: The maximum dry density and optimum moisture content of Soil Type 2 was determined in accordance with ASTM D-1557. The results are presented in Table 4. TABLE4 Location I Soll I MuimamDry I Optimum Moisture I Type Denlitt «-~n Content {•I!!·%} B-1 @} 2' I 2 I 130.3 I 9 I 4. Moisture-Density Tests (Undisturbed Rine Samples): In-place dry density and moisture content of representative soil deposits beneath the site were determined from relatively undisturbed ring using weights and measurements test method. Results are presented in Table 5 and tabulated on the attached Boring Logs at corresponding locations. TABLES Sample Soll Field Moisture FieldDry Mu.Dry In-Place Degree of Location Type Content Deatlty Deallty Relative Saturadon (c.,.•/4) l'rd-Dcft --Conmactlon St%\ t• B-1 @ 2' 2 5 117.l 130.3 90 32 B-1 @ 7' 2 9 115.6 130.3 89 (1) 55 B-2 @ 3' 2 4 -121 Sample Disturbed - (1) Sample at 7 feet somewhat disturbed. Assumptions and relationships: In-place Relative Compaction = (T d + i m) X 100 Gs= 2.65 e =(Gs iw+id)-1 S = (w Gs)+ e 5. Expansion Index Test: One expansion index (EI) test was performed on a representative sample of Soil Type 2 in accordance with the ASTM D-4829. The test results are presented in Table 6. I I I I I I I I I I I I I Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page8 TABLE6 Sample Soll Molded Degree of Final Initial Dry Measnrecl EI Location Type (a) Saturation (a) Deuity EI 50% (%) (o/e) (o/e) (PCF) Saturation B-2 @ 2½' 2 ----Non-plastic Non-expansive ( w) = moisture content in percent. El50 = Elmeas -(50 -Smeas} ((65 + Elmeas} + (220 -Smeas}} Expansion Index (El} Expansion Potential 0 -20 Very Low 21 -50 Low 51 -90 Medium 91 -130 High ) 130 Very Hicli 6. Direct Shear Test: One direct shear test was performed on a representative sample of Soil Type 2. The prepared specimen was soaked overnight, loaded with normal loads of 1, 2, and 4 kips per square foot respectively, and sheared to failure in an undrained condition. The test result is presented in Table 7. TABLE7 Sample Soll Sample Wet Angle of Apparent Deaslty lat. Frie. Cohesion Location Type Condition (rw-nd\ , .. Des!.) (c-nd\ B-1 <@ 2' 2 Remolded to 90% ofYm ~ % wopt 127.7 30 0 7. pH and Resistivity Test: pH and resistivity of a representative sample of Soil Type 2 was determined using "Method for Estimating the Service Life of Steel Culverts," in accordance with the California Test Method (CTM) 643. The test result is tabulated in Table 8. TABLES S le Location Soil Minimum Reliltlvl B B-1 @2' 2 3900 7.5 8. Sulfate Test: A sulfate test was performed on a representative sample of Soil Type 2 in accordance with the California Test Method (CTM) 417. The test result is presented in Table 9. I I I I I I I I I I I I I I I I I I Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page9 I VI. TABLE9 Sample Location Soil Type Amount of Water Soluble Sulfate In Soil lo/e bv WtP!lohtl B-1 ~ 2' 2 0.002 9. Chloride Test: A chloride test was performed on a representative sample of Soil Type 2 in accordance with the California Test Method (CTM) 422. The test result is presented in Table 10. TABLE 10 Sample Location Soll Type Amount of Water Soluble Chloride In Soll c•;. by Weleht) B-1 @2' I 2 I 0.003 I SITE CORROSION ASSESSMENT A site is considered to be corrosive to foundation elements, walls and drainage structures if one or more of the following conditions exist: * Sulfate concentration is greater than or equal to 2000 ppm (0.2% by weight). * Chloride concentration is greater than or equal to 500 ppm (0.05 % by weight). * pH is less than 5.5. For structural elements, the minimum resistivity of soil (or water) indicates the relative quantity of soluble salts present in the soil ( or water). In general, a minimum resistivity value for soil ( or water) less than 1000 ohm-cm indicates the presence of high quantities of soluble salts and a higher propensity for corrosion. Appropriate corrosion mitigation measures for corrosive conditions should be selected depending on the service environment, amount of aggressive ion salts (chloride or sulfate), pH levels and the desired service life of the structure. Results of limited laboratory tests performed on selected representative site samples indicated that the minimum resistivity is greater than 1000 ohm-cm suggesting presence of low quantities of soluble salts. Test results further indicated that pH levels are greater than 5.5, sulfate concentration are less than 2000 ppm and chloride concentration levels are less than 500 ppm. Based on the results of the corrosion analyses, the project site is considered non-corrosive. The project site is not located within a 1000 feet of salt or seawater. -.. --------------.. ---• -.. -------• 11111 • 11111 • Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page 10 Based upon the result of the tested soil sample, the amount of water soluble sulfate (SO4) was found to be 0.002 percent by weight which is considered negligible according to_ ACI 318 (SO Exposure Class with Not Applicable severity). Portland cement Type II and concrete with minimum 28 days compressive strength (f c) of2500 psi and 0.50 water-cement ratio are typically considered adequate for SO Exposure Class, unless otherwise specified or noted. VII. CONCLUSIONS Based upon the foregoing investigation, the proposed 3-story, 4-unit residential redevelopment project, as currently planned at the project property, is feasible from a geotechnical viewpoint. The project property is underlain by competent sandstone Terrace Deposits at shallow depths overlain by a section of loose undifferentiated fill/topsoil cover. The following factors are unique to the property and will most impact project construction procedures and associated costs from a geotechnical viewpoint: 1. Evidence oflandslides, faults, liquefaction, seismically induced settlements or other adverse geologic hazards which could preclude the planned redevelopment and new construction were not indicated at project property. 2. Relatively shallow fill/topsoil, on the order of2 ½ feet maximum, mantle the project property in the planned new building areas, as exposed in our exploratory test borings. The fill/topsoil is expected to thicken in a westerly direction in the planned recreation areas, outside the new building envelop, and may be estimated to occur as backfill soils approaching 5 feet thick behind the western property line retaining wall. Below the upper fill/topsoil mantle, natural Terrace Deposits consisting of dense to very dense and tight to cemented silty sandstone occurs. Underlying natural Terrace Deposits below the upper fill/topsoil mantel are competent deposits which can suitably support the planned new fills, structures and improvement. 3. Site upper fill/topsoil mantles are loose deposits not suitable for structural support and should be stripped (removed) to the underlying dense Terrace Deposits, as approved in the field, and compacted as properly compacted fills in accordance with the recommendations of this report. 4. Stripping and recompaction remedial grading work will be required under all proposed new constructions and improvements in order to construct uniform bearing and subgrade soil conditions throughout, as specified in the following sections. There should be at least 12 inches of well-compacted fills below bottom of the deepest footing(s), and site improvements, unless otherwise approved. Consequently, cut-fill daylight transition is not expected to be a factor in the planned site redevelopment. • ... .. .. .. • • -- -.. -.. • .. -... -.. .. • • • • .. .. Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page 11 5. The existing graded pad at the property is generally characterized by relatively level surfaces, and large natural or graded slopes are not present at or near the immediate vicinity of the project site. Level pad grade elevation transition along the northern and western property boundaries are provided by existing CMU retaining walls, on the order of 5 to 6 feet high maximum. The CMU walls were apparently constructed at the time of the original site and neighboring developments. Records of engineering observation and testing pertaining to the development of existing level pad surfaces, as well as subsequent building constructions, are unavailable . 6. Significant grade modifications or the creation of large graded slopes is not planned in connection with the proposed redevelopment and new building construction. However, minor cut-fill and fine grading on the order of 2 feet maximum may be expected for reestablishing a level building pad and achieving final design grades. Slope stability is not considered a geotechnical factor in the redevelopment of the project property. All earthwork, remedial and fine grading efforts should be completed in accordance with requirements of the following sections. 7. Soil generated from the project stripping, removals and over-excavations will generally consist of silty sand deposits which are considered suitable for reuse as site new fills and backfills, provided they are adequately processed and prepared in accordance with the requirements of this report. Construction debris generated from the demolition of site existing structures, foundations and improvements should be properly removed and disposed of from the site . 8. Based on our field observations and laboratory testing, final bearing and subgrade soils at the project property are expected to chiefly consist of silty sand (SM/SP) deposits with very low expansion potential (expansion index less than 20) based on ASTM D-4829 classification. Expansive soils are not considered to be a major geotechnical factor in the planned new construction . 9. Construction setbacks on the order of 7 feet will be maintained from the northern and southern property lines, while 20 and 15 feet setbacks will be observed from the eastern and western property boundaries, respectively. Consequently, considering the anticipated relatively shallow excavations and stripping depths necessary for the project remedial grading efforts, significant construction impacts on the nearby off-site structures and improvements are not anticipated. In general, added care will be required to avoid any damages to the existing nearby on and off site structures, retaining walls and improvements due to site excavations, remedial earthwork grading and construction works. For this purpose, completing remedial grading along the northern property margins in a limited section(s) may be necessary based on actual field conditions, as discussed in the following sections . -----• -• -.. ----------- -.. ----... -.. • -1111 -• Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page 12 10. Natural groundwater was not encountered in our exploratory test borings, to the depths explored, and is not expected to be a factor in the planned new construction. As with all graded sites, the proper control of surface drainage and storm water is a critical component to overall site and building performance. Runoff water should not pond upon graded surfaces, and irrigation water should not be excessive. Over-watering of site vegetation may also create perched water and the creation of excessively moist areas at finished surfaces and should be avoided. Storm water and drainage control facilities should be designed and installed for proper control and disposal of surface water as shown on the approved grading or drainage improvement plans. 11. Soil collapse and post construction settlements are not expected to be a major geotechnical concern provided our remedial grading and foundation recommendations are followed. Post construction settlements are expected to be less than approximately 1 inch and should occur below the heaviest loaded footing(s). The magnitude of post construction differential settlements of site fill deposits, as expressed in terms of angular distortion, is not anticipated to exceed ½-inch between similar adjacent structural elements. VIII. RECOMMENDATIONS The following recommendations are provided based on the available geotechnical data generated during this effort and scheme of the proposed redevelopment and new building construction, as understood. Added or modified recommendations may also be appropriate and should be provided at the time of final plan review phase: A. Gradin2 and Earthworks Significant grade alterations are not anticipated and site earth work operations are expected to mostly consist oflimited cut-fill (fine) grading with relatively minor to modest remedial efforts in order to achieve final design grades and construct safe and stable building and improvement surfaces. All site excavations, grading, earthwork, construction, and bearing/sub grade soil preparations should be completed in accordance with Chapter 18 (Soils and Foundations) and Appendix "J" ( Grading) of the 2013 California Building Code ( CBC), City of Carlsbad Ordinances, the Standard Specifications for Public Works Construction, and the requirements of the following sections wherever applicable . 1. Existing Underground Utilities and Structures: All existing underground waterlines, sewer lines, pipes, storm drains, utilities, tanks, structures, and improvements at or nearby the project site should be thoroughly potholed, identified and marked prior to the initiation of the actual site excavations, grading and earthworks. Specific geotechnical engineering recommendations may be required based on the actual field locations, invert elevations, backfill conditions, and proposed grades in the event of a grading conflict. .. .. .. ... .. .. - -.. - - .. .. .. • Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page 13 Utility lines may need to be temporarily redirected, if necessary, prior to earthwork operations and reinstalled upon completion of pad constructions. Alternatively, permanent relocations may be appropriate as shown on the approved plans. Abandoned irrigation lines, pipes, and conduits should be properly removed, capped or sealed off to prevent any potential for future water infiltrations into the foundation bearing and subgrade soils. Voids created by the removals of the abandoned underground pipes, tanks and structures should be properly backfilled with compacted fills in accordance with the requirements of this report. 2. Clearing and Grubbing: Remove all existing surface and subsurface structures, improvements, pipes and conduits, old foundations, vegetation, tress, roots and stumps, and all other unsuitable materials and deleterious matter from all areas proposed for new fills, improvements, and structures plus a minimum of 3 horizontal feet outside the perimeter, where possible and as approved in the field . All trash debris and unsuitable materials generated from site demolitions and clearing efforts should be properly removed and disposed of from the site. Trash, vegetation and construction debris should not be allowed to occur or contaminate new site fills and backfills . The prepared grounds should be inspected and approved by the project geotechnical consultant or his designated field representative prior to grading and earthworks. 3. Stripping and Removals: All existing loose upper surficial fill/topsoil deposits in areas of the planned new fills, structures and improvements plus a minimum of 3 horizontal feet outside the perimeter, where possible and as directed in the field, should be stripped (removed) to the underlying dense and competent Terrace deposits and placed back as properly compacted fills. Actual stripping depths should be established and approved by the project geotechnical consultant based on field observations and testing of bottom exposures. However, based on the available exploratory test borings, typical stripping depths are expected to be on the order of 2½ below the existing grades, or 12 inches below the bottom of deepest footing( s ), whichever is more. There should be at least 12 inches of compacted fills below bottom of the deepest footing(s) throughout, unless otherwise approved. There should also be a minimum of 12 inches of compacted fill below rough finish subgrade in the planned improvement areas, as directed in the field Locally deeper removals may also be necessary based on the actual field exposures and final grades and should be anticipated. Bottom of all striping and removal exposures should be additionally ripped, processed and recompacted to a minimum depth of 6 inches, as a part of initial fill lift placement, as directed in the field. The exposed stripping and removal bottoms should be observed and approved by the project geotechnical consultant or his designated field representative prior to fill placement. Ill ... , .. .. .. ... ,. .. .. ... .. ... .. .. .. .. Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page 14 4. Excavation Setbacks and Temporary Slopes: Temporary open excavations and trenching necessary for the project redevelopment are expected to be relatively shallow to be on the order of3 feet deep maximum. Adequate construction setbacks on the order of 7 feet will be maintained from the northern and southern property lines, while 20 and 15 feet setbacks will be observed from the eastern and western property boundaries, respectively. Consequently, significant construction impacts on the nearby off-site structures and improvements are not anticipated. Excavations and removals adjacent to the existing foundations, improvements and structures should be performed under observations of the project geotechnical engineer. Undermining existing adjacent foundations, structures, improvements and underground utilities to remain should not be allowed by the project removals and earthwork operations. Temporary excavations and trenching less than 3 feet maximum may be developed at near vertical gradients, unless otherwise noted or directed in the field. However, performing excavations and remedial grading in limited sections ( one-half or one-third lengths) may become necessary near the exiting CMU retaining wall along the northern property boundary based on the actual field exposures and wall foundation conditions. For this purpose, we recommend some pot-holing in the northern margins of remedial grading areas prior to developing removal excavations along the entire length. We also recommend that the pre-construction conditions of the existing northern CMU retaining and immediate off-site structures and improvements to be well documented, recorded (photographs and video), and instrumented for monitoring if necessary, and as appropriate. More specific recommendations should be given in the field by the project geotechnical consultant based on actual site exposures. Revised temporary excavation and trenching recommendations including laid back slopes, larger setbacks, completing excavations and remedial grading in smaller limited sections and the need for temporary shoring/trench shield support may be necessary and should be anticipated. The project contractor shall also obtain appropriate permits, as needed, and conform to Cal-OSHA and local governing agencies' requirements for trenching/open excavations and safety of the workmen during construction. 5. Fill/Backfill Materials: Site stripping, removals, and excavations will chiefly generate a silty to sandy soil mixture which are considered suitable for reuse as new fills and backfills, provided it is adequately prepared, processed, placed and compacted in accordance with the requirements of this report. Vegetation, roots and stumps, buried pipes and conduits, construction debris, and organic matter, where encountered, should be throughly removed and separated from the fill/backfill mixture to the satisfaction and approval of the project geotechnical consultant. - ---------... -----.. • -• ... tllll .. .. 11111 - -• -- Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page 15 6. Fill/Backfill Placement, Spreading and Compaction: Uniform bearing and subgrade soil conditions should be constructed throughout the building and improvement surfaces by the minor cut-fill (fine) and remedial grading earthwork operations. Site soils should be adequately processed, thoroughly mixed, moisture conditioned to slightly (2%) above the optimum moisture levels, or as directed in the field, placed in thin (8 inches maximum) uniform horizontal lifts and mechanically compacted to a minimum of 90% of the corresponding laboratory maximum dry density per ASTM D-1557, unless otherwise specified. 7. Surface Drainage and Erosion Control: A critical element to the continued stability of graded building pads and improvement sites is an adequate stormwater and surface drainage control. Surface water should not be allowed to flow toward and pond near the building foundations or impact the graded construction and improvement sites. For this purpose some fine grading of the building perimeter may be necessary to establish positive drainage (minimum 5%) away from the site building and improvements onto a suitable drainage collection and disposal facility. Roof gutters and area drains should be installed. Over-watering of the site landscaping should also not be allowed. Only the amount of water to sustain vegetation should be provided. Site drainage improvements should be shown on the project approved plans. 8. Engineering Observations: All bearing and subgrade soil preparation and earthwork operations including stripping and removals, suitability of earth deposits used as compacted fills and backfills, and compaction procedures should be continuously observed and tested by the project geotechnical consultant and presented in the final as- graded compaction report. The nature of finished bearing and sub grade soils should be confirmed in the final compaction report at the completion of grading. Geotechnical engineering observations should include but not limited to the following: * Initial observation -After the site clearing and staking of project limits but before grading/brushing starts . * Bottom of stripping (removal) observation -After dense and competent Terrace Deposits are exposed and prepared to receive fill or backfill, but before fill or backfill is placed. * Fill/backfill observation -After the fill/backfill placement is started but before the vertical height of fill/backfill exceeds 2 feet. A minimum of one test shall be required for each 100 lineal feet maximum, in every 2 feet in vertical gain. Finish rough and final pad grade tests shall be required regardless of fill thickness. ---.. ---.. --------- Ill .. • 11111 Ill 11111 .. • .. • .. -• • -- Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page 16 * Foundation trench and subgrade soils observation -After the foundation trench excavations and prior to the placement of steel reinforcing for proper moisture and specified compaction levels. There should be at least 12 inches of compacted fills below bottom of the deepest footing( s) throughout ( or at least 3 feet of compacted fill below rough finish pad grades, i.e. 2 ½ feet stripping plus 6 inches ofin-place ripping of the bottom, and-recompaction), unless otherwise approved. There should also be a minimum of 12 inches of compacted fill below rough finish subgrade in the planned improvement areas. * Geotechnical foundation/slab steel observation -After the steel placement is completed but before the scheduled concrete pour. * Underground utility/plumbing trench observation -After the trench excavations but before placement of pipe bedding or installation of the underground facilities. Local and Cal-OSHA safety requirements for open excavations apply. Observations and testing of pipe bedding may also be required by the project geotechnical engineer. * Underground utility/plumbing trench backfill observation -After the backfill placement is started above the pipe zone but before the vertical height of backfill exceeds 2 feet. Testing of the backfill within the pipe zone may also be required by the governing agencies. Pipe bedding and backfill materials shall conform to the governing agencies' requirements and project soils report if applicable. All trench backfills should be mechanically compacted to a minimum of 90% compaction levels unless otherwise specified. Plumbing trenches more than 12 inches deep maximum under the floor slabs should also be mechanically compacted and tested for a minimum of 90% compaction levels. Flooding or jetting techniques as a means of compaction method should not be allowed . * Improvement subgrade observation -Prior to the placement of concrete for proper moisture and specified compaction levels. B. Footin2s and Slab-on-Grade Foundations The following recommendations are consistent with the anticipated silty sand (SM/SP) bearing soils with very low expansion potential ( expansion index less than 20), and site indicated geotechnical conditions. All design recommendations should be further confirmed and/or revised as necessary at the final plan review phase, and at completion of remedial grading works based on actual testing of final bearing and subgrade soils: 1. Conventional shallow stiff concrete footings and slab-on-grade floor type foundations may be considered for support of the new building. All foundations should be supported on well-compacted fills, placed in accordance with the requirements of this report. There should be at least 12 inches of compacted fills below bottom of the deepest footing( s) -.... ---------------------------.. ---• -• -- Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page 17 throughout ( or at least 3 feet of compacted fill below rough finish pad grades, i.e. 2 ½ feet stripping plus 6 inches of in-place ripping of the bottom, and-recompaction), unless otherwise approved. 2. Perimeter and interior continuous strip footings should be sized at least 18 inches wide and 24 inches deep for three-story building loading conditions. Spread pad footings, if any, should be at least 30 inches square and 18 inches deep. Exterior continuous footings should enclose the entire perimeter. Perimeter continuous and interior strip foundations should be reinforced by at least 2-#5 reinforcing bars top and bottom, and #3 ties at 30 inches center to center maximum. Reinforcement details for spread pad and isolated post footings should be provided by the project architect/structural engineer. 3. Interior slabs should be a minimum of 5 inches in thickness reinforced with minimum #4 reinforcing bars spaced 18 inches on center maximum each way placed mid-height in the slab. Provide re-entrant comer reinforcement for all interior slabs based on slab geometry and/or interior column locations, as generally depicted on the enclosed Figure 6. Slabs should be underlain by 4 inches of clean sand (SE 30 or greater) which is provided with a well-performing moisture barrier/vapor retardant (minimum 10-mil Stego) placed mid-height in the sand. Alternatively, a 4-inch thick base of compacted ½-inch clean aggregate provided with the vapor barrier (minimum 15-mil Stego) in direct contact with (beneath) the concrete may also be considered provided a concrete mix which can address bleeding, shrinkage and curling are used. Provide "softcut" contraction/control joints consisting of sawcuts spaced 10 feet on centers each way for the all interior slabs. Cut as soon as the slab will support the weight of the saw and operate without disturbing the final finish which is normally within 2 hours after final finish at each control joint location or 150 psi to 800 psi. The sawcuts should be minimum I-inch in depth but should not exceed 1 ¼-inches deep maximum. Anti-ravel skid plates should be used and replaced with each blade to avoid spalling and raveling. A void wheeled equipments across cuts for at least 24 hours. 4. Foundation trenches and slab subgrade soils should be inspected and tested for exposing suitable bearing strata, proper moisture and specified compaction levels and approved by the project geotechnical consultant prior to the placement of concrete. C. Soil DesiKD Parameters The following soil design parameters are based upon tested representative samples of on-site earth deposits. All parameters should be re-evaluated when the characteristics of the final as-graded soils have been specifically determined: - ------------------------------------ Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page 18 1. Design soil unit weight = 127. 7 pcf. 2. Design angle of internal friction of soil= 30 degrees. 3. Design active soil pressure for retaining structures = 42 pcf (EPP), level backfill, cantilever, unrestrained walls. 4. Design at-rest soil pressure for retaining structures = 64 pcf (EPP), non-yielding, restrained walls. 5. Design passive soil resistance for retaining structures= 383 pcf (EPP), level surface at the toe. 6. Design coefficient of friction for concrete on soils= 0.36. 7. Net allowable foundation pressure (minimum 18 inches wide by 24 inches deep footings) = 2100 psf. 8. Allowable lateral bearing pressure (all structures except retaining walls)= 200 psf/ft. Notes: * * * * * Added lateral pressures caused by surcharge loading of by nearby foundations and improvements should also be considered in the wall designs, if applicable and where appropriate. Use a minimum safety factor of 1.5 for wall over-turning and sliding stability. However, because large movements must take place before maximum passive resistance can be developed, a minimum safety factor of 2 may be considered for sliding stability particularly where sensitive structures and improvements are planned near or on top of retaining walls. When combining passive pressure and frictional resistance the passive component should be reduced by one-third. The indicated net allowable foundation pressure provided herein was determined based on a minimum 18 inches wide by 24 inches deep footings and may be increased by 20% for each additional foot of depth and 20% for each additional foot of width to a maximum of 5500 psf. The allowable foundation pressures provided herein also apply to dead plus live loads and may be increased by one-third for wind and seismic loading. The lateral bearing earth pressures may be increased by the amount of designated value for each additional foot of depth to a maximum 1500 pounds per square foot. D. Exterior Concrete Slabs and Flatwork 1. All exterior slabs (walkways, patios) supported on potentially very low expansive subgrade soils should be a minimum of 4 inches in thickness, reinforced with #3 bars at 18 inches on centers in both directions placed mid-height in the slab. The subgrade soils should be compacted to minimum 90% compaction levels at the time of fine grading and before placing the slab reinforcement. ---- ------------------------------• -• Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page 19 Reinforcements lying on subgrade will be ineffective and shortly corrode due to lack of adequate concrete cover. Reinforcing bars should be correctly placed extending through the construction joints tying the slab panels. In construction practices where the reinforcements are discontinued or cut at the construction joints, slab panels should be tied together with minimum 18 inches long #3 dowels at 18 inches on centers placed mid-height in the slab (9 inches on either side of the joint). 2. Provide "tool joint" or "softcut" contraction/control joints spaced 10 feet on center (not to exceed 12 feet maximum) each way. The larger dimension of any panel shall not exceed 125% of the smaller dimension. Tool or cut as soon as slab will support weight, and can be operated without disturbing the final finish which is normally within 2 hours after final finish at each control joint location or 150 psi to 800 psi. Tool or softcuts should be a minimum of 1-inch but should not exceed 1 ¼-inch deep maximum. In case of softcut joints, anti-ravel skid plates should be used and replaced with each blade to avoid spalling and raveling. A void wheeled equipments across cuts for at least 24 hours. Joints shall intersect free-edges at a 90° angle and shall extend straight for a minimum of 1 ½ feet from the edge. The minimum angle between any two intersecting joints shall be 80°. Align joints of adjacent panels. Also, align joints in attached curbs with joints in slab panels. Provide adequate curing using approved methods ( curing compound maximum coverage rate= 200 sq. ft./gal.). 3. All exterior slab designs should be confirmed in the final as-graded compaction report. 4. Subgrade soils should be tested for proper moisture and specified compaction levels and approved by the project geotechnical consultant prior to the placement of concrete. E. Asphalt and PCC Pavement Desi&n Specific pavement designs can best be provided at the completion of rough grading based on R-valuetests of the actual finish subgrade soils; however, the following structural sections may be considered for initial planning phase cost estimating purposes only (not for construction): 1. Asphalt Pavings: A minimum section of 4 inches asphalt on 6 inches Caltrans Class 2 aggregate base, or the minimum section required by the City of Carlsbad, whichever is more, may be considered for the onsite asphalt paving surfaces outside the private and public right-of-way. Actual design will also depend on the design TI and the approval of the City of Carlsbad. The Class 2 aggregate base shall meet or exceed the requirements set forth in the current California Standard Specification (Caltrans Section 26-1.02). Base materials should be compacted to a minimum 95% of the maximum dry density. Sub grade soils beneath the pavement base layer should also be compacted to a minimum 95% of the corresponding maximum dry density within the upper 12 inches . -----------------.. -• -.. • • -• .. .. .. .. -.. -• -- Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page20 2. PCC Pavings: Residential PCC driveways and parking supported on very low expansive ( expansion index less than 20) granular subgrade soils should be a minimum of 5 inches in thickness, reinforced with #3 reinforcing bars at 16 inches on centers each way placed at mid-height in the slab. Subgrade soil beneath the PCC driveways and parking should be compacted to a minimum 90% of the corresponding maximum dry density, unless otherwise specified. Reinforcing bars should be correctly placed extending through the construction ( cold) joints tying the slab panels. In construction practices where the reinforcements are discontinued or cut at the construction joints, slab panels should be tied together with minimum 18 inch long (9 inches on either side of the joint) #3 dowels (dowel baskets) at 16 inches on centers placed mid-height in the slab. Provide ''tool joint" or "softcut" contraction/control joints spaced 10 feet on center (not to exceed 15 feet maximum) each way. The larger dimension of any panel shall not exceed 125% of the smaller dimension. Tool or cut as soon as the slab will support the weight and can be operated without disturbing the final finish which is normally within 2 hours after final finish at each control joint location or 150 psi to 800 psi. Tool or softcuts should be a minimum of I-inch in depth but should not exceed 1 ¼-inches deep maximum. In case of softcut joints, anti-ravel skid plates should be used and replaced with each blade to avoid spalling and raveling. A void wheeled equipments across cuts for at least 24 hours. Joints shall intersect free-edges at a 90° angle and shall extend straight for a minimum of 1 ½ feet from the edge. The minimum angle between any two intersecting joints shall be 80°. Align joints of adjacent panels. Also, align joints in attached curbs with joints in slab panels. Provide adequate curing using approved methods ( curing compound maximum coverage rate= 200 sq. ft./gal.) . 3. General Paving: Base section and subgrade preparations per structural section design, will be required for all surfaces subject to traffic including roadways, travelways, drive lanes, driveway approaches and ribbon (cross) gutters. Driveway approaches within the public right-of-way should have 12 inches subgrade compacted to a minimum of 95% compaction levels and provided with a 95% compacted Class 2 base section per the structural section design . Base layer under curb and gutters should be compacted to a minimum of 95%, while sub grade soils under curb and gutters, and base and sub grade under sidewalks should be compacted to a minimum of 90% compaction levels, unless otherwise specified. Base section may not be required under curb and gutters, and sidewalks, in the case of very low to non-expansive subgrade soils (expansion index less than 20). More specific recommendations should be given in the final as-graded compaction report. - -------------------- 411111 .. • • • .. ---.. .. --.. -- Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California F. General Recommendations January 11, 2016 Page 21 1. The minimum foundation design and steel reinforcement provided herein are based on soil characteristics and are not intended to be in lieu of reinforcement necessary for structural considerations. 2. Adequate staking and grading control are critical factors in properly completing the recommended remedial and site grading operations. Grading control and staking should be provided by the project grading contractor or surveyor/civil engineer, and is beyond the geotechnical engineering services. Staking should apply the required setbacks shown on the approved plans and conform to setback requirements established by the governing agencies and applicable codes for off-site private and public properties and property lines, utility easements, right-of-ways, nearby structures and improvements, leach fields and septic systems, and graded embankments. Inadequate staking and/or lack of grading control may result in illegal encroachments or unnecessary additional grading which will increase construction costs. 3. Open or backfilled trenches parallel with a footing shall not be below a projected plane having a downward slope of 1-unit vertical to 2 units horizontal (50%) from a line 9 inches above the bottom edge of the footing, and not closer than 18 inches from the face of such footing. 4. Where pipes cross under-footings, the footings shall be specially designed. Pipe sleeves shall be provided where pipes cross through footings or footing walls, and sleeve clearances shall provide for possible footing settlement, but not less than 1-inch all around the pipe . 5. Foundations where the surface of the ground slopes more than 1 unit vertical in 10 units horizontal (10% slope) shall be level or shall be stepped so that both top and bottom of such foundations are level. Individual steps in continuous footings shall not exceed 18 inches in height and the slope of a series of such steps shall not exceed 1 unit vertical to 2 units horizontal (50%) unless otherwise specified. The steps shall be detailed on the structural drawings. The local effects due to the discontinuity of the steps shall also be considered in the design of foundations as appropriate and applicable. 6. All underground utility and plumbing trenches should be mechanically compacted to a minimum of 90% of the maximum dry density of the soil unless otherwise specified . Care should be taken not to crush the utilities or pipes during the compaction of the soil. Non-expansive, granular backfill soils should be used. Trench backfill materials and compaction levels beneath pavements within the public right-of-way shall conform to the requirements of governing agencies. - ---------------------.. • • llii -.. -• -.. -• -- Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page22 7. New retaining walls are not planned and existing perimeter retaining walls are outside the limits of proposed new redevelopment areas. In general, expansive clayey soils should not be used for backfilling of any retaining structure. All retaining walls should be provided with a 1: 1 wedge of granular, compacted backfill measured from the base of the wall footing to the finished surface and a well-constructed back drainage system as shown on the enclosed Plate 7. Planting large trees behind site building retaining walls should be avoided. 8. Site drainage over the finished pad surfaces should flow away from structures onto the street in a positive manner. Care should be taken during the construction, improvements, and fine grading phases not to disrupt the designed drainage patterns. Rooflines of the buildings should be provided with roof gutters. Roof water should be collected and directed away from the buildings and structures to a suitable location. 9. Final plans should reflect preliminary recommendations given in this report. Final foundations and grading plans may also be reviewed by the project geotechnical consultant for conformance with the requirements of the geotechnical investigation report outlined herein. More specific recommendations may be necessary and should be given when final grading and architectural/structural drawings are available. 10. All foundation trenches should be inspected to ensure adequate footing embedment and confirm competent bearing soils. Foundation and slab reinforcements should also be inspected and approved by the project geotechnical consultant. 11. The amount of shrinkage and related cracks that occurs in the concrete slab-on-grades, flatworks and driveways depend on many factors the most important of which is the amount of water in the concrete mix. The purpose of the slab reinforcement is to keep normal concrete shrinkage cracks closed tightly. The amount of concrete shrinkage can be minimized by reducing the amount of water in the mix. To keep shrinkage to a minimum the following should be considered: * Use the stiffest mix that can be handled and consolidated satisfactorily. * Use the largest maximum size of aggregate that is practical. For example, concrete made with %-inch maximum size aggregate usually requires about 40-lbs. more (nearly 5-gal.) water per cubic yard than concrete with I-inch aggregate. * Cure the concrete as long as practical. The amount of slab reinforcement provided for conventional slab-on-grade construction considers that good quality concrete materials, proportioning, craftsmanship, and control tests where appropriate and applicable are provided. -------------------- - --------------- Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page23 IX. 12. A preconstruction meeting between representatives of this office, the property owner or planner, city inspector as well as the grading contractor/builder is recommended in order to discuss grading and construction details associated with site development. GEOTECHNICAL ENGINEER OF RECORD (GER} SMS Geotechnical Solutions, Inc. is the geotechnical engineer of record (GER) for providing a specific scope of work or professional service under a contractual agreement unless it is terminated or canceled by either the client or our firm. In the event a new geotechnical consultant or soil engineering firm is hired to provide added engineering services, professional consultations, engineering observations and compaction testing, SMS Geotechnical Solutions, Inc. will no longer be the geotechnical engineer of the record. Project transfer should be completed in accordance with the California Geotechnical Engineering Association (CGEA) Recommended Practice for Transfer of Jobs Between Consultants. The new geotechnical consultant or soils engineering firm should review all previous geotechnical documents, conduct an independent study, and provide appropriate confirmations, revisions or design modifications to his own satisfaction. The new geotechnical consultant or soils engineering firm should also notify in writing SMS Geotechnical Solutions, Inc. and submit proper notification to the City of Carlsbad for the assumption of responsibility in accordance with the applicable codes and standards (1997 UBC Section 3317.8). X. LIMITATIONS The conclusions and recommendations provided herein have been based on available data obtained from the review of pertinent reports and plans, subsurface exploratory excavations as well as our experience with the soils and formational materials located in the general area. The materials encountered on the project site and utilized in our laboratory testing are believed representative of the total area; however, earth materials may vary in characteristics between excavations. Of necessity, we must assume a certain degree of continuity between exploratory excavations and/or natural exposures. It is necessary, therefore, that all observations, conclusions, and recommendations be verified during the grading operation. In the event discrepancies are noted, we should be contacted immediately so that an inspection can be made and additional recommendations issued if required. The recommendations made in this report are applicable to the site at the time this report was prepared. It is the responsibility of the owner/developer to ensure that these recommendations are carried out in the field. It is almost impossible to predict with certainty the future performance of a property. The future behavior of the site is also dependent on numerous unpredictable variables, such as earthquakes, rainfall, and on-site drainage patterns. ... -.. .. .. 11111 -.. --------... -·--... .. • .... .. • -• -• -.. • 11111 .. Geotechnical Investigation, Proposed 3-Story 4-Unit Residence 2637 Jefferson Street, Carlsbad, California January 11, 2016 Page24 The firm of SMS Geotechnical Solutions, Inc., shall not be held responsible for changes to the physical conditions of the property such as changing final grades, addition of fill soils, added cuts, or modifying drainage patterns which occur without our inspection or control. This report should be considered valid for a period of one year and is subject to review by our firm following that time. If significant modifications are made to your plans, especially with respect to building layout and finish pad grades, this report must be presented to us for review and possible revision. This report is issued with the understanding that the owner or his representative is responsible for ensuring that the information and recommendations presented herein are provided to the project architect, civil and structural engineer so that they can be incorporated into the pertinent plans, as applicable and appropriate. Necessary steps shall also be taken to ensure that the project general contractor and subcontractors carry out such recommendations during construction. SMS Geotechnical Solutions, Inc., warrants that this report has been prepared within the limits prescribed by our client with the usual thoroughness and competence of the engineering profession. No other warranty or representation, either expressed or implied, is included or intended. Once again, should any questions arise concerning this report, please do not hesitate to contact this office. Reference to our Project No. GI-15-12-50 will help to expedite our response to your inquiries . We appreciate this opportunity to be of service to you . SMS Geotechnical Solutions, Inc . ~m.,~~,) StevenJ.Melzer CEG#2362 Distribution: Addressee (5, e-mail) SMS GEOTECHNICAL SOLUTIONS, INC. Consulting Geotechnical Engineers & Geologists ---------------.. -----• • -• -------• -- REFERENCES Annual Book of ASTM Standards, Section 4 -Construction, Volume 04.08: Soil and Rock (I); D 420 -D 5876, 2012. Annual Book of ASTM Standards, Section 4 -Construction, Volume 04.09: Soil and Rock (II); D 5876 -Latest, 2012. Highway Design Manual, Caltrans. Fifth Edition. Corrosion Guidelines, Caltrans, Version 1.0, September 2003. California Building Code (CBC), California Code of Regulations Title 24, Part 2, Volumes 1 & 2, 2013, International Code Council. "The Green Book" Standard Specifications for Public Works Construction, Public Works Standards, Inc., BNi Building News, 2015 Edition . California Geological Survey, 2008 (Revised), Guidelines for Evaluating and Mitigating Seismic Hazards in California, Special Publication 117 A, 108p. California Department of Conservation, Division of Mines and Geology (California Geological Survey), 1986 (revised), Guidelines for Preparing Engineering Geology Reports: DMG Note 44. California Department of Conservation, Division of Mines and Geology (California Geological Survey), 1986 (revised), Guidelines to Geologic and Seismic Reports: DMG Note 42 . EQFAULT, Ver. 3.00, 1997, Deterministic Estimation of Peak Acceleration from Digitized Faults, Computer Program, T. Blake Computer Services and Software. EQSEARCH, Ver 3.00, 1997, Estimation of Peak Acceleration from California Earthquake Catalogs, Computer Program, T. Blake Computer Services and Software. Tan S.S. and Kennedy, M.P., 1996, Geologic Maps of the Northwestern Part of San Diego County, California, Plate(s) 1 and 2, Open File-Report 96-02, California Division of Mines and Geology, 1 :24,000. "Proceeding of The NCEER Workshop on Evaluation of Liquefaction Resistance Soils," Edited by T. Leslie Youd and Izzat M. Idriss, Technical Report NCEER-97-0022, Dated December 31, 1997. "Recommended Procedures for Implementation ofDMG Special Publication 117 Guidelines For Analyzing and Mitigation Liquefaction in California," Southern California Earthquake Center; USC, March 1999. .. .. -----.. .. .. ---.. ----• .. • .. 11111 -.. ------.. .. - REFERENCES (continued) "Soil Mechanics," Naval Facilities Engineering Command, DM 7.01. "Foundations & Earth Structures," Naval Facilities Engineering Command, DM 7.02. "Introduction to Geotechnical Engineering, Robert D. Holtz, William D. Kovacs . "Introductory Soil Mechanics and Foundations: Geotechnical Engineering," George F. Sowers, Fourth Edition . "Foundation Analysis and Design," Joseph E. Bowels. Caterpillar Performance Handbook, Edition 29, 1998. Jennings, C. W ., 1994, Fault Activity Map of California and Adjacent Areas, California Division of Mines and Geology, Geologic Data Map Series, No. 6. Kennedy, M.P., 1977, Recency and Character of Faulting Along the Elsinore Fault Zone in Southern Riverside County, California, Special Report 131, California Division of Mines and Geology, Plate 1 (East/West), 12p. Kennedy, M.P. and Peterson, G.L., 1975, Geology of the San Diego Metropolitan Area, California: California Division of Mines and Geology Bulletin 200, 56p . Kennedy, M.P. and Tan, S.S., 1977, Geology of National City, Imperial Beach and Otay Mesa Quadrangles, Southern San Diego Metropolitan Area, California, Map Sheet 24, California Division of Mines and Geology, 1 :24,000 . Kennedy, M.P., Tan, S.S., Chapman, R.H., and Chase, G.W., 1975, Character and Recency of Faulting, San Diego Metropolitan Areas, California: Special Report 123, 33p. "An Engineering Manual For Slope Stability Studies," J.M. Duncan, A.L. Buchignani and Marius De Wet, Virginia Polytechnic Institute and State University, March 1987 . "Procedure to Evaluate Earthquake-Induced Settlements in Dry Sandy Soils," Daniel Pradel, ASCE Journal ofGeotechnical & Geoenvironmental Engineering, Volume 124, #4, 1998. "Minimum Design Loads For Buildings and Other Structures," ASCE 7-10, American Society of Civil Engineers (ASCE). I I I I I I I I I I I I I I I 5 6 7 ( REGIONAL INDEX MAP] ~,(., ,.,., .. PACIFIC OCEAN CARLSBAD 02006 Thomas Bros. Maps STATE -/ ' C D F G 2637 Jefferson St.: Carlsbad, 1106-E4 ( FIGURE 1) 1 1 , , ., ,., I ,; I ,, I ,, ,j ,j ,, J 15'-0" 6' HIGH CMU WALL UP ~[p)[p)~©~aM~T~ ~air~ [p)[L~[N] ~a=lJ ~~~ ~=~© PROPERTY LINE 150.00' POWER POL£ • DOWN ::::!: iiJ Stairs to second r CM"W," -------~~-----Ooo,~~~-C\I I I fRecreation7 Area I 8f at 2s'-4" I I ~I I I I I I I I CMUWall @ 36" Existing pool (NOT -A-PARl) r L ______ _ ~B-1 Qt PROPOSED THREE STORY, 4 UNIT RESIDENCE Qt 0 ' I I 8-~ I I I I I I I I I _____________________________ J • .:,,! ::::!: 0 C") a, v £l 20'-0" Setback CMUWa!I @ 36" Qt f (E) Driveway7 ~w . -------------------------------. ---------------------- 2637 JEFFERSON ST. CARLSBAD GEOTECHNICAL LEGEND • Approx. Boring Location af Fill/Wall Backfill Qt Terrace Deposits I I lb IC! I~ I~ 1 ~ __.__...,__ Sidewalk 10::: I o::: UJ~ Landscape Face of Curb IQ. I ...,: Cl) z 0 Cl) 0::: UJ u. Li. w -, N (l'llf.) SCALE: 1/16" approx. 1' ( FIGURE 2 J I I I I I I I I I I I I I I KEY TO BORING/ TEST PIT LOGS DRILLING & SAMPLING SYMBOLS: e Split Spoon · 1·3/8" 1.D., 2" O.D., unless othelwise noted HS: Hollow Stem Auger 0 Chunk Sample ST: Thin-Walled Tube · 2" O.D., unless otherwise noted PA: rlJ Ring Sampler· 2.375" 1.0., 2.S' O.D., Unless othe!wise noted P<merAuger • Sandcone Density Test HA: Hand Auger DB: Diamond Bit Coring • 4", N, B II Bulk Sample or Auger Sample WB: Wash Boring or Mud Rotary RB: Rod< Bit The number of blows required to advance a standard 2-lnch 0 .0. split-spoon sampler (SS) the last 12 inches of the total 18--inch penetration with a 140-pound hammer faffing 30 inches is considered the "Standard Penetration· or "N-value". For2..5'"0.D. ring samplers (RS} the penetration value is reported as the number of blows required to advance the sampler 12 inches using a 140-pound hammer falling 30 inches, reported as "blows per foot,• and is not considered equivalent to the "Standard Penetration" or "N-value." WATER LEVEL MEASUREMENT SYMBOLS: Wl; Water LeYel WS: Whlle Sempring NIE: Not Encountered WCI: Wet Cave In WD: WhlleDrlling DCI: Dry Cavein BCR: Before Casing Removal "13: AAerBomg ACR: After Cesing Removal Water levels indicated on the boring logs are the levels measured In the borings at the times lndlcated. Groundwater levels at other times and other locations across the site could vary. In pervious soils, the indicated levels may reflect the location of groundwater. In low permeability soils, the accurate determination of groundwater levels may not be possible with only short-term obsefvations. DESCRIPTIVE SOIL CLASSIFICATION: Soil classification Is based on the Unified Classification System. Coarse Grained Soils have more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Solls have less than 50% of their dry weight retalned on a #200 sieve; they are principally described as clays if they are plastic, and silts if they are slightly plastic or non-plastic. Major constituents may be added as modlfiefs and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils are defined on the basis of their in-place relative density and fine-grained softs on the basis of their consistency. CONSISTENCY OF FlNE·GRAINED SOILS Unconfined Standard comp[fffJve Penetration or Strength, Qu, N•YJIY• {SS} 2!f Blows/Ft. < 500 <2 500 -1,000 2-3 1,001 -2,000 4-6 2,001 -4,000 7-12 4,001 -8,000 13-26 8,000+ -26+ Conslftff!CY Very Soft Soft Medium Stiff Stiff Very Stiff Hard . RELATIVE PROPORTIONS OF SAND AND GRAVEL Descrtptiv, Ttrrnltl of other Percent of coot1UY•nts Dry WtJaht Trace With Modifier < 15 15-29 >30 RELATJ\IE PROPORTIONS OF FINES Descrfptiw T,rmC,l of other constituents Trace With Modifiers ptgntof DryW,tqht <5 5-12 > 12 RELATIVE DENSITY OF COARSE-GRAINED SOILS Standard Penetration or N·Ylfyt C§Sl Blowa/Ft. 0-3 4-9 10-29 30-49 50+ Ring Sampler {RS) QloWJlFt, 0-6 7-18 19-58 59-98 99+ Relatfvt Density Very Loose Loose Medium Dense Dense Very Dense GRAIN SIZE TERMINQLQGY Malor Compoo,nt orsampfe Particie Size Bouldera Over 12 in. (300mm} Cobbles 12 in. to 3 in. (300mm to 75 mm) Gravel 3 in. to #4 sieve {75mm to 4.75 mm) Sand #4 to #200 sieve (4.75mm to 0.075mm) Silt or Clay Passing #200 Sieve (0.075mm) PLASTICITY DESCRIPTION Itr:m Non-plastic Low Medium High Pluticfty Index 0 1-10 11-30 30+ ----------------~ !Ml~ Geotechnical Solutions, Inc. I I I I I UNIFIED SOIL CLASSIFICATION SYSTEM (USCS) Criteria for Assigning Group Symbols and Group Names Using Llboratory Test__. Cont GraiQtd Sool$ More than 50% retained on No. 200 sieve 50% or more puses the No. 200 sieve ~ More lhan 50% of coarse fraction retained on No. 4 sieve ~ 50% or more of coarse fraction passes No. -4 sieve SU,SandQavs Liquid limit less than 50 SJHi and CJl't1 LlqlA<! limit 50 or more CleaoGcaveis Less lhan 5% finese Gram with flnts More than 12% finese Cfllo Sands Less than 5% fines0 Sands with Fm More lhan 12'.4 fw1es0 inorganic Cu2:4 and 1 s Ce:S31 Fona ciusify as ML or MH Fines classify as CL or CH Cu2:6and 1 sCes31 Cu< 6 ar.d/or 1 > Ce> 31 FIIIN classify as Ml or MH Fina Classtfy • Cl or CH Pl> 7 and plots on or above "Kline' Pl< -4 or plola be4ow "A" line' Liquid limit -oven dried Liquid limlt -not dried Pl plots on or aboYe "A" lne Pl plots be4ow "A" rone Liquid linwt -oven dried Liquid limit -not dried <0.75 < 0.75 Soil Classiflcatlon Group SvmbQI Group N•me' GW Well-graded gravel' GP Pool1y graded p.,.f GM Silly gravel'·"-" GC Clayey gravel'·0" SW Wei-graded sand' SP Poorty graded sand' SM Silty sand°·H.J SC Clayey sancfJU CL lNn cJefL.M Ml Sft"L"' Ol Organic~ Organic alttK.'-"'-0 CH Fat da,tJ-" MH OH Organlcda~ Olganlc~M.0 Primarily organic matter, dat1c In color, and organic odor PT Peat • Based on lhe material pasing 1ht 3-ln. (75-mm) sieve 1 If field sample contained oobblts or boulders, or both, add 'With cobbles or boulder$, or both" lo group nerne. e Gravela with 510 12% mes require dual aymboll: GW-GM -'ilradtd gravel with 11ft. GW- GC well-graded gt'S','91 with ciay, GP-GM poorly gl'9ded gra\181 with allt, GP-GC poorly graded gravel with clay. o Sanda with 5 ID 12% firWI require dual symbols: SW-SM ~ aand with silt, SW-SC wel11raded sand with day, SP-SM poorly graded sand with 1111, SP-SC poorly graded sand with day __@&__ •cu:nin Ce= .....,~,. Dio X 0.0 'If soil contains 2: 15% und, add "Mth sand" to group name. 0 If fines d..ify as CL-Ml., Ult dual aymbol Ge-GM, or SC-SM. 90 · .. ' . , . 7" : For dalalflNtion of ....... led _eol9and .......... trectiorl 50 : . of coarse p-.d NIii Equalion ol "A"• Int Horiza1lal at Pl=4 10 1.1.,,25.5. 40 • then Ph0.73 (Ll-20) - i ~olV·line YWical at ~16 lo Pt,.7, 30 ! then Pl.0.9 (Ll-1) 20 . l . "If tines ara organic, add "with o,vank: tlnN" to group name. 1 If aoil contains 2: 15% gravel, add "With graver to group name. ' If A1s.rt>wv limits plot in ahadad a,_, soil II a CL-Ml, lilly clay. • If soil contains 15 to 211% plus No. 200, add "with sand" or "With gravel," whk:hever is l)r9dominent L If soil contains 2: 30% plus No. 200 predominantty sand, add "HIidy" to group name. "If aoll __,,,. 2: 30% plua No. 200, pradomlnantly grawl, add ·Qfavelly" to group name. • Pl 2 4 and plots on or above "A" lne. 0 Pl < -4 or ploCs below "A" lne . • Pl plots on or above • A" line. 0 Pt plots below"A· tine. UH or OH 10· ·--I ·--• __j__ - 10 16 20 30 40 so 70 UOUID LIMIT (Lll 10 I I __ i •• ; ·-·· ---- 100 no L---------------~ fMJ ~Geotechnical Solutions, Inc. I I I I I I I I I I SMSGEOTECHNICAL SOLUTIONS, INC. Boring: B-1 PROJECT: 3-Story 4-Unit Residence CLIENT: Ohms Collaborative.Mr. Hector Aramburo PROJECT No.: Gl-15-12-50 PROJECT LOCATION: 2637 Jefferson St. Carlsbad DATE LOGGED: 12/18/2015 BOREHOLE DIA: 6" LOGGED BY: SMS CONTRACTOR: Pa::ific Drilling DRILL METHOD: Tri-Pod Mounted Beaver Drill. Solid Stem Au,,.,,._ SAMPLE METHOD: 140 LB. Hirnmer dronDM 30-inches bv rooe & cahecd. 5-foot Iona AW drill rods. REMARKS: No Cavina. No Groundwater. u ui w ~~ WI-~~ ~~ ~Q ~c, C::z DEPTH MATERIAL DESCRIPTION (.) Ir~ =>w-I-V5-l!Ji..-oz t;i--;;e ::::>-(ft) ~'.3 ui :::Ei'.: s8 _z-~-:5~~ ffi:,-::i ~ (.) 00 ~~ !l!c ~~ C, ::EU <:-: ,-.. : .... :-:··. Fl LL/TOPSOIL (af) ........ _ . .. . ·-· ·. :-': -:_:-:_\ :-:'· . SM .. • .. Da-k ta, to gray-brown silty fineSclld. .• :-··:-· ... 2 :::: :: .. ~: :? Undifferentiaed fill/ toproil. Moist to very moist. ...... \ Loose. Rootlets in upper 3 inches. I ~ ...... 30-50/5" 5 117.1 90 32 ...... ST-1 . . .. . . . . ... . . . .. . . . . . . . . . . . . . . ...... TERRACE DEPOSIT (Qt) . . .. . . ...... ... 4 -. . . . .. ...... Yellow to ora,ge-brown silty Sclldstone. Fineto .. . . .. ~ 9-12-13 ...... .. . . . . mEdi um gra ned. Moist . Daise to very daise. ...... (25) ~ ...... . . ' . . . Cernerrted. . . .. . . ...... ST-2 . ' .. ' . . . . . . . .... 5_ ...... .. . . . . .. . . .. .. . . .. .. . . .. .. . . . . SP ...... Continues .. .. .. Becomes mEdi um to c:oa-se gra ned a 7' . H ...... . . .. .. ...... moist. Daise to very daise aid very tight. Driller 10-16-35 ...... 9 115.6 89 55 ..... 8 -...... a::lded waer to ad drilling. Semple a 7' may be (53) .. . . .. somewha disturbed . H . . . . . . . . . . . . . . . . . . . . . . .. . . .. .. . . .. .. . . .. .. .. . . . . . . . . . . .. . . . . '-10-...... .. . . .. . . . . . . . . . . . . . . . . . . . . . . . . -: : : : : : ...... . . . . . . .. .. . . . . .. . . -12-.. .. . . . . . . . From 12' color chaigesto white/ light ta, brown . More ...... silty. Moist. Daise to very dense. Ind udes some ~ 10-15-14 ...... . . .. . . ...... rounded pebbles. (29) -...... . . .. . . . . .. . . . . . . . ' ...... . . . . . . ~14-...... ...... Becomes coa-se gra ned aid continues very daise to . . . . .. .. . . . . very tight aid canented a 14' . . . .. . . .. . . .. . . . . . . . . . . .. . . . . . . ...... ...... ~ 12-26-33 . . . . . . --16-...... (61) ...... . . . .. . Bottom of ooraiole a 10.::> TE!E!C. B STANDARD 1%1 MODIFIED • BULK "SL GROUND FIGURE 3 PENETRATION CALIFORNIA SAMPLE -WATER TEST SAMPLER I I I I I I I I I I SMSGEOTECHNICAL SOLUTIONS, INC. Boring: B-2 PROJECT: 3-Story 4-Unit Residence CLIENT: OhmsCollaborative Mr. Hector Aramburo PROJECT No.: Gl-15-12-50 PROJECT LOCATION: 2637 Jefferaon St. Carlsbad DATE LOGGED: 12/18/2015 CONTRACTOR: Pa:ific Drilling BOREHOLE DIA: --=6'--" _ LOGGED BY: SMS ORI LL MET HOD: Tri-Pod Mounted Beaver Drill. Solid Stem Aunff. SAMPLE MET HOD: 140 LB . Hanmer dronNrl 30-inches bv rone & caheoo. 5-foot Iona AW drill rods. REMARKS: No Gavina. No Groundwater. (.) ~(!) DEPTH MATERIAL DESCRIPTION (ft) ~g (!) . ·.· -:_:·.·_·:.-:,:··. :::_:.:::_::\ FILL/TOPSOIL (af) Brown silty fine said. Undiffa-enticted fill/topsoil. Moist. Loose. Rootlets in uppa-3 inches. ST-1 ui w 3:~ Li Ir It' oz ui ::.~ ...J5 ::i ch mu SM w~ ii ~~ <rz ~~~ ::::,-~111 ->-. :s~c o~-~~ ;:.U ~o "-0 O;:: ~~" (!):,-gfi IX •1 OU'4 4 _ ~e _ ,-....... 't---+--+---1t, istu,..,... ~ 4 -..... . ~ 6 -...... TERRACE DEPOSIT (Qt) Yellow to ora,~brown si lty saidstone. Fine to medium graned. Dry to slightly moist. Va-y dense to va-y tight. Highly cema,ted. Va-y slow drilling. Drilla-a::fded waa-to ad drilling. Drilla-SNitched to a rock bit. ST-2 t::iottom or oor0"101e a: t .:> Teec. ~ STANDARD r9! MODIFIED • BULK a PENETRATION IA! CALIFORNIA SAMPLE TEST SAMPLER n GROUND -¥-WATER SP 21-25-19 (44) '---- FIGURE 4 I I I I I I I I I I 0 0 7.9 ----Fault 30 20 FAULT -EPICENTER MAP SAN DIEGO COUNTY REGION 10 0 INDICATED EARTHQUAKE EVENTS THROUGH 75 YEAR PERIOD (1900-1974) This Map data is compiled from various sources including the California Division of Mines and Geology, California Institute of Technology, and the National Oceanic and Atmospheric Administration. This Map is reproduced from the California Division of Mines and Geology, "Earthquake Epicenter Map of California; Map Sheet 39." ........ :: 30 MILES ( FIGURE 5 JI (a) (b) ISOLATION JOINTS CONTRACTION JOINTS RE-ENTRANT CORNER REINFORCEMENT NO. 3 BARS PLACED MID-HEIGHT IN SLAB (c) RE-ENTRANT CORNER CRACK I NO SCALE I NOTES: 1 . Isolation joints around the columns should be either circular as shown in (o) or diamond shaped as shown in (b). if no isolation joints ore used around columns, or if the corners of the isolation joints do not meet the contraction joints, radial crocking as shown in (c) may occur (reference ACI). 2 . In order to control crocking at the re-entont corners ( + /-270 degree corners), provide reinforcement as shown in (c). 3. Re-entrant corner reinforcement shown herein is herein is provided as o general guideline only and is subject to verification and changes by the project architect and /or structural engineer based upon slob geometry, location, and other engineering and construction factors. SMS GEOTECHNICAL SOLUTIONS, INC. 1645 S. RANCHO SANTA FE ROAD, SUITE 208 SAN MARCOS, CA 92078 PHONE: 760-761-0799 EMAIL: sms;eosol.inc@gmall.com lYPICAL ISOLATION JOINTS AND RE-ENTRANT CORNER REINFORCEMENT PROJECT NO: FIGURE NO: Gl-15-12-50 6 I I I I I I I I I I I I SPECIFICATIONS FOR CALTRANS CLASS 2 PERMEABLE MATERIAL (68-1 .025) U.S. STANDARD SIEVE SIZE l" 3/4 3/8 No. 4 No. 8 No. 30 No. 50 No. 200 %PASSING 100 90-100 40-100 25-40 18-33 5-15 0-7 0-3 SAND EQUIVALENT > 75 RETAINING WALL FILTER MATERIAL, 3/4" · 1t• CRUSHED ROCKS (WRAPPED IN FILTER FABRIC OR CAL TRANS CLASS 2 PERMEABLE MATERIALS (SEE SPECIFICATIONS) WATERPROOFING (TYP) FINISH GRADE 6"MIN. CONCRETE-LINED DRAINAGE DITCH FILTER MATERJAL, 3/4' · lf CRUSHED ROCKS (WRAPPED IN FILTER FABRIC OR CAL TRANS CLASS 2 PERMEABLE MATERIALS (SEE SPECIFICATIONS) WATERPROOFING (TYP) PROPOSED GRADE CONSTRUCTION SPECIFICATIONS: I NO SCALE I I NO SCALE I GROUND SURFACE MIN. 90% COMPACTED FILL APPROVED FILTER FABRIC (MIRAFI 140N) 12' OVERLAP, TYP. 4' PVC PERFORATED PIPE MIN. (SCH 40 OR SDR35) MIN. 1 /2% FALL TO APPROVED OUTLET (SEE REPORT) NATURAL OR GRADED SLOPE TEMPORARY 1 : 1 CUT SLOPE PROPERLY COMPACTED (MIN. 90%) BACKFILLED GROUND .._ ____ BENCH AND TIGHTLY KEY INTO TEMPORARY BACKCUT AS BACKFILLING PROGRESSES APPROVED FILTER FABRIC (MIRAFI 140N) 12' OVERLAP, TYP. '-------4' PVC PERFORATED PIPE MIN. (SCH 40 OR SDR35) MIN. 1 /2% FALL TO APPROVED OUTLET (SEE REPORT) 1 . Provide granular, non-expansive backfill soil in 1 : 1 gradient wedge behind wall. compact backfill to minimum 90% of laboratory standard. 2. Backdroin should consist of 4" diameter PVC pipe (Schedule 40 or equivalent) with perforations down. Drain to suitable at minimum~%. Provide 3/4" -l ~" crushed rocks filter materials wrapped in fabric (Mirafi 140N or equivalent). Delete filter fabric wrap if Coltrons Class 2 permeable material is used. Compact Closs 2 permeable material to minimum 90% of laboratory standard. 3. Seal bock of wall with approved waterproofing in accordance with architect's specifications. 4. Provide positive drainage to disallow ponding of water above wall. Drainage to flow away from wall at minimum 2%. Provide concrete-lined drainage ditch for slope toe retaining walls. 5. Use 1 ~ cubic feet per foot with granular backfill soil and 4 cubic foot per foot if expansive backfill is used. SMS GEOTECHNICAL SOLUTIONS, INC. 1.645 S. RANCHO SANTA FE ROAD, SUITE 208 SAN MARCOS, CA 92078 1YPICAL RETAINING WALIL BACK DRAINAGE PHONE: 760-761-0799 EMA[L: smsgeosol.inc@gmail.com PROJECT NO: FIGURE NO: Gl-15-12-50 7 I I I I I I I I I I I I I I I I I APPENDIX I I muscm Design Maps Summary Report I I I I I I I I I I I I I I I User-Specified Input Report Title Ohms Collaborative -2637 Jefferson St., Carlsbad Thu December 10, 2015 23:26:10 UTC Building Code Reference Document ASCE 7-10 Standard (which utilizes USGS hazard data available in 2008) Site Coordinates 33.1664°N, 117.3487°W Site Soil Classification Site Class D -"Stiff Soil" Risk Category I/II/III USGS-Provlded Output Ss = 1.148 g S1 = 0.440 g Oceansadc{ SMs = 1.195 g SM1 = 0 .687 g ,. Sos= 0.797g S01 = 0.458 g Escondido' For information on how the SS and S1 values above have been calculated from probabilistic (risk-targeted) and deterministic ground motions in the direction of maximum horizontal response, please return to the application and select the "2009 NEHRP" building code reference document. MCE" Response Spectrum Design Response Spectrum 0.i2 1 20 \) ,o ' "" 0 72 C· ~G o.~, <) 1r1, (I!, -a o n 'i, OU II C ,o Ill ~ o ~o ~ 0 41,l 0 ;: .,, /) ;;4 C 24 o,, • 12 o ,;,a 11(1 --• ... ~ . ~ IJ 1'·p i • --t---t .... • O.•:.r O.ZO o. •o O.S(l o . .:o I : 0 l :o 1 40 l ,o l £0 ;: ClO 0.07 0.2: o.,: o.,:, O . .:, l.~Cr 1.:0 1.40 l fO l ;:;o :Z 00 Period, T (nc) Period, T bed For PGAM, TL, CRS, and CR, va lues, please view the detailed report. - ------.. - IIUSGS Design Maps Detailed Report ASCE 7-10 Standard (33.1664°N, 117.3487°W) Site Class D -"Stiff Soil", Risk Category I/II/III Section 11.4.1 -Mapped Acceleration Parameters Note: Ground motion values provided below are for the direction of maximum horizontal spectral response acceleration. They have been converted from corresponding geometric mean ground motions computed by the USGS by applying factors of 1.1 (to obtain Ss) and 1.3 (to obtain S,). Maps in the 2010 ASCE-7 Standard are provided for Site Class B. -Adjustments for other Site Classes are made, as needed, in Section 11.4.3. ----------- ----.. - From Figure 22-1 rii Ss = 1.148 g ------------ From Figure 22-2 r21 s, = 0.440 g Section 11.4.2 -Site Class The authority having jurisdiction (not the USGS), site-specific geotechnical data, and/or the default has classified the site as Site Class D, based on the site soil properties in accordance with Chapter 20. Table 20.3-1 Site Classification Site Class A. Hard Rock B. Rock C. Very dense soil and soft rock D. Stiff Soil E. Soft clay soil ·------·-------- Vs Nor Net, Su >5,000 ft/s N/A N/A 2,500 to 5,000 ft/s N/A N/A 1,200 to 2,500 ft/s >50 >2,000 psf 600 to 1,200 ft/s 15 to 50 1,000 to 2,000 psf <600 ft/s <15 <1,000 psf Any profile with more than 10 ft of soil having the characteristics: • Plasticity index PI > 20, • Moisture content w 2: 40%, and • Undrained shear strength Su < 500 psf -F. Soils requiring site response analysis in See Section 20.3.1 accordance with Section 21.1 -For SI: 1ft/s = 0.3048 m/s 11b/ft2 = 0.0479 kN/m2 ------- -.. ------------------------------------ Section 11.4.3 -Site Coefficients and Risk-Targeted Maximum Considered Earthquake (MCER) Spectral Response Acceleration Parameters Site Class A B C D E F Site Class A B C D E F Table 11.4-1: Site Coefficient F, Mapped MCE R Spectral Response Acceleration Parameter at Short Period Ss $ 0.25 Ss = 0.50 Ss = 0.75 Ss = 1.00 0.8 0.8 0.8 0.8 1.0 1.0 1.0 1.0 1.2 1.2 1.1 1.0 1.6 1.4 1.2 1.1 2.5 1.7 1.2 0.9 See Section 11.4. 7 of ASCE 7 Note: Use straight-line interpolation for intermediate values of Ss For Site Class= D ands.= 1.148 g, F. = 1.041 Table 11.4-2: Site Coefficient F. Ss.::: 1.25 0.8 1.0 1.0 1.0 0.9 Mapped MCE R Spectral Response Acceleration Parameter at 1-s Period S1 $ 0.10 S1 = 0.20 S1 = 0.30 S1 = 0.40 S1.::: 0.50 0.8 0.8 0.8 0.8 0.8 1.0 1.0 1.0 1.0 1.0 1.7 1.6 1.5 1.4 1.3 2.4 2.0 1.8 1.6 1.5 3.5 3.2 2.8 2.4 2.4 See Section 11.4.7 of ASCE 7 Note: Use straight-line interpolation for intermediate values of S1 For Site Class= D and S, = 0.440 g, F. = 1.560 ----Equation (11.4-1): SMs = F.Ss = 1.041 X 1.148 = 1.195 g --Equation (11.4-2): SMl = F.51 = 1.560 X 0.440 = 0.687 g - • Section 11.4.4 -Design Spectral Acceleration Parameters -------------------.. ----.. -• -- Equation (11.4-3): Sos=¾ SMs = ¾ X 1.195 = 0.797 g ----------------~-------------------- Equation (11.4-4): 501 = ¾ SMl = ¾ X 0.687 = 0.458 g -----·--··------------ Section 11.4.5 -Design Response Spectrum From Figure 22-12 c3i TL = 8 seconds 'ii -• Ill ' 1 " "' "' ,( " II l rt ii .. t " , -------·----· Figure 11.4-1: Design Response Spectrum s" .. o. 191 S::n = 0.458 T:i = 0.115 T, = 0 . .575 T<T0 :S. = S111 (0-• +0.6T /T1 ) r,:s;T ~ r,: s.• sDI T, <T~ TL :s. = Soi IT 1.000 Period, TC1ec) ----- Section 11.4.6 -Risk-Targeted Maximum Considered Earthquake (MCER) Response Spectrum The MCE. Response Spectrum is determined by multiplying the design response spectrum above by -1.5. -----------------------.. -.. -.. .. -- • Ill t 1,1 1,1 C ., ' a: 'i j s"' .. 1.195 S lof] = 0. 6 8 7 -,... ----------~ ---------- T, = 0 575 l. 000 ---------------------------.. ------... --- Section 11.8.3 -Additional Geotechnical Investigation Report Requirements for Seismic Design Categories D through F From Figure 22-7 c41 PGA = 0.454 Equation (11.8-1): PGAM = FPGAPGA = 1.046 x 0.454 = 0.475 g Table 11. 8-1: Site Coefficient FPGA Site Mapped MCE Geometric Mean Peak Ground Acceleration, PGA Class PGA :5 PGA = PGA = PGA = PGA ~ 0.10 0.20 0.30 0.40 0.50 A 0.8 0.8 0.8 0.8 0.8 B 1.0 1.0 1.0 1.0 1.0 C 1.2 1.2 1.1 1.0 1.0 D 1.6 1.4 1.2 1.1 1.0 E 2.5 1.7 1.2 0.9 0.9 F See Section 11.4.7 of ASCE 7 Note: Use straight-line interpolation for intermediate values of PGA For Site Class= D and PGA = 0.454 g, F .... A = 1.046 Section 21.2.1.1 -Method 1 (from Chapter 21 -Site-Specific Ground Motion Procedures for Seismic Design) From Figure 22-17 151 CRS = 0.944 From Figure 22-18r61 CR1 = 0.995 - --Section 11.6 -Seismic Design Category -Table 11.6-1 Seismic Design Category Based on Short Period Response Acceleration Parameter -RISK CATEGORY VALUE OF Sos I or II III IV --Sos< 0.167g A A A 0.167g S Sos< 0.33g B B C -0.33g S Sos < 0.S0g C C D -0.S0g S Sos D D D -For Risk Category= I and Sos= 0.797 g, Seismic Design Category= D -Table 11.6-2 Seismic Design Category Based on 1-S Period Response Acceleration Parameter -RISK CATEGORY -VALUE OF So1 I or II III IV -So1 < 0.067g A A A -0.067g S So1 < 0.133g B B C -0.133g S So1 < 0.20g C C D -0.20g S So1 D D D For Risk Category = I and S01 = 0.458 g, Seismic Design Category = D -• Note: When S1 is greater than or equal to 0. 75g, the Seismic Design Category is E for buildings in Risk Categories I, II, and III, and F for those in Risk Category IV, irrespective • of the above . • ---• ------------ Seismic Design Category = "the more severe design category in accordance with Table 11.6-1 or 11.6-2" = D Note: See Section 11.6 for alternative approaches to calculating Seismic Design Category . References 1. Figure 22-1: http://earthquake.usgs.gov/hazards/designma ps/downloads/pdfs/201 0_ASCE-7 _Figure_22-1. pdf 2. Figure 22-2: http://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/201 0_ASCE-7 _Figu re_22-2. pdf 3. Figure 22-12: http://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/20l0_ASCE-7_Figure_22- 12.pdf 4. Figure 22-7: http ://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7 _Figure_22-7. pdf 5. Figure 22-17: http ://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7 _Figure_22- 17 .pdf 6. Figure 22-18: http://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22- 18.pdf