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Home My WebLink AboutTract Map 35481 Highgate Senior Center Geotechnical Reports • , 1 " 1 1 1 � 11 1 1 • ' • 1 1 • • • 1 . 1 I I 11 : iWao v:! Mir f ✓� !f P "+ „�Y � • ,./ / r 'r"�'1 ��.> -.h .y4�� I! r. 'S:t_a7 �i11� �'�...�1 i• ,. Ai- NCO1,=� �1A1=� 11a/' ff1- .u,� ��' �''` �,y{(mow •�`• _ ��>s _, 3 .0 1.www 1�1 — f'd 1-0 f�..�� T!•�1�� r ry 1 A r rt•tom. ( kl � r jj .f9 f p - '�'� R. us.w '7dr,w�i �►� ■��rr� r J rilIr® a rj .d ' •e*./.e� "j1r'/ ��"�R err; 1°'"�T � �. Vvn+� � /fir• Y 1 / ] !`:_la�,.'.1' r r,l e� �+�,`�� _ �_ J � 1t rA� IE4Y' / r ia- I4 1.5:6'fY `/ /f✓: �� /a r' � / � �� .� �Zftfi�.^-,1 � �n iiiMMMj�� s} :.r. f :R:ys� 75.�'1:� / s,�./��yJR '�♦r1 +�F�j/11tt1� " ' '�,Ix�.\, �Fi -vjv tp1'4U "°f<5+ y �, f Ir �(•! Ir t/`�"'r �d ,:J•� .tf .�If 'a'./®' it ter& ..:� 'g,,. ..�. PW . 1 --N-- - e ---------- Earx-tI� Strata, 117/,c., Geofeahnloal,Env/mnmenhl and Mawtals Testing Consultants BETTER PEOPLE.BETTER SERVICE.BETTER RESULTS March 12, 2008 Project No. 07220-30A Mr. Robert Crisell RANCHO VIEW PROFESSIONAL CENTER,LP 29377 Rancho California Road,Suite 101 Temecula, CA 92591 Subject: Geotechnical Report of Rough Grading, Rancho View Professional Center, Located on the Southwest Corner of Rancho California Road and Moraga Road, City of Temecula, Riverside County,California INTRODUCTION Per your authorization, Earth-Strata, Inc. has provided observations and testing services during rough grading for the proposed professional center, located on the southwest corner of Rancho California Road and Moraga Road in the City of Temecula, Riverside County, California. This report summarizes the geotechnical conditions observed and tested during rough grading. Conclusions and recommendations with regard to the suitability of the grading for the proposed project are provided herein, along with foundation design recommendations based on the earth materials present at the completion of grading. Grading commenced in order to develop two (2) building pads for construction of one- and/or two-story structures. The proposed development will consist of commercial buildings utilizing slab on grade,wood or steel-framed construction. Grading operations began in January 2008 and were completed in March 2008. REGULATORY COMPLIANCE Observations and selective testing have been performed by representatives of Earth-Strata, Inc. during the removal and recompaction of low-density near surface earth materials. Our services were performed in general accordance with the recommendations presented in the referenced reports (see References), the grading code of the reviewing agency, and as dictated by conditions encountered in the field. The earthwork described herein has been reviewed and is considered adequate for the construction now planned. The recommendations presented in this report were prepared in conformance with generally accepted professional engineering practices in this area at the time of this report and no further warranty is expressed or implied. ENGINEERING GEOLOGY Geologic Units Earth materials noted during grading operations included previously placed artificial fill, topsoil, and bedrock EARTH-STRATA,INC.•26047 JEFFERSON AVENUE,SUITE C,MURRIETA,CA 92562.OFFICE(951)461-4028•FAX(951)461-4058•W W W.EARTH-STRATA-COM BETTER PEOPLE - BETTER SERVICE - BETTER RESULTS Geolo}-ic Structure Geologic conditions exposed during grading operations were observed and mapped by Earth-Strata, Inc. The bedrock is generally massive to nearly horizontally bedded and lacks significant structural planes. Groundwater Groundwater was not encountered during grading operations. Felting No evidence of significant faulting was observed during grading operations. EARTHWORK OBSERVATIONS AND DENSITY TESTING Site Clearing and Grubbing Prior to grading, all trees,brush,shrubs,and grasses were stripped and removed from the compacted fill. Ground Preparation Keyway removals within the northeast corner of the site ranged from approximately 2 to 3 feet below original grades, with locally deeper removals. excavations within the proposed building areas were extended into competent bedrock to reduce material variations by constructing a uniform compacted fill with a minimum thickness of 3 feet Prior to placing compacted fill, the exposed bottom surfaces were scarified to depths of 6 to 8 inches, watered or air dried as necessary to achieve near optimum moisture content and then compacted to a minimum relative compaction of 90 percent. Oversize Rock Oversize rock, generally greater than 1 foot in maximum dimension, was not encountered during the grading operations. Fill Placement and Testing All.fills were placed in lifts restricted to approximately 6 to 8 inches in maximum thickness, watered or air dried as necessary to achieve near optimum moisture content, then compacted to a minimum relative density of 90 percent by rolling with a bulldozer, sheepsfoot, or loaded scrapers. The maximum vertical depth of compacted fill as a result of grading within the proposed building pads is approximately 3 feet Benching into competent earth materials was observed during fill placement and compaction operations. Field density and moisture content tests utilizing nuclear gauge methods were performed in accordance with ASTM Test Methods D2922 and D3017. Field density and moisture content tests conducted utilizing sand cone methods were performed in accordance with ASTM Test Method D1556. Visual classification EARTH-STRATA, INC. 2 March 12, 2008 of the earth materials in the field was the basis for determining which maximum dry density value was applicable for a given density test Test results are presented in Table 1 and test locations are shown on' the enclosed As-Graded Geotechnical Map, Plate 1. A summary of maximum and minimum fill thicknesses has been provided in Table 2 - LotSummary. Compacted fills were tested to verify that a minimum relative density of 90 percent had been achieved. At least one density test was taken for each 1,000 cubic yards and/or for every 2 vertical feet of compacted fill placed. The actual number of tests taken per day varied depending on the site conditions and the quantity and type of equipment utilized. When field density tests yielded results less than the minimum required relative density, the approximate limits of the substandard fill were established. The substandard area was then reworked (most common) or removed, moisture conditioned, recompacted, and retested until the minimum relative density was achieved. In most.cases, failed density tests were noted then retested in the same general vicinity at nearly the same elevation as the failed test Slopes Slopes constructed within the subject property consist of 22 feet high 2:1 (h:v) compacted fill slopes and cut slopes varying to a maximum height of 5 feet. LABORATORY TESTING Maximum Da Density Maximum dry density and optimum moisture content for representative earth materials noted during grading operations were determined using,the guidelines of ASTM Test Method D 1557-00. Pertinent test values are summarized in Appendix B. Expansion Index Tests. Expansion index tests were performed on representative earth materials sampled near finish grade for select building pads using the guidelines ofASTM D 4829-01 Test results are summarized in Appendix B. Soluble Sulfate Analyses The soluble sulfate content of select samples was determined using the guidelines of California Test Method (CTM) 417. Test results are summarized in Appendix B. Chloride Chloride content of select samples was determined using the guidelines of CTM 422. Test results are summarized in Appendix B. Minimum Resistivity and pH Minimum resistivity and pH tests of select samples were determined using the guidelines of CTM 643. Test results are summarized in Appendix B. EARTH-STRATA, INC. 3 March 12, 2008 POST GRADING CONSIDERATIONS Slope Landscaping and Maintenance Control of site drainage is important for the performance of the proposed project. Engineered slopes should be landscaped with deep rooted, drought tolerant, maintenance free plant species, as recommended by the project landscape architect. Unprotected slopes are highly susceptible to erosion and surficial slumping. Therefore to reduce this potential, we recommend that the slopes be covered with an erosion inhibitor until healthy plant growth is well established. To further reduce the potential for surficial instability, measures to control burrowing rodents should be performed as well. Site Drainaee Adequate slope and building pad drainage is essential for-the long term performance of the subject site. The gross stability of,graded slopes should not be adversely affected, provided all drainage provisions are properly constructed and maintained. ' Roof gutters are recommended for the proposed structures. Pad and,roof drainage should be collected and transferred to driveways, adjacent streets, storm-drain facilities, or other locations approved by the building official in non- erosive. drainage devices.. Drainage should not be allowed to pond on' the pad or against any foundation or retaining wall. Drainage should not be allowed to flow uncontrolled over any descending slope. Planters located within .retaining wall backfill should be sealed to prevent moisture intrusion into the backfill. Planters located next to raised floor type construction should be sealed to the depth of the footings. Drainage control devices require periodic cleaning, testing, and maintenance to remain effective. . At a,minimum, pad drainage should be designed at the minimum gradients required by the UBC.• To divert water away from foundations, the ground surface adjacent to foundations should be graded at the minimum gradients required per the CBC. Utility Trenches All utility trench backfill should be compacted to a minimum relative density of 90 percent. This includes within the street right-of-ways, utility easements, under footings, sidewalks, driveways and building Floor slabs, as well as within or adjacent to any slopes. Backfill should be placed in approximately 6 to 8 inch maximum loose lifts and then mechanically compacted with a hydro- hammer, rolling with a sheepsfoot, pneumatic tampers, or similar equipment. The utility trenches should be tested by the project geotechnical engineer or their representative to verify minimum compaction requirements are obtained. In order to minimize the penetration of moisture below building slabs, all utility trenches should be backfilled with compacted fill, lean concrete, or concrete slurry where they undercut the perimeter foundation. Utility trenches that are proposed parallel to any building footings (interior and/or exterior trenches), should not be located within a 1:1 (h:v) plane projected downward from the outside bottom edge of the footing. EARTH-STRATA, INC. 4 March 12, 2008 FOUNDATION DESIGN RECOMMENDATIONS General Conventional shallow foundations are recommended for support of the proposed structures. Foundation recommendations are provided herein. Allowable Bearing Values An allowable bearing value of 2,000 pounds per square foot (psf) is recommended for design of 24 inch square pad footings and 12 inch wide continuous footings founded at a minimum depth of 12 inches below the lowest adjacent final grade. This value may be increased by 20 percent for each additional 1-foot of width and/or depth to a maximum value of 3,000 psf. Recommended allowable bearing values include both dead and frequently applied live loads and may be increased by one third when designing for short duration wind or seismic forces. Settlement Based on the settlement characteristics of the earthmaterials that underlie the building sites and the anticipated loading, we estimate that the maximum total settlement of the footings will be less than approximately 3/4 inch. Differential settlement is expected to be about % inch over a horizontal distance of approximately 20 feet, for an angular distortion ratio of 1:480. It is anticipated that the majority of the settlement will occur during construction or shortly after the initial application of loading. The above settlement estimates are based on the assumption that the construction is performed in accordance with the recommendations presented in this report and that the project geotechnical consultant will observe or test the earth material conditions in the footing excavations: Lateral Resistance Passive earth pressure of 250 psf per foot of depth to a maximum value of 2,500 psf may be used to establish lateral bearing resistance for footings. Where structures are planned in or near descending slopes, the passive earth pressure should be reduced to 150 psf per foot of depth to a maximum value of 1,500 psf. A coefficient of friction of 0.38 times the dead load forces may be used between concrete and the supporting earth materials to determine lateral sliding resistance. The above values may be increased by one-third when designing for short duration wind or seismic forces. When combining passive and friction for lateral resistance,the passive component should be reduced by one third. The above lateral resistance values are based on footings for an entire structure being placed directly against compacted fill. Structural Setbacks Structural setbacks are required per the 2007 California Building Code (CBC). Additional structural setbacks are not required due to geologic or geotechnical conditions within the site. Improvements constructed in close proximity to natural or properly engineered and compacted slopes can, over time, be affected by natural processes including gravity forces, weathering, and long term secondary settlement. As a result, the CBC requires that buildings and structures be setback or footings deepened to resist the influence of these processes. EARTH-STRATA, INC. 5 March 12, 2008 For structures that are planned near ascending and descending slopes, the footings should be embedded to satisfy the requirements presented in the CBC, Section 1806.3.1 as illustrated in the following Foundation Clearances From Slopes diagram. FOUNDATION CLEARANCES FROM SLOPES ~-- :------- 2007 CALIFORNIA BUILDING CODE Barth — Strata lac. BUILDING SETBACK DIMENSIONS rq a .oa � wwrwmwrm Oe®101��tL i iI'll �Q When determining the required clearance from ascending slopes with a retaining wall at the toe, the height of the slope shall be measured from the top of the wall to the top of the slope. FootinK Observations Prior to the placement of forms, concrete, or steel, all foundation excavations should be observed by the geologist, engineer, or his representative to verify that they have been excavated into competent bearing materials. The excavations should be moistened, cleaned of all loose materials, trimmed neat, level and square and any moisture softened earth materials should be removed prior to concrete placement. EARTH-STRATA, INC. 6 March 12, 2008 Earth materials from foundation excavations should not be placed in slab on grade areas unless the materials are tested for expansion potential and compacted to a minimum of 90 percent of the maximum dry density. Expansive Soil Considerations Laboratory test results indicate onsite earth materials exhibit an expansion potential of VERY LOW as classified in accordance with 2007 CBC Section 1802.3.2 and ASTM D4829-03. The following recommendations should be considered the very minimum requirements, for the earth materials tested. It is common practice for the project architect or structural engineer to require additional slab thickness, footing sizes,and/or reinforcement. Very Low Expansion Potential (Expansion Index of 20 or Less) Our laboratory test results indicate that the earth' materials onsite exhibit a VERY LOW expansion potential as classified in accordance with 2007 CBC Section 1802.3.2 and ASTM D 4829-03. Since the onsite earth materials exhibit expansion indices of 20 or less, the design of slab on ground foundations is exempt from the procedures outlined in Sections 1805.8.1-and 1805.8.2. Foohnes • Exterior continuous footings may be founded at the minimum depths below the lowest adjacent final grade (i.e. 12 inch minimum depth for one-story, 18 inch minimum depth for two-story, and 24 inch minimum depth for three-story construction). Interior continuous footings for one-,two-,and three-story construction may.be founded at a minimum depth of 12 inches below the lowest adjacent final grade. All continuous footings should have a minimum width of 12, 15, and 18 inches, for one-, two-, and three-story structures, respectively, per Table 1805.4.2 of the 2007 CBC and should be reinforced with a minimum of four (4) No. 4 bars, two (2) top and two (2) bottom. • Exterior pad footings intended to support roof overhangs, such as second story decks, patio covers and similar construction should be a of of 24 inches square and founded at a minimum depth of 18 inches below the lowest adjacent final grade. No special reinforcement of the pad footings will be required. Building Floor Slabs • Building Floor slabs should be a minimum of 4 inches thick and reinforced with a minimum of No. 3 bars spaced a maximum of 24 inches on center, each way. All Floor slab reinforcement should be supported on concrete chairs or bricks to ensure the desired placement at mid- depth. • Interior floor slabs, within living or moisture sensitive areas, should be underlain by a minimum 10-mil thick moisture/vapor barrier to help reduce the upward migration of moisture from the underlying earth materials. The moisture/vapor barrier used should meet the performance standards of an ASTM E 1745 Class A material, and be properly installed in accordance with ACI publication 318-05. It is the responsibility of the contractor to ensure that the moisture/vapor barriers are free of openings, rips, or punctures prior to placing concrete. As an option for additional moisture reduction, higher strength concrete, such as a EARTH-STRATA, INC. 7 March 12, 2008 minimum 28-day compressive strength of 5,000 pounds per square inch (psi) may be used. Ultimately, the design of the moisture/vapor barrier system and recommendations for concrete placement and curing are the purview of the foundation engineer, taking into consideration the project requirements provided by the architect and owner.. • The subgrade earth materials below all floor slabs should be pre-watered to promote uniform curing of the concrete and minimize the development of shrinkage cracks, prior to placing concrete. Corrosiy tV Corrosion is defined by the National Association of Corrosion Engineers (NACE) as "a deterioration of a substance or its properties because of a reaction with its environment." From a geotechnical viewpoint, the"substances"are the reinforced concrete foundations or buried metallic elements (not surrounded by concrete) and the "environment' is the prevailing earth materials in contact with them. Many factors can contribute to corrosivity, including the presence of chlorides, sulfates,.salts, organic materials, different oxygen levels, poor drainage, different soil types, and moisture content. It is not considered practical or realistic to test for all of the factors which may contribute to corrosivity. The potential for concrete exposure to chlorides is based upon the recognized Caltrans reference standard 'Bridge Design Specifications"; under Subsection 8.22.1 of that document, Caltrans has determined that"Corrosive water or soil contains more than 500 parts per million (ppm)of chlorides". Based on limited preliminary laboratory testing, the onsite earth materials have chloride contents less than 500 ppm. As such,specific requirements resulting from elevated chloride contents are not required. Specific guidelines for concrete mix design are provided in 2007 CBC Section 1904.3 and ACI 318, Section 4.3_Table 4.3.1 when the soluble sulfate content of earth materials exceeds 0.1 percent by weight. Based on limited preliminary laboratory testing, the onsite earth materials are classified in accordance with Table 4.3.1 as having a negligible sulfate exposure condition. Therefore, structural concrete in contact with onsite earth materials should utilize Type I or 11. Based on our laboratory testing of resistivity, the onsite earth materials in contact with buried steel should be considered moderately corrosive. Additionally, pH values below 9.7 are recognized as being corrosive to most common metallic components including, copper, steel, iron, and aluminum. The pH values for the earth materials tested were lower than 9.7. Therefore, any steel or metallic materials that are exposed to the earth materials should be encased in concrete or other measures should be taken to provide corrosion protection. The test results for corrosivity are based on limited samples in accordance with the current standard of care. Laboratory test results are presented in Appendix B. RETAINING WALLS Active and At-Rest Earth Pressures Foundations may be designed in accordance with the recommendations provided in the Foundation Design Recommendation section of this report. The following table provides the minimum recommended equivalent fluid pressures for design of retaining walls a maximum of 10 feet high. The EARTH-STRATA, INC. 8 March 12, 2008 active earth pressure should be used for design of unrestrained retaining walls, which are free to tilt slightly. The at-rest earth pressure should be used for design of retaining walls that are restrained at the top,such as basement walls, curved walls with no joints, or walls restrained at corners. For curved walls, active pressure may be used if tilting is acceptable and construction joints are provided at each angle point and at a minimum of 15 foot intervals along the curved segments. BACKSLOPE CONDITION rAiRe7stEarth RE TYPE •v h Pressure 35 52 Pressure 53 78 The retaining wall parameters provided do not account for hydrostatic pressure behind the retaining walls. Therefore,the subdrain system is a very important part of the design. All retaining walls should be designed to resist surcharge loads imposed by other nearby walls,structures,or vehicles should be added to the above earth pressures, if the additional loads are being applied within a 1:1 plane projected up from the heel of the retaining wall footing. As a way of minimizing surcharge loads and the settlement potential of nearby buildings,the footings for the building can be deepened below the 1:1 plane projected up from the heel of the retaining wall footing. Upon request and under a separate scope of work, more detailed analyses can be performed to address equivalent Fluid pressures with regard to stepped retaining walls, actual retaining wall heights, actual backfill inclinations,specific backfill materials,etc. Subdrain System We recommend a perforated pipe and gravel subdrain system be provided behind all retaining walls to prevent the build up of hydrostatic pressure behind the retaining walls. The perforated pipe should consist of 4 inch minimum diameter Schedule 40 PVC or ABS SDR-35, placed with the perforations facing down. The pipe should be surrounded by 1 cubic foot per foot of 3/4- or 1% inch open graded gravel wrapped in filter fabric. The filter fabric should consist of Mirafi 140N or equivalent to prevent infiltration of fines and subsequent clogging of the subdrain system. In lieu of a perforated pipe and gravel subdrain system, weep holes or open vertical masonry joints may be provided in retaining walls to prevent the build up of hydrostatic pressure behind the retaining walls. Weep holes should be a minimum of 3 inches in diameter and provided at intervals of at least every 6 feet along the wall. Open vertical masonry joints should be provided at a minimum of 32 inch intervals. A continuous gravel fill, a minimum of 1 cubic foot per foot, should be placed behind the weep holes or open masonry joints. The gravel should be wrapped in filter fabric consisting of Mirafi 140N or equivalent. The retaining walls should be coated on the backfilled side of the walls with a proven waterproofing compound by an experienced professional to inhibit infiltration of moisture through the walls. Temporary Excavations All excavations should be made in accordance with OSHA requirements. Earth-Strata is not responsible for job site safety. EARTH-STRATA, ]INC. 9 March 12, 2008 Wall Backfill Retaining-wall backfill materials should be approved by the geotechnical engineer or his representative prior to placement as compacted fill. Retaining wall backfill should be placed in lifts no greater than 6 to 8 inches,watered or air dried as necessary to achieve near optimum moisture contents. All retaining wall backfill should be compacted to a minimum of 90 percent of the maximum density as determined by ASTM D 1557. Retaining wall backfill should be capped with a paved surface drain. CONCRETE FLATWORK Thickness and Joint Spacing Concrete sidewalks and patio type slabs should be at least 4 inches thick and provided with construction or expansion joints every 6 feet or less, to reduce the potential for excessive cracking. Concrete driveway slabs should be at least 5 inches thick and provided with construction or expansion joints every 10 feet or less. Subgrade Preparation In order to reduce the potential for unsightly cracking, subgrade earth materials underlying concrete flatwork should be compacted to a minimum relative density of 90 percent and then moistened to at least optimum or slightly above optimum moisture content. This moisture should extend to a depth of at least 12.inches below subgrade and be maintained prior to placement of concrete. Pre-watering of the earth materials prior to placing concrete will promote uniform curing of the concrete and minimize the development of shrinkage cracks. The project geotechnical engineer or his representative should verify the density and moisture content of the earth materials and the depth of moisture penetration prior to placing concrete. Cracking within concrete flatwork is oftener result of factors such'as the use of too high a water to cement ratio and/or inadequate steps taken to prevent moisture loss during the curing of the concrete. Concrete distress can be reduced by proper concrete mix design and proper placement and curing of the concrete. Minor cracking within concrete flatwork is normal and should be expected. POST GRADING OBSERVATIONS AND TESTING It is the property owner's sole responsibility to notify Earth-Strata at the appropriate times for observation and testing services. Earth-Strata can not be responsible for any geotechnical recommendations where the appropriate observations and testing have not been performed. It is of the utmost importance that the owner or their representative request observations and testing for at least the following phases of work. Structure Construction Observe all foundation excavations prior to placement of concrete or steel to verify adequate depth and competent bearing conditions. If necessary, re-observe all foundation excavations after deficiencies have been corrected. EARTH-STRATA, INC. 10 March 12, 2008 Retaining Wall Construction Observe all foundation excavations prior to placement of concrete or steel to verify adequate depth and competent bearing conditions. If necessary, re-observe all foundation excavations after deficiencies have been corrected. Observe and verify proper installation of subdrain systems prior to placing retaining wall backfill. Observe and test retaining wall backfill operations. Garden Walls Observe all foundation excavations prior to placement of concrete or steel to verify adequate depth and competent bearing conditions. If necessary, re-observe all foundation excavations after deficiencies have been corrected. Exterior Concrete Flatwork Construction Observe and test subgrade earth materials below all concrete flatwork to verify recommended density and moisture content. UtililTrench Backfill Observe and test all utility trench backfill operations. Re-Gradfne Observe and test the placement of any additional fill materials placed onsite. GRADING AND CONSTRUCTION RESPONSIBILITY It is the responsibility of the contractor or his subcontractors to meet or exceed the project specifications for grading and construction. The responsibilities of Earth-Strata did not include the supervision or direction of the contractor's personnel, equipment, or subcontractors performing the actual work. Our field representative onsite was intended to provide the owner with professional advice, opinions, and recommendations based on observations and limited testing of the contractor's work. Our services do not relieve the contractor or his subcontractors of their responsibility, should defects in their work be discovered. The conclusions and recommendations herein are based on the observations and test results for the areas tested, and represent our engineering opinion as to the contractor's compliance with the project specifications. EARTH-STRATA, INC. 11 March 12, 2008 REPORT LIMITATIONS This report has not been prepared for use by parties or projects other than those named or described herein. This report may not contain sufficient information for other parties or other purposes. Our services were performed using the degree of care and skill ordinarily exercised, under similar circumstances, by reputable soils engineers and geologists, practicing at the time and location this report was prepared. No other warranty, expressed or implied, is made as to the conclusions and professional advice included in this report. Earth materials vary in type, strength, and other geotechnical properties between points of observation and testing. Groundwater and moisture conditions can also vary due to natural processes or the works of man on this or adjacent properties. This report was prepared with the understanding that it is the responsibility of the owner or their representative, to ensure that the conclusions and recommendations contained herein are brought to the attention of the other project consultants and are incorporated into the plans and specifications. The owners' contractor should properly implement the conclusions and recommendations during construction and notify the owner if they consider any of the recommendations presented herein to be unsafe or unsuitable. Earth-Strata sincerely appreciates the opportunity to provide our services and advice on this project. Respectfully presented, G%NEERIWO O EARTH-STRATA, INC. � Q E' WF4 o w No� Chad E.Welke, PG, CEG, PE 0T�TF OF C FOP�NV Principal Geologist/Engineer ,f 8810,V4 �M1CN4 f! �y S�No. 692 o T St phen M. Poole, PE, GE W Ex . Ze Principal Engineer �`p" IG/CW/SMP/bb/am OF ca��F°� Attachments: Appendix A- References Appendix B - Laboratory Procedures and Test Results Table 1 -Summary of Field Density Tests Plate 1 -As-Graded Geotechnical Map Distribution: (6) Addressee EARTH-STRATA, INC. 12 March 12, 2008 i APPENDIX A REFERENCES APPENDIX A REFERENCES California Building Standards Commission, 2007, 2007 California Building Code, California Code of Regulations Title24,Part Volume oft, Based on 2006 International Building Code. Geocon, 2007, Geotechnical Investigation, Rancho California ice, Temecula, California, dated February 12. National Association of Corrosion Engineers, 1984, Corrosion Basics An Introduction, page 191. Southern California Earthquake Center (SCEC), 1999, Recommended Procedures for Implementation of DMG Special Publication 117, Guidelines for Analyzing and Mitigating Liquefaction Hazards in California, March., APPENDIX B LABORATORY PROCEDURES AND TEST RESULTS. APPENDIX B Laboratory Procedures and Test Results Laboratory testing provided quantitative and qualitative data involving the relevant engineering properties of the representative earth materials selected for testing. The representative samples were tested in general accordance with American Society for Testing and Materials (ASTM) procedures and/or California Test Methods (CTM). Soil Classification: Earth materials encountered during exploration were classified and logged in general accordance with the Standard Practice for Description and Identification of Soils (Visual- Manual Procedure) of ASTM D 2488. Upon completion of laboratory testing sample descriptions were reconciled to reflect laboratory test results with regard to ASTM D 2487. Maximum Density Tests: The maximum dry density and optimum moisture content of representative samples were determined using the guidelines of ASTM D 1557. The test results are presented in the table below. SAMPLE AIMMO NUMBER CONTENT(%) l Silty fine to medium sand with fine gravel 132.0 8.5 2 Silty fine to medium sand 119.5 10.0 mansion Index: The expansion potential of representative samples was evaluated using the guidelines of ASTM D 4829. The test results are presented in the table below. SAMPLE MATERIAL EXPANSION INDEX EXPANSION TENTIAL LOCATION DESCRIPTION West Building Pad Silty SAND 1 14 Vety Low Minimum Resistivity and pH Tests: Minimum resistivity and pH tests of select samples were performed using the guidelines of CTM 643. The test results are presented in the table below. WWIZ UM LOCATION DESCRIPTION pH (ohm-cm) West Building Pad Silty SAND 7.9 1,600 Soluble Sulfate: The soluble sulfate content of select samples was determined using the guidelines of CTM 417. The test results are presented in the table below. SA SUL MPLE MATERIAL LOCATION DESCRIPTION (%by weight) SULFATE EXPOSURE West Building Pad Silty SAND 0.009 Negligible Chloride Content: Chloride content of select samples was determined using the guidelines of CTM 422. The test results are presented in the table below. West Building Pad Siltv SAND 90 1 , TABLE 1 SUMMARY OF FIELD ,DENSITY- TESTS TABLE 1 RANCHO VIEW PROFESSIONAL SUMMARY OF FIELD DENSITY TESTS 07220-30A Test Test Test Test Elevation Soil Dry Moisture Max. Rel. Test Location Density Content Density Density No. Type Date of (. Type tPct7 (070) (Pen (%) 1A N 01 04 08 NG East Pad -3 1 112.2 3.5 132.0 85 2A N 01 04 08 NG East Pad -3 1 112.3 2.8 132.0 85 3A N 01 10 08 NG East Pad -3 1 112.6 2.4 132.0 85 4A N 01 11 08 NG West Pad -3 1 113.3 3.2 132.0 86 SA N 01 11 08 NG West Pad -3 1 112.3 3.3 132.0 85 6A N 01 11 08 CF East Pad -1.5 2 112.8 8.8 119.5 94 7A N 01 11 08 CF East Pad -1.5 2 113.2 8.9 119.5 95 BA N 01 11 08 CF West Pad -1.5 2 115.5 8.5 119.5 97 9A N 01 14 08 NG West Pad -3 2 108.8 14.1 119.5 91 10A N 01 14 08 NG West Pad -3 1 112.8 12.8 132.0 85 11A N 01 14 08 CF West Pad -.5 2 113.4 8.9 119.5 95 12A N 01 14 08 CF West Pad -.5 2 114.8 8.1 119.5 96 13A N 01 16 08 CF West Pad -2 1 118.6 9.3 132.0 90 13A-R N 01 17 08 CF West Pad -2 1 118.9 8.0 132.0 90 14A N 01 16 08 CF West Pad -1.5 2 113.6 8.6 119.5 1 95 15A N 01 18 08 CF East Pad FG 2 111.6 8.1 119.5 93 16A N 01 18 08 CF East Pad FG 2 113.0 9.1 119.5 95 17A N 01 21 08 CF West Pad FG 2 111.3 10.9 119.5 93 18A N 01 21 08 CF West Pad FG 2 110.9 9.5 119.5 93 19A N 01 21 08 CF Parking Area FG 1 119.1 8.4 132.0 90 20A N 01 21 08 CF Parking Area FG 1 119.5 7.1 132.0 91 21A N 01 21 08 CF Parking Area FG 2 111.8 7.4 119.5 94 22A N 01 21 08 CF Parking Area FG 1 121.7 7.9 132.0 92 23A N Ol 21 08 CF Parkin Area FG 2 116.7 8.5 119.5 96 24A N 01 21 08 CF Parking Area FG 1 119.9 8.6 132.0 91 25A N 01 21 08 CF Parkin Area FG 2 116.8 10.5 119.5 98 26A N101/21/081 CF I Parking Area PG 1 124.0 7.8 132.0 94 N - Nuclear Test Method FG- Finish Grade SC-Sand Cone Method NG- Native Ground (90%Not Required) MARCH 2O08 CF- Compacted Fill TABLE 1 RANCHO VIEW PROFESSIONAL SUMMARY OF FIELD DENSITY TESTS 07220-30A Test Test Test Test Elevation Soil Dry Moisture Max. Rel. e Date of Test _ T e Density Content Density Density YP (PCf) (% 1 N 02 27 08 CF Keyway Northeast Corner 1113 2 110.3 10.5 119.5 9Z 2 N 02 27 08 CF Keyway Midline North Side 1115 2 109.7 11.0 119.5 92 3 N 02 27 08 CF Keyway North Side Eastern 1 3 1117 2 110.1 10.0 119.5 92 4 N 02 28 08 CF Keyway East Corner East Side 1119 1 120.1 10.7 132.0 91 S N 1 02 28 08 CF Keyway East Side Midline 1121 1 122.5 10.4 132.0 93 6 N 02 28 08 CF North Side Midwestern 1/2 1123 2 114.5 10.0 119.S 96 7 N 02 28 08 CF North Side West End 1125 2 114.6 10.4 119.5 96 8 N 02 29 08 CF Northeast Corner Midline 1122 1 125.1 10.0 132.0 95 9 N 02 29 08 CF Noth Side Midline Eastern 1 3 1124 1 124.1 10.7 132.0 94 10 N 02 29 08 CF North Side Midline 1126 1 121.9 11.2 132.0 92 11 N 02 29 08 CF North Side Midline 1127 1 119.5 11.7 132.0 91 12 N 02 29 08 CF North Side Western 113 1128 2 109.5 11.5 119.5 92 13 N 02 29 08 CF East Side Midline 1124 2 109.9 11.3 119.S 92 14 N 02 29 08 CF East Side South End 1129 2 112.2 12.4 119.5 94 15 N 03 03 08 CF Northeast Comer Mid Sloe 1127 1 119.5 10.6 132.0 91 16 N 03/03/08 CF North Side Midline Midslo a 1130 1 122.0 10.8 132.0 92 17 N 03/03/08 CF North Side Midline Western 1/2 1129 1 120.8 10.9 132.0 92 18 N 03/03/08 CF East Side Midline Southern 1/2 1130 1 120.8 11.3 132.0 92 19 N 03 03 06 CF North Side Middle 1/2 Middle Sloe 1129 1 122.8 9.2 132.0 93 20 N 03/03/08 CF North Side West End 1130 1 124.8 10.3 132.0 95 21 N 03 04 08 CF lNortheast Comer Top Sloe 1131 1 121.0 10.8 132.0 92 EN 03 04 08 CF North Side Mid To Sloe 1132 1 122.1 11.7 132.0 93 03 04 08 CF North Side West End Sloe F G 1128 1 119.6 10.2 132.0 91 03 05 08 CF East End Mid Sloe F G 1130 1 120.0 11.0 132.0 91 03 05 08 CFNorthSideMiddle 1/2 To SloeF G1132 1121.6 11.0 132.0 9203 OS 08 Clf lEast End Top of Sloe I F G 11291 1 1 120.3 10.1 132.D 91 N- Nuclear Test Method FG- Finish Grade SC -Sand Cone Method NG- Native Ground MARCH 2O08 CF- Compacted Fill LEGEND G"Iogk urn n. >' r Y F-aovmrm wun i -I,L I.t- �IIN� EYMmeIMmM 4nq•'Afc Qps \ s 1 Qps,� Qps Qpir _L AS-GRADED GEOTECHNICAL NAP �'r./ b � �� -' �-.. � �• -0 mx•naw.len oe•,wrowsoww.we .� �.�4n••sunrr[cuw c4iaw � � Vb1 tllll O�FIaf0�Ml4 �� 1` ------------- Earth - Strata,, Inc. Itants REPORT • , / ROUGH GRADING e PROPOSED • , • , , SENIOR CENTER, PARCEL 2 OF PARCEL MAP 35481, R 2 SSESSOR 94 1 1 1 • 1 1 • LOCATED ,N'S PARCEL NUMBER , • / / 16 1 1 THE SOUTHWEST • • , • 1 , CALIFORNIA • / 1 1 AND , • 1 / ROAD, ISSUED: / • • 24, 2015 CITY OF TEMECULA, RIVERSIDE • 1 j ep CALIFORNIA s ` *r! A . V 14 11� J) O•�b�'�,1 1 iRdb� Y 1 1�. f 'iY t•AW :ET as gr F. j Im will! ciao gul AN r � fnr�y r' r p I:F �. ----- ' Earth o Strata,, Inc. GwWhnks1,Emhan wI and M]IwY6 T"dm CanauHaMa BETTER PEOPLE•BETTER SERNCE•BETTERRESIE." ,- ' November 24, 2015 Project No. 14625-30A ' Ms. Dianne Grover BURON INC. 1177 West Hastings Street, Suite 2133 ' Vancouver, BC V6E 21t3 ' Subject: Geotechnical Report of Rough Grading, Proposed Highgate Senior Living Center, Parcel 2 of Parcel Map 35481, Assessor's Parcel Number 944-290-029, Located on the Southwest Corner of Rancho California Road and Morago Road, City of Temecula, ' Riverside County, California INTRODUCTION Per your authorization, Earth-Strata, Inc. has provided observations and testing services during rough t grading for the proposed Senior Living Facility, located on the southwest corner of Rancho California Road and Morago Road in the City of Temecula, Riverside County, California. This report summarizes the geotechnical conditions observed and tested during rough grading. Conclusions and recommendations ' with regard to the suitability of the grading for the proposed project are provided herein, along with foundation design recommendations based on the earth materials present at the completion of grading. Grading commenced in order to develop one (1) building pad for construction of one- and/or two-story structures. The proposed development will consist of a Senior Living Facility utilizing slab on grade, wood or steel-framed construction. Grading operations began in October 2015 and were completed in November 2015. REGULATORY COMPLIANCE ' Observations and selective testing have been performed by representatives of Earth-Strata, Inc. during the removal and recompaction of low-density near surface earth materials. Our services were performed in general accordance with the recommendations presented in the referenced reports (see References), the grading code of the reviewing agency, and as dictated by conditions encountered in the field. The earthwork described herein has been reviewed and is considered adequate for the construction now ' planned. The recommendations presented in this report were prepared in conformance with generally accepted professional engineering practices in this area at the time of this report and no further warranty is expressed or implied. ENGINEERING GEOLOGY ' Geologic Units Earth materials noted during grading operations included previously placed artificial fill and bedrock. ' FART"II -STRATA.INC. •42211 RIO NI-DO ROAD,SUITE A-104, 1LMU I IA.CA 1121911.OFFICE 1911I 4 6 1-4 0213•FAX 19111461-4011 W W W.EARTFI-STRA I-A.COM BETTER PEOPLE• BETTER SERVICE•BETTER RESULTS 1 ' Groundwater Groundwater was not encountered during grading operations. Faulting ' No evidence of significant faulting was observed during grading operations. ' EARTHWORK OBSERVATIONS AND DENSITY TESTING ' Site Clearine and Grubbing Prior to grading, all trees, brush,shrubs, and grasses were stripped and removed from the compacted fill. ' Ground Preparation Removals throughout most of the site ranged from approximately 3 to 4 feet below original grades, with locally deeper removals. ' Prior to placing compacted fill, the exposed bottom surfaces were scarified to depths of 6 to 8 inches, watered or air dried as necessary to achieve near optimum moisture content and then compacted to a minimum relative compaction of 90 percent ' Oversize Rock Oversize rock, generally greater than 1 foot in maximum dimension, was not encountered during the grading operations. ' Fill Placement and Testing All fills were placed in lifts restricted to approximately 6 to 8 inches in maximum thickness, watered or ' air dried as necessary to achieve near optimum moisture content, then compacted to a minimum of 90 percent of the maximum dry density by rolling with .a bulldozer, sheepsfoot, or loaded scrapers. The maximum vertical depth of compacted fill as a result of grading within the proposed building pad is ' approximately 4 feet. Benching into competent earth materials was observed during fill placement and compaction operations. Field density and moisture content tests utilizing nuclear gauge methods were performed in accordance with ASTM Test Methods D2922 and D3017. Visual classification of the earth materials in the field was the basis for determining which maximum dry density value was applicable for a given density test. Test ' results are presented in Table 1 and test locations are shown on the enclosed As-Graded Geotechnical Map, Plate 1. 1 t EARTH-STRATA, INC. 2 Project No. 14625-30A 1 Compacted fills were tested to verify that a minimum of 90 percent of the maximum dry density had been achieved. At least one density test was taken for each 1,000 cubic yards and/or for every 2 vertical feet of ' compacted fill placed. The actual number of tests taken per day varied depending on the site conditions and the quantity and type of equipment utilized. When field density tests yielded results less than the minimum required density, the approximate limits of the substandard fill were established. The ' substandard area was then reworked (most common) or removed, moisture conditioned, recompacted, and retested until the minimum density was achieved. In most cases, failed density tests were noted then retested in the same general vicinity at nearly the same elevation as the failed test. 1 Slopes ' No slopes were constructed. ' LABORATORY TESTING Maximum Da Density ' Maximum dry density and optimum moisture content for representative earth materials noted during grading operations were determined using the guidelines of ASTM Test Method D 1557-00. Pertinent test ' values are summarized in Appendix B. Expansion Index Tests ' Expansion index tests were performed on representative earth materials sampled near finish grade for select building pads using the guidelines of ASTM D 4829-03. Test results are summarized in Appendix B. ' Soluble Sulfate Analyses ' The soluble sulfate content of select samples was determined using the guidelines of California Test Method (CTM) 417. Test results are summarized in Appendix B. ' Chloride Chloride content of select samples was determined using the guidelines of CTM 422. Test results are ' summarized in Appendix B. Minimum Resistivity and pH ' Minimum resistivity and pH tests of select samples were determined using the guidelines of CTM 643. Test results are summarized in Appendix B. 1 1 ' EARTH-STRATA, INC. 3 Project No. 14625-30A 1 1 POST GRADING CONSIDERATIONS ' Slope Landscaping and Maintenance Control of site drainage is important for the performance of the proposed project. Engineered slopes ' should be landscaped with deep rooted, drought tolerant, maintenance free plant species, as recommended by the project landscape architect. Unprotected slopes are highly susceptible to erosion and surficial slumping. Therefore to reduce this potential, we recommend that the slopes be covered ' with an erosion inhibitor until healthy plant growth is well established. To further reduce the potential for surficial instability, measures to control burrowing rodents should be performed as well. ' Site Drainage Adequate slope and building pad drainage is essential for the long term performance of the subject site. ' The gross stability of graded slopes should not be adversely affected, provided all drainage provisions are properly constructed and maintained. Roof gutters are recommended for the proposed structures. Pad and roof drainage should be collected and transferred to driveways, adjacent streets, storm-drain ' facilities, or other locations approved by the building official in non-erosive drainage devices. Drainage should not be allowed to pond on the pad or against any foundation or retaining wall. Drainage should not be allowed to Flow uncontrolled over any descending slope. Planters located within retaining wall ' backfill should be sealed to prevent moisture intrusion into the backfill. Planters located next to raised Floor type construction should be sealed to the depth of the footings. Drainage control devices require periodic cleaning, testing, and maintenance to remain effective. ' At a minimum, pad drainage should be designed at the minimum gradients required by the CBC. To divert water away from foundations, the ground surface adjacent to foundations should be graded at the ' minimum gradients required per the CBC. Utility Trenches ' All utility trench backfill should be compacted to a minimum of 90 percent of the maximum dry density determined by ASTM D 1557-00. For utility trench backfill in pavement areas the upper 6 inches of ' subgrade materials should be compacted to 95 percent of the maximum dry density determined by ASTM D 1557-00. This includes within the street right-of-ways, utility easements, under footings, sidewalks, driveways and building Floor slabs, as well as within or adjacent to any slopes. Backfill should be placed ' in approximately 6 to 8 inch maximum loose lifts and then mechanically compacted with a hydro- hammer, rolling with a sheepsfoot, pneumatic tampers, or similar equipment. The utility trenches should be tested by the project geotechnical engineer or their representative to verify minimum compaction ' requirements are obtained. In order to minimize the penetration of moisture below building slabs, all utility trenches should be 1 backfilled with compacted fill, lean concrete, or concrete slurry where they undercut the perimeter foundation. Utility trenches that are proposed parallel to any building footings (interior and/or exterior trenches), should not be located within a 1:1 (h:v) plane projected downward from the outside bottom ' edge of the footing. ' EARTH-STRATA, INC. 4 Project No. 14625-30A 1 1 FOUNDATION DESIGN RECOMMENDATIONS ' General Conventional foundations are recommended for support of the proposed structures. Foundation ' recommendations are provided herein. Allowable Bearine Values An allowable bearing value of 2,000 pounds per square foot (psf) is recommended for design of 24 inch square pad footings and 12 inch wide continuous footings founded at a minimum depth of 12 inches ' below the lowest adjacent final grade. This value may be increased by 20 percent for each additional 1-foot of width and/or depth to a maximum value of 2,500 psf. Recommended allowable bearing values include both dead and frequently applied live loads and may be increased by one third when designing ' for short duration wind or seismic forces. Settlement ' Based on the settlement characteristics of the earth materials that underlie the building sites and the anticipated loading, we estimate that the maximum total settlement of the footings will be less than t approximately 3/4 inch. Differential settlement is expected to be about % inch over a horizontal distance of approximately 20 feet, for an angular distortion ratio of 1:480. It is anticipated that the majority of the settlement will occur during construction or shortly after the initial application of loading. ' The above settlement estimates are based on the assumption that the construction is performed in accordance with the recommendations presented in this report and that the project geotechnical ' consultant will observe or test the earth material conditions in the footing excavations. Lateral Resistance ' Passive earth pressure of 250 psf per foot of depth to a maximum value of 2,500 psf may be used to establish lateral bearing resistance for footings. A coefficient of friction of 0.36 times the dead load forces ' may be used between concrete and the supporting earth materials to determine lateral sliding resistance. The above values may be increased by one-third when designing for short duration wind or seismic forces. When combining passive and friction for lateral resistance, the passive component should be t reduced by one third. In no case shall the lateral sliding resistance exceed one-half the dead load for clay, sandy clay,sandy silty clay, silty clay, and clayey silt. ' The above lateral resistance values are based on footings for an entire structure being placed directly against either compacted fill or competent bedrock. ' Structural Setbacks Structural setbacks are required per the 2013 California Building Code (CBC). Additional structural ' setbacks are not required due to geologic or geotechnical conditions within the site. Improvements constructed in close proximity to natural or properly engineered and compacted slopes can, over time, be affected by natural processes including gravity forces, weathering, and long term secondary settlement. ' EARTH-STRATA, INC. 5 Project No. 14625-30A 1 As a result, the CBC requires that buildings and structures be setback or footings deepened to resist the influence of these processes. For structures that are planned near ascending and descending slopes, the footings should be embedded to satisfy the requirements presented in the CBC, Section 1808.7 as illustrated in the following ' Foundation Clearances From Slopes diagram. ' FOUNDATION CLEARANCES FROM SLOPES ' atnc. 2013 CALIFORNIA BUILDING CODE Eart6- Stra, I Arai, , nc- - -- BUILDING SETBACK DIMENSIONS ' w��urraowrm oe®rlerr�a 1 rMa w.rrt'.w�r.sm rwsrM.. ' n[a ' When determining the required clearance from ascending slopes with a retaining wall at the toe, the height of the slope shall be measured from the top of the wall to the top of the slope. 1 1EA1(TIH(-S'] RA\TA\, ➢NC. 6 Project No. 14625-30A 1 1 Footing Observations ' Prior to the placement of forms, concrete, or steel, all foundation excavations should be observed by the geologist, engineer, or his representative to verify that they have been excavated into competent bearing materials. The excavations should be moistened, cleaned of all loose materials, trimmed neat, level and ' square and any moisture softened earth materials should be removed prior to concrete placement. Earth materials from foundation excavations should not be placed in slab on grade areas unless the ' materials are tested for expansion potential and compacted to a minimum of 90 percent of the maximum dry density. tExpansive Soil Considerations Laboratory test results indicate onsite earth materials exhibit an expansion potential of VERY LOW as ' classified in accordance with 2010 CBC Section 1803.5.3 and ASTM D4829-03. The following recommendations should be considered the very minimum requirements, for the earth materials tested. It is common practice for the project architect or structural engineer to require additional slab thickness, ' footing sizes,and/or reinforcement. Vey Low Expansion Potential (Expansion Index of 20 or Less) Our laboratory test results indicate that the earth materials onsite exhibit a VERY LOW expansion potential as classified in accordance with 2010 CBC Section 1803.5.3 and ASTM D 4829-03. Since the ' onsite earth materials exhibit expansion indices of 20 or less, the design of slab on ground foundations is exempt from the procedures outlined in Sections 1808.6.1 and 1808.6.2. ' Footings • Exterior continuous footings may be founded at the minimum depths below the lowest adjacent final grade (i.e. 12 inch minimum depth for one-story, 18 inch minimum depth for two-story, and 24 inch minimum depth for three-story construction). Interior continuous footings for one-, two-, and three-story construction may be founded at a minimum depth of 12 ' inches below the lowest adjacent final grade. All continuous footings should have a minimum width of 12, 15, and 18 inches, for one-, two-, and three-story structures, respectively, per Table 1809.7 of the 2010 CBC and should be reinforced with a minimum of two (2) No. 4 bars, ' one (1) top and one(1) bottom. • Exterior pad footings intended to support roof overhangs, such as second story decks, patio t covers and similar construction should be a minimum of 24 inches square and founded at a minimum depth of 18 inches below the lowest adjacent final grade. No special reinforcement of the pad footings will be required. ' Building Floor Slabs ' • Building Floor slabs should be a minimum of 4 inches thick and reinforced with a minimum of No. 3 bars spaced a maximum of 24 inches on center, each way. All Floor slab reinforcement should be supported on concrete chairs or bricks to ensure the desired placement at mid- EARTH-STRATA, INC. 7 Project No. 14625-30A depth. ' • Interior floor slabs, within living or moisture sensitive areas, should be underlain by a minimum 10-mil thick moisture/vapor barrier to help reduce the upward migration of moisture from the underlying earth materials. The moisture/vapor barrier used should meet the performance standards of an ASTM E 1745 Class A material, and be properly installed in accordance with ACI publication 318-05. It is the responsibility of the contractor to ensure that the moisture/vapor barriers are free of openings, rips, or punctures prior to placing ' concrete. As an option for additional moisture reduction, higher strength concrete, such as a minimum 28-day compressive strength of 5,000 pounds per square inch (psi) may be used. Ultimately, the design of the moisture/vapor barrier system and recommendations for ' concrete placement and curing are the purview of the foundation engineer, taking into consideration the project requirements provided by the architect and owner. ' • Garage Floor slabs should be a minimum of 4 inches thick and should be reinforced in a similar manner as living area Floor slabs. Garage Floor slabs should be placed separately from adjacent wall footings with a positive separation maintained with % inch minimum felt expansion joint ' materials and quartered with weakened plane joints. A 12 inch wide turn down founded at the same depth as adjacent footings should be provided across garage entrances. The turn down should be reinforced with a minimum of two (2) No. 4 bars, one (1) top and one (1) bottom. 1 • The subgrade earth materials below all Floor slabs should-be pre-watered to promote uniform curing of the.concrete and minimize the development of shrinkage cracks, prior to placing ' concrete. The pre-watering should be verified by Earth-Strata during construction. Corrosivity ' Corrosion is defined by the National Association of Corrosion Engineers (NACE) as "a deterioration of a substance or its properties because of a reaction with its environment." From a geotechnical viewpoint, ' the "substances" are the reinforced concrete foundations or buried metallic elements (not surrounded by concrete) and the "environment" is the prevailing earth materials in contact with them. Many factors can contribute to corrosivity, including the presence of chlorides, sulfates, salts, organic materials, different ' oxygen levels, poor drainage, different soil types, and moisture content. It is not considered practical or realistic to test for all of the factors which may contribute to corrosivity. ' The potential for concrete exposure to chlorides is based upon the recognized Caltrans reference standard 'Bridge Design Specifications", under Subsection 8.22.1 of that document, Caltrans has determined that "Corrosive water or soil contains more than 500 parts per million (ppm) of chlorides". ' Based on limited preliminary laboratory testing, the onsite earth materials have chloride contents less than 500 ppm. As such, specific requirements resulting from elevated chloride contents are not required. ' Specific guidelines for concrete mix design are provided in 2010 CBC Section 1904.5 and ACI 318, Section 4.3 Table 4.3.1 when the soluble sulfate content of earth ma ter ials.exceeds 0.1 percent by weight. Based on limited preliminary laboratory testing, the onsite earth materials are classified in accordance with ' Table 4.3.1 as having a negligible sulfate exposure condition. Therefore, structural concrete in contact with onsite earth materials should utilize Type 1 or IL ' EARTH-STRATA, INC. 8 Project No. 14625-30A 1 Based on our laboratory testing of resistivity, the onsite earth materials in contact with buried steel should be considered mildly corrosive. Additionally, pH values below 9.7 are recognized as being ' corrosive to most common metallic components including, copper, steel, iron, and aluminum. The pH values for the earth materials tested were lower than 9.7. Therefore, any steel or metallic materials that are exposed to the earth materials should be encased in concrete or other measures should be taken to ' provide corrosion protection. The test results for corrosivity are based on limited samples in accordance with the current standard of ' care. Laboratory test results are presented in Appendix B. ' RETAINING WALLS Active and At-Rest Earth Pressures ' Foundations may be designed in accordance with the recommendations provided in the Foundation Design Recommendation section of this report. The following table provides the minimum ' recommended equivalent fluid pressures for design of retaining walls a maximum of 8 feet high. The active earth pressure should be used for design of unrestrained retaining walls, which are free to tilt slightly. The at-rest earth pressure should be used for design of retaining walls that are restrained at the ' top,such as basement walls, curved walls with no joints, or walls restrained at corners. For curved walls, active pressure may be used if tilting is acceptable and construction joints are provided at each angle point and at a minimum of 15 foot intervals along the curved segments. ' MINI] ATIC HQ TROMMOOMMMMMS SPcf� ' Active Earth Pressure _ 40 63 At-Rest Earth Pressure 00 95 The retaining wall parameters provided do not account for hydrostatic pressure behind the retaining ' walls. Therefore,the subdrain system is a very important part of the design. All retaining walls should be designed to resist surcharge loads imposed by other nearby walls,structures, or vehicles should be added to the above earth pressures, if the additional loads are being applied within a 1:1 plane projected up from the heel of the retaining wall footing. As a way of minimizing surcharge loads and the settlement potential of nearby buildings,the footings for the building can be deepened below the 1:1 plane projected up from the heel of the retaining wall footing. tUpon request and under a separate scope of work, more detailed analyses can be performed to address equivalent Fluid pressures with regard to stepped retaining walls, actual retaining wall heights, actual ' backfill inclinations,specific backfill materials,etc. Subdrain System ' We recommend a perforated pipe and gravel subdrain system be provided behind all proposed retaining walls to prevent the buildup of hydrostatic pressure behind the proposed retaining walls. The perforated ' EARTH-STRATA, INC. 9 Project No. 14625-30A pipe should consist of 4 inch minimum diameter Schedule 40 PVC or ABS SDR-35, placed with the perforations facing down. The pipe should be surrounded by 1 cubic foot per foot of 3/4- or 1% inch open ' graded gravel wrapped in filter fabric. The filter fabric should consist of Mirafi 140N or equivalent to prevent infiltration of fines and subsequent clogging of the subdrain system. ' In lieu of a perforated pipe and gravel subdrain system, weep holes or open vertical masonry joints may be provided in the lowest row of block exposed to the air to prevent the buildup of hydrostatic pressure behind the proposed retaining walls. Weep holes should be a minimum of 3 inches in diameter and ' provided at intervals of at least every 6 feet along the wall. Open vertical masonry joints should be provided at a minimum of 32 inch intervals. A continuous gravel fill, a minimum of 1 cubic foot per foot, should be placed behind the weep holes or open masonry joints. The gravel should be wrapped in filter ' fabric consisting of Mirafi 140N or equivalent. The adequate retaining walls should be coated on the backfilled side of the walls with a proven t waterproofing compound by an experienced professional to inhibit infiltration of moisture through the walls. ' Temporary Excavations All excavations should be made in accordance with OSHA requirements. Earth-Strata is not responsible ' for job site safety. Wall Backfill ' Retaining-wall backfill materials should be approved by the geotechnical engineer or his representative prior to placement as compacted fill. Retaining wall backfill should be placed in lifts no greater than 6 to ' 8 inches,watered or air dried as necessary to achieve near optimum moisture contents. All retaining wall backfill should be compacted to a minimum of 90 percent of the maximum density as determined by ASTM D 1557. Retaining wall backfill should be capped with a paved surface drain. CONCRETE FLATWORK ' Thickness and loint Spacing ' Concrete sidewalks and patio type slabs should be at least 4 inches thick and provided with construction or expansion joints every 6 feet or less, to reduce the potential for excessive cracking. Concrete driveway slabs should be at least 5 inches thick and provided with construction or expansion joints every 10 feet or less. Subgrade Preparation In order to reduce the potential for unsightly cracking, subgrade earth materials underlying concrete flatwork should be compacted to a minimum of 90 percent of the maximum dry density and then moistened to at least optimum or slightly above optimum moisture content. This moisture should extend to a depth of at least 12 inches below subgrade and be maintained prior to placement of concrete. Pre- EARTH-STRATA,H-STRATA, INC. 10 Project No. 14625-30A ' watering of the earth materials prior to placing concrete will promote uniform curing of the concrete and minimize the development of shrinkage cracks. The project geotechnical engineer or his representative ' should verify the density and moisture content of the earth materials and the depth of moisture penetration prior to placing concrete. ' Cracking within concrete flatwork is often a result of factors such as the use of too high a water to cement ratio and/or inadequate steps taken to prevent moisture loss during the curing of the concrete. Concrete distress can be reduced by proper concrete mix design and proper placement and curing of the concrete. ' Minor cracking within concrete flatwork is normal and should be expected. ' POST GRADING OBSERVATIONS AND TESTING It is the property owner's sole responsibility to notify Earth-Strata at the appropriate times for ' observation and testing services. Earth-Strata can not be responsible for any geotechnical recommendations where the appropriate observations and testing have not been performed. It is of the utmost importance that the owner or their representative request observations and testing for at least ' the following phases of work. Structure Construction ' • Observe all foundation excavations prior to placement of concrete or steel to verify adequate depth and competent bearing conditions. ' - If necessary, re-observe all foundation excavations after deficiencies.have been corrected. ' RetaininL7 Wall Construction Observe all foundation excavations prior to placement of concrete or steel to verify adequate ' depth and competent bearing conditions. If necessary, re-observe all foundation excavations after deficiencies have been corrected. ' Observe and verify proper installation of subdrain systems prior to placing retaining wall backfill. • Observe and test retaining wall backfill operations. 1 Garden Walls ' - Observe all foundation excavations prior to placement of concrete or steel to verify adequate depth and competent bearing conditions. ' • If necessary, re-observe all foundation excavations after deficiencies have been corrected. ' EARTH-STRATA, INC. 11 Project.No. 14625-30A 1 Exterior Concrete Flatwork Construction Observe and test subgrade earth materials below all concrete Flatwork to verify recommended density and moisture content. Utility Trench Backfill ' • Observe and test all utility trench backfill operations. Re-Grading • Observe and test the placement of any additional fill materials placed onsite. ' GRADING AND CONSTRUCTION RESPONSIBILITY ' It is the responsibility of the contractor or his subcontractors to meet or exceed the project specifications for grading and construction. The responsibilities of Earth-Strata did not include the supervision or direction of the contractor's personnel, equipment, or subcontractors performing the actual work. Our ' field representative onsite was intended to provide the owner with professional advice, opinions, and recommendations based on observations and limited testing of the contractor's work. Our services do not relieve the contractor or his subcontractors of their responsibility, should defects in their work be ' discovered. The conclusions and recommendations herein are based on the observations and test results for the areas tested, and represent our engineering opinion as to the contractor's compliance with the project specifications. REPORT LIMITATIONS ' This report has not been prepared for use by parties or projects other than those named or described herein. This report may not contain sufficient information for other parties or other purposes. Our ' services were performed using the degree of care and skill ordinarily exercised, under similar circumstances, by reputable soils engineers and geologists, practicing at the time and location this report was prepared. No other warranty, expressed or implied, is made as to the conclusions and professional advice included in this report. Earth materials vary in type, strength, and other geotechnical properties between points of observation and testing. Groundwater and moisture conditions can also vary due to natural processes or the works of man on this or adjacent properties. ' This report was prepared with the understanding that it is the responsibility of the owner or their representative, to ensure that the conclusions and recommendations contained herein are brought to the attention of the other project consultants and are incorporated into the plans and specifications. The ' owners' contractor should properly implement the conclusions and recommendations during construction and notify the owner if they consider any of the recommendations presented herein to be unsafe or unsuitable. ' EARTH-STRATA, INC. 12 Project No. 14625-30A 1 Earth-Strata sincerely appreciates the opportunity to provide our services and advice on this project. 1 Respectfully presented, ' EARTH-STRATA, INC. Q?OfESSIn WC114l- °y y i No. 692 c �' Exp. o ,_ d'l49 `�TfCi;"4GQ�,p Stephen M. Poole, PE,GE q4FaF CAUE� ' Principal Engineer SMP/mw ' Attachments: Appendix A- References Appendix B - Laboratory Procedures and Test Results t Table 1 - Summary of Field Density Tests Plate 1 -As-Graded Geotechnical Map Distribution: (2) Addressee t 1 ' ]EART HI S'7f R ATA, INC. 13 Project No. 14625-30A 1 APPENDIX A REFERENCES 1 ' APPENDIX A ' REFERENCES ' California Building Standards Commission, 2010, 2010 California Building Code, California Code of Regulations Title 24, Part2, Volume 2 of 2, Based on 2009 International Building Code. ' Earth-Strata, Inc., 2014, Revised Updated Preliminary Geotechnical Interpretive Report Proposed Highgate Senior Living Center, Parcel 2 of Parcel Map 35481,Assessor's Parcel Number 944-290- 029, Located on the Southwest Corner of Rancho California Road and Morago Road, City of ' Temecula, Riverside County, California, dated November 17. National Association of Corrosion Engineers, 1984, Corrosion Basics.An Introduction, page 191. 1 Southern California Earthquake Center (SCEC), 1999, Recommended Proceduresfor.lmplementation of DMG Special Publication 117, Guidelines for Analyzing and Mitigating Liquefaction Hazards in ' California, March. 1 1 1 1 1 1 1 APPENDIX B LABORATORY PROCEDURES AND TEST RESULTS ' APPENDIX B ' Laboratory Procedures and Test Results Laboratory testing provided quantitative and qualitative data involving the relevant engineering properties of the ' representative earth materials selected for testing. The representative samples were tested in general accordance with American Society for Testing and Materials (ASTM) procedures and/or California Test Methods (CTM). ' Soil Classification: Earth materials encountered during exploration were classified and logged in general accordance with the Standard Practice for Description and Identification of Soils (Visual- Manual Procedure) of ASTM D 2488. Upon completion of laboratory testing sample descriptions were reconciled to reflect laboratory test results with regard to ASTM D 2487. ' Maximum Density Tests: The maximum dry density and optimum moisture content of representative samples were determined using the guidelines of ASTM D 1557. The test results are presented in the table below. 1 Silty fine to medium 132.0 8.5 SAND with gravel 2 Silty fine to medium 119.5 10.0 ' SAND with gravel Expansion Index: The expansion potential of representative samples was evaluated using the guidelines of ASTM D 4829. The test results are presented in the table below. SAMPLE MATERIAL EXPAASION POTENTIAL DESCRIPTI ' East Side @ 0-2 feet Silty SAND 10 Very Low West Side @ 0-2 feet Silty SAND 6 Very Low Minimum Resistivity and pH Tests: Minimum resistivity and pH tests of select samples were performed using the guidelines of CTM 643. The test results are presented in the table below. a., -- OCATION ., DESCRIPTION _ ON p (ohm-cmy ' East Side @ 0-2 feet Silty SAND 7.4 8,000 West Side @ 0-2 feet Silty SAND 7.2 5,900 1 ' Soluble Sulfate: The soluble sulfate content of select samples was determined using the guidelines of CTM 417. The test results are presented in the table below. 1 LOCATION DESCRIPTION SMI %by we' t) ' East Side @ 0-2 feet Silty SAND No Detection Negligible West Side @ 0-2 feet Silty SAND 30 Negligible 1 Chloride Content: Chloride content of select samples was determined using the guidelines of CTM ' 422. The test results are presented in the table below. ' East Side @ 0-2 feet Silty SAND 30 West Side @ 0-2 feet Silty SANDIF 30 1 1 1 1 1 ' TABLE 1 SUMMARY OF FIELD DENSITY TESTS ' Test Test ° No. Type ' 1 N 10 30 15 CF Over Excavation Bottom,North Side 1120 1 118.8 9.5 132.0 90 2 N 10 30 15 CF Over Excavation Fill,North Side 1122 1 122.8 11.9 132.0 93 3 N 10 30 15 CF Over Excavation Fill,North Side 1124 1 126.3 9.4 132.0 96 ' 4 N 10 30 15 CF Over Excavation Fill,North Side 1126 1 119.4 10.5 132.0 90 5 N 10 30 15 CF South Side Building,Midline 1123 1 119.6 10.5 132.0 91 6 N 10 30 15 CF South Side Building,West of Midline 1125 1 118.8 11.7 132.0 90 7 N 10 30 15 CF Midline West End 1127 1 119.3 12.0 132.0 90 ' 8 N 11 02 15 CF South Roadway,Midline West End 1129 2 115.1 9.1 119.5 96 9 N 11 02 15 CF West Building South Side 1121 1 2 118.4 9.1 119.5 99 10 N 11 02 15 CF East of West Building,North Side 1122 2 111.4 11.2 119.5 93 ' 11 N 11 02 15 CF South Roadway,Midline West End 1122 1 119.9 11.7 132.0 91 12 N 11 02 15 CF South Side Building,East of Midline 1123 1 119.8 11.1 132.0 91 13 N 11 02 15 CF North Side Buildin&West End 1126 2 110.3 11.9 119.5 92 14 N 11 02 15 CF West End Buildin&Midline 1128 2 109.9 9.0 119.5 92 ' 15 N 11 02 15 CF Southside in Parkway,Midline 1129 2 1 108.9 12.8 119.5 91 16 N 11 03 15 CF Parking Area,East End,South Parldng 1128 2 108.4 17.1 119.5 91 17 N 11 03 15 CF East End,In Parkway,Northside 1126 2 110.9 9.5 119.5 93 ' 18 N 11 03 15 CF North Side Building,East End 1127 1 124.2 9.8 132.0 94 19 N 11 03 15 CF Midline 1129 1 121.4 11.9 132.0 92 20 N 11 03 15 CF East of West End Building 1128 2 110.7 9.7 119.5 93 21 N 11 03 15 CF South Side Building,West End 1125 2 116.4 10.7 119.5 97 22 N 11 03 15 CF South Side Building,Midline 1127 1 125.1 9.5 132.0 95 23 N 11/03 15 CF Main Entrance,South Side 1129 1 121.8 9.3 132.0 1 92 24 N 11/03 15 CF North Side Building,East End 1128 2 116.5 12.3 119.5 97 t 25 N 11 04 15 CF North Side Building,Midline 1128 1 124.9 12.0 132.0 95 26 N 11 04 15 CF Open Area Between Building,West Side 1128 2 117.4 8.9 119.5 98 27 N 11 04 15 CF Southside Building West of Midline 1129 2 118.7 12.1 119.5 99 ' 28 N 11 04 15 CF In Roadway,East End,South Side 1129 2 108.6 8.9 119.5 91 29 N 11 04 15 CF North Building 1130 1 123.7 8.6 132.0 94 30 N 11 04 15 CF West of Midline,Between Buildings 1130 2 113.6 9.8 119.5 95 31 N 11 04 15 CF Main Entrance,East Side,North Building 1130 1 118.9 6.7 132.0 90 ' 32 N 11 04/15 CF South Side Building,West End 1130 1 119.6 7.0 132.0 91 33 N 11 04 15 CF Main Entrance,East Side,South Buildin 1130 1 127.4 8.4 132.0 97 34 N 11 13/15 1 CF West End Building SG 1 130.5 8.8 132.0 99 ' 35 N ft13 CF West End Building,South West Corner SG 1 126.1 6.0 132.0 96 36 N CF South Side Buildin ,Midline SG 1 130.2 10.0 132.0 99 37 N CF South Side Buildin ,East End SG 1 127.5 5.9 132.0 97 38 N CF Midline Between Buildin s,West End SG 1 129.6 8.0 132.0 98 39 N CF North Side Buildin s,West End SG 1 120.9 9.0 132.0 92 40 N CF North Side Buildin s SG 1 126.7 5.8 132.0 96 41 N CF North Side Buildin s,East End SG 1 120.7 6.8 132.0 91 42 N CF Main Entrance East,Midline in Roadwa SG 2 113.4 8.2 119.5 95 43 N 11 13 15 CF South West Corner in RoadwaySG 2 116.2 6.1 119.5 97 44 N 11 13 15 CF South Side Midline in Roadway SG 2 112.1 6.0 119.5 94 45 N 11/13/151 CF Midline of Roadway SG 1 124.7 6.7 132.0 94 1 N - Nuclear Test Method Project No.: 14625-30A SG -Sub Grade November 2015 ' CF- Compacted Fill LEGEND ALL LOCATIONS ARE APPROXIMATE Geologic Units Afc - Artificial Fill, Compacted ....I............I. Symbols Limits of Report r 4 0 r I r Lt 44- - - - - 0 , I . . _. , � ; a - Field Density Test Location p , 7 _ limits of Overexcavation / Fill 1 ' 19 I D 109 7 1 � ` rrj 1 r - Removal Depth Below Existing • Afcl, Grade _35 1 • �� a • a �-- ° —{jl lei L J O J ' ` ' ❑ O a I • L _Jib1..f7 L J LIT -T- 3 I All Ir r KATI - A&GRADED GEOTECHNICAL MAP 3 LOCATED AT 24325 WASHINGTON AVENUE CITY OF MURRIETA, RIVERSIDE COUNTY, CALIFORNIA PROJECT ANTHEM MEMORY CARE CLIENT MDMG PROJECT NO. 14625-30A DATE NOVEMBER 2015 SCALE 1:40 DWG XREFS REVISION DRAWN B Y CS PLATE 1 ------------------- Ea ir 65 trai ita, hn C, Geotechnical, Environmental and Materials Testing Consultants ____ ---- -_ - -..-__--'_ ------------------------------------- BETTER PEOPLE . BETTER SERVICE . BETTER RESULTS