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HomeMy WebLinkAboutTract Map 9833-3 Lot 7 Geotechnical ReportHOBBS, CONSULTING s 92 COPPER LANTERN, UNIT A DANA POINT CALIFORNIA 92629 Date: December 1, 2014 Project No: 14089-1 Jose and Leonilla Maldonado c/o Infinity Construction 30395 Ainsworth Lake Elsinore, California 92530 Subject: Limited Preliminary Geotechnical Evaluation, Proposed Single Family Residence and Grading 43411 Calle De Velardo, City of Temecula, California 92591 APN 945-150-007 Dear Mr. and Mrs. Maldonado, Pursuant to an authorization from the project engineer and architect, a limited preliminary geotechnical evaluation was conducted on the subject site in accordance with the 2013 California Building Code, Section 1803.5.11. Attached as Plate 1, the Geotechnical Map is a reduced image of the topographic map indicating the proposed location of the residence and pertinent geotechnical information. The scope of work performed for this study included the following: 1. Onsite observation and documentation of existing site geometry and any minor existing grading that has taken place with respect to the location of the proposed residence 2. Excavation by drilling rig into the existing grades for sample recovery for laboratory .�. testing and observation of subsurface conditions. 3. Engineering analysis to develop design specifications for grading and preliminary foundation design. 4. Preparation of report of findings, including conclusions and recommendations for grading and minimum foundation design. . & Mrs. Maldonado, Preliminary Geotechnical Report Project No: 14089-1 Executive Summary y This investigation has been conducted resulting from a 2013 California Building Code Chapter 18 requirement for preliminary geotechnical investigation being conducted for all projects in Seismic Category D. This investigation will address geotechnical conditions existing on the site as they may pertain to a proposed single family residence that is to be constructed in the vicinity of the eastern end of the parcel. It is our understanding that the residence with by a typical single or multistory type V structure. Contained herein also are preliminary recommendations for foundation design for the proposed residence. The site consists of irregular shaped parcel located on the west side of Calle De Velardo in the City of Temecula. It envelops approximately 3.87 acres. The site is currently and variably covered in annual grasses and chaparral type brush. It has a small ravine that carries drainage along the southern boundary of the site to the west. There appears no appreciable evidence of any grading onsite to date, save for minor grading work at the extreme western end resulting from MWD access to aqueducts. Based on a very preliminary grading sketch, none of the proposed grading will take place on MWD easements at the western and southern portions of the site. .M� Field work on the site consisted making two excavation made by drilling rig for recovering samples of representative earth materials for laboratory testing and observing the -- conditions of the soils near the pad area. Also, observations were made in nearby excavated slopes in road cuts and on adjacent sites to establish uniformity of conditions on the site. Logs of the excavations are contained in Appendix A. Observation of the excavations indicates the site, where work is proposed, is underlain by a thin mantle of topsoil, on the order of 1-2 feet, and transitions quickly to a more dense �- undisturbed bedrock type material. The USGS Geologic Map of the Temecula Quadrangle indicates the formation underlying the site to be Pauba Formation and or younger valley alluvium. Bedrock is described as a dense to very dense sandstone and alluvium has variable density (loose to med. dense) where encountered. W. C. HOBBS, CONSULTING ENGINEER Mr. & Mrs. Maldonado, Preliminary Geotechnical Deport Project No: 14089-1 Testing of recovered soil sample (representative of the area) consisted of a laboratory maximum density test (ASTM D1557-12), Expansion index (ASTM D 4829). The results of testing are indicated in Appendix A. The development of the site as proposed is both feasible and safe from a geotechnical standpoint provided that the recommendations contained herein are implemented during design and construction. 1. According to the grading plan, the proposed pad and residence construction will 4r occur approximately in the eastern to central portion of the site with driveway extending east and connecting to Calle De Velardo. 2. Observation of excavations indicates that bedrock is suitable material for support of fill and or structures and is near the surface on the site. Valley alluvium is not suitable for support of fills and exists at variable depths along the southern boundary of the site. All earth materials encountered on the site are suitable for use as compacted structural fill. 3. Observation, classification, and testing indicate that the near surface soils have a very low expansion potential (EI<20). Please refer to Plate 1, the Geotechnical Map for site geometry and corresponding relationships of earth units described in this and the following section(s). In general, the entire subject site is underlain by Cretaceous -age granitic bedrock (Morton & Kennedy, 2005). Alluvium is present in shallow amounts (1'-12') in a shallow ravine and is within the proposed development limits. Granitic bedrock (Tonalite, of the Tucalota Valley Pluton) was exposed at the ground surface and various depths throughout the pad as noted. This unit can be described as light gray to yellow brown, coarse grained, dry to slightly moist, slightly weathered, massive and loose near the surface and density increases with depth. This unit directly underlies the aforementioned topsoil, Alluvium and the remainder of the site. W. C. HOBBS, CONSULTING ENGINEER r. & Mrs. Maldonado, Preliminary Geotechnical Report Page: 4 Project No: 14089-1 Younger valley infill alluvium is typically medium grained slightly silty sand with variable density and is found at the channel level of most ravines. It is a moderate to high energy deposit and based on its young age, has considerable settlement potential remaining. It is identified on the Geotechnical Plate attached to this report and is discussed further in the grading recommendations section following. -' Soil liquefaction is the loss of soil strength due to increased pore water pressures caused by a significant ground shaking (seismic) event. Liquefaction typically consists of the re- arrangement of the soil particles into a denser condition resulting, in this case, in localized areas of settlement, sand boils, and flow failures. Areas underlain by loose to medium dense cohesionless soils, where groundwater is within 30 to 40 feet of the surface, are particularly susceptible when subject to ground accelerations such as those due to earthquake motion. The liquefaction potential is generally considered greatest in saturated loose, poorly graded fine sands with a mean grain size (D50) in the range of 0.075 to 0.2mm. Typically, liquefaction has a relatively low potential at depths greater than 45-ft and is virtually unknown below a depth of 60-ft. Procedures outlined in two publications, 1) The Guidelines for Evaluation and Mitigation of Seismic Hazards in California, Special Publication 117: Department of Conservation, Division of Mines and Geology (1997); and 2) Recommendations for Implementation of DMG Special Publication 117: Guidelines of Analyzing and Mitigation, Liquefaction Hazards in California: Southern California Earthquake Center University of Southern California (1997), provide for a "screening study" in lieu of a complete liquefaction analysis. It is our opinion that, owing to the absence of shallow groundwater and the dense to very dense granitic bedrock underlying the subject site, liquefaction and other shallow groundwater related hazards are not anticipated, and further analysis appears to be unwarranted at this time. Eased on the above information, the liquefaction potential is anticipated to be negligible. Secondary Seismic Hazards Due to the distance from mapped faults nearby and the dense nature of the bedrock, seismically induced ground rupture, soil settlement of the bedrock, landsliding, rock fall potential, seiches and tsunamis are not considered potential hazards of the site. W. C. HOBBS, CONSULTING ENGINEER Mr. & Mrs. Maldonado, Preliminary Geotechnical Report Project No: 14089-1 The recommendations contained herein are contingent upon the undersigned providing the services listed in the Construction section in order to confirm design assumptions and review the field conditions of any excavations for possible anisotropic properties. If subsequent observation indicates that the conditions are different than those indicated in this report, additional, or modifications to the recommendations may become necessary. The sketch grading plan indicates that grading will consists of the creation of a pad, cut and fill slopes, and a driveway accessing east to Calle De Velardo. It is estimated that the grading will utilize all excavated materials into the fill area at the southern reaches of the pad. No import or export of soils is anticipated at this time. A representative of this firm shall be present to observe the bottoms of all excavations. A representative of this firm shall be present during all fill placement operations to monitor and test as the earth materials are being placed. This observation and testing is intended to assure compliance with the recommendations of this report as well as project specifications as they relate to earthwork construction, County and State ordinances and Table 1705.6 of the 2013 California Building Code. Earthwork shall be conducted in such a way that all structural fills are founded on approved and observed competent bedrock. This means that all topsoil and younger valley fill alluvium shall be removed from areas where structures and or fill is proposed. Soils derived from excavations will be suitable for use as structural fill provided they are free of large rock {8" or larger) and organic debris or construction waste. Approved fill material should be placed in 6 to 8-inch loose lifts, brought to optimum moisture content, and compacted to a minimum of 90% of the maximum laboratory dry density, as determined by the ASTIVI D 1557-12 test method. No rocks larger than 8 inches in diameter should be used as fill material as they inhibit the compaction process. Rocks larger than 8 inches may be removed or crushed and used as fill material. Rocks larger than 8 inches that cannot be crushed, organic materials, asphaltic concrete or oil bearing surface aggregate should be removed from the graded area and in the case of oil bearing materials, removed and taken to an appropriate dump site that is designed to handle such. W. C. HOBBS, CONSULTING ENGINEER r. & Mrs. Maldonado, Preliminary Geotechnical Report Project No: 14089-1 Rocks larger than 8 inches may also be set aside for re -use as energy dissipaters at the terminus of approved drainage devises where concentrated flow is returned to sheet type flow (low energy). No structural fill shall be placed on any ground without first being observed by a representative of the company providing this report and then providing written certification that the ground is competent and prepared to receive fill. In the case where the building is transacting or very close to a cut fill transition line, the cut side of the building area shall be over excavated such that there is a minimum of 6 feet fill thickness over the entire building area. That over excavation shall also extend a minimum of 6 feet beyond the building line, or to an extent equal to the thickness of the fill, whichever is the greater. ,oft All earthwork should be done in accordance with the specifications contained in Appendix C. Additionally, it will be the responsibility of the owner and or the grading contractor to provide this firm with schedule information for grading activities that require observation and testing. It is preferred that we have a minimum of 48 hours of notice for such. Baring Value and Footing Geometry A safe allowable bearing value for foundations embedded into observed and competent native ground is 2,500 psf. Continuous footings should have a minimum width of 12 inches and depth of 12 inches and conform to the minimum criteria of the 2013 CBC for very low expansive soils (EI<20). The use of isolated column footings is not discouraged, however, where utilized, should have a minimum embedment of 18 inches below lowest soil grade. The minimum distance of the bottom outside edge of all footings and any slope face shall be 5 feet. All footings should be embedded a minimum of 12 inches into observed competent native bedrock materials or properly compacted fill, regardless of depth below the adjacent ground surface. The bearing value recommended above reflects a total settlement of 0.5" and a differential settlement of 0.5" within a horizontal distance of 10 feet (IJ240). Most of this settlement is expected to occur during construction and as the loads are being applied. W. C. HOBBS, CONSULTING ENGINEER r. & Mrs. Maldonado, Preliminary Geotechnical Report Page: i Project No: 14089-1 All concrete slabs on grade should be 4 inches thick, nominal. They should be underlain by 2 inches of sand or gravel or approved non expansive onsite materials. Imported or approved onsite materials may be utilized for this purpose. Contractors should be advised that when pouring during hot or windy weather conditions, they should provide large slabs with sufficiently deep weakened plane joints to inhibit the development of irregular or unsightly cracks. Also, 4 inch thick slabs should be jointed in panels not exceeding 8 feet in both directions to augment proper crack direction and development. Reinforcement From a Geotechnical standpoint, continuous footings should be reinforced with a minimum of one number 4 steel bar placed at the top and bottom. In no case should the low content of steel in concrete footings be less than the recommended minimums of the appropriate sections of the A.C.I. standards. Slabs should be reinforced with a minimum of number 3 steel bars placed at the center of thickness at 18-inch centers both ways (CBC 2013). These are considered minimums and additional requirements may be imposed by other structural engineering design requirements. Type V portland cement concrete will not be required for the subject site. Lateral Loads The bearing value of the soil may be increased by one third for short duration loading (wind, seismic). Lateral loads may be resisted by passive forces developed along the sides of concrete footings or by friction along the bottom of concrete footings. The value of the passive resistance for level ground may be computed using an equivalent fluid density of 300 pcf for level ground. The total force should not exceed 3,000 psf. A coefficient of friction of .40 may be used for the horizontal soil/concrete interface for resistance of lateral forces. If friction and passive forces are combined, then the passive values should be reduced by one third. W. C. HOBBS, CONSULTING ENGINEER r. & Mrs. Maldonado, Preliminary Geotechnical Report Page: 8 Project No: 14089-1 Retaining walls should be designed to resist the active pressures summarized in the following table. The active pressure is normally calculated from the lowermost portion of the footing to the highest ground surface at the back of the wall. The active pressures indicated in the table are equivalent fluid densities. Walls that are not free to rotate or that are braced at the top (at rest) should use active pressures that are 50% greater than those indicated in the table. RETAINING WALL DESIGN PRESSURES Slope_of Active Pressure Passive Pressure adiacent ground LEVEL 32 pcf 350 pcf 2:1 48 pcf 175 pcf These pressures are for retaining walls backfilled with non -cohesive (EI<20), granular materials and provided with drainage devices such as weep holes or subdrains to prevent the build-up of hydrostatic pressures beyond the design values. It is imperative that all retaining wall backfills be compacted to a minimum of 90 percent relative compaction in order to achieve their design strength. Failure to provide proper drainage and minimum compaction may result in pressures against the wall that will exceed the design values indicated above. Surface waters should be directed away from retaining wall backfill areas so as not to intrude into the backfill materials. Utility Trench Beckfill All trench excavations should be conducted in accordance with Cal -OSHA standards as a minimum. The soils encountered within our exploratory trenches are generally classified as Type "C" soil in accordance with the CAL/OSHA (2007) excavation standards. Based upon a soil classification of Type "C", the temporary excavations should not be inclined steeper than 1.5 : 1 (horizontal : vertical) for a maximum depth of 20-ft. For temporary excavations deeper than 20-ft or for conditions that differ from those described for Type "C" in the CAL/OSHA excavation standards, the project geotechnical engineer should be contacted. W. C. HOBBS, CONSULTING ENGINEER Mr. & Mrs. Maldonado, Preliminary Geotechnical Report Project No: 14089-1 r1r_Jr9§TAT= Utility trench backfill should be compacted to a minimum of 90 percent of the maximum dry density determined in laboratory testing by the ASTIVI D 1557-12 test method. It is our opinion that utility trench backfill consisting of onsite or approved sandy soils can best be placed by mechanical compaction to a minimum of 90 percent of the maximum dry density, The upper 1-ft of utility trench excavations located within pavement areas should be compacted to a minimum of 95 percent of the maximum dry density. Fine grading of areas outside of the residence should be accomplished such that positive drainage exists away from all footings in accordance with 2013 CBC and local governing agency requirements. Run-off should be conducted in a non -erosive manner toward approved drainage devices per approved plans. No run-off should be allowed to concentrate and flow over the tops of slopes. Seismic design of structures should be in accordance with design parameters set forth Appendix B. Seismic Design Category D is used and the longitude and latitude of the site were utilized in the tool to determine design horizontal accelerations and other design parameters of the site. W. C. HOBBS, CONSULTING ENGINEER Mr. & Mrs. Maldonado, Preliminary Geotechnical Report Page: 10 Project No: 14089-1 Recommendations, continued W. C. Hobbs, Consulting Engineer, or a duly designated representative, should be present during all earthwork construction in accordance with the standard specifications contained at the back of this report, to test and or confirm the conditions encountered during this study. In addition, post earthwork construction monitoring should be conducted at the following stages: • At the completion of final grading of the building pad so that a finished surface compaction test may be obtained. Moisture content near optimum will necessarily need to be maintained, both to maintain proper compaction and to prevent wind erosion of the pad. At the completion of foundation excavations, but prior to the placement of steel and or other construction materials in them. As a requirement of this report, the undersigned must, in writing, certify that the foundations meet the minimum requirements of this report and the building plans for depth and width along with the earth materials being the appropriate moisture content and compaction. Backfilling of over deepened footings with earth materials will not be allowed and must be poured with concrete. Consequential changes and differences may exist throughout the earth materials on the site. It may be possible that certain excavations may have to be deepened slightly if earth materials are found to be loose or weak during these observations. • Any other pertinent post construction activity where soils are excavated or manipulated or relied upon in any way for the performance of buildings or hardscape features. Supplemental Recommendations If at any time during grading or construction on this site, conditions are found to be different than those indicated in this report, it is essential that the soil engineer be notified. The soil engineer reserves the right to modify in any appropriate way the recommendations of this report if site conditions are found to be different than those indicated in this report. W. C. HOBBS, CONSULTING ENGINEER r. & Mrs. Maldonado, Preliminary Geotechnical Report Project No: 14089-1 Our investigation was performed using the degree of care and skill ordinarily exercised, under similar circumstances, by reputable Geotechnical Engineers and Geologists practicing in this or similar localities. No other warranty, expressed or implied, is made as to the conclusions and professional advice included in this report. This report is issued with the understanding that it is used only by the owner and it is the sole responsibility of the owner or their representative to ensure that the information and recommendations contained herein are brought to the attention of the architect, engineer, and appropriate jurisdictional agency for the project and incorporated into the plans, and the necessary steps are taken to see that the contractor and subcontractors carry out such recommendations contained herein during construction and in the field. The samples taken and used for testing and the observations made are believed representative; however, soil and geologic conditions can vary significantly between test locations. The evaluation or identification of the potential presence of hazardous or corrosive materials was not part of the scope of services provided by W. C. Hobbs, Consulting Engineer. The findings of this report are valid as of the present date. However, changes in the conditions of a property can occur with the passage of time, whether due to natural processes or the works of man on this or adjacent properties. In addition, changes in applicable or appropriate standards may occur, whether they result from legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and revision as changed conditions are identified. The firm that performed the geotechnical investigation for this project should be retained to provide testing observation services during construction to maintain continuity of geotechnical interpretation and to check that the recommendations presented herein are implemented during site grading, excavation of foundations and construction of improvements. If another geotechnical firm is selected to perform the testing and observation services during construction operations, that firm should prepare a letter indicating their intent to assume the responsibilities of project geotechnical engineer of record. Selection of another firm to perform any of the recommended activities or failure to retain the undersigned to perform the recommended activities wholly absolves W. C. Hobbs, Consulting Engineer, the undersigned, and its assigns from any and all liability arising directly or indirectly from any aspects of this project. W. C. HOBBS, CONSULTING ENGINEER Mr. & Mrs. Maldonado, Preliminary Geotechnical Report Page: 12 Project No: 14089-1 The opportunity to be of service is appreciated. Should questions or comments arise pertaining to this document, or if we may be of further service, please do not hesitate to call our office. Respectfully Submitted, Bil bs, RCE 42265 Civil Engineer ELM 42,26-5 am Distribution: Addressee (3) Attachments: Plate 1, Geotechnical Map 60 Appendix A, Summary of Test Results Appendix B, Seismic Design Information Appendix C, General Earthwork and Grading Specifications References: Grading Plan, Parcel 3 of Parcel Map No: 18015, Calle De Velardo, dated 9/3/2014 by Civil Consulting of Corona. Geologic Map of the Temecula 7.5' Quadrangle, Riverside County, California, Version 1.0 by D. M. Morton and M. P. Kennedy, 2005, USGS, CGS W. C. HOBBS, CONSULTING ENGINEER GRAPHIC SCALE 100 0 50 100 200 400 1 INCH : 100 FT rl uo 04 A �!lk W. C. HOBBS, CONSULTING ENGINEER QP0 lf:(T NA- idnqQ-1 BORING" 1 . ......... Lu Lu DEPTH SAMPLE SOIL cl) IN FEET NO: CLASS (USCS) ELEVATION: 1195 MSL DATE: NOVEMBER 14,2014 Lu cf> C�k Lu izi j.— U) (D EQUIPMENT. CME 55,2R DRILLING, INC. BY. WCH 1 cr- ca MATERIAL DESCRIPTION 0 TOPSOIL: sm-sw TAN TO YELLOW BROWN, DRY TO DAMP, FINE TO COARSE GRAINED, SLIGHTLY SILTY, TOP 12" LOOSE, BECOMES DENSE TO VERY DENSE AT 1'. —291504" 121.2 11.7 BEDROCK, PALIBA FORMATION (Opfs): B-1 TAN FINE TO MEDIUM SAND, SLIGHTLY SILTY, NON PLASTIC, DAMP, DENSE 5 2 sw 29139 119.9 15,8 @ 6BROWN FINE TO MEDIUM SAND, SLIGHTLY SILTY, NON PLASTIC, DAMP, VERY DENSE 151 — — — — — ---- — — — — — — — — - - — — — — — — SM-SW — — — — — — — — — — — — — — — — — — — — TAN FINE TO MEDIUM SAND, TRACE SILT AND CLAY, VERY LOW PLASTIC, DAMP TO MOIST, VERY DENSE 20' 25 — — — — — — — — — — — — — — — — — — — — — — — — — — — — — ---- DARK GRAY SAND, COARSE, MOIST, VERY DENSE — — — — — — — — - 30' — — — — — — — — — — — — — — — — — — — — — — — — — — — - BECOMING VERY MOIST AT 34'-35' 7-- LOG OF BORING 1, PAGE 1 OF 2 BULK SAMPLE STANDARD PENETRATION TEST RING SAMPLE UNDISTURBED SAMPLE SYMBOLS. NO SAMPLE CHUNK SAMPLE V WATER TABLE OR SEEPAGE NOTE, THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT Ttit VA I L INVf(;A I tU 7 IS NOT WARRANTED TO BE REPRESENTATIVE OF THE SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. W. C. HOBBS, CONSULTING ENGINEER PP0-I1:rTNn- 140AP-1 DEPTH IN FEET SAMPLE NO: SOIL CLASS (USCS) "G 1 BORIN ELEVATION. 1195 MSL DATE: NOVEMBER 4,2014 EQUIPMENT, CME 55,2R DRILLING, INC. BY: WCH L u- uj 0� C.5 U-1 Cf> C-1 LU c.3 - er tu MATERIAL DESCRIPTION GROUNDWATER AT 35', HOLE LEFT OPEN TO STABILIZE WATER SURFACE. CUTTINGS WET, DENSE, INTERBEDS OF FINE TO MED, COARSE SANDS 401- 45t BORING TERMINATED AT 46 FEET GROUNDWATER @ 35' HOLE BACKFILLED WITH AUGER CUTTINGS 501 551 601 65' LOG OF BORING 1, PAGE 2 OF 2 SAMPLE SYMBOLS' BULK SAMPLE STANDARD PENETRATION TEST RING SAMPLE UNDISTURBED NO SAMPLE CHUNK SAMPLE WATER TABLE OR SEEPAGE NOTE. THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF THE SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. W. C. HOBBS, CONSULTING ENGINEER DDf) 1170T Kin- IAIIAO-1 ............ - -- -------- BORING 2 DEPTH SAMPLE SOIL ct IN FEET NO: CLASS (USCS) ELEVATION: 1187 MSL DATE: NOVEMBER 14,2014 Lu to C) --2! Lu Lu c cc: u3 EQUIPMENT. CME 55,2R DRILLING, INC. BY., WCH cl- Lu cr- MATERIAL. DESCRIPTION 0 ALLUVIAL VALLEY DEPOSITS (Qyv): SM-ML BROWN TO DARK BROWN SILTY FINE TO MEDIUM SAND, MODERATELY PLASTIC, MEDIUM DENSE, MOIST B-2 - - - - - - - - - - - - - - - - - - - - - - - - - --- 51 - - SP TAN TO LIGHT BROWN SAND, POORLY GRADED, DAMP TO MOIST, MEDIUM DENSE BEDROCK, PAUBA FORMATION (Qpfs): 1— 5 TAN TO LIGHT GRAY SAND, COARSE, DAMP TO MOIST, VERY DENSE 201 BORING TERMINATED AT 21 FEET 0 GROUNDWATER ENCOUNTERED NO DOLE BACKFILLED WITH AUGER CUTTINGS 25'- 30' LOG OF BORING 2. PAGE 1 OF 1 BULK SAMPLE STANDARD PENETRATION TEST RING SAMPLE UNDISTURBED SAMPLE SYMBOLS, NO SAMPLE Q CHUNK SAMPLE WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENGN LUCA I IUN AND A I JHtUAlt(NU LAILU IT IS NOT WARRANTED TO BE REPRESENTATIVE OF THE SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES, W. C. HOBBS, CONSULTING ENGINEER Expansion Index = 11 ASTM D 4829 Expansion Classification = VERY LOW MISCELLANEOUS TESTING ph test results = 7.2 S- 1. 1 ow. S. Resistivity = 11 00ohm/cm SM 2520B Sulfate = 38 ppm Ion Chromatagraph W. C. HOBBS, CONSULTING ENGINEER .- rA Xg 04 4 T. F- -1-1 U I SEISMIC DESIGN INFORMATION W. C. HOBBS, CONSULTING ENGINEER Design Maps Summary Report Page I of 2 WISM Design maps Summary Report a& User -Specified Input Report Title Calle De Velardo I -y 142015 Ned �L - 16:36:38 UT 3anua� Building C® Reference Document 2012 International Building Code (wNdh ut'H7-2s USGS c�at'a ava_Hab_;'e ir 20,08" Site Coordinates 33.490N, 117.1187OW Site Soil Classification Site Class D - "Stiff Soil" Risk Category I/II/III ITI =-1 S, ® 1.903 g S1. = 0.775 g 9�1�= Sus = 1.2689 ©, = 0.775 g For information on how the SS and S. 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 NEHRV building code reference document. MCER Response Spectrum I 2.20 — 2. 0?5 b.0 - - GO + Ch 1,00 W .00 0. 40 0.00 0.2ri o.40 0.20 1.00 L20 L40 1.50 1.90 2-00 Period, T (sec) Design Response Spectrum 0. C-5 - 0. 2G 0. 00 0.00 0.6.0 0.90 1.00 L20 1.40 LGG 1.20 2,00 Period, T (seck http://ehp3-earthquake.wr.usgs.gov/designmaps/us/summary.php.Aemplate=minimal&latit... 1/14/2015 Design Maps Summary Report Page 2 of 2 dftI In Aitr,ough,irfcrmaa-10n 1s 1-1 product cf thlle '-,,,S, Geo cc-lk-El SWNEY, We P'Fcvno v,,a� rant y, exores -aincd, ltherein. �l -o! not a substit f c r � — v 1, - . L i I , 'r� �c - -1, a c v 0 e�l , a, a - http://ehp3-earthquake.wr.usgs.gov/designmaps/us/summary.phpAemplate—minimal&latit... 1/1.4/2015 Design. Maps Detailed Report Page 1. of 4 ��� �����'O[l Maps Detailed ����rf ���������� Design . . , ~.~~~" ~. Report 2012In1ernationa! Building Code(33.49oN, 117.1187»VV) Site Class D — 'Stiff Soil", Risk Category I/II/III Section 1G13.3.1—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 S") and 1.3 (to obtain B,). Maps in the 2012 International Building Code are provided for Site Class B. Adjustments for other Site Classes are made, as needed, in Section 1613.3.3. F r omm �x Ss = 1.903 g From ;« Sz= 0.775g Section 1613.3.2 — Site class definitions The authority having jurisdiction (not the USGS), site-specificgeotechnico( data, and/or the default has classified the site as Site [lass O, based on the site soil properties in accordance with Section 1613. 2o1omscs-7Standard - Table zo.s-1 SITE CLASS DEFINITIONS WWW54Q=11- F.Soils requiring site response analysis maccordance with Section 2z.1 >5,0000/s N/A N/A 2,500to5,000ft/s N/A N/A 1,200to2,500M/s >50 >2,000nsr 800to 1,200ft/s /5tu50 z,OUUto z,000psf <eoOft/s <15 <1,000ps/ Any profile with more than zo ft of soil having the characteristics: ° Plasticity index PI > 20, " Moisture content w > 40%, and ° Undramed shear strength s, < 500 psf See Section 20.3.1 For SI:Ift/s =o.304emlsub/ft2 =o.0479 kN/m` Design Maps Detailed Report Section 1613.3.3 --Sit000effdents and adjusted rnavdrnunn considered earthquake spectral response acceleration parameters TABLE 1613.3.3(x) VALUES opSITE COEFFICIENT F, Site Class Mapped Spectral Response Acceleration at Short Period S, :5 O.25 E, = 0.50 S" = 0.75 S, = 1.80 Ss �!: 1.25 B 1.0 1.8 1.8 1.0 1.0 C 1.2 1.2 1.z 1.0 1.0 D 1.6 1.4 1.2 1.11.0 -- 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 S, TABLE 1613.3.3(2) vxLues OF SITE COEFFICIENT F, Site Class Mapped Spectral Response Acceleration at 1-s Period S, :5 O.zO E, = 0.20 E, = 0.20 S, = 0.40 S, �: 0.50 A 0.8 0.8 0.8 0.8 0.8 B 1.0 1.0 1.0 1.0 1.0 ) [ 1.7 1.6 1.5 1.4 1.3 D 2.4 2.0 1.8 1.6 1.5 E 3.5 3.2 2.8 2.4 2.4 F Sea Section 11.4.7 ofAS[E 7 Note: Use straight-line interpolation for intermediate values of Si | 1/14/2015 Design Maps Detailed Report Page 3 of 4 Mid I 1.000 x 1.903 = 1.903 �* Section 1613.3.4 — Design spectral response acceleration parameters Equation (16-39)'. S, = % Sms = I/, x 1.903 = 1.268 g Equation (16-40): S,), = 1/3 Sm, = 1/3 x 1.162 = 0.775 g http://ehp3-earthquake.wr.usgs-govldesignmapsluslreport-php?template=minimal&l.atitude... 1/ 14/2015 Design Maps Detailed Report Page 4 of 4 Section 1613.3.5 — Determination of seismic design category TABLE 1613.3.5(l) Qr-T--MTr- nFqT(-,N CATFGORY BASED ON SHORT -PERIOD (0.2 second) RESPONSE ACCELERATION �^^ TABLE 1613.3.5(2) -- NA,, "==T=h1 I-^-r==""vn^C=n nm ,-=prnmo pFnrnn neSpomssAccsuenxnuOm AWL RISK CATEGORY Note: When S, is greater than or equal to 0.75g, the Seismic Design Category is E for buildings in Risk Categories l, II, and III, and F for those in Risk Category D/, irrespective ofthe above. Seismic Design Category =_ "the more severe design category in accordance with Table 1613.3.5(l) or 1613.3.5(2)"= E Note: See Section 1613.3.5.1 for alternative approaches to calculating Seismic Design References 1. Fi7une1613.3.1(1): http://earthouake.usgs.yov/hazords/designrnaps/dmwn|oads/pdfs/IBC-2O12- Plg1613p3p1(1).pdf - 2. Fignure1613.3.1/2):http///eam:hquake.usgs.gov/hezards/des)gnnmaps/dnwn1oods/pdfs/IBC-2O12- Fig1613p3p1(2).pdf l/l4/2O}5 W. C. HOBBS, CONSULTING ENGINEER These specifications present general procedures and requirements for grading and earthwork as shown on the approved grading plans, including preparation of areas to be filled, placement of fill, installation of subdrains, and excavations. The recommendations contained in the geotechnical report are a part of the earthwork and grading specifications and shall supersede the provisions contained hereinafter in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new recommendations of the geotechnical report. 2.0 EARTHWORK OBSERVATION AND TESTING Prior to the commencement of grading, a qualified geotechnical consultant (soils engineer and engineering geologist, and their representatives) shall be employed for the purpose of observing earthwork and testing the fills for conformance with the recommendations of the geotechnical report and these specifications. It will be necessary that the consultant provide adequate testing and observation so that he may determine that the work was accomplished as specified. It shall be the responsibility of the contractor to assist the consultant and keep him apprised of work schedules and changes so that he may schedule his personnel accordingly. It shall be the sole responsibility of the contractor to provide adequate equipment and methods to accomplish the work in accordance with applicable grading codes or agency ordinances, these specifications and the approved grading plans. If in the opinion of the consultant, unsatisfactory conditions, such as questionable soil, poor moisture condition, inadequate compaction, adverse weather, etc., are resulting in a quality of work less than required in these specifications, the consultant will be empowered to reject the work and recommend that construction be stopped until the conditions are rectified. Maximum dry density tests used to determine the degree of compaction will be performed in accordance with the American Society of Testing and Materials tests method ASTM D1557-12. 3.0 PREPARATION OF AREAS TO BE FILLED 3.1 Clearing and Grubbing: All brush, vegetation and debris shall be removed or piled and otherwise disposed of. 3.2 Processing: The existing ground which is determined to be satisfactory for support of fill shall be scarified to a minimum -- depth of 6 inches. Existing ground which is not satisfactory shall be over excavated as specified in the following section. Scarification shall continue until the soils are broken down and free of large clay lumps or clods and until the working surface is reasonably uniform and free of uneven features which would inhibit uniform compaction. 3.3 Over excavation: Soft, dry, spongy, highly fractured or otherwise unsuitable ground, extending to such a depth that the surface processing cannot adequately improve the condition, shall be over excavated down to firm ground, approved by the consultant. 3.4 Moisture Conditioning: Over excavated and processed soils shall be watered, dried -back, blended, and/or mixed, as required to attain a uniform moisture content near optimum. 3.5 Recomipaction: Over excavated and processed soils which have been properly mixed and moisture- conditioned shall be recompacted to a minimum relative compaction of 90 percent. 3.6 Benching: Where fills are to be placed on ground with slopes steeper than 5: 1 (horizontal to vertical units), the ground shall be stepped or benched. The lowest bench shall be a minimum of 15 feet wide, shall be at least 2 feet deep, shall expose firm material, and shall be approved by the consultant. Other benches shall be excavated in firm material for a minimum width of 4 feet. Ground sloping flatter than 5:1 shall be benched or otherwise over excavated when considered necessary by the consultant. W. C. HOBBS, CONSULTING ENGINEER 3.7 Approval: All areas to receive fill, including processed areas, removal areas and toe -of -fill benches shall be approved by the consultant prior to fill placement. 4.0 FILL MATERIAL 4.1 General: Material to be placed as fill shall be free of organic matter and other deleterious substances, and shall be approved by the consultant. Soils of poor gradation, expansion, or strength characteristics shall be placed in areas designated by consultant or shall be mixed with other soils to serve as satisfactory fill material. 4.2 Oversize: Oversize material defined as rock, or other irreducible material with a maximum dimension greater than 12 inches, shall not be buried or placed in fills, unless the location, materials, and disposal methods are specifically approved by the consultant. Oversize disposal operations shall be such that nesting of oversize material does not occur, and such that the oversize material is completely surrounded by properly compacted fill. Oversize material shall not be placed within 10 feet vertically of finish grade or within the range of future utilities or underground construction, unless specifically approved by the consultant. 4.3 Import: If importing of material is required for grading, the import material shall meet the requirements of Section 4.1. 5.0 FILL PLACEMENT AND COMPACTION 5.1 Fill Lifts: Approved fill material shall be placed in areas prepared to receive fill in near -horizontal layers not exceeding 6 inches in compacted thickness. The consultant may approve thicker lifts if testing indicates the grading procedures are such that adequate compaction is being achieved with lifts of greater thickness. Each layer shall be spread evenly and shall be thoroughly mixed during spreading to attain uniformity of material and moisture in each layer. 5.2 Fill Moisture: Fill layers at a moisture content less than optimum shall be watered and mixed, and wet fill layers shall be aerated by scarification or shall be blended with drier material. Moisture -conditioning and mixing of fill layers shall continue until the fill material is at a uniform moisture content or near optimum. 5.3 Compaction of Fill: After each layer has been evenly spread, moisture conditioned, and mixed, it shall be uniformly compacted to not less than 90 percent of maximum dry density. Compaction equipment shall be adequately sized and shall be either specifically designed for soil compaction or of proven reliability, to efficiently achieve the specified degree of compaction. 5.4 Fill Slopes: Compaction of slopes shall be accomplished, in addition to normal compacting procedures, by backfilling of slopes with sheepsfoot rollers at frequent increments of 2 to 3 feet in fill elevation gain, or by other methods producing satisfactory results. At the completion of grading, the relative compaction of the slope out to the slope face shall be at least 90 percent. 5.5 Compaction Testing: Field tests to check the ill moisture and degree of compaction will be performed by the consultant. The location and frequency of tests shall be at the consultant's discretion. In general, the tests will be taken at an interval not exceeding 2 feet in vertical rise and/or 1,000 cubic yards of embankment. 6.0 SUBDRAIN INSTALLATION Subdrain systems, if required, shall be installed in approved ground to conform to the approximate alignment and details shown on the plans or herein. The subdrain location or materials shall not be changed or modified without the approval of the consultant. The consultant, however, may recommend and upon approval, direct changes in subdrain line, grade or material. All subdrains should be surveyed for line and grade after installation, and sufficient time shall be allowed for the surveys, prior to commencement of filling over the subdrains. W. C. HOBBS, CONSULTING ENGINEER Excavation and cut slopes will be examined during grading. If directed by the consultant, further excavation or over excavation and refilling of cut areas shall be parfonned, and/or remedial grading of cut slopes shall be performed. Where fill -over -cut slopes are tobegraded, unless otherwise oppnoved,thecutporUonoftheo|npeohaUmadeandappnovedbvtheoonoultant prior to placement ofmaterials for construction ofthe fill portion of the slope. 8.0 TRENCH BACKFILL 8'1 Supervision: Trench excavations for the utility pipes shall be backfilled under engineering supervision. 8.2 Pipe Zone: After the utility pipe has been laid, the space under and around the pipe shall be backfilled with clean sand or approved granular soil to a depth of at least one foot over the top of the pipe. The sand backfill shall be uniformly jetted into place before the controlled bankfi||iaplaced over the sand. 8.3 Fill Placement: The onoitematerials, orother soils approved bythe engineer, shall bewatered and mixed aonecessary prior toplacement |nlifts over the sand bookDU. 8.4 Compaction: The oon1no||ad backfi|| shall be compacted to at least 80 percent of the maximum laboratory density as determined bythe A8TN1compaction method described above. 8.5 Observation and Testing: Field density tests and inspection of the backfill procedures shall be made by the soil engineer during backfi|||ng too see that the proper moisture content and uniform compaction is being maintained. The contractor shall provide test holes and exploratory pits as required by the soil engineer to enable sampling and testing. W. C. HOBBS, CONSULTING ENGINEER