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HomeMy WebLinkAboutMS 14-11; MATHIS RESIDENCE SFR PARCEL 3; RESPONSE TO THIRD PARTY GEOTECHNICAL REVIEW BY HETHERINGTON ENGINEERING 3144 LEVANTE ST; 2020-08-25EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. 10925 HARTLEY ROAD, SUITE "I" SANTEE, CALIFORNIA 92071 TEL. 619-258-7901 RECORD Copy It!tjtjfll Date Dennis & Robin Mathis August 25, 2020 3128 Levante Street Street Project No. 02-1147)2 Carlsbad, California 92009 Subject: Response to Third Party Geotechnical Review by Hetherington Engineering 3144 Levante Street, APN 223-170-65 Carlsbad, California 92009 Carlsbad Project ID: GR20190034 - DWG 498.1B Reference Third Party Geotechnical Review (First), Proposed Single Family Residence, 3144 Levante Street, APN 223-170765, Carlsbad, California, Project ID: GR2019-0034 - DWG 498.1B, by Hetherington Engineering, dated August 13, 2019 Dear Mr. and Mrs. Mathis: The following is our response to the above-referenced third-party geotechnical review by Hetherington Engineering. In accordance with Hetherington Engineering's request (their review Item 1) we have prepared an updated geotechnical report, dated August 25, 2020. The updated report is presented separately with this response Jétter. Items 3 through 15 of the Hetherington Engineering review are addressed in our updated geotechnical report. Item 2 (review of grading and foundation plans) will be addressed separately once the plans have been prepared. This opportunity to be of service is appreciated. If you have any questions, or we can be of further service, please do not hesitate to call or contact us. Respectfully Submitted, AmtkXavt4..", Martin R. Owen, PE, GE Geotechnical Engineer RECEIVED DEC 0 7 2020 LAND DEVELOPMENT ENGINEERING (1 1 EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. 10925 HARTLEY ROAD, SUITE "I" SANTEE, CALIFORNIA 92071 TEL. 619-258-7901 Dennis& Robin Mathis August 25, 2020 3128 Levante Street Street Project No. 02-1147J2 Carlsbad, California 92009 Subject: lJpdatedGeotechnical Report for Proposed Single-Family Residence 3144 Levánte Street,APN 223-170-65 Carlsbad, California 92009 Project ID; GR2019-0034 - DWG 498.1B References: See attached Figure 1 Dear Mr. and Mrs. Mathis: In accordance with your request, we are pleased to submit this updated geotechnical report for the proposed new residence. We have reviewed our previous geotechnical report (Figure 1, Reference No. 5), dated July 25,2002, reinspected. the site and performed additional subsurface exploration and soil testing. The site was previously graded to its present grade and configuration in late 2002. The lot is Lot 3 of a 4-lot subdivision. The recommendations presented in our previous geotechnical report have been partially modified and updated to reflect changes in the industry standard of practice and the California Building Code. SITE CONDITIONS The site location is shown on the attached Vicinity Map, Figure 2. We inspected the site on August 18, 2020. The site conditions are similar to those described following the 2002 site grading (Figure 1,. Reference No. 4). During our present site visit and additional subsurface exploration, we encountered approximately 2-foot of loose soils that had been placed on the building pad. It is our understanding that the building pad will be regraded to accommodate the proposed construction. PROPOSED CONSTRUCTION The proposed construction consists of a new, two-story residence and detached garage. The residence will be founded on conventional shallow footings and will have slab-on- grade floor. A retaining wall is also planned on the north side -of the Lot. Updated Geotechnical Report for Proposed Single-Family Residence Page 2 3144 Lcvante.Street, APN 223-170-65 - August 25, 2020 Carlsbad, California 92009 . Project No. 02-1147J2 ADDITIONAL SUBSURFACE SOIL EXPLORATION As part of our recent site reinspection, we performed additional subsurface exploration consisting of hand auguring two test borings to a depth of 3 feet, at the locations shown on the attached Figure 3. The borings were drilled in the area of the.proposed residence. Logs of the test borings are presented on Figure 4. In addition, an updated geotechnical map using the current grading plan is shown on Figure 5. SUBSURFACE SOIL CONDITIONS The subsurface materials encountered during the subsurface soil exploration consisted of approximately 2 feet of undocumented fill comprised of dry to moist, loose, silty sand over previously compacted fill consisting of dry to moist, silty sand. The fill was derived from on-site and off-site sources. There is a maximum of approximately 10 feet of fill beneath Lot 3. GEOLOGY From published geologic maps, the site is underlain at depth by sedimentary bedrock of the Santiago Formation. There are no known geologic hazards such as landslides, liquefaction-prone areas, or earthquake faults at the site. However, the proposed single-family residence is subject to ground shaking and possible damage from earthquakes on nearby, or more distant, active faults. SEISMIC DESIGN VALUES Updated seismic design values are presented on the attached Figure 5. CONCLUSIONS The site is suitable for construction of the new, two-story residence and detached garage. The following recommendations should be incorpo ated into the design and construction of the project. EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC.. Updated GEotechnical Report for Proposed Single-Family Residence Page 3 3144 Levante Street, APN 223-170-65 August 25, 2020 Carlsbad, California 92009 Project No. 02-1147J2 RECOMMENDATIONS SITE GRADING Site Clearing The area of the proposed construction should be cleared of vegetation and other deleterious materials. Vegetation and debris from the clearing operation should be properly disposed of off- site. Removal of Loose Fill Soils The upper 2 feet of loose, undocumented fill soils and an additional 1 foot of the underlying compacted fill within the proposed building area and to a distance of at least 5 feet outside building limits should be removed and recompacted to a minimum depth of 3 feet below existing grades. Compaction and Method of Filling Prior to fill placement, the exposed subgrade soils should be scarified to a depth of 6 to 8 inches, moisture conditioned to slightly above optimum moisture content and compacted to at least 90 percent relative compaction. The on-site soils may be reused as compacted fill, provided they are free of organic materials and debris, and rocks or cobbles over 6 inches in dimension. Any imported fill soils should be predominantly granular and approved by our field representative. All fill should be compacted to a minimum relative compaction of 90 percent as determined by ASTM D1557. Fill should be placed at a moisture content slightly above optimum moisture content, in lifts 6 to 8 inches thick, with each lift compacted by mechanical means. Utility trench backfill and retaining wall backfill should also be compacted to at least 90 percent relative compaction. All grading, fill placement, and compaction should be performed in accordance with the grading requirements of the City of Carlsbad. Fill placement and compaction should be observed and tested as necessaiy by our held representative. FOUNDATIONS Footings for the new, two-story residence and detached garage should be founded in properly compacted fill. Footings should have a minimum depth of 18 inches below building pad grade or lowest adjacent, finished grade, whichever is deeper. EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Updated Geotechnical Report for PropOsed Single-Family Residence Page 4 3144 Levante Street, APN 223-170-65 August 25, 2020 Carlsbad, California 92009 Project No. 02-1147J2 Continuous footings should be at least 15 inches wide and reinforced with a minimum of four #4 steel bars; with tvo bars placed near the top of the footings and the other two bars placed near the bottom of the footings. Individual footings should be at least 18 inches square and reinforced with a grid of #4 bars spaced 12 inches on centers (each way) and placed on concrete blocks at the bottom of the footing. An allowable soil bearing value of 2,000 pounds per square foot may be used for the design of continuous and/or individual spread footings bearing in properly compacted fill. This value may be increased by one-third for short term wind or seismic loads. Total and differential settlements of 1/2 inch may be assumed. Lateral loads may be resisted by an equivalent fluid passive soil pressure of 350 pounds per cubic foot. A coefficient of friction of 0.35 may also be used. If passive and friction values are used together, the friction value should be reduced by one-third. All footing excavations should be inspected and approved by our field representative. Footing excavations should be thoroughly cleaned prior to inspection. For design purposes, total and differential settlements of 1/2 inch may be assumed. FLOOR SLABS Floor slabs should be at least 5 inches thick and reinforced with #4 bars placed at 18 inches On centers in two directions in the middle of the slab. The reinforcing steel should be supported on steel chairs or concrete blocks. Floor slabs should be underlain by 2 inches of clean sand over a 10-mil visqueen moisture barrier over 2 inches of clean sand. To minimize the potential for shrinkage cracks, foundation and floor slab concrete should have ajninimum compressive strength of 3,000 psi. Special testing of concrete. is not. required. Some shrinkage cracks are still posible. PATIO AND OTHER EXTERIOR SLABS Patio and other, -exterior slabs should be at least 5 inches thick and reinforced with #4 bars placed at 18 inches on centers in two directions in the middle of the slab. Patio slabs should be provided with construction joints no more than 10 feet apart to minimize shrinkage cracking. CONCRETE PAVER RECOMMENDATIONS Based on the subgrade soil conditions, the following hydrologic paver section is recommended in accordance with the Interlocking Concrete Pavement Institute (ICPI) specifications. Minimum 3-1/8-inch hydrologic payers 1.5" to 2" bedding course (Typ. No. 8 Aggregate) EAST COUNTY SOIL CONSULTATION AND ENGINEERING. INC. Updated Ceotechnical Report for Proposed Single-Family Residence Page 5 i 3144 Levante Street, APN 223-170-65 August 25, 2020 Carlsbad, California 92009 Project No. 02-1147J2 6-inch Class 2 aggregate base compacted to 95 percent relative compaction (ASTM D1557) The upper 12 inches of the existing fill soils should be scarified, moisture conditioned to approximately 2 percent over optimum moisture content and compacted to a minimum of 95 percent relative compaction (ASTM D1557). CORROSION TESTING Based upon the corrosion test results (Figure No. 8), we recommend Type I or II Portland cement for construction with a water-cement ratio no greater than 0.5. For standard concrete containing six sacks of cement per cubic yard and 3 inches of concrete cover over steel, the estimated time to corrosion of reinforced concrete substructures is 100 years based on California Test Method 532. In addition, the minimum estimated time to perforation of a 16-gauge steel culvert is 30 years based on California Test Method 643. SOIL PRESSURES FOR RETAINING WALL DESIGN The proposed cantilever retaining wall on the north side of the lot may be designed for an active equivalent fluid soil pressure of 35 pcf assuming a level backfill. For a 2:1 sloping backfill the active soil pressure should be increased to 55 pcf. Should the wall be subject to a àniform surcharge load behind the wall, it should be designed for an additional, uniform lateral pressure equal to one-third the anticipated surcharge pressure. These pressures are based on the backfill soils being free draining and non-expansive (El less than 20). For seismic design of retaining walls over 6 feet in height, a horizontal seismic coefficient Kh=SDS/2.5 should be used.. See a1so. attached Figure 6 for seismic design values. An inverted, triangular soil pressure distribution should be assumed against the retaining walls. The resultant, horizontal earthquake force F=3/8*Kh*Soil density*Wall height (H)"2 may be assumed to act at a distance of 0.6*H above the base of the wall. A soil density of 130 pcf may be assumed. RETAINING WALL FOUNDATION DESIGN An allowable soil bearing value of 2,000 pounds per square foot may be used for the design of retaining wall footings founded at least 12 inches into properly compacted fill. This value may be increased by.one third for short term seismic loads. Footing depths should be verified by our field representative. Lateral loads may be resisted by an equivalent fluid passive soil pressure of 300 pounds per cubic foot. A coefficient of friction of 0.4 may also be used. If passive and friction values are used together, the friction value should be reduced by one-third. EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Updated Geotechnical Report for Proposed Single-Family Residence Page 6 1 3144 Levante Street, APN 223-170-65 August 25, 2020 Carlsbad, California 92009 Project No. 024147J2 RETAINING WALL DRAINAGE The retaining wall should be provided with appropriate waterproofing and wall drainage. Please see attached Figure 7 for recommended wall drainage. Wall drainage and backfill materials should be approved by our field representative prior to placement and compaction. All backfill should be compacted to at least 90 percent relative compaction based On ASTM D 1557, and observed and tested as necessary by our field representative. CONSTRUCTION IMPACT Based on the recommended grading and proposed construction, it is our opinion that the proposed development will not destabilize or result in settlement of the adjacent properties. LIMITATIONS OF INVESTIGATION Our updated geotechnical report was prepared using the skill and degree of care ordinarily exercised under similar circumstances by reputable soil engineers and geologists practicing in this or similar localities. No other warranty, expressed or implied, is made regarding the conclusions and professional advice included in this report. This report provides no warranty, either expressed or implied, concerning future building performance. Future damage from geotechnical or other causes is a possibility. This report is prepared for the sole use of our client and may not be assigned to others without the written consent of the client and ECSC&E, Inc. This report is issued with the understanding that it is the responsibility of the owner, or his/her representative to ensure that the information and recommendations contained herein are brought to the attention of the project architect and engineer. Appropriate recommendations should be incorporated into the structural plans. The necessary steps should be taken to see that the contractor and subcontractors carry out such recommendations in the field. The findings of this report are valid as of this present date. However, changes in the conditions of a property can occur with the passage of time, whether they are due to natural processes or the works of man on this or adjacent properties. In addition, changes in applicable or appropriate standards may occur from legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly or partially by changes outside of our control. Therefore, this report is subject to review and should be updated after a period of two years. EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Updated Geotechnical Reportfor Proposed Single-Family Residence Page 7 3144 Levante Street, APN 223-17065 August 25, 2020 Carlsbad, California 92009 Project No. 02-1147J2 ADDITIONAL SERVICES The review of plans and specifications, field observations and testing under our direction are integral parts of the recommendations made in this report. If East County Soil Consultation and Engineering, Inc. is not retained, for these services, the client agrees to assume our responsibility for any potential claims that may arise during construction. Observation and testing are additional services, which are provided by our firm, and should be budgeted within the cost of development. This opportunity to be of service is. appreciated. If you have any questions, or we can be of further service, please do not hesitate to call or contact us. Respectfully Submitted, Martin R. Owen, PE, GE Geotechnical Engineer Attachments: Figure 1 through 8 EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Updated Geotechnical Report for Proposed Single-Family Residence Page 8 3144 Levante Street, APN 223-170-65 August 25, 2020 Carlsbad, California 92009 Project No. 02-1147J2 FIGURE 1 REFERENCES L "Grading Plans for Mathis Residence, 3144 Levante Street, Carlsbad CA 92009", Prepared by La Costa Engineering, Inc. 2. "Geotechnical Report Update (Revised), Proposed Single-Family Residence on Southwestern Parcel, Levante Street, APN 223-170-18 & 19, La Costa Area, City of Carlsbad, California", Project No.. 02-3147J2, Prepared by East County Soil Consultation and Engi.neeiing, inc., Dated September 19, 2016. "Addendum to Limited Site Investigation; Four Proposed Single-Family Residences, Lot 230 & 231 Levante Street, APN 223-170-18 & 19, City of Carlsbad, California", Project No. 02- 1147J2, Prepared by East County Soil Consultation and Engineering, Inc., Dated November 12, 2002. "Report of Field Density Tests, Four Proposed Single-Family Residences, Lot 230 & 231 Levante Street, APN 223-170-18 & 19, City of Carlsbad, California", Project No. 02-1147J2, Prepared by East County Soil Consultation and Engineering, Inc., Dated September 12, 2002. "Limited Site Investigation, Four Proposed Single-Family Residences, Lot 230 & 231 Levante Street, APN 223-170-18 & 19, City of Carlsbad, California", Project No. 02-1147J2, Prepared by East County Soil Consultation and Engineering, Inc., Dated July 25, 2002. EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Updated Geotechnical Report for Proposed Single-Family Residence i 3144 Levante Street, APN 223-170-65 Carlsbad, California 92009 FIGURE 3 LOCATIONS OF TEST BORINGS -S -- ------- AS r - .5 0 Page 10 August 25. 2020 Project No. 02-1147J2 5, S LEGEND APPROXIMATE LOCATION OF TEST BORING EAST COUNTY SOIL CONSULTATION AND ENGINEERING. INC. Updated Geotechnical Report for Proposed Single-Family Residence Page 11 3144 Levaute Street, APN 223-170-65 August 25, 2020 Carlsbad, California 92009 Project No. 02-1147J2 FIGURE 4 LOGS OF TEST BORINGS BORING B-i DEPTH SOIL DESCRIPTION Y Surface UNDOCUMENTED FILL: tan brown, dry to moist, loose, silty sand 1.0' It " S If to 101.2 8.7 2.0' COMPACTED FILL: tan brown, dry to moist, medium dense to dense, silty sand 3.0' bottom of test boring, no caving, no groundwater .112.7 11.8 test boring backfilled 8/18/2020 BORING B-2 DEPTH SOIL DESCRIPTION S Y M Surface UNDOCUMENTED FILL: tan brown, dry to moist, loose, silty sand 2.0' COMPACTED FILL: tan brown, dry to moist, medium dense to dense, silty sand 3.0' bottom of test boring, no caving, no groundwater test boring bacldilled 8/18/2020 Y = DRY DENSITY IN PCF M = MOISTURE CONTENT IN % EAST COUNTY SOIL CONSULTATION AND ENGINEERING. INC. - Updated Geotechnical Reportfor Proposed Single-Family Residence Page 13 i 3144 Levante Street, APN 223-170-65 August 25, 2020 Carlsbad, California 92009 Project. No. 02-1147J2 FIGURE 6 SEISMIC DESIGN VALUES 3144 Levante St, Carlsbad, CA 92009, USA Date Design Code Reference Document Risk Category Site Class Type Value SE 0.966 0.352 1.075 S,.1. null -See Section 11.4.8 Sns • 0.717 null -See Section 11.4.8 Type Value SOC null -See Section 11.4.8 F3 1.114 null -See Section 11.4.8 8/24/2020, 8:21:55 AM ASCE7-16 II D - Stiff Soil Description MCER ground motion. (for 0.2 second period) 1%4CEA ground motion. (for lOs period) Site -mod ifiedspectral acceleration value Site-modified spectral acceleration value Numeric seismic design value at 0.2 second SA Numeric seismic design value at 1.0 second SA Description Seismic design category Site amplification factor at 0.2 second Site amplification factor at 1.0 second EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Updated Ceotechnical Report for Proposed Single-Family Residence 3144 Levante Street, APN 223-170-65 Carlsbad, California 92009 Page 14 August 25,2020 Project No. 02-1147J2 FIGURE 7 RETAINING WALL DRAINAGE 2 T >1 1 •• [H I :-?EE-r WIDE P?J 01 CALTRA:. CLA5 P?2.EASLZ -i MATEP.IAL PLACED o 'rr 1 FOOT O OR OF -VALL wArEpppoopt:c- 4-:C9 DL4TEP.. ZP2C'P_sTED 5CIDtLE 40 ?VC PIPE WTAP?ED FILlEt'. J OCt. O SPECIFICATIONS FOR CALTRANS CLASS II PERMEABLE MATERIAL The.percemage composition by weight of Class IlPenneable Material should comply with the follo,winst graduation requirements: Sieve Size Percentage Passin2 100 34 90-100 3 S" 40-100 No.4 25-40 Yo.S 18-33 No. 30 5-15 No.50 0-7 No. 200 0-3 Class 2 Penneable Material should also have a sand equivalent value of at least 75. EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. Updated Geotechnical Report for Proposed Single-Family Residence 314 Levante Street, APN 223-170-65 Carlsbad, California 92009 Page 15 August 25, 2020 Project No. 02-1147J2 FIGURE 8 CORROSION TEST RESULTS LABORATORY REPORT Telephone (619) 425-1993 Fax 425-7917 Established 1928 CLARKSON. LABORATORY AND SUPPLY INC. 350 Trousdale Dr. Chula Vista, Ca. 91910 www.clarksonlab.com ANALYTICAL AND CONSULTING CHEMISTS Date: October 10, 2019 Purchase Order Number: NONE Sales Order Number: 45907 Account Number: EASCS To: a-------------------------------------------------* East County Soil Consultation and Engineering Inc. 10925 Hartley Road Suite I Santee, Ca 92071 Attention: Michael Duncan Laboratory Number: 507546 Customers Phone: 619-258-7901 Fax: 619-258-7902 Sample Designation: *-------------------------------------------------* One soil sample received on 10/09/19 at 9:15am, marked as Mathis-Levante St, Carlsbad. Analysis By California Test 643, 1999, Department of Transportation Division of Construction, Method for Estimating the Service Life of Steel Culverts. pE 8.0 Water Added (ml) Resistivity (ohm-cu) 10 1700 5 - 1100 5 930 5 920 5 980 5 1100 30 years to perforation for a 16 gauge metal culvert. 38 years to perforation for a 14 gauge metal culvert. 53 years to perforation for a 12 gauge metal culvert. 68 years to perforation for a 10 gauge metal culvert. 83 years to perforation for a 8 gauge metal culvert. Water Soluble Sulfate Calif. Test 417 0.018% Water Soluble Chloride Calif. Test 422 0.009% RV4;~ Rasa bernal BMB/ilv EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC 10925 HARTLEY ROAD, SUITE "I" SANTEE, CALIFORNIA 92071 619 258-7901 Fax 619 258-7902 Dennis & Robin Mathis September 19, 2016 3128 Levante Street Project No. 02-1147.12 Carlsbad, California 92009 Subject: Geotechnical Report Update (Revised) Proposed Single-Family Residence on Southwestern Parcel Levante Street, APN 223-170-18 & 19 La Costa Area, City of Carlsbad, California 92009 References: See Attached Dear Mr. & Mrs. Mathis: In accordance with your request, we have reviewed the referenced soil reports and visited the subject site on September 2, 2015. Site conditions were found as described in the referenced soil report (Reference No. 3) and are suitable for the construction of the proposed single-family residence. Therefore. .the recommendations provided in the referenced geotechnical report (Reference No. 4) are still valid for the development of the southwestern parcel. 2013 CBC Seismic Design Criteria Seismic design criteria have been updated in accordance with the 2013 California Building Code as follows: PARAMETER. ..VALUE 2O13CBC/ASCE1.REFERENCES. Site Class D Table 20.3-1/ ASCE 7, Chapter 20 Mapped Spectral Acceleration For Short Periods, S5 1.037g Figure 16 13.3.1(l) Mapped Spectral Acceleration For a 1-Second Period, S1 0.401 g Figure 1613.3.1(2) Site Coefficient, F. 1.085 Table 1613.3.3(1) Site Coefficient, F 1.599 Table 1613.3.3(2) Adjusted Max. Considered Earthquake Spectral Response Acceleration for Short Periods, SMS 1.125g Equation 16-37 Adjusted Max. Considered Earthquake Spectral Response Acceleration for 1-Second Period, SMI 0.641g Equation 16-38 5 Percent Damped Design Spectral Response Acceleration for Short Periods, SDS 0.750g Equation 16-39 5 Percent Damped Design Spectral Response Acceleration for I-Second Period, SDI 0.428g Equation 16-40 DENNIS & ROBIN MATHIS/LEVANTE STREET PROJECT NO. 02-1/47J2 In addition, we have reviewed the grading plan prepared by La Costa Engineering of Carlsbad, California to address the proposed surface drainage around the the proposed single-family residence. A minimum gradient of 2 percent may be implemented away from the structure within hardscape areas to a minimum distance of 10 feet. In earth areas, this will be 5 percent. Earth swales should have a minimum gradient of 2 percent and be directed to approved drainage receptors. Should you have any questions, please do not hesitate to contact our office. Respectfully submitted, ?9.OFESSl Of ok GE 2704 (ri t EXP I - 1*4 Mamadou Saliou Diallo, P.E. RCE 54071, GE 2704 MSDmd DENNIS & ROBIN MA THIS/ LE VANTE STREET PROJECT NO. 02-1147J2 - S REFERENCES "Foundation Excavation Observation, Proposed Single-Family Residence, 3128 Levante Street, APN 223-170-18 & 19, City of Carlsbad, California" Project No. 02-I l47J2(B), Prepared by East County Soil Consultation and Engineering, Inc., Dated January 9, 2003. 'Addendum to Limited Site Investigation, Four Proposed Single-Family Residences, Lot 230 & 231 Leante Street, APN 223-170-18 & 19, City of Carlsbad, California" Project No. 02- I 147J2(B), Prepared by East County Soil Consultation and Engineering, Inc., Dated November 12, 2002. "Report of Field Density Tests, Four Proposed Single-Family Residences, Lot 230 & 231 Levante Street, APN 223-170-18 & 19, City of Carlsbad, California" Project No. 02-I I47J2(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated Sctember 12, 2002. 4; "Limited Site investigation,. Four Proposed Single-Family Residences, Lot 230 & 231 Levante Street, APN 223-170-18 & 19,City of Carlsbad, California" Project No. 02-1147J2, Prepared by East County Soil Consultation and Engineering, Inc., Dated July 25, 2002. EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. 10925 HARTLEY ROAD, SUITE I SANTEE, CALIFORNIA 92071 (619)258-7901 . Fax 258-7902 Dennis Mathis Construction . . September 12, 2002. 3351 Venado Street S Project No. 02-1147J2(A) Rancho La Costa, California 92009 Subject: Report of Field Density of Tests Four Proposed Single Family Residences Lots 230 & 231 Levante Street, APN 223-170-18 & 19 City of Carlsbad, California Reference: "Limited Site Investigation, Four Proposed Single Family Residences, Lot 230 & 231 Levante Street, APN 223-170-18 & 19, City of Carlsbad, California", Project No. 02-1147J2, Prepared by East County Soil Consultation and Engineering, Inc., Dated July 25, 2002 Dear Mr. Mathis: This report presents the results of field density tests performed on the building pads for the four proposed single family residences at the subject site. In accordance with your request, in-place field density tests were taken in conformance with ASTM D1556-90 (Sand Cone) . Site grading was performed between July 26 and August 20, 2002 under the observation and testing of a representative of East County Soil Consultation and Engineering, Inc. The results of the field density tests are presented on Page T-1 under "Table of Test Results". The laboratory determinations of the maximum dry density and optimum moisture content results are set forth an Page L-1 under "Laboratory Test Results". The approximate test locations are shown on Plate No. 1. DENNIS MA THIS CONSTRUCTION PROJECT NO. 02-1147J2(A) . sI Prior to the remedial grading operation, brush and vegetation were. remove .d from the subject site. Subgrade soils were overexcavated to a minimum depth-of 3 -feet below •proposed grade into competent bearing soils. These soils were scarified to a depth of. approximately 6 inches, moisture. conditioned and recompacted. On-site soils consisting of silty sandand clayey sand were placed and compacted in excess of 90 percent relative density while maintaining a moisture content around optimum. Compaction was achieved with the use of Caterpillar 983B and 977L • trackloaders. Based on our field observations and density test results, it is our opinion that the grading operation for the proposed single family residences was performed in accordance with the referenced soil investigation report and local grading ordinances. If we can be of further assistance, please do not hesitate to contact our office. Pages T-1, L-1 and Plate No. 1 are attached. Respectfully Submitted, Mamadou Saliou Diallo, P.E. RCE 54071 MSD/md 2 DENNIS MA THIS CONSTRUCTION PROJECT NO. 02-1147J2(A) PAGE 1-1 TABLE OF TEST RESULTS ASTM D1556-90 MAXIMUM DEPTH FEILD DRY DRY TEST SOIL OF FILL MOISTURE DENSITY DENSITY PERCENT NO. TYPE IN FEET %DRY WT. P.C.F. P.C.F COMPACTION I I 0' 12.0 108.9 119.0 91 2 2 IS 11.2 107.8 118.0 91 3 2 2' 9.8 106.3 118.0 90 4 3 4' 17.1 111.9 120.5 93 5 3 3' 13.9 113.9 120.5 94 6 3 6'FG 13.8 111.5 120.5 93 7 2 4TG 14.3 105.4 118.0 90 8 3 0' 13.3 109.7 120.5 91 9 2 I' 13.7 107.1 118.0 91 10 2 21 16.7 108.9 118.0 92 II 2 2 16.6 110.5 118.0 94 12 3 2' 17.2 110.7 120.5 92 13 3 . 2' 15.1 112.3 120.5 93 14 3 2' 13.3 112.1 120.5 93 15 2 1.5' 14.9 107.1 118.0 91 16 2 3'FG 12.3 109.3 118.0 93 17 2 3'FG 11.7 111.9 118.0 95 18 3 4'FG 13.7 109.7 120.5 91 19 2 1.5' 12.1 112.2 118.0 95 20 2 4TG 12.0 111.7 118.0 95 21 3 3'FG 11.6 115.0 120.5 95 22 2 3'FG 13.2 112.5 118.0 95 FG = FINISH GRADE TEST 3 REMARKS -11 - DENiWS MA THIS CONSTRUCTION PROJECT NO. 02-1147J2(A) PAGE L-1 LABORATORY TEST RESULTS RESULTS OF MAXIMUM DENSITY TEST• The maximum dry densities and optimum moisture contents of the fill materials as determined by ASTM D1557-91, Procedure A which uses 25 blows of a 10 pound slide hammer falling from a height of 8 inches on each of 5 equal layers in a 4 inch diameter 1/30 cubic foot compaction cylinder and Procedure C which uses 56 blows of a 10 pound slide hammer falling from a height of 18 inches on each of 5 equal layers in a 6 inch diameter 1/13.3 cubic foot compaction cylinder are presented as follows: OPTIMUM MAXIMUM MOISTURE DRY DENSITY CONTENT SOIL TYPE/ PROCEDURE LB/ CU. FT. % DRY WI. 1/A TAN SILTY FINE GRAINED SAND 119.0 11.7 2/A TAN BROWN SILTY FINE 118.0 11.4 GRAINED SAND 3/A TAN BROWN CLAYEY SAND 120.5 11.3 4 ==:::~ ~ r —... : .% 0 ) .., \*i \ q . 'r1 : ••-j - zz5 VA1V 7L • ,'p =t_ LV5/7Y7 7E __- EAST COUNTY SOIL CONSULTATION & ENGINEERING, INC. 10925 HARTLEY RD.. SUITE ISANTEE, CA 92071 (619) 258-7901 Fax (619) 258-7902 t'e'V#v'y ,37Xf/5 v517 74/ ''2—//47V2 4) EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC 10925 HARTLEY ROAD, SUITE "I" SANTEE, CALIFORNIA 92071 619 258-7901 Fax 619 258-7902 Dennis & Robin Mathis September 4, 2015 3128 Levante Street Project No. 02-1147J2 Carlsbad, California 92009 Subject: Geotechnical Report Update Proposed Single-Family Residence on Southwestern Parcel Levante Street, APN 223-170-18 & 19 La Costa Area, City of Carlsbad, California 92009 References: See Attached Dear Mr. & Mrs. Mathis: In accordance with your request, we have reviewed the referenced soil reports and visited the subject site on September 2, 2015. Siie conditions were found as described in the referenced soil report (Reference No. 3). Therefore, the recommendations provided in the referenced geotechnical report (Reference No. 4) are still valid for the development of the southwestern parcel. 2013 CBC Seismic Design Criteria Seismic design criteria have been updated in accordance with the 2013 California Building Code as follows: PARAMETER Site Class D Table 20.3-1/ ASCE 7, Chapter 20 Mapped Spectral Acceleration For Short Periods, 1.037g Figure 1613.3.1(1) Ss Mapped Spectral Acceleration For a 1-Second 0-401g Figure 1613.3.1(2) Period, S1 Site Coefficient, F. 1.085 Table 1613.3.3(1) Site Coefficient, F 1.599 Table 1613.3.3(2) Adjusted Max. Considered Earthquake Spectral 1.125g Equation. 16-3 7 Response Acceleration for Short Periods, SMS Adjusted Max. Considered Earthquake Spectral 0.641g Equation 16-38 Response Acceleration for 1-Second Period, SMI 5 Percent Damped Design Spectral Response 0.750g Equation 16-39 Acceleration for Short Periods, SDS 5 Percent Damped Design Spectral Response 0.428g Equation 16-40 Acceleration for 1-Second Period, SDI - DENNIS & ROBIN MA THIS! LE VANTE STREET PROJECT NO. 02-1147J2 Should you have any questions, please do not hesitate to contact our office. Respectfully submitted, Mamadou Saliou Diallo, P.E. RCE 54071, GE 2704 MSD\md 2 DENNIS & ROBIN MATHIS/LEVANTE STREETPROJECTNO. 02-1147J2 REFERENCES L "Foundation Excavation Observation, Proposed Single-Family Residence, 3128 Levante Street, APN 223-170-18 & 19, City of Carlsbad, California" Project No. 02-1147J2(B), Prepared by East County Soil Consultation and Engineering, Inc., Dated January 9, 2003. "Addendum to Limited Site Investigation, Four Proposed Single-Family Residences, Lot 230 & 231 Levante Street, APN 223-170-18 & 19, City of Carlsbad, California" Project No. 02- 1 147J2(B), Prepared by East County Soil Consultation and Engineering, Inc., Dated November 12, 2002. "Report of Field Density Tests, Four Proposed Single-Family Residences, Lot 230 & 231 Levante Street, APN 223-170-18 & 19, City of Carlsbad, California" Project No. 02-114712(A), Prepared by East County Soil Consultation and Engineering, Inc., Dated Setember 12, 2002. "Limited Site Investigation, Four Proposed Single-Family Residences, Lot 230 & 231 Levante Street, APN 223-170-18 & 19, City of Carlsbad, California" Project No. 02-114712, Prepared by East County Soil Consultation and Engineering, Inc., Dated July 25, 2002. 3 EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. 10925 HARTLEY ROAD, SUITE "I" SANTEE, CALIFORNIA 92071 (619) 258-7901.. Fax 258-7902 Dennis Mathis Construction November 12, 2002 7044 Whitewater Street Project No. 02-1147J2(B) Rancho La Costa, California 92009 Subject: Addendum to Limited Site Investigation Four Proposed Single Family Residences Lots 230 & 231 Levante Street, APN 223-170-18 & 19 City of Carlsbad, California Reference: "Limited Site Investigation, Four Proposed Single Family Residences, Lot 230 & 231 Levante Street, APN 223-170-18 & 19, City of Carlsbad, California", Project No. 02-1147J2, Prepared by East County Soil Consultation and Engineering, Inc., Dated July 25, 2002' Dear Mr. Mathis: In accordance with your request, we have prepared this addendum letter to address the reinforcing steel for the proposed foundations at the subject site. Steel reinforcement in the continuous footings may consist of two # 5 bars, one bar placed near the top of the footings and the other bar placed near the bottom of the footing. These recommendations .are based on the low potential for expansion of the subgrade soils and are not intended to be in lieu of the Structural Engineer requirements. If we can be of any further assistance, please do not hesitate to contact our office. Respectfully s ¼ Mamadou Saliou Diallo, P.E. RCE 54071 MSD/rnd EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. 10925 HARTLEY ROAD, SUITE I SANTEE, CALIFORNIA 92071 (619) 258-7901 Fax 258-7902 Dennis Mathis Construction September 12, 2002 3351 Venado Street Project No. 02-1147J2(A) Rancho La Costa, California 92009 Subject: Report of Field Density of Tests Four Proposed Single Family Residences Lots 230 &.231 Levante Street, APN 223-170-18 & 19 City of Carlsbad, California Reference: "Limited Site Investigation, Four Proposed Single Family Residences, Lot 230 & 231 Levante Street, APN 223-170-18 & 19, City of Carlsbad, California", Project No. 02-1147J2, Prepared by East County 'Soil Consultation and Engineering, Inc., Dated July 25, 2002 Dear Mr. Mathis: This report presents the results of field density tests performed on the building pads for the four proposed single family residences at the subject site. In accordance with your request, in-place field density tests were taken in conformance with ASTM D1556-90 (Sand Cone). Site grading was performed between July 26 and August 20, 2002 under the observation and testing of a representative of East County Soil Consultation and Engineering, Inc. The results of the field density T-1 under "Table of Test determinations of the maximum moisture content results are s "Laboratory Test Results". The are shown on Plate No. 1. tests are presented on Page Results". The laboratory dry density and optimum t forth on Page L-1 under approximate test locations .• - DENNIS MA THIS CONSTRUCTION PROJECT NO. 02-1147J2('A) Prior to the remedial grading operation, brush and vegetation were removed from the. subject site. Subgrade soils were overex.cavated to a minimum depth of 3 feet below proposed grade into 'competent bearing soils. These soils were scarified to a depth' of approximately 6 inches, moisture conditioned and recompacted. On-site soils' consisting of silty sand and clayey sand were placed and compacted in excess of 90 percent relative density while maintaining a moisture content around optimum. Compaction was achieved with the use of Caterpillar 983B and 977L .trackloaders. Based on Our field observations and density test results, it is our opinion that the grading operation for the 'proposed single family residences was performed in accordance with the referenced soil investigation report and local grading ordinances. If we can be of further assistance, please do not hesitate to contact our office. Pages T-1, L-1 and Plate No. 1 are attached. Respectfully Submitted, Mamadou Saliou Diallo, P.E. RCE 54071 MSD/md 2 • S ...• DEPTH FEILD . DRY MAXIMUM . DRY TEST* SOIL . OF-FILL MOISTURE DENSITY DENSITY NO. TYPE IN FEET %DRY WT. : P.C.F. P.C.F I 1 0' 12.0 108.9 119.0 2 2 IS 11.2 107.8 118.0 3 2 9.8 106.3 118.0 .4 3 4' 17.1 111.9 120.5 S 3 3' 13.9 113.9 120.5 6 3. 6'FG 13.8 II i.5 120.5 7 2 4'FG 14.3 105.4 118.0 8 3 0' 13.3 109.7 120.5 9• 2 it 13.7 107.1 118.0 10 2 2' 16.7 108.9 118.0 11 2 2' 16.6 110.5 118.0 12 3 2' 17.2 110.7 120.5 13 3 2' 15.1 112.3 . 120.5 14 3 2 13.3 112.1 120.5 15 2 IS 14.9 107.1 118.0 16 2 3'FG . 12.3 109.3 118.0 17. 2 3'FG . 11.7 111.9 118.0 18 3 4'FG 13.7 109.7 120.5 19 2 1.5' 12.1 112.2 118.0 20 2 4'G 12.0 111.7 118.0 21 3 3'FG 11.6 115.0 120.5 22 2 3'FG 13.2 112.5 118.0 PERCENT COMPACTION REMARKS 91 91 90 93 94 93 90 91 91 92 94 92 93 93 91 93 95 91 95 95 95 95 DENNIS MA THIS CONSTRUCTION PROJECT NO. 02-1147J2(A) PAGE T-1 TABLE OF TEST RESULTS ASTM D1556-90 FG = FINISH GRADE TEST 3 DENNIS M4 THIS CONSTRUCTION PROJECT NO. 02-1147J2(,4) PAGE L-1 LABORATORY TEST RESULTS RESULTS OF MAXIMUM DENSITY TEST The maximum dry densities and optimum moisture contents of the fill materials as determined by ASTM D1557-91, Procedure A which uses 25 blows of a 10 pound slide -hammer falling from a.height of 18 inches on each of 5 equal layers in a 4 inch diameter 1/30 cubic foot compaction cylinder and Procedure C which uses 56 blows of a 10 pound slide hammer falling from a height of 18 inches on each of 5 equal layers in a 6 inch diameter 1/13.3 cubic foot compaction cylinder are presented as follows: OPTIMUM MAXIMUM MOISTURE DRY DENSITY CONTENT SOIL TYPE/ PROCEDURE LB/ CU. FT. % DRY WT. 1/A TAN SILTY FINE GRAINED SAND 119.0 11.7 2/A TAN BROWN SILTY FINE 118.0 11.4 GRAINED SAND 3/A TAN BROWN CLAYEY SAND 120.5 11.3 4 r - '-c--- ____-;;.---- - r I _- •.tr\ (:. .. • : ........ '..- - y - ti ---------- / VAW7 • 7- __AVC 0' - EAST COUNTY SOIL CONSULTATION & ENGINEERING, INC. 10925 HARTLEY RD.. SUITE I. SANTEE, CA 92071 (619) 2511.790I Fax (619) 2.5.7902 . . I et2 445/7)' 7E575 .•.f i .•. EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. 10925 HARTLEY ROAD, SUITE "I" SANTEE, CALIFORNIA 92071 (619) 258-7901 Fax 258-7902 Dennis Mathis Construction July 25, 2002 3351 Venado Street Project No. 02-1147J2 Rancho La Costa, California 92009 Subject: Limited Site Investigation Four Proposed Single Family Residences Lot 230 & 231 Levante Street APN 223-170-18 & 19 City of Carlsbad, California Dear Mr. Mathis: In accordance with your request, we have performed a limited investigation of the soil conditions at the subject site. The investigation was undertaken to provide the soil engineering criteria for site grading and to recommend an appropriate foundation system for the proposed residences. The site was previously graded as cut and fill pads with a maximum depth of fill of approximately 12 feet. Underlying the fill soils was dense sandstone of the Santiago Formation. It is our opinion that the proposed development is feasible provided the recommendations herein are implemented during construction. Respectfully submitted, M"'J It" - Mamadou Saliou Diallo, P.E RCE 54071 DENNIS MA THIS CONSTRUCTION PROJECT NO. 01-1147J2 INTRODUCTION This is to present the findings and conclusions of a soils investigation for four proposed single family residences to be located on the north side of Levante Street, in the City of Carlsbad, California. The objectives of the investigation were to determine the existing soils conditions and provide recommendations for site development. In order to accomplish these objectives, eight (8) exploratory trenches were excavated to a maximum depth of 13.0 feet; undisturbed and loose bag samples were obtained, and laboratory tests were performed. SITE DESCRIPTION AND PROPOSED CONSTRUCTION The subject site is located on the north side of Levante Street, in the City of Carlsbad, California. The site was previously graded as cut and fill pads. Prior to the grading operation, the site sloped moderately to the west. Vegetation consists of grass. The proposed development includes the construction of four two- story, wood-framed, single-family residences to be founded on continuous footings with a slab-on-grade floor system. FIELD INVESTIGATION On March 28, 2002, eight exploratory trenches were excavated to a maximum depth of 13.0 feet by a Caterpillar 416B backhoe equipped with a 24 inch bucket. The approximate locations of the trenches are shown on the attached Plate No. 1, entitled "Location of Exploratory Trenches". A continuous log of the soils encountered was recorded at the time of excavation and is shown on Plates No. 2 through 4 entitled "Summary Sheet". The soils were visually and texturally classified according to the filed identification procedures set forth on the attached Plate No. 5 entitled "Uniform Soil Classification Chart. SURFACE CONDITIONS The surface soils encountered during the course of our investigation were fill soils to a maximum depth of twelve (12) feet. These soils consist of tan clayey sand and silty sand, with a loose to medium dense consistency. The fill soils were underlain by dense sandstone of the Santiago Formation (Tsa). 2 DENNIS MA THIS CONSTRUCTION PROJECT NO. 01-1147J2 EXPANSIVE SOILS An expansion test was performed on a representative sample of the fill soils to determine volumetric change characteristics with change in moisture content. An expansion index of 40 indicates a low potential for expansion. GROUNDWATER Groundwater was not encountered during the course of our investigation. Groundwater is anticipated at a depth greater than 150 feet. We do not expect groundwater to affect the proposed development. GEOLOGIC HAZARDS A review of the available geological literature pertaining to the site indicates the existence of the Rose Canyon Fault Zone approximately 10.5 Km to the west. Ground shaking from this fault or one of the major active faults in the region is the most likely happening to affect the site. With respect to this hazard, the site is comparable to others in the general area. The proposed residential structures should be designed in accordance with seismic design requirements of the 1997 Uniform Building Code or the Structural Engineers Association of California using the following seismic design criteria: PARAMETER VALUE UBC REFERENCE Seismic Zone Factor, Z 0.40 Table 16-I Soil Profile Type SD Table 16-J Seismic Coefficient, Ca 0.44 Table 16-Q Seismic Coefficient, Cv 0.64 Table 16-R Near-Source Factor, Na 1.0 Table 16-S Near-Source Factor, Nv 1.0 Table 16-T Seismic Source B Table 16-U Based on the absence of shallow groundwater, type and consistency of the underlying soils, it is our opinion that the potential for liquefaction is very low. 3 DENNIS MA THIS CONSTRUCTION PROJECT NO. 01-1147J2 CONCLUSIONS AND RECOINDATIONS The following conclusions and recommendations are based upon the analysis of the data and information obtained from our soil investigation. This includes visual inspection; field investigation; laboratory testing and our general knowledge of the soils native to the site. The site is suitable for the proposed development provided the recommendations set forth are implemented during construction. GRADING AND EARTHWORK Site grading should begin with clearing and grubbing, e.g. the removal of vegetation and deleterious materials. It is our understanding that the two existing pads will be graded into four individual pads. Due to the transition between cut and fill on the existing pads and the loose consistency in the upper 3 feet of the existing fill soils, we recommend that the subgrade soils be overexcavated to a minimum depth of three feet below proposed pad grades, moisture conditioned 2 to 4 percent over optimum and compacted to a minimum of 90 percent relative density. The overexcavation should extend a minimum of 5 feet beyond perimeter footings. The actual depth and extent of removal should be evaluated in the field at the time of excavation by a representative of this firm. Grading should be done in accordance with the attached appendix A. FOUNDATION AND SLAB Continuous footings and/or spread footings are suitable for use and should extend a minimum of 18 inches for the two story residential dwellings into the compacted fill soils. Continuous footings should be 15 inches wide and reinforced with four #4 steel bars; two bars placed near the top of the footings and the other two bars placed near the bottom of the footings. Concrete floor slabs should be a minimum 4 inches thick. Reinforcement should consist of #3 bars placed at 16 inches on center each way. Slab reinforcement should be placed within the middle third of the slab by supporting the steel on chairs or concrete blocks "dobies". The slab should be underlain by 2 inches of clean sand over a 10-mil visqueen moisture barrier. The effect of concrete shrinkage will result in cracks in virtually all concrete slabs. To reduce the extent of shrinkage, the concrete should be placed at a maximum of 4-inch slump. The minimum steel recommended is not intended to prevent shrinkage cracks. 4 DENNIS MA THIS CONSTRUCTION PROJECT NO. 01-1147J2 c. Where moisture sensitive floor coverings are anticipated over the slab, the 10-mil plastic moisture barrier should be underlain by a capillary break at least 4 inches thick, consisting of sand, gravel or crushed rock not exceeding 3/4 inch in size with no more than 5 percent passing the #200 sieve. SOIL BEARING VALUE An allowable soil bearing value of 1500 pounds per square foot may be used for the design of continuous and spread footings founded a minimum of 12 inches into the compacted fill soils. This value may be increased by 20 percent for each additional foot of width or depth to a maximum value of 4500 lb/ft2 as set forth in the 1997 Edition of the Uniform Building Code, Table No. 18-1-A. LATERAL SOIL PRESSURE Lateral resistance to horizontal movement may be provided by the soil passive pressure and the friction of concrete to soil. An allowable passive pressure of 200 pounds per square foot per foot of depth may be used. A coefficient Df friction of 0.35 is recommended. The soils passive pressure as well as the bearing value may be increased by 1/3 for wind and seismic loading. RETAINING WALLS Unrestrained, cantilevered retaining walls with a level backfill may be designed to resist an active equivalent fluid pressure of 35 pounds per cubic foot, while retaining walls with a 2 to 1 sloping backfill may be designed to resist an active equivalent fluid pressure of 45 pounds per cubic foot. This pressure is based on the backfill soils being free draining and non-expansive. Backfill materials must be approved by the soils engineer prior to use. SETTLEMENT Settlement of compacted fill soils is normal and should be anticipated. Because of the minor thickness of the fill soil under the proposed footings and the light building loads, the settlement should be within acceptable limits. 5 DENNIS MA THIS CONSTRUCTION PROJECT NO. 01-1147J2 UTILITY TRENCH EXCAVATIONS Excavations for on-site utility trenches may be made vertically for shallow depths and must be either shored or sloped at 1H: lv for depths greater than 4 feet. Utilities should be bedded and backfilled with clean sand or approved granular soil to a depth of at least one foot over the pipe. This backfill should be uniformly watered and compacted to a firm condition for pipe support. The remainder of the backfill may be on-site soils or non-expansive imported soils, which should be placed in thin lifts, moisture conditioned and compacted to at least 90 % relative compaction. SLOPE SETBACK Compacted fill soils that occur within 8 feet of the face of slope possess poor lateral stability, even though they have been certified with a relative compaction of 90 percent or better. Proposed structures and other improvements that are located within 8 feet of the face of compacted fill slopes could suffer differential movement as a result of the poor lateral stability of these soils. Therefore, foundations and footings for the proposed structures or other improvements should be placed at least 8 feet back from the top of these slopes. Foundations placed closer to the top of slope than 8 feet should be deepened such that the bottom of the foundation is at least 8 feet back from the face of the slope. DRAINAGE Adequate measures shall be undertaken to properly finish grade the site after the structures and other improvements are in place, such that the drainage water within the site and adjacent properties is directed away from the foundations, footings, floor slabs and the tops of slopes via surface swales and subsurface drains towards the natural drainage for this area. Proper surface and subsurface drainage will be required to minimize the potential of water seeking the level of the bearing soils under the foundations, footings and floor slabs, which may otherwise result in undermining and differential settlement of the structures and other improvements. DENNIS MA THIS CONSTRUCTION PROJECT NO. 01-1147J2 LIMITS OF INVESTIGATION The recommendations provided in this report pertain only to the site investigated and based upon the assumption that the soil conditions do not deviate from those disclosed in the trenches. If any variations or undesirable conditions are encountered during construction, or if the proposed construction will differ from that planned at the present time, East County Soil Consultation and Engineering, Inc. should be notified so that supplemental recommendations can be provided. Plates No. 1. through 5, Page L-1 and L-2, References and Appendix A are parts of this report. Respectfully submitted, S. CD No.Cd011 zr * LN Mamadou Saliou Diallo RCE 54071 MS D /md 7 I, 1170 ev 20: /'Q k it - 7ry 7'1 —17 7V,00g'P (527AI 54 - i- fi77D/ 9F d6X-774V EAST COUNTY SOIL CONSULTATION & ENGINEERING, INC. 10925 HARTLEY RD.. SUITE I. SANTEE, CA 92071 (619) 258-7901 Fax (619) 258-7902 'VM *f'9?77'15 44TAf f 1Q.*?y 74q5 em ,tZ4,7: A0. / DENNIS MA THIS CONSTRUCTION PROJECT NO. 01-1147J2 PLATE NO. 2 SUMMARY SHEET NO. 3. TRENCH NO. 1 DEPTH SOIL DESCRIPTION Surface FILL (Qaf) tan, dry to moist, loose to medium dense, silty, fine grained sand (SM) 2.0' 2.5' medium brown, moist, medium dense, silty, fine grained sand(SM) 3.5' tan, moist, medium dense, silty fine grained sand 5.0' reddish brown, moist, medium dense, silty, fine to medium grained sand 6.0' SANTIAGO FORMATION (Tsa) tan, moist, dense, fine grained silty sand (SM) 6.5' bottom of trench trench backfilled 3/28/02 Y M 107.9 9.6 104.8 7.5 -------------------------------------------------------------------- TRENCH NO. 2 DEPTH SOIL DESCRIPTION Y M Surface FILL (Qaf) tan, dry to moist, loose to medium dense, silty, fine grained sand (SM) 1.0' SANTIAGO FORMATION (Tsa) tan, moist, dense, fine grained silty sand (SM) 2.0' 110.7 11.5 2.5' bottom of trench trench backfilled 3/28/02 ------------------------------------------------------------------------ TRENCH NO. 3 DEPTH SOIL DESCRIPTION Y M Surface FILL (Qaf) tan, dry to moist, loose to medium dense, silty, fine grained sand (SM) 2.0' medium brown, moist, medium dense, 103.8 20.8 clayey sand(SC) 4.01 SANTIAGO FORMATION (Tsa) tan, moist, dense, fine 101.6 5.8 grained silty sand (SM) 5.5' bottom of trench trench backfilled 3/28/02 ------------------------------------------------------------------------ DENNIS MA THIS CONSTRUCTION PROJECT NO. 01-1147J2 PLATE NO. 3 SUMMARY SHEET NO. 2 TRENCH NO. 4 DEPTH SOIL DESCRIPTION Y M Surface FILL (Qaf) tan, dry to moist, loose silty, fine grained sand (SM) 2.0' tan, moist, medium dense, silty, fine grained sand(SM) 5.0' reddish brown, moist, medium dense, clayey sand (SC) 6.0' SANTIAGO FORMATION (Tsa) tan, moist, dense, fine grained silty sand (SM) 6.5' bottom of trench trench backfilled 3/28/02 ------------------------------------------------------------------------ TRENCH NO. 5 DEPTH SOIL DESCRIPTION Y M Surface FILL (Qaf) tan, dry to moist, loose to medium dense, silty, fine grained sand (SM) 2.01 .106.4 12.3 4.0' 102.4 9.6 4.5' SANTIAGO FORMATION (Tsa) medium brown, moist, medium dense, clayey sand(SC) 6.0' tan, moist, dense, fine grained silty sand (SM) 6.5' bottom of trench trench backfilled 3/28/02 ------------------------------------------------------------------------ TRENCH NO. 6 DEPTH SOIL DESCRIPTION Y M Surface FILL (Qaf) tan, dry to moist, loose to medium dense, silty, fine grained sand (SM) 4.51 SANTIAGO FORMATION (Tsa) medium brown, moist, medium dense, clayey sand(SC) 6.0' tan, moist, dense, fine grained silty sand (SM) 6.5' bottom of trench trench backfilled 3/28/02 DENNIS MA THIS CONSTRUCTION PROJECT NO. 01-1147J2 PLATE NO. 4 SUMMARY SHEET NO. 3 TRENCH NO. 7 DEPTH SOIL DESCRIPTION Surface FILL (Qaf) tan, dry to moist, loose to 2.01 , medium dense 2.01 -5.51 , silty, fine grained sand (SM) 5.5' brown, moist, medium dense, clayey sand(SC) 7.0' SANTIAGO FORMATION (Tsa) tan, dry, dense, fine grained silty sand (SM) 7.5' bottom of trench trench backfilled 3/28/02 Y M TRENCH NO. 8 * DEPTH SOIL DESCRIPTION Y Surface FILL (Qaf) tan, dry to moist, loose to medium dense, silty, fine grained sand (SM) 4.0' 105.6 4.5' medium brown, moist, medium dense, silty, fine grained sand(SM) 5.5' tan, moist, medium dense, silty fine grained sand 6.0' 102.0 8.0' . reddish brown, moist, medium dense, 99.1 clayey sand 12.0' SANTIAGO FORMATION (Ts a) tan, dry, dense, fine grained silty sand (SM) 13.0' bottom of trench trench backfilled 3/28/02 ------------------------------------------------------------------- 16.9 22.5 22.1 10 * a 20 IC - MAJOR DIVISIONS SYMBOL - DESCRIPTION GW WELL. GRADED GRAVELS OR GRAVEL- SAND MIXTURES. LITTLE OR NO FINES GRAVELS (MORE THAN '/ OF COARSE GP __________ POORLY GRADED GRAVELS OR GRAVEL-SAND MIXTURES. LITTLE OR NO FINES __________________________________ GM SILTY GRAVELS, GRAVEL-SAND-SILT MIXTURES FRACTION >NO. 4 SIEVE COARSE GRAINED SOILS SIZE) GC CLAYEY GRAVELS, GRAVEL-SAND-CLAY MIXTURES (MORE THAN t4 OF SOIL> NO. 200 SIEVE SIZE) sw WELL GRADED SANDS OR GRAVELLY SANDS, LITTLE OR NO FINES SANDS (MORE THAN ,' OF COARSE FRACTION < NO. 4 SIEVE SP POORLY GRADED SANDS OR GRAVELLY SANDS, LITTLE OR NO FINES ___________________________________ SM SILTY SANDS, SILT-SAND MIXTURES SIZE) SC CLAYEY SANDS, SAND-CLAY MIXTURES SILTS & ML INORGANIC SILTS AND VERY FINE SANDS, ROCK FLOUR, SILTY OR CLAYEY FINE SANDS OR CLAYEY SILTS WITH SLIGHT PLASTICITY FINE GRAINED SOILS (MORE THAN Y3OF SOIL < NO. 200 SIEVE SIZE) CLAYS LIQUID LIMIT <so _________ CL INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY CLAYS, SANDY CLAYS. SILTY CLAYS. LEAN CLAYS OL ________ ORGANIC SILTS AND ORGANIC SILTY CLAYS OF LOW PLASTICITY SILTS & ryIH INORGANIC SILTS. MICACEOUS OR DIATOMACEOUS FINE SANDY OR SILTY SOILS. ELASTIC SILTS CH INORGANIC CLAYS OF HIGH PLASTICITY, FAT CLAYS CLAYS LIQUID LIMIT 350 OH ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY, ORGANIC SILTY CLAYS. ORGANIC SILTS HIGHLY ORGANIC SOILS Pt PEAT AND OTHER HIGHLY ORGANIC SOILS CLASSIFICATION CHART (UNIFIED SOIL CLASSIFICATION SYSTEM) 70 CLASSIFICATION RANGE OF GRAIN SIZES U.S. STANDARD GRAIN SIZE IN SIEVE SIZE I MILLIMETERS BOULDERS Above 12 Inches I Above 305 COBBLES 12 Inches To 3 Inches 305 To 76.2 GRAVEL 3 Inches to No.4 76.2 to 4.76 Coarse 3 Inches to 'A Inch 76.2 to 19.1 Fine 'A Inch to No.4 19.1 to 4.76 SAND No. 4 to No. 200 4.76 to 0.074 Coarse No. 4 to No. 10 4.76 to 2.00 Medium No. 10 to No. 40 2.00 to 0.420 Fine No. 40 to No. 200 0.420 to 0.074 SILT AND CLAY Below No. 200 Below 0.074 GRAIN SIZE CHART EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. 10925 HARTLEY ROAD, SUITE 9" SANTEE, CALIFORNIA 92071 DENNIS MATHIS CONSTRUCTION PROJECT I PROJECT NO. 02-1147J2 PLATE NO. 5 7/10/02 I U.S.C.S. SOIL CLASSIFICATION I j 0 0 IC 20 30 40 30 00 70 60 10 ICC liQUID UIiT (U.). PLASTICITY CHART IAR DENNIS M4 THIS CONSTRUCTION PROJECT NO. 01-1147J2 PAGE L-1 LABORATORY TEST RESULTS RESULTS OF EXPANSION INDEX TEST An expansion test in conformance with UBC 18-2 was performed on a representative sample of on- site soils to determine volumetric change characteristics with change in moisture content. The recorded expansion of the sample is presented as follows: INITIAL SATURATED INITIAL DRY MOISTURE MOISTURE DENSITY EXPANSION CONTENT% CONTENT% LB./CU. FT. INDEX LOCATION 13.0 22.1 99.1 40 T-3@2.5' RESULTS OF PARTICLE SIZE ANALYSIS U.S. Standard . Sieve Size . (ASTM D422) Percent Passing Percent Passing T-8@4.5' 1" - 100 1/2" - 98 3/8" 100 95 #4 98 90 #8 88 85 #16 80 76 #30 75 70 #60 61 58 #100 44 46 #200 33 40 USCS SM Sc 11 DENNIS M4 THIS CONSTRUCTION PROJECT NO. 01-1147J2 PAGE L-2 LABORATORY TEST RESULTS RESULTS OF MAXIMUM DENSITY TESTS The maximum dry densities and optimum moisture contents of the fill materials as determined by ASTM D1557-91, Procedure A which uses 25 blows of a 10 pound slide hammer falling from a height of 18 inches on each of 5 equal layers in a 4 inch diameter 1/30 cubic foot compaction cylinder and Procedure C which uses 56 blows of a 10 pound slide hammer falling from a height of 18 inches on each of 5 equal layers in a 6 inch diameter 1/13.3 cubic foot compaction cylinder are presented as follows: OPTIMUM MAXIMUM MOISTURE DRY DENSITY CONTENT SOIL TYPE/ PROCEDURE LB/CU. FT. % DRY WI. LOCATION 1/A TAN BROWN SILTY FINE 119.0 11.7 T-1@2.5' GRAINED SAND 2/A TAN SILTY FINE GRAINED SAND 118.0 11.4 T-3@1.0' 12 DENNIS MA THIS CONSTRUCTION PROJECT NO. 01-1147J2 REFERENCES 1: "1997 Edition, Uniform Building Code, Volume 2, Structural Engineering and Design Provisions". "Maps of Known Active Fault Near-Source Zones in California and Adjacent Portions of Nevada", Page 0-38, used with the 1997 Edition of the Uniform Building Code, Published by International Conference of Building Officials. "Geologic Maps of the Northwestern Part of San Diego County, California. Plate No. 2, Geologic Maps of the Encinitas and Rancho Santa Fe 7.5' Quadrangles", by Siang S. Tan and Michael P. Kennedy, 1996. "Geologic Maps of the Northwestern Part of San Diego County, California. Plate No. 2, Geologic Maps of the Encinitas and Rancho Santa Fe 7.5' Quadrangles", by Siang S. Tan and Michael P. Kennedy, 1996. 13 EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. 10925 HARTLEY ROAD, SUITE I SANTEE, CALIFORNIA 92071 (619) 258-7901 APPENDIX A RECOMMENDED EARTHWORK SPECIFICATIONS 1. General Description The intent of these specifications is to obtain uniformity and adequate strength in filled ground so that the proposed structures may be safely supported. The procedures include the clearing and preparation of the land to be filled, processing the fill soils, the spreading, and compaction of the filled areas to conform with the lines and grades as shown on the approved plans. The owner shall retain a Civil Engineer qualified in soil mechanics (herein referred to as engineer) to inspect and test earthwork in accordance with these specifications. The engineer shall advise the owner and grading contractor immediately if any unsatisfactory conditions are observed to exist and shall have the authority to reject the compacted filled ground until such time that corrective measures are taken, necessary to comply with the specifications. It shall be the sole responsibility of the grading contractor to achieve the specified degree of compaction. Preparing Areas to be Filled All brush, vegetation and any biodegradable refuse shall be removed or otherwise disposed of so as to leave the areas to be filled free of vegetation and debris. Any uncompacted filled ground or loose compressible natural ground shall be removed unless the report recommends otherwise. Any buried tanks or other structures shall be removed and the depression backfihled to the satisfaction of the engineer. The natural ground which is determined, to be satisfactory for the support of the filled ground shall then be plowed or scarified to a depth of at least 12 inches (12"). After the natural ground has been prepared, it shall then be brought to the proper moisture content and compacted to not less than 90 percent of maximum dry density in accordance with ASTM D1557-91. Where fills are made on slopes greater than 20 percent, horizontal benches shall be cut into the firm natural ground. The initial bench at the toe of the fill shall be at least 15 feet in width on firm undisturbed natural ground. The width of all succeeding benches shall be at least 6 feet. -• : APPENDIX A .. 3. Fill Materials All material shall be approved by the engineer and shall consist of materials free from vegetable matter, and other lumps greater than 6 inches in diameter. If, during grading operations, soils are found which were not encountered and tested in the preliminary investigation, tests on these soils shall be performed to determine their physical characteristics. Any special treatment recommended in the preliminary or subsequent soils reports not covered herein shall become an addendum to these specifications. 4. Placing and Compacting Fill Materials When the moisture content of the fill material is below that specified, water shall be added until the moisture content• is near optimum to assure uniform mixing and effective compaction. S When the moisture content of the fill materials is above that specified, the fill material shall be aerated by blading and scarifying or other satisfactory methods until the moisture content is near optimum as specified. After processing, the suitable fill materials shall be placed in layers which, -when compacted, shall not exceed six inches (6"). Each layer shall be spread evenly and shall be thoroughly mixed during the spreadinjinsure uniformity of materials and moisture in each layer. After each layer has been placed, mixed and spread evenly, it shall be thoroughly compacted to not less than the density set forth in paragraph 2 (c) above. Compaction shall be accomplished with approval types of compaction equipment. Rolling shall be accomplished while the fill material is at the specified moisture content. In place density tests shall be performed in accordance with ASTM D1556-90. The surfaces of the fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compacting operations shall be continued until the slopes are stable and until there. is no appreciable amount of loose soil on the slopes. 5. Inspection Sufficient inspection by our firm or the Soil's Engineer of record and/or his/her representative shall be maintained during the filling and compacting operations so that he/she can verify that the fill was constructed in accordance with the accepted specifications. 6. Seasonal Limits No fill material shall be placed, spread, or rolled if weather conditions increase the moisture content above permissible limits. When the work is interrupted by rain, fill operations shall not be resumed until the moisture content and density of fill are as previously specified. All recommendations presented in the attached report are a part of these specifications. 2