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Home My WebLink AboutPD 2018-0052; REED RESIDENCE; GEOTECHNICAL INVESTIGATION AT 1375 BUENA VISTA WAY; 2020-09-12. CONSULTANTS geotechnical & forensic engineering September 12, 2020 1941-A Friendship Drive El Cajon, CA 92020 TEL (619) 258-9000 wwiv.applied-consuItanti corn Holly Reed 1375 Buena Vista Way Carlsbad, CA 92008 C/O Brian Enright Design Drafting Via E-mail - bpeddp@gmail.com, Subject: Geotechnical Investigation at the Subject Property Located at 1375 Buena Vista Way, Carlsbad, CA 92008 Dear Mrs. Reed: In accordance with your request we have prepared this geotechnical investigation report for the subject property located at 1375 Buena Vista Way, Carlsbad, CA 92008. The purpose of this geotechnical investigation was to provide geotechnical parameters for the design of the proposed development. The proposed development is the demolition of the existing residence and construction of a new single family residence and ADU. GEOTECHNICAL INVESTIGATION CONCLUSIONS After reviewing the results of our geotechnical investigation we conclude that there are no significant geotechnical or geologic constraints that cannot be mitigated by proper planning, design, and the utilization of sound construction practices. We certify that the development of the site is feasible from a geotechnical standpoint. We approximate a removal and recompaction of the upper three feet. All deleterious and oversized materials shall be screened and removed from the fill soils. The bottom of excavation shall be approved by a representative of our firm. Upon approval, the upper 6"of the key shall be scarified, and the fill soils recompacted to greater than 90% of optimum compaction to the required finish grade. The removal and recompaction shall extend to at least 5 feet outside the proposed building footprint. Design of the shallow foundation system of the proposed structures shall be based on a 2,000 psf allowable bearing capacity. IIECEIIVEII DEC 172020 1375 Buena Vista Way - Geotechriical Investigation JED 9/12/2020 Page 1 of 24 LAND DEVELOPMENT ENGNEERNG We appreciate this opportunity to be of service. Shall you have any questions, please call our office at (619) 258-9000. Sincerely, - Joshua E. Devera PE77618 Bernard J. Luther, RCE 63653, President CEO Ol"id4L 'N j)j 00 C653 r\>1 \0.CQ1 CALIF 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 2 of 24 TABLE OF CONTENTS 1.0 SITE DESCRIPTION ..........................................................................................................4 Fig. I Site Location........................................................................................................................5 2.0 SURFACE AND GROUND WATER.................................................................................6 3.0 SITE GEOLOGY.................................................................................................................6 3.1 Geologic Literature Review and Field Findings ..............................................................6 3.2 Tectonic Setting................................................................................................................7 Fig. 2 Geologic Map .....................................................................................................................8 3.3 Seismic Design Recommendations ..................................................................................9 3.5 Geologic hazards..............................................................................................................9 Fig. 3 Flood Insurance Rate Map................................................................................................10 4.0 FIELD WORK AND SOIL SAMPLING .......................................................................... 11 4.1 Subsurface Investigation ................................................................................................11 4.2 Soil Sample Analyses.....................................................................................................11 5.0 FINDINGS ......................................................................................................................... 11 5.1 Soils Laboratory Analyses Findings...............................................................................11 Table 1: Soils Analyses Results...........................................................................................11 6.0 CONCLUSIONS................................................................................................................12 6.1 Impact of Geologic Hazards upon Subject Property......................................................12 6.2 Geotechnical Investigation Conclusions ........................................................................12 7.0 RECOMMENDATIONS...................................................................................................13 7.1 Grading...........................................................................................................................13 7.2 Shallow Foundations......................................................................................................14 7.3 Concrete Slabs On-Grade ............................................................................................... 14 8.0 REVIEW, OBSERVATIONS, AND TESTING ...............................................................15 FIGURES......................................................................................................................................18 GENERAL EARTHWORK AND GRADING ............................................................................20 GUIDELINES................................................................................................................................20 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 3 of 24 1.0 SITE DESCRIPTION The location of the property is at latitude 33°10'6.8"N and longitude 117°20'314"W. The subject property is located in a residential neighborhood of Carlsbad, California (Figure 1). The subject property is bounded to the north by Buena Vista Way; and to the east, west, and south by existing single family residences. Review of the current topographic map for the site indicates that the subject property is at approximately 0 feet above average mean sea level (NAVD88). The subject property is a rectangular shaped parcel of land of approximately 0.4 acres. Site topography at the subject property is relatively flat. The proposed development is the demolition of the existing structures and the construction of a new 2-story dwelling and detached ADU. 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 4of24 I Cener SUBJECT PROPERTY Geographic Location 1375 Buena Vista Way, Carlsbad, CA 92008 APPLIED Vicinity Map Fig. I CONSULTANTS ,rtlro,,I,Ict, Ia! t (e/t5I <! 375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 5 of 24 2.0 SURFACE AND GROUND WATER We performed our field investigation was performed on August 28, 2020. Two exploratory test pits were dug. We obtained bulk and in-situ density samples within the vicinity of the proposed development. No groundwater was encountered in the exploratory trenches to the maximum depth of five feet below existing grade. 3.0 SITE GEOLOGY 3.1 Geologic Literature Review and Field Findings We reviewed the Geologic Map of the Oceanside 30'x 60' Quadrangle, California (Kennedy and Tan, 2005) for references concerning the geologic structure underlying the subject property and surrounding areas. Review of the geologic map indicates that the site is underlain by Old Paralic deposits, Units 2- 4 (Qop2-4). These Old Paralic deposits, Units 2-4 are described as "Mostly poorly sorted, moderately permeable, reddish-brown, interfingered strandline, beach, estuarine and colluvial deposits composed of siltstone, sandstone and conglomerate." is Locally the materials encountered in the borings are: Boring #1 (B-i): Topsoil was encountered from grade to 3 inches below grade. From 3 inches below grade to 18 inches below grade a fine to medium grained, reddish brown poorly graded sand with silt (SP-SM) was encountered. From 18 inches below grade to 36 inches below grade a fine to medium grained, dense reddish light brown poorly graded sand with silt (SP-SM) was encountered. Boring #2 (B-2): Topsoil/gravel was encountered from grade to 6 inches below grade. From 6 inches below grade to 18 inches below grade a fine to medium grained, reddish light brown poorly graded sand with silt (SP-SM) was encountered. From 18 inches below grade to 60 inches below grade a fine to medium grained, moist reddish brown poorly graded sand with silt (SP-SM) was encountered. 1375 Buena Vista Way - Geotecimical Investigation JED 9/12/2020 Page 6of24 3.2 Tectonic Setting Southern California, including Oceanside and surrounding areas, is located in an area of late Tertiary to Quaternary-aged fault zones (Kennedy 1975) which strike conservatively to the northwest. Some of these fault zones are known to be active according to the California Division of Mines and Geology. "Active" faults are ones which have had faulting activity within the Holocene Epoch, or the last 11,000 years (California Division of Mines and Geology). Based upon magnitude of the earthquake event and distance from the subject property, an earthquake on any of the above mentioned faults would cause slight to severe shaking at the subject property. S 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 7of24 Geographic Location 1375 Buena Vista Way, Carlsbad, CA 92008 APPLIED CONSULTANTS Ii/Ci(IfIl(Zt K t,It'f,II(I,fl Geologic Map Fig. 2 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 8 of 24 3.3 Seismic Design Recommendations The proposed development shall be designed in accordance with seismic considerations contained in the 2019 California Building Code (2019 CBC), American Society of Civil Engineers/Structural Engineering Institute (ASCE/SEI) Standard 7-16: Minimum Design Loads for Buildings and other Structures and City of Carslbad requirements. Based on 2019 CBC and ASCE/SEI 7-16, the following parameters may be considered for design: Seismic Importance Factor (I): 1.0 (ASCE/SEI 7-16) Occupancy Category: II (2016 CB9) Site Class: D (2019 CBC) Spectral Response Coefficient (SDS) 0.837g (ASCE/SEI 7-16) Seismic Design Category (SDS - based) D (2019 CBC) 3.5 Geologic hazards The most significant probable earthquake to affect the subject site would be a 7.0 magnitude earthquake on the Newport-Inglewood/Rose Canyon fault. We feel that the potential for damages due to earthquake is high. Liquefaction of cohesionless soils can be caused by strong cyclic accelerations resulting from nearby earthquakes. Research and historical data indicate that loose, granular materials saturated by a near-surface groundwater table are most susceptible to liquefaction. The risk of seismically induced liquefaction to affect the proposed construction is considered low due to the relatively dense underlying soil. The Federal Emergency Management Agency, Flood Insurance Rate Map, states that the subject property does not rest upon a flood zone. The subject property is categorized as, "Areas determined to be outside the 0.2% annual chance floodplain (Other areas, Zone X)." Based upon the local topography and the FEMA Flood Insurance Rate Map, we feel that the potential for flooding at the subject property is low. The Geologic Map of the Oceanside 30' x 60' Quadrangle, California does not indicate any near landslides. Additionally, site topography is relatively flat. We feel that the potential for failure in landslide is low. 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 9of24 Geographic Location 1375 Buena Vista Way, Carlsbad, CA 92008 OTHER AREAS ZONE X Areas determined to be outside the 0.2% annual chance floodplain. FEMA YAPPL1ED Flood Insurance Rate Map Fig. 3 CONSULTANTS en nuecr,q 1375 Buena Vista Way - Geotechnical Investigation () In 4.0 FIELD WORK AND SOIL SAMPLING 4.1 Subsurface Investigation On August 28, 2020 we performed a field investigation at the subject property. Two exploratory borings were dug within the outline of the proposed development. Boring #1 (B-i) was augered towards the northwestern portion of the proposed structure to a depth of thirty six inches below existing grade. Boring #2 (B-2) was augered towards the southeasterb portion of the proposed structure to a depth of sixty inches below existing grade. 4.2 Soil Sample Analyses We collected bulk and in-situ samples to determine the soil's physical characteristics through laboratory testing. We performed the following tests - Optimum Moisture Content and Maximum Density - ASTM D1557 - Particle-Size Analysis of Soils - ASTM D422 - Liquid Limit, Plastic Limit, and Plasticity Index - ASTM D4318 - Standard Test Method for Unconfined Compressive strength of Soil - ASTM D2166 5.0 FINDINGS 5.1 Soils Laboratory Analyses Findings The following table (Table 1) is a compilation of our soils analyses results from the samples collected within the vicinity of the subject property: Table 1: Soils Analyses Results Sample ID Opt. Moist. Max Density (%) (pcf) B-1@24"-36" 1 ii 1245 B-2 @ 48"-60" 1 10.5 127.5 E.I. - Expansion Index pcf - pounds per cubic foot Pot. - Potential psf - pounds per square foot 1375 Buena Vista Way - Geotecimical Investigation JED 9/12/2020 Page 11 of 24 6.0 CONCLUSIONS 6.1 Impact of Geologic Hazards upon Subject Property In Applied Consultants' professional opinion, geologic hazards of significant magnitude are not present. Based upon our field work and historical research results, Applied Consultants makes the following conclusions: Ground Shaking is a likely hazard to the site. Seismic activity on any active and potentially active faults would cause ground movement at the subject property that will be proportional to the magnitude of seismic event. Ground movement at the subject property would be moderated by the distance from the epicenter of the seismic event. It is expected that the structure will have to endure this to some degree. Liquefaction. Due to the soil characteristics at the subject property we feel that the potential for soil liquefaction at the subject site is low. Flooding. Given the topography of the site, flooding is not considered a hazard. Landslide and Earth Movement is not a likely hazard to the site. Topography and geology of the subject property are not susceptible to earth movement. We feel that the potential for earth movement or landslide at the subject property is low. 40 6.2 Geotechnical Investigation Conclusions After reviewing the results of our geotechnical investigation Applied Consultants concludes that there are no significant geotechnical or geologic constraints that cannot be mitigated by proper planning, design, and the utilization of sound construction practices. Consequently, it is our opinion that the development of the site is feasible from a geotechnical standpoint. Due to potential differential settlement we recommend removal and replacement of the upper three feet. Removal of the upper thirty six inches within a five foot offset of the proposed structure shall be performed.. All deleterious and oversized materials shall be screened and removed. The bottom of excavation shall be approved by a representative of our firm. Upon approval, the upper 6"of the key shall be scarified, and the fill soils recompacted to greater than 90% of optimum compaction to the required finish grade. The removal and recompaction shall extend to at least 5 feet outside the proposed building footprint. Design of a shallow foundation system of the proposed residence shall be based on a 2,000 psf allowable bearing capacity. 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 12 of 24 7.0 RECOMMENDATIONS 7.1 Grading General All earthwork shall comply with the grading requirements of the City of Carlsbad, and California Building Code 2019 except where specifically superseded in this section. Prior to grading a representative of Applied Consultants shall be present to discuss the current conditions of the site, grading guidelines and schedule of the earthwork to be completed. Grubbing / Clearing Grading shall begin with the removal of all structures and improvements as well as all vegetation. These materials shall be hauled off the site to a suitable location. C. Site Preparation Removal of the upper thirty six inches within a five foot offset of the proposed structure shall be performed. All deleterious and oversized materials shall be screened and removed. The bottom of excavation shall be approved by a representative of our firm. Upon approval, the upper 6"of the key shall be scarified, and the fill soils recompacted to greater than 90% of optimum compaction to the required finish grade. The removal and recompaction shall extend to at least 5 feet outside the proposed building footprint. Fill Material The materials onsite may be used as compacted fill. If it is necessary to import fill material, the material shall be approved by the geotechnical consultant. All fill material must be compacted uniformly to 90% of the maximum dry density (ASTM D1557). Please refer to section III and IV of the "GENERAL EARTHWORK AND GRADING GUIDELINES" provided at the end of this geotechnical investigation report for further recommendations on fill material and fill placement and compaction. Grading Observation It is necessary for a soils engineer, or their representative, to be present and test the compaction during the basic grading operations and placement of fill material. The engineer will be able to confirm the conditions stated in this report and verify that the grading operations are in compliance with all plans and specifications. . 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 13 of 24 7.2 Shallow Foundations . General The proposed structure can be constructed on a shallow foundation supported on recompacted soils Where foundations are to be located seven feet and further away from the top of slopes, standard design may take place in conformance with the recommended soil bearing values. In situations where foundations, footings, walls, etcetera, are located closer than seven feet from the top of slope they shall be deepened so that the bottom edge of the footing is 7 feet horizontally from daylight in the slope. Dimensions and reinforcement In our opinion the foundation design for this project may be conventional spread and/or continuous footings. The spread footings shall be embedded a minimum of 18 inches for a one-story structure and have a minimum width of 12 inches. The spread footings shall be embedded a minimum of 24 inches for a two-story structure and have a minimum width of 18 inches. The steel reinforcement for the spread footings shall consist of a minimum of two #4 rebar placed near the top and bottom of the footing with a minimum of 3" of concrete covering the top and bottom layers. The continuous footings shall be embedded a minimum of 18 inches for a one story structure below the lowest grade of the finished pad and must have a width of at least 18 inches. The continuous footings shall be embedded a minimum of 24 inches for a two story structure below the lowest grade of the finished pad and must have a width of at least 15 inches. The steel reinforcement for the continuous footings shall consist of a minimum of two #4 rebar placed near the top and bottom of the footing with a minimum of 3" of concrete covering the top and bottom layers. C. Bearing Capacity A safe soil bearing capacity of 2,000 Pounds per Square Foot may be used in the design of shallow foundation with recompacted soils. 7.3 Concrete Slabs On-Grade a. Floor Slab If any interior floor slabs are used for this project they shall be no less than 4" (actual). For one-story or greater structures, slab reinforcement shall consist of minimum of #3 rebar placed at 18" on center. All slab reinforcement shall rest on concrete chairs or a suitable substitute. 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 14 of 24 b. Moisture Protection The areas covered by the interior floor slab shall be covered with a 10 mil Visqueen moisture barrier. The moisture barrier shall rest on finish grade and be overlain by two inches of clean sand. 8.0 REVIEW, OBSERVATIONS, AND TESTING The final foundation/grading plans shall be provided to our office for review in order to evaluate the acceptability of the recommendations presented herein, and provide additional recommendations, as appropriate. All construction activities during grading and foundation excavations shall be continuously monitored and observed by the Geotechnical Engineer and Engineering Geologist of Record. All grading and foundation excavations on-site shall be observed and tested as required, by a representative of the Geotechnical Engineer and or Engineering Geologist to verify conformance with the intent of the geotechnical/geological recommendations provided herein and to evaluate the acceptability of these recommendations for the actual site conditions. fl 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 15 of 24 CONSTRUCTION INSPECTION AND LIMITATIONS The recommendations contained within this report are based upon Applied Consultants' field investigation. The interpolated subsurface conditions shall be checked during construction by a representative of Applied Consultants. We recommend that all grading operations be observed by a representative of this firm. The recommendations contained within this report are based upon our field study, laboratory analyses, and our understanding of the proposed construction. If any soil conditions are encountered differing from those assumed in this report, Applied Consultants shall be immediately notified so that we can review the situation and make supplementary recommendations. Additionally, if the scope of proposed work changes from that described in this report, Applied Consultants shall be notified. This report has been prepared in accordance with generally accepted soil and foundation engineering practices within the greater San Diego area. Professional judgments contained herein are based upon our evaluation of the technical information gathered, our understanding of the proposed work, and our general experience in the geotechnical field. Our engineering work and judgments rendered meet current professional standards. We do not guarantee the performance of the project in any respect. We do not direct the contractor's operations and we cannot be responsible for the safety of field personnel on the site; therefore, the safety of field personnel during construction is the responsibility of the contractor. The contractor shall notify the owner if he considers any of the recommended actions contained herein to be unsafe. It is a pleasure to be of service to you. Shall any questions arise, please contact our office at 619- 258-9000. 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 16 of 24 REFERENCES is 1. American Society of Civil Engineers/Structural Engineering Institute (ASCE/SEI) Standard 7-16. Bearing Capacity for Shallow Foundations -T. William Lambe & Robert V. Whitman, "Soil Mechanics", John Wiley & Sons, 1969. California Building Code (CBC 2019), 2019 California Mines and Geology Division (DMG), 1974, "Maximum Credible Rock Acceleration From Earthquakes in California", Roger W. Greens felder. California Department of Conservation, Division of Mines and Geology (CDMG), 1987. "CSMIP Strong-Motion Records from the Whittier, California Earthquake of 1 October, 1987", OMS Report 87-05. City of San Diego Seismic Safety and Geologic Hazards Maps 25, April 3, 2008 Geology of the Oceanside 30'x 60', California Division of Mines and Geology, Michael P. Kennedy and Siang S. Tan, 2005. TOPO! [Computer Software] 1997wi1dflower productions (www.topo.com) San Francisco, CA: ESRI Structural Engineers Association of California - Seismic design maps https://seismicmaps.orgl ASCE 7 Hazard Tool https://asce7hazardtool.online/ 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 17 of 24 FIGURES 1375 Buena Vista Way - Geotechnical Investigation lED 9/12/2020 Page 18 of 24 42t 21 10 DEPOSITS, UNITS 2-4 r —'i REMEDIAL GRADING J LIMITS ch REFERENCE: This map was PROPERTY LINE 188.55' prepared from a Site Plan by Brian Enright & Adrian Deadwyler Design Drafting and from the field investigation performed by APPLIED CONSULTANTS. 4MAPPLIED FIFURE A: GEOLOGIC I GEOTECHNICAL MAP CONSULTANTS 1375 BUENA VISTA WAY, Date: 8/28/20 -,,, _w• CARLSBAD, CALIFORNIA 92008 Drawn by: JLVG ASCE AMENCAN SOC4ETY OF OU. EWNEERS Address: 1375 Buena Vista Way Carlsbad, California 92008 ASCE 7 Hazards Report Standard: ASCE/SEI 7-16 Elevation: 0 ft (NAVD 88) Risk Category: I Latitude: 33.168558 Soil Class: D - Default (see Longitude: -117.342058 Section 11.4.3) Wind Results: Wind Speed; 89 Vmph 10-yearMRI 66Vmph 25-year MRI 72 Vrnph 50-year MRI 77 Vnph 100-year MRI 82 Vnph Data Source ASCE/SEI 7-16, Fig. 26.5-1A and Figs. CC.2-1—CC.24 Date Accessed: Sat Sep 12 2020 Value provided is 3-second gust wind speeds at 33 ft above ground for Exposure C Category, based on linear interpolation between contours. Wind speeds are interpolated in accordance with the 7-16 Standard. Wind speeds correspond tc approximately a 15% probability of exceedance in 50 years (annual exceedance probability = 0.00333, MRI = 300 years). Site is not in a hurricane-prone region as defined in ASCE/SEI 7-16 Section 26.2. Mountainous :errain, gorges, ocean promontories, and special wind regions should be examined for unusual wind conditions. https://asce7hazrdtool.onIine/ Page 1 of 3 Sal Sep 12 2020 . MCN saaETyavt 4GN Seismic Site Soil Class: 0 - Default (see Section 11.4.3) Results: Ss : 1.047 S01 N/A S1 : 0.38 TL: 8 Fa 1.2 PGA: 0.46 F N/A PGA m: 0.552 SMS : 1.256 FPGA : 1.2 SM1 : N/A le : 1 SDS 0.837 C, : 1.309 Ground motion hazard analysis may be required. See ASCE/SEI 7-16 Section 11.4.8. Data Accessed: Sat Sep 12 2020 Date Source: USGS Seismic Design Maps htts://asce7hazardtool.oriline/ Page 2 of 3 Sat Sep 12 2020 -A 2~1z~ N,ICAN SE1Y OF aV. ENNS The ASCE 7 Hazard Tool is provided for your convenience, for informational purposes only, and is provided "as is and without warranties of any kind. The location data included herein has been obtained from information developed, produced, and maintained by third party providers; or has been extrapolated from maps incorporated in the ASCE 7 standard. While ASCE has made every effort to use data obtained from reliable sources or methodologies, ASCE does not make any representations or warranties as to the accuracy, completeness, reliability, currency, or quality of any data provided herein. Any third-party links provided by this Tool should not be construed as an endorsement, affiliation, relationship, or sponsorship of such third-party content by or from ASCE. ASCE does not intend, nor should anyone interpret, the results provided by this Tool to replace the sound judgment of a competent professional, having knowledge and experience in the appropriate field(s) of practice, nor to substitute for the standard of care required of such professionals in interpreting and applying the contents of this Tool or the ASCE 7 standard. In using this Tool, you expressly assume all risks associated with your use. Under no circumstances shall ASCE or its officers, directors, employees, members, affiliates, or agents be liable to you or any other person for any direct, indirect, special, incidental, or consequential damages arising from or related to your use of, or reliance on, the Tool or any information obtained therein. To the fullest extent permitted by law, you agree to release and hold harmless ASCE from any and all liability of any nature arising out of or resulting from any use of data provided by the ASCE 7 Hazard Tool. https://asce7hazardtool.online/ Page 3 of 3 Sat Sep 12 2020 EXPLORATORY BORINGS S S S 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 19 of 24 S S S Project Name: 1375 BUENA VISTA WAY I Address: 1375 BUENA VISTA WAY I CARSLBAD, CA I Location: NORTHWEST PORTION OF PROPERTY Date: 8/28/2020 Logged By: JLVG Reviewed By: BJL Footing Thickness (in.): Test Pit/Test Boring ID: B-1 I Excavation Method- AUGER I Sample Type: BULK Total Depth (ft):3.0 I Depth to Water (ft): —NA Caving: NONE (Depth of Footing:NA Depth (Inches) Gradc- 6 12 24 30 96 102 - 108 Soil Description gradedSand with Silt (SP-SM): HPoorly Sample - Discrete Sample Interval Bulk Sample Interval Lithology & Footing Details V 6— - 12— 18- 24— 30— 36— - 42- 48- 54- 60- 66- 72- 78- 84- 90- 96- 102- 108 114— - Type - Topsoil ID Poorly graded Sand with Silt (SP-SK : MC% - fine to medium graded, reddish brown poorly graded sand with silt ------ 18-- fine to medium graded, dense reddish light brown poorly graded sand with silt _____ B-i 24fl_36t _ _ - - 36— END OF BORING @36" - ____ - 42— - 48— 54— 60— 66— 72 — 78 — 94 90 — - APPLIED CONSULTANTS BORING LOG: B# 1 1375 BUENA VISTA I_ CARLSBAD, CA DATE: 8/28/2020 Drawn By: JLVG S S Project Name: 1375 BUENA VISTA WAY Address: 1375 BUENA VISTA WAY CARSLBAD, CA Location: SOUTHEAST PORTION OF PROPERTY Date: 8/28/2020 Logged By: JLVG Reviewed By:_BJL Footing Thickness (in.): Test Pit/Test Boring ID: B-2 (Excavation Method: AUGER I Sample Type: BULK Depth (ft): 5.0 Depth to Water (ft): NA Caving: NONE Depth of Footing: NA Depth (Inches) Grade— 12 36 54 102 - 108 - 1141 Soil Description ------- Poorly graded Sand with Silt (SP-SM): - Sample - Discrete Sample Interval 1 Bulk Sample Interval Lithology & Footing Details 6"-18"12— 6 - 18- 24- 30— - 36— - 42- 48— 54— 60- - 66- 72- 78- 84- 90- 96- 102- 108 114 Type Topsoil ID MC% 6 -- - ____ B-2 - - fine to medium graded, reddish light brown poorly graded sand with silt - ------ Poorly graded Sand with Silt (SP-SK: - 18 - - _____ - 24— 30— - - fine to medium graded, moist reddish brown poorly graded sand with silt. ______ 42— - 48— - _____ B-2 48"-60" _ - p - - 6C— - END OF BORING @36't - 66— 72 — 78 — 84 — 90 — 96 — APPLIED CONSULTANTS — BORING LOG: B# 2 1375 BUENA VISTA I CARLSBAD, CA DATE: 8/28/2020 Drawn By: JLVG GENERAL EARTHWORK AND GRADING GUIDELINES 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 20 of 24 S . GENERAL EARTHWORK AND GRADING GUIDELINES EARTHWORK OBSERVATION AND TESTING Prior to commencement of grading, a qualified geotechnical consultant shall be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report and these specifications. The consultant is to provide adequate testing and observation so that he may determine that the work was accomplished as specified. It shall be the responsibility of the contractor to assist the consultant and keep him apprised of work schedules and changes so that the consultant may schedule his personnel accordingly. The contractor is to provide adequate equipment and methods to accomplish the work in accordance with applicable grading codes or agency ordinances, these specifications, and the approved grading plans. If in the opinion of the consultant, unsatisfactory conditions are resulting in a quality of work less than required in these specifications, the consultant may reject the work and recommend that construction be stopped until the conditions are rectified. Maximum dry density tests used to determine the degree of compaction shall be performed in accordance with the American Society for Testing and Materials Test Method ASTM: D 1557- 82. PREPARATION OF AREAS TO BE FILLED Clearing and Grubbing: All brush, vegetation, and debris shall be removed and properly disposed of. The Geotechnical Consultant shall evaluate the extent of removal of these items depending on site conditions. Fill material shall not contain more than 1 percent of organic material by volume. No fill shall contain more than 5 percent organic matter. No fill shall contain hazardous materials or asphalt pavement. If asphalt pavement is removed, it shall be disposed of at an appropriate location. Concrete fragments which are free of reinforcing steel may be placed in the fills. Processing: the existing ground which is evaluated to be satisfactory for support of fill shall be scarified to a minimum depth of 6 inches. Existing ground which is not satisfactory shall be over-excavated as specified in the following section. Scarification shall continue until the soils are broken down and free of large clay lumps or clods and until the working surface is reasonably uniform and free of uneven features which would inhibit uniform compaction. Overexcavation: Soft, dry, spongy, or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, shall be over- excavated down to firm ground as approved by the consultant. Moisture Conditioning: Over-excavated and processed soils shall be watered, dried-back, blended, and/or mixed, as necessary to attain a uniform moisture content approximately 2 percent over optimum. 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 21 of 24 Recompaction: Over-excavated and processed soils which have been properly mixed and moisture-conditioned shall be compacted to a minimum relative compaction of 90 percent according to ASTM: D1557-82. Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical units), the ground shall be benched. The lowest bench shall be: a minimum of 15 feet wide, at least 2 feet deep with a minimum 2% slope into the fill bank for horizontal stability, expose firm materials, and be approved by the consultant. Other benches shall excavate into firm material for a minimum width of 4 feet. Ground sloping flatter than 5:1 shall be benched or otherwise over-excavated when considered necessary by the consultant. Approval: All areas to receive fill, including processed areas, removal areas, and toe-of-fill benches shall be approved by the consultant prior to fill placement. III. FILL MATERIAL 1. General: Material to be placed as fill shall be free of organic matter and other deleterious substances, and shall be approved by the consultant. Soils of poor gradation, expansion, or strength characteristics shall be placed in areas designated by the consultant or mixed with other soils until suitable to serve as satisfactory fill material. 2, Oversize: Oversize material defined as rock, or other irreducible material, with a . maximum dimension of greater than 4 inches, shall not be buried or placed in fill unless the location, materials, and disposal methods are specifically approved by the consultant. Oversize disposal operations shall be such that nesting of oversized material does not occur, and such that the oversized material is completed surrounded by compacted or densified fill. Oversize material shall not be placed within the range of future utilities or underground construction, unless specifically approved by the consultant. Import: If import fill is necessary for grading, the import material shall be approved by the geotechnical consultant. IV. FILL PLACEMENT AND COMPACTION Fill Lifts: Approved fill material shall be placed in areas prepared to receive fill in near-horizontal layers not exceeding 6 to 8 inches in compacted thickness. The consultant may approve thicker lifts if testing indicates that the grading procedures are such that adequate compaction is being achieved with lifts of greater thickness. Each layer shall be spread evenly and shall be thoroughly mixed during spreading to attain uniformity of material and moisture in each layer. Fill Moisture: Fill layers at a moisture content less than optimum shall be watered and mixed, and wet fill layers shall be aerated by scarification or blended with drier materials. Moisture conditioning and mixing of fill layers shall continue until the fill material is at a uniform moisture content at or near two percent over optimum. 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 22 of 24 Compaction of Fill: After each layer has been evenly spread, moisture conditioned and mixed, it shall be uniformly compacted to not less than 90 percent of maximum dry density in accordance with ASTM: D1557-82. Compaction equipment shall be adequately sized and either specifically designed for soil compaction or of proven reliability, to efficiently achieve the specified degree of compaction. Fill Slopes: Compacting of slopes shall be accomplished, in addition to normal compaction procedures, by backrolling of slopes with sheepsfoot rollers at frequent intervals of 2 to 3 feet in fill elevation gain, or by other methods producing satisfactory results. At the completion of grading, the relative compaction of the slope out to the slope face shall be at least 90 percent. Compaction Testing: Field tests to check the fill moisture and degree of compaction will be performed by the consultant. The location and frequency of tests shall be at the consultant's discretion. In general, the tests shall be taken at an interval not exceeding 2 feet in vertical rise and/or every 1000 cubic yards of embankment. SUBDRA1N INSTALLATION Subdrain systems, if required, shall be installed in approved ground to conform to the approximate alignment and details shown on the plans or shown herein. The subdrain location or materials shall not be changed or modified without the approval of the consultant. The consultant, however, may recommend and upon approval, direct changes in subdrain line, grade or material. . All subdrains shall be surveyed for line and grade after installation and sufficient time allowed for surveys, prior to commencement of filling over the subdrains. EXCAVATIONS Excavations and cut slopes shall be examined during grading. If directed by the consultant, further excavation or overexcavation and refilling of cut areas shall be performed, and/or remedial grading of cut slopes performed. Where fill-over-cut slopes are to be graded, unless otherwise approved, the cut portion of the slope shall be made and approved by the consultant prior to placement of the fill portion of the slope. Excavations may require the consultant to produce an alternate sloping plan if the excavation TRENCH BACKFILL The Contractor shall follow all OSHA and CAL/OSHA requirements for maintaining safety of trench excavations. The bedding and backfill of utility trenches shall be done with the applicable provisions of Standard Specifications of Public Works Construction. Bedding material shall have a sand equivalent of (SE >30). Bedding shall be placed 1 foot above the top of pipe. All backfill shall be compacted to 90 percent from 1 foot above the pipe to the surface. 3. The geotechnical consultant shall test the trench backfill for relative compaction. At least one test shall be performed for every 300 feet of trench and every two feet of trench fill. 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 23of24 The lift thickness of the trench backfill shall not exceed what is allowed in the Specifications of Public Works Construction unless the contractor can demonstrate that the fill can be compacted by an alternative means to the minimum relative compaction. All work associated with trenches, excavations and shoring must conform to the local regulatory requirements, State of California Division of Industrial Safety Codes, and Federal OSHA requirements. VIII. FOUNDATIONS NEAR TOP OF SLOPES Where foundations, footings, walls and other similar proposed structures are to be located seven feet and further away from the top of slopes, standard design may take place in conformance with the recommended soil beating value. In situations where foundations, footings, walls, et cetera, are located closer than seven feet from the top of slope they shall be deepened so that the bottom edge of the footing is 7 feet horizontally from daylight in the slope. 1375 Buena Vista Way - Geotechnical Investigation JED 9/12/2020 Page 24 of 24