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HomeMy WebLinkAboutSDP 2023-0014; CARLSBAD VILLAGE MIXED-USE - SB 330; GEOTECH STUDY - NOVEMBER 21, 2022; 2022-11-21 4373 Viewridge Avenue Suite B San Diego, California 92123 858.292.7575 944 Calle Amanecer Suite F San Clemente, CA 92673 949.388.7710 www.usa-nova.com NOVA Project NO. 2022210 November 21, 2022 Carlsbad Village Mixed-Use 945-1065 Carlsbad Village Drive Carlsbad, California Submitted to: GRT Carlsbad Village LLC 2001 Wilshire Boulevard, Suite 240 Santa Monica, CA 90403 GEOTECHNICAL INVESTIGATION GEOTECHNICAL MATERIALS SPECIAL INSPECTION DVBE  SBE  SDVOSB  SLBE 4373 Viewridge Avenue, Suite B San Diego, CA 92123 P: 858.292.7575 www.usa-nova.com 944 Calle Amanecer, Suite F San Clemente, CA 92673 P: 949.388.7710 Andrew Cerrina November 21, 2022 GRT Carlsbad Village LLC NOVA Project No. 2022210 2001 Wilshire Boulevard, Suite 240 Santa Monica, CA 90403 Subject: Geotechnical Investigation Carlsbad Village Mixed-Use 945-1065 Carlsbad Village Drive Carlsbad, California Dear Andrew: NOVA Services, Inc. (NOVA) is pleased to present this report describing the geotechnical investigation performed for the proposed Carlsbad Village Mixed-Use project in Carlsbad, California. The investigation was conducted in general conformance with the scope of work presented in our proposal dated October 12, 2022. The site is considered geotechnically suitable for the proposed development provided the recommendations within this report are followed. NOVA appreciates the opportunity to be of service to GRT Carlsbad Village LLC on this project. If you have any questions regarding this report, please call us at 858.292.7575 x 406. Sincerely, NOVA Services, Inc. _________________________ ___________________________ Tom Canady, PE 50057 Andrew K. Neuhaus, CEG 2591 Principal Engineer Senior Engineering Geologist Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 i GEOTECHNICAL INVESTIGATION Carlsbad Village Mixed-Use 945-1065 Carlsbad Village Drive Carlsbad, California TABLE OF CONTENTS 1. INTRODUCTION ............................................................................................................ 1 2. SCOPE OF WORK ......................................................................................................... 3 2.1. Field Investigation ............................................................................................................. 3 2.2. Laboratory Testing ............................................................................................................ 4 2.3. Borehole Percolation Testing ............................................................................................ 4 2.4. Analysis and Report Preparation ...................................................................................... 4 3. SITE AND PROJECT DESCRIPTION ........................................................................... 5 3.1. Site Description ................................................................................................................ 5 3.2. Proposed Construction ..................................................................................................... 5 3.3. Anticipated Earthwork ....................................................................................................... 5 4. GEOLOGY AND SUBSURFACE CONDITIONS ........................................................... 6 4.1. Regional Geology ............................................................................................................. 6 4.2. Site-Specific Geology ....................................................................................................... 7 5. GEOLOGIC HAZARDS .................................................................................................. 9 5.1. Faulting and Surface Rupture ........................................................................................... 9 5.1. Site Class ....................................................................................................................... 10 5.2. Seismic Design Parameters ............................................................................................ 10 5.3. Liquefaction and Dynamic Settlement ............................................................................. 10 5.4. Flooding, Tsunamis, and Seiches ................................................................................... 10 5.5. Subsidence ..................................................................................................................... 11 5.6. Hydro-Consolidation ....................................................................................................... 11 6. CONCLUSIONS ........................................................................................................... 12 7. PRELIMINARY RECOMMENDATIONS ...................................................................... 13 Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 ii 7.1. Earthwork ....................................................................................................................... 13 7.1.1 Site Preparation ................................................................................................. 13 7.1.2 Remedial Grading - Building Pad ....................................................................... 13 7.1.3 Remedial Grading - Pedestrian Hardscape ........................................................ 14 7.1.4 Remedial Grading - Vehicular Pavements ......................................................... 14 7.1.5 Remedial Grading - Site Walls ........................................................................... 14 7.1.6 Expansive Soil ................................................................................................... 14 7.1.7 Compacted Fill ................................................................................................... 15 7.1.8 Imported Soil ..................................................................................................... 15 7.1.9 Subgrade Stabilization ....................................................................................... 15 7.1.10 Excavation Characteristics ................................................................................. 15 7.1.11 Oversized Material ............................................................................................. 15 7.1.12 Temporary Excavations ..................................................................................... 16 7.1.13 Temporary Shoring ............................................................................................ 16 7.1.14 Groundwater Seepage ....................................................................................... 16 7.1.15 Slopes ............................................................................................................... 16 7.1.16 Surface Drainage ............................................................................................... 17 7.1.17 Grading Plan Review ......................................................................................... 17 7.2. Foundations .................................................................................................................... 17 7.2.1 Spread Footings ................................................................................................ 18 7.2.2 Mat Foundations ................................................................................................ 18 7.2.3 Lateral Resistance for Shallow Structural Elements ........................................... 18 7.2.4 Settlement Characteristics ................................................................................. 19 7.2.5 Foundation Plan Review .................................................................................... 19 7.2.6 Foundation Excavation Observations ................................................................ 19 7.3. Interior Slabs-On-Grade .................................................................................................. 19 7.4. Pedestrian Hardscape .................................................................................................... 19 7.5. Vehicular Pavement Section Recommendations ............................................................ 20 7.6. Conventional Retaining Walls ......................................................................................... 20 7.7. Pipelines ......................................................................................................................... 22 7.8. Corrosivity....................................................................................................................... 23 8. INFILTRATION FEASIBILITY ...................................................................................... 24 8.1. Overview ........................................................................................................................ 24 Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 iii 8.2. Percolation Testing ......................................................................................................... 25 8.3. Recommendation for No Infiltration ................................................................................. 25 9. CLOSURE .................................................................................................................... 26 10. REFERENCES ........................................................................................................... 27 List of Figures Figure 1-1. Site Vicinity Map Figure 1-2. Site Location Map Figure 2-1. Subsurface Exploration Map Figure 4-1. Regional Geology Map Figure 4-2. Fill in Boring B-1 Figure 4-3. Topsoil in Boring B-2 Figure 4-4. Old Paralic Deposits in Boring B-4 Figure 4-5. Santiago Formation in Boring B-4 Figure 5-1. Regional Faulting in the Site Vicinity Figure 7-1. Typical Conventional Retaining Wall Backdrain Detail Figure 8-1. Infiltration Restriction Considerations List of Tables Table 5-1. 2019 CBC and ASCE 7-16 Seismic Design Parameters Table 7-1. AC and PCC Pavement Sections Table 8-1. Summary of Borehole Percolation Tests List of Plates Plate 1 Geotechnical Map Plate 2 Geologic Cross-Sections List of Appendices Appendix A Use of the Geotechnical Report Appendix B Boring Logs Appendix C Laboratory Testing Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 1 1. INTRODUCTION This report presents the results of the geotechnical investigation NOVA performed for the proposed Carlsbad Village Mixed-Used project in Carlsbad, California. We understand the project will consist of demolishing the existing buildings and improvements and designing and constructing three one-story retail buildings, two five-story residential buildings, a five-level parking structure, and associated site improvements on an approximately 4-acre property. The buildings will be constructed at grade. No below-grade structures are anticipated. The purpose of NOVA’s work is to provide conclusions and recommendations regarding the geotechnical aspects of the project. Figure 1-1 presents a site vicinity map. Figure 1-2 presents a site location map. Figure 1-1. Site Vicinity Map Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 2 Figure 1-2. Site Location Map Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 3 2. SCOPE OF WORK 2.1. Field Investigation NOVA’s field investigation consisted of drilling six geotechnical borings (B-1 through B-6) to depths up to about 19½ feet below the ground surface (bgs) and two percolation borings (P-1 and P-2) to a depth of about 5 feet bgs using a truck-mounted drill rig equipped with a hollow stem auger. Figure 2- 1 presents the approximate locations of the borings. Appendix B presents the boring logs. Soils are classified according to the Unified Soil Classification System. Figure 2-1. Subsurface Exploration Map A NOVA geologist logged the borings and collected samples of the materials encountered for laboratory testing. Relatively undisturbed samples were obtained using a modified California (CAL) sampler, a ring-lined split tube sampler with a 3-inch outer diameter and 2½-inch inner diameter. Standard Penetration Tests (SPT) were performed in the borings using a 2-inch outer diameter and 1⅜-inch inner diameter split tube sampler. The CAL and SPT samplers were driven using an automatic hammer with a calibrated Energy Transfer Ratio (ETR) of 73.9%. The number of blows needed to drive the sampler the final 12 inches of an 18-inch drive is noted on the logs. Sampler refusal was encountered when 50 blows were applied during any one of the three 6-inch intervals, a total of 100 Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 4 blows was applied, or there was no discernible sampler advancement during the application of 10 successive blows. The field blow counts, N, were corrected to a standard hammer (cathead and rope) with a 60% ETR. The corrected blow counts are noted on the boring logs as N60. Disturbed bulk samples were obtained from the SPT sampler and the drill cuttings. Logs of the borings are presented in Appendix B. Soils are classified according to the Unified Soil Classification System. 2.2. Laboratory Testing NOVA tested selected samples to evaluate soil classification and engineering properties and develop geotechnical conclusions and recommendations. The laboratory tests consisted of in place moisture and density, particle-size distribution, Atterberg limits, expansion index, R-value, and corrosivity. The results of the laboratory tests and brief explanations of the test procedures are presented in Appendix D. 2.3. Borehole Percolation Testing Borehole percolation tests were performed in P-1 and P-2 to evaluate the feasibility of on-site stormwater infiltration. Borehole percolation testing was performed in accordance with the test method described in the City of Carlsbad BMP Design Manual, For Permanent Site Design, Storm Water Treatment, and Hydromodification Management, Revised: September 1, 2021. The procedure is discussed in Section 8 of this report. 2.4. Analysis and Report Preparation The results of the field and laboratory testing were evaluated to develop conclusions and preliminary recommendations regarding the geotechnical aspects of the proposed construction. This report presents our findings, conclusions, and preliminary recommendations. Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 5 3. SITE AND PROJECT DESCRIPTION 3.1. Site Description The site is an irregular-shaped property located at 945-1065 Carlsbad Village Drive in Carlsbad, California. The site is bordered by Carlsbad Village Drive on the northwest, an onramp to southbound Interstate 5 on the northeast, Oak Avenue on the southeast, and an unnamed alley on the southwest. The site is currently occupied by a shopping center consisting of a grocery store, hardware store, liquor store, and various smaller storefronts with a central parking lot. The site has general sheet flow toward the southwest with ground surface elevations ranging between about 73 feet in the northeast to about 63 feet in the southwest. A review of historic aerial photography indicates that in 1938, the date of earliest historical aerial imagery, the site was occupied by agricultural land and several residences. Additional housing was constructed in the southeast portion of the site by 1947, and the freeway established the eastern boundary by 1953. Grading and construction of the shopping center began by 1964 and was completed by 1967. The site has generally remained in this configuration since at least 1985, when a kiosk in the center of the site along Carlsbad Village Drive was constructed. 3.2. Proposed Construction We understand the proposed construction will consist of demolishing the existing buildings and improvements and designing and constructing three, one-story retail buildings, two five-story residential buildings, and a five-level parking structure. The buildings will be constructed at grade. No below-grade structures are anticipated. Site improvements will include a swimming pool, courtyards, vehicular pavements, pedestrian hardscape, above and below ground utilities, and stormwater BMP facilities. 3.3. Anticipated Earthwork Grading plans are not currently available; therefore, the proposed site grading is not known. However, due to the existing site topography, minor cuts and fills are anticipated. Earthwork is anticipated to consist of remedial and fine grading, excavations for foundations, backfilling retaining walls and underground utilities, subgrade preparation, and pavement construction. Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 6 4. GEOLOGY AND SUBSURFACE CONDITIONS 4.1. Regional Geology The project site is located within the Peninsular Ranges Geomorphic Province of California, which stretches from the Los Angeles basin to the tip of Baja California in Mexico. In general, the province consists of northwest trending mountains underlain by Tertiary sedimentary rocks, Cretaceous igneous rocks of the western Peninsular Ranges Batholith, and Mesozoic meta-volcanic and metasedimentary rocks (CGS, 2002). The Peninsular Ranges Province is traversed by a group of sub- parallel faults and fault zones trending roughly northwest. Several of these faults are considered active. The Elsinore, San Jacinto, and San Andreas Fault Zones are active systems located east of the project area and the Newport-Inglewood, Agua Blanca-Coronado Bank, and San Clemente Fault Zones are active systems located offshore, west of the site. The majority of these faults have right- lateral, strike-slip movement. Uplift associated with these faults has created a diverse topographic environment that has also brought hazards such as landslides, mudslides, and hillside creep (gradual downhill soil movement). Regional geologic maps of the subject property and vicinity (CGS, 2008a) indicate the subject property is underlain by middle Pleistocene old paralic deposits (Qop). The old paralic deposits generally consist of interfingered strandline, beach, estuarine, and colluvial deposits composed of siltstone, sandstone, and conglomerate. Figure 4-1 presents the regional geology in the vicinity of the site. Figure 4-1. Regional Geology Map Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 7 4.2. Site-Specific Geology As encountered in our borings, the site is underlain by fill, topsoil, and old paralic deposits. Descriptions of the materials encountered are presented below. Plate 1 presents a geotechnical map. Plate 2 presents geologic cross-sections. Fill (af): Fill was encountered beneath the existing pavement in borings B-1, B-2, P-1, and P- 2 to a depth of about 2 feet bgs. As encountered in the borings, the fill consisted of medium dense silty sand and clayey sand with some construction debris. NOVA has no records regarding the placement and compaction of the fill; therefore, it is considered undocumented and at risk of wide variations in quality. Figure 4-2 presents a photograph of the fill encountered in Boring B-1. Figure 4-2. Fill in Boring B-1 Topsoil: Topsoil was encountered beneath the fill in boring B-2 and beneath the existing pavement in boring B-5 to depths up to about 3½ feet bgs. As encountered in the borings, the topsoil consisted of loose to medium dense silty sand. Figure 4-3 presents a photograph of the topsoil encountered in boring B-2. Figure 4-3. Topsoil in Boring B-2 Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 8 Old Paralic Deposits (Qop): Late to middle Pleistocene old paralic deposits were encountered beneath the fill and topsoil in each of the borings. As encountered in the borings, the old paralic deposits consisted of medium dense to dense, friable to moderately cemented poorly graded sand, silty sand, and clayey sand with varying amounts of gravel and cobbles. Figure 4-4 presents a photograph of the old paralic deposits encountered in Boring B-4. Figure 4-4. Old Paralic Deposits in Boring B-4 Santiago Formation (Tsa): Santiago Formation was encountered beneath the old paralic deposits in borings B-1 and B-3 through B-6 at depths of about 15 to 15½ feet bgs. As encountered in the borings, the Santiago Formation consisted of very dense, weakly cemented clayey sandstone. Figure 4-4 presents a photograph of the Santiago Formation encountered in boring B-4. Figure 4-5. Santiago Formation in Boring B-4 Groundwater: Groundwater was encountered in borings B-2 through B-6 at depths between about 11½ and 15 feet bgs. Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 9 5. GEOLOGIC HAZARDS 5.1. Faulting and Surface Rupture The site is located in a seismically active area, and the potential for strong ground motion is considered significant during the design life of the proposed structure. Major known active faults in the region consist generally of en echelon, northwest striking, right-lateral, strike-slip faults. The tectonic setting of the metropolitan San Diego area includes major north and northwest striking fault zones, the most prominent and active of which is the Newport Inglewood Rose Canyon Fault Zone (NIRCFZ). The NIRCFZ can generate earthquakes of magnitude MW = 6.99. Earthquake Fault Zones have been established along known active faults in California in accordance with the Alquist-Priolo Earthquake Fault Zoning Act. The site is not located in an Alquist-Priolo Earthquake Fault Zone. No active surface faults are mapped across the site. The nearest active fault is the Oceanside Section of the NIRCFZ, located about 4.65 miles to the southwest. Evidence of active faulting was not observed at the site during our field investigation. No active faults are known to underlie or project toward the site. The probability of fault rupture is considered low. Figure 5-1 shows the locations of known faults in the site vicinity. Figure 5-1. Regional Faulting in the Site Vicinity Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 10 5.1. Site Class Site Class is determined by the weighted average of shear-wave velocity or standard penetration resistance (N-value) within the upper 100 feet of the soil and rock beneath a site. Sites underlain by soil and rock with a weighted average standard penetration resistance greater than 50 blows per foot within the upper 100 feet are classified as Site Class C. Based on the penetration resistances encountered in our borings, the site is classified as Site Class C in accordance with Table 20.3-1 and the formulas in Section 20.4 of ASCE 7-16. 5.2. Seismic Design Parameters A geologic hazard likely to affect the project is ground shaking as a result of movement along an active fault zone in the vicinity of the project site. The site coefficients and maximum considered earthquake (MCER) spectral response acceleration parameters in accordance with the 2019 California Building Code (CBC) and ASCE 7-16 are presented in Table 5-1. Table 5-1. 2019 CBC and ASCE 7-16 Seismic Design Parameters Site Coordinates Latitude: 33.16185° Longitude: -117.34305° Site Coefficients and Spectral Response Acceleration Parameters Value Site Class C Site Coefficients, Fa 1.2 Site Coefficients, Fv 1.5 Mapped Spectral Response Acceleration at Short Period, Ss 1.063g Mapped Spectral Response Acceleration at 1-Second Period, S1 0.385g Mapped Design Spectral Acceleration at Short Period, SDS 0.851g Design Spectral Acceleration at 1-Second Period, SD1 0.385g Site Peak Ground Acceleration, PGAM 0.562g 5.3. Liquefaction and Dynamic Settlement Liquefaction occurs when loose, saturated, generally fine sands and silts are subjected to strong ground shaking. The soils lose shear strength and become liquid, resulting in large total and differential ground surface settlements, as well as possible lateral spreading during an earthquake. Given the dense nature of the materials beneath the project site, the potential for liquefaction and dynamic settlement to occur is low. 5.4. Flooding, Tsunamis, and Seiches The project site is mapped within an area of minimal flood hazard (FEMA, 2012). The site is not located within a mapped area on the State of California Tsunami Inundation Maps (Cal EMA, 2009); therefore, damage due to tsunamis is considered negligible. Seiches are periodic oscillations in large bodies of Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 11 water such as lakes, harbors, bays, or reservoirs. The site is not located adjacent to any lakes or confined bodies of water; therefore, the potential for a seiche to affect the site is considered low. 5.5. Subsidence The site is not located in an area of known subsidence associated with fluid withdrawal (groundwater or petroleum); therefore, the potential for subsidence due to the extraction of fluids is considered negligible. 5.6. Hydro-Consolidation Hydro-consolidation can occur in recently deposited sediments (less than 10,000 years old) that were deposited in a semi-arid environment. Examples of such sediments are eolian sands, alluvial fan deposits, and mudflow sediments deposited during flash floods. The pore spaces between the particle grains can re-adjust when inundated by groundwater, causing the material to consolidate. Given the age and relatively dense nature of the old paralic deposits and Santiago Formation, these deposits are not considered susceptible to hydro-consolidation. The fill and topsoil, however, may be susceptible to hydro-consolidation. The potential for hydro-consolidation can be mitigated by removing and replacing the susceptible soils with compacted fill. Recommendations for remedial grading are provided in this report. Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 12 6. CONCLUSIONS Based on the results of our investigation, we consider the proposed construction feasible from a geotechnical standpoint provided the recommendations contained in this report are followed. Geotechnical conditions exist that should be addressed prior to construction. Geotechnical design and construction considerations include the following. • There are no known active or potentially active faults underlying the site. The primary seismic hazard at the site is the potential for moderate to severe ground shaking in response to large- magnitude earthquakes generated during the lifetime of the proposed construction. The risk of strong ground motion is common to all construction in southern California and is typically mitigated through building design in accordance with the CBC. While strong ground motion could affect the site, the risk of liquefaction is considered low. • The site is underlain by undocumented fill, topsoil, old paralic deposits, and Santiago Formation. The formational materials (old paralic deposits and Santiago Formation) are suitable for support of structural or fill loads. The undocumented fill and topsoil, however, are potentially compressible and therefore unsuitable for support of structural or fill loads. Recommendations for remedial grading are provided in this report. • The on-site soils tested have a very low expansion potential. These soils are suitable for reuse as compacted fill. Expansive clays, if encountered, are not considered suitable for direct support of structures or heave-sensitive improvements. Recommendations for expansive soils are provided herein. • In general, excavations should be achievable using standard heavy earthmoving equipment in good working order with experienced operators. However, cemented formational materials, cobbles, and construction debris may require extra excavation effort and may also generate oversized material that will require extra effort to screen for use as compacted fill or export from the site. • The proposed buildings can be supported on shallow foundations (spread footings and/or mat foundations) with bottom levels bearing either entirely on formational materials or entirely on compacted fill. Recommendations for foundations are provided herein. • Groundwater was encountered in borings B-2 through B-6 at depths between about 11½ and 15 feet bgs. Additional groundwater may occur in the future due to rainfall, irrigation, broken pipes, or changes in site drainage. Because groundwater seepage is difficult to predict, such conditions are typically mitigated if and when they occur. • The infiltration feasibility condition category is “No Infiltration” due to the presence of relatively shallow groundwater beneath the site. Infiltration is discussed in Section 8. Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 13 7. PRELIMINARY RECOMMENDATIONS The remainder of this report presents preliminary recommendations regarding earthwork construction and design of the proposed structures and improvements. These recommendations are based on empirical and analytical methods typical of the standard-of-practice in southern California. If these recommendations appear not to address a specific feature of the project, please contact NOVA for additions or revisions to the recommendations. The recommendations presented herein may need to be updated once final plans are developed. 7.1. Earthwork Grading and earthwork should be conducted in accordance with the CBC and the recommendations of this report. The following recommendations are provided regarding specific aspects of the proposed earthwork construction. The recommendations should be considered subject to revision based on field conditions observed by NOVA field representatives during grading. 7.1.1 Site Preparation Site preparation should begin with the removal of existing improvements, vegetation, and debris. Subsurface improvements that are to be abandoned should be removed, and the resulting excavations should be backfilled and compacted in accordance with the recommendations of this report. Pipeline abandonment can consist of capping or rerouting at the project perimeter and removal within the project perimeter. If appropriate, abandoned pipelines can be filled with grout or slurry as recommended by and observed by the geotechnical consultant. 7.1.2 Remedial Grading - Building Pad The proposed buildings should be supported either entirely on formational materials or entirely on a relatively uniform thickness of compacted fill. Individual buildings should not be underlain by cut/fill transitions or transitions from shallow fill to deep fill. Remedial grading recommendations for both foundation support options are provided below. Footings Supported on Formational Materials: Beneath the proposed building pad, existing fill and topsoil should be excavated to expose competent formational materials. Additionally, if a cut/fill transition exists at finished pad grade, the cut portion of the pad should be excavated to a depth of 2 feet below finished pad grade. Horizontally, excavations should extend at least 5 feet outside the planned perimeter foundations or up to existing improvements or the limits of grading, whichever is less. NOVA should observe the conditions exposed in the bottom of excavations to evaluate if additional excavation is recommended. The excavation should be filled to the finished pad grade with compacted fill having an expansion index (EI) of 50 or less. To accommodate uniform bearing on formational materials, 2-sack sand/cement slurry can be placed between the bottom of footing and the underlying formation. Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 14 Footings Supported on Compacted Fill: Beneath the proposed building pad, existing fill and topsoil should be excavated to expose competent formational materials. Additionally, formational materials should be excavated to a depth of at least 3 feet below the proposed pad elevation or 1 foot below the deepest planned foundation bottom, whichever is deeper. Horizontally, excavations should extend at least 5 feet outside planned perimeter foundations or up to existing improvements or the limits of grading, whichever is less. NOVA should observe the conditions exposed in the bottom of excavations to evaluate whether additional excavation is recommended. The resulting excavation should be filled to finished pad grade with compacted fill having an EI of 50 or less. 7.1.3 Remedial Grading - Pedestrian Hardscape Beneath proposed pedestrian hardscape areas, the existing soils should be excavated to a depth of at least 2 feet below existing grade or planned subgrade elevation, whichever is deeper. Horizontally, excavations should extend at least 2 feet outside hardscape or up to existing improvements or the limits of grading, whichever is less. If suitable formational materials are exposed, excavation need not be performed. NOVA should observe the conditions exposed in the bottom of excavations to evaluate whether additional excavation is recommended. The excavation should be filled with compacted fill having an EI of 50 or less. 7.1.4 Remedial Grading - Vehicular Pavements Beneath proposed vehicular pavement areas, the existing soils should be excavated to a depth of at least 1 foot below existing grade or planned subgrade elevation, whichever is deeper. Horizontally, excavations should extend at least 2 feet outside the planned pavement or up to existing improvements or the limits of grading, whichever is less. If suitable formational materials are exposed, excavation need not be performed. NOVA should observe the conditions exposed in the bottom of excavations to evaluate whether additional excavation is recommended. The excavation should be filled with material suitable for use as compacted fill. 7.1.5 Remedial Grading - Site Walls Beneath proposed site walls and site retaining walls not connected to buildings, the existing soils should be excavated to a depth of at least 2 feet below bottom of footing. Horizontally, excavations should extend at least 2 feet outside the planned wall footing or up to existing improvements or the limits of grading, whichever is less. If suitable formational materials are exposed, excavation need not be performed. NOVA should observe the conditions exposed at the bottom of excavations to evaluate whether additional excavation is recommended. Any required fill should have an EI of 50 or less. 7.1.6 Expansive Soil The on-site soils tested have an EI of 0, classified as very low expansion potential. To reduce the potential for expansive soil heave, the top 2 feet of material beneath building footings, concrete slabs- on-grade, site wall and retaining wall footings, and hardscape should have an EI of 50 or less. Horizontally, the soils having an EI of 50 or less should extend at least 5 feet outside the planned Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 15 perimeter building foundations, at least 2 feet outside site/retaining wall footings and hardscape, or up to existing improvements or the limits of grading, whichever is less. We expect that the on-site sands will meet the EI criteria. We expect that the on-site silty sand, clayey sand, and poorly graded sand will meet the EI criterion. Clays, if encountered, are not expected to meet the EI criterion. 7.1.7 Compacted Fill Excavated soils free of organic matter, construction debris, rocks greater than 6 inches, and expansive soil as described above should generally be suitable for reuse as compacted fill. Areas to receive fill should be scarified to a depth of 6 to 8 inches, moisture conditioned to near optimum moisture content, and compacted to at least 90% relative compaction. If competent formational materials are exposed, scarification and recompaction need not be performed. Fill and backfill should be placed in 6- to 8- inch-thick loose lifts, moisture conditioned to near optimum moisture content, and compacted to at least 90% relative compaction. The top 12 inches of subgrade beneath pavements should be compacted to at least 95% relative compaction. The maximum density and optimum moisture content for the evaluation of relative compaction should be determined in accordance with ASTM D1557. 7.1.8 Imported Soil Imported soil should consist of predominately granular soil, free of organic matter and rocks greater than 6 inches. Imported soil should be observed and, if appropriate, tested by NOVA prior to transport to the site to evaluate suitability for the intended use. 7.1.9 Subgrade Stabilization Excavation bottoms should be firm and unyielding prior to placing fill. In areas of saturated or yielding subgrade, a reinforcing geogrid such as Tensar® Triax® TX-5 or equivalent can be placed on the excavation bottom, and then at least 12 inches of aggregate base placed and compacted. Once the surface of the aggregate base is firm enough to achieve compaction, then the remaining excavation should be filled to finished pad grade with suitable material. 7.1.10 Excavation Characteristics It is anticipated that excavations can be achieved with conventional earthwork equipment in good working order. However, difficult excavation should be anticipated in cemented zones within the formational materials. Cobbles and construction debris should be anticipated that will require extra effort to screen prior to reuse as compacted fill or export from the site. 7.1.11 Oversized Material Oversized material is defined as rocks or cemented clasts greater than 6 inches in largest dimension. Oversized material, if encountered, should be broken down to no greater than 6 inches in largest dimension for use in fill, used as landscape material, or disposed of off-site. Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 16 7.1.12 Temporary Excavations Temporary excavations 3 feet deep or less can be made vertically. Deeper temporary excavations in fill should be laid back no steeper than 1:1 (horizontal:vertical). Deeper temporary excavations in cemented formational materials should be laid back no steeper than ¾:1 (h:v). The faces of temporary slopes should be inspected daily by the contractor’s Competent Person before personnel are allowed to enter the excavation. Any zones of potential instability, sloughing, or raveling should be brought to the attention of the engineer and corrective action implemented before personnel begin working in the excavation. Excavated soils should not be stockpiled behind temporary excavations within a distance equal to the depth of the excavation. NOVA should be notified if other surcharge loads are anticipated so that lateral load criteria can be developed for the specific situation. If temporary slopes are to be maintained during the rainy season, berms are recommended along the tops of slopes to prevent runoff water from entering the excavation and eroding the slope faces. Slopes steeper than those described above will require shoring. Additionally, temporary excavations that extend below a plane inclined at 1½:1 (h:v) downward from the outside bottom edge of existing structures or improvements will require shoring. Soldier piles and lagging, internally braced shoring, or trench boxes could be used. If trench boxes are used, the soil immediately adjacent to the trench box is not directly supported. Ground surface deformations immediately adjacent to the pit or trench could be greater where trench boxes are used compared to other methods of shoring. 7.1.13 Temporary Shoring For the design of cantilevered shoring with level backfill, an active earth pressure equal to a fluid weighing 35 pounds per cubic foot (pcf) can be used. An additional 20 pcf should be added for 2:1 (h:v) sloping ground. The surcharge loads on shoring from traffic and construction equipment working adjacent to the excavation can be modeled by assuming an additional 2 feet of soil behind the shoring. For the design of soldier piles, an allowable passive pressure of 350 pounds per square foot (psf) per foot of embedment can be used, over two times the pile diameter up to a maximum of 5,000 psf. Soldier piles should be spaced at least three pile diameters, center to center. Continuous lagging will be required throughout. Soldier piles should be designed for the full anticipated lateral pressure; however, the pressure on the lagging will be less due to arching in the soils. For the design of lagging, the earth pressure can be limited to a maximum of 400 psf. 7.1.14 Groundwater Seepage Groundwater seepage should be anticipated in excavations. If dewatering is necessary, the dewatering method should be evaluated and implemented by an experienced dewatering subcontractor. 7.1.15 Slopes Permanent slopes should be constructed no steeper than 2:1 (h:v). Faces of fill slopes should be compacted either by rolling with a sheepsfoot roller or other suitable equipment, or by overfilling and cutting back to design grade. Fills should be benched into sloping ground inclined steeper than 5:1 (h:v). In NOVA’s opinion, slopes constructed no steeper than 2:1 (h:v) will possess an adequate factor Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 17 of safety. An engineering geologist should observe cut slopes during grading to ascertain that no unforeseen adverse geologic conditions are encountered that require revised recommendations. Slopes are susceptible to surficial slope failure and erosion. Water should not be allowed to flow over the top of slope. Additionally, slopes should be planted with vegetation that will reduce the potential for erosion. 7.1.16 Surface Drainage Final surface grades around structures should be designed to collect and direct surface water away from structures, including retaining walls, and toward appropriate drainage facilities. The ground around the structure should be graded so that surface water flows rapidly away from the structure without ponding. In general, we recommend that the ground adjacent to the structure slope away at a gradient of at least 2%. Densely vegetated areas where runoff can be impaired should have a minimum gradient of at least 5% within the first 5 feet from the structure. Roof gutters with downspouts that discharge directly into a closed drainage system are recommended on structures. Drainage patterns established at the time of fine grading should be maintained throughout the life of the proposed structures. Site irrigation should be limited to the minimum necessary to sustain landscape growth. Should excessive irrigation, impaired drainage, or unusually high rainfall occur, saturated zones of perched groundwater can develop. 7.1.17 Grading Plan Review NOVA should review the grading plans and earthwork specifications to ascertain whether the intent of the recommendations contained in this report have been implemented and that no revised recommendations are needed due to changes in the development scheme. 7.2. Foundations The foundation recommendations provided herein are considered generally consistent with methods typically used in southern California. Other alternatives may be available. NOVA’s recommendations are only minimum criteria based on geotechnical factors and should not be considered a structural design, or to preclude more restrictive criteria of governing agencies or by the structural engineer. The design of the foundation system should be performed by the project structural engineer, incorporating the geotechnical parameters described herein and the requirements of applicable building codes. The proposed buildings can be supported on shallow foundations (spread footings and/or mat foundations) with bottom levels bearing either entirely on formational materials or entirely on compacted fill. Individual buildings should not be underlain by cut/fill transitions or transitions from shallow fill to deep fill. To accommodate uniform bearing on formational materials, 2-sack sand/cement slurry can be placed between the bottom of footing and the underlying formational materials. Site walls and retaining walls not connected to buildings can be supported on shallow spread footings bearing on formational materials or on compacted fill. Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 18 7.2.1 Spread Footings Footings should extend at least 24 inches below lowest adjacent finished grade. A minimum width of 18 inches is recommended for continuous footings and 24 inches for isolated or retaining wall footings. An allowable bearing capacity of 3,500 psf can be used for spread footings supported on competent formation or on 3-sack sand/cement slurry extending down to competent formation. An allowable bearing capacity of 2,500 psf can be used for footings supported on compacted fill. The allowable bearing capacity can be increased by 500 psf for each foot of depth below the minimum and 250 psf for each foot of width beyond the minimum up to a maximum of 6,500 psf on formation or 5,000 psf on compacted fill. The bearing value can be increased by ⅓ when considering the total of all loads, including wind or seismic forces. Footings located adjacent to or within slopes should be extended to a depth such that a minimum horizontal distance of 10 feet exists between the lower outside footing edge and the face of slope. 7.2.2 Mat Foundations The allowable bearing capacity provided in the spread footings section of this report are also applicable to mat foundations. Mat foundations typically experience some deflection due to loads placed on the mat and the reaction of the soils underlying the mat. A design modulus of subgrade reaction, K, of 225 pounds per cubic inch (pci) can be used for the subgrade soils in evaluating such deflections. This value is based on an area of 1 square foot and should be adjusted for larger mats. Adjusted values of the modulus of subgrade reaction, Kv, can be obtained from the following equation for square mats of various widths: 𝐾𝐾𝑉𝑉=𝐾𝐾�B + 12B�2 (𝑝𝑝𝑝𝑝𝑝𝑝) Where B is the width of the mat in feet. Adjusted values of the modulus of subgrade reaction, K’, can be obtained from the following equation for rectangular mats: 𝐾𝐾′=𝐾𝐾𝑣𝑣�1 + 0.5 �𝐵𝐵𝐿𝐿��1.5 (𝑝𝑝𝑝𝑝𝑝𝑝) Where B is the width and L is the length of the mat in feet. 7.2.3 Lateral Resistance for Shallow Structural Elements Lateral loads will be resisted by friction between the bottoms of foundations and passive pressure on the faces of foundations and other structural elements below grade. An allowable coefficient of friction of 0.35 can be used. An allowable passive pressure of 350 psf per foot of depth below the ground surface can be used for level ground conditions where the ground is horizontal for a distance of at least 10 feet or three times the height generating the passive pressure. The passive pressure should be reduced for sloping ground conditions. For 2:1 (h:v) descending ground, an allowable passive Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 19 pressure of 130 psf per foot of depth below the ground surface can be used. The passive pressure can be increased by ⅓ when considering the total of all loads, including wind or seismic forces. The upper 1 foot of soil should not be relied on for passive support unless the ground is covered with pavements or slabs. 7.2.4 Settlement Characteristics Total foundation settlements are estimated to be less than 1 inch. Differential settlements between adjacent columns and across continuous footings are estimated to be less than ¾ inch over a distance of 40 feet. Settlements should be completed shortly after structural loads are applied. 7.2.5 Foundation Plan Review NOVA should review the foundation plans to ascertain that the intent of the recommendations in this report has been implemented and that revised recommendations are not necessary as a result of changes after this report was completed. 7.2.6 Foundation Excavation Observations A representative from NOVA should observe the foundation excavations prior to forming or placing reinforcing steel. 7.3. Interior Slabs-On-Grade Interior concrete slabs-on-grade should be underlain by at least 2 feet of material with an EI of 50 or less. The top 12 inches of subgrade soils should be scarified, moisture conditioned to near optimum moisture content, and compacted to at least 90% relative compaction. Subgrade preparation should be performed immediately prior to placement of the concrete slab. We recommend that concrete slabs-on-grade be at least 5 inches thick and reinforced with at least No. 4 bars at 18 inches on center each way. To reduce the potential for excessive cracking, concrete slabs should be provided with construction or ‘weakened plane’ joints at frequent intervals. The project structural engineer should design on-grade building slabs and joint spacing. Moisture protection should be installed beneath slabs where moisture sensitive floor coverings will be used. The project architect should review the tolerable moisture transmission rate of the proposed floor covering and specify an appropriate moisture protection system. Typically, a plastic vapor barrier is used. Minimum 15-mil plastic is recommended. The plastic should comply with ASTM E1745. The vapor barrier installation should comply with ASTM E1643. The slab can be placed directly on the vapor barrier. 7.4. Pedestrian Hardscape Pedestrian hardscape should be underlain by at least 2 feet of material with an EI of 50 or less. The top 12 inches of subgrade soils should be scarified, moisture conditioned to near optimum moisture content, and compacted to at least 90% relative compaction. If competent formational sandstone is Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 20 exposed, scarification and recompaction need not be performed. Subgrade preparation should be performed immediately prior to placement of the hardscape. Exterior slabs should be at least 4 inches in thickness and reinforced with at least No. 3 bars at 18 inches on center each way. Slabs should be provided with weakened plane joints. Joints should be placed in accordance with the American Concrete Institute (ACI) guidelines. The project architect should select the final joint patterns. A 1-inch maximum size aggregate mix is recommended for concrete for exterior slabs. The corrosion potential of on-site soils with respect to reinforced concrete will need to be taken into account in concrete mix design. Coarse and fine aggregate in concrete should conform to the “Greenbook” specifications. 7.5. Vehicular Pavement Section Recommendations An R-value of 15 was assumed for design of preliminary pavement sections. The actual R-value of the subgrade soils should be determined after grading, and the final pavement sections should be provided. Based on an R-value of 15, the following preliminary pavement structural sections are provided for the assumed Traffic Indexes in Table 7-1. Table 7-1. AC and PCC Pavement Sections Traffic Type Traffic Index Asphalt Concrete (inches) Portland Cement Concrete (inches) Parking Stalls 4.5 3 AC / 7 AB 6 PCC / 4 AB Driveways 6.0 4 AC / 10 AB 7 PCC / 6 AB Fire Lanes 7.5 5 AC / 13 AB 7½ PCC / 6 AB AC: Asphalt Concrete AB: Aggregate Base PCC: Portland Cement Concrete Subgrade preparation should be performed immediately prior to placement of the pavement section. The upper 12 inches of subgrade should be scarified, moisture conditioned to near optimum moisture content, and compacted to at least 95% relative compaction. If competent formational sandstone is exposed, scarification and recompaction need not be performed. All soft or yielding areas should be stabilized or removed and replaced with compacted fill or aggregate base. Aggregate base and asphalt concrete should conform to the Caltrans Standard Specifications or the “Greenbook” and should be compacted to at least 95% relative compaction. Aggregate base should have an R-value of not less than 78. All materials and methods of construction should conform to good engineering practices and the minimum local standards. 7.6. Conventional Retaining Walls Conventional retaining walls can be supported on spread footings. The recommendations for spread footings provided in the foundation section of this report are also applicable to conventional retaining walls. Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 21 The active earth pressure for the design of unrestrained retaining walls with level backfill can be taken as equivalent to the pressure of a fluid weighing 35 pcf. The at-rest earth pressure for the design of restrained retaining wall with level backfill can be taken as equivalent to the pressure of a fluid weighing 55 pcf. These values assume a granular and drained backfill condition. Higher lateral earth pressures would apply if walls retain clay soils. An additional 20 pcf should be added to these values for walls with 2:1 (h:v) sloping backfill. An increase in earth pressure equivalent to an additional 2 feet of retained soil can be used to account for surcharge loads from light traffic. The above values do not include a factor of safety. Appropriate factors of safety should be incorporated into the design. If any other surcharge loads are anticipated, NOVA should be contacted for the necessary increase in soil pressure. The seismic earth pressure can be taken as equivalent to the pressure of a fluid pressure weighing 12 pcf. This value is for level backfill and does not include a factor of safety. Appropriate factors of safety should be incorporated into the design. This pressure is in addition to the un-factored, active earth pressure. The total equivalent fluid pressure can be modeled as a triangular pressure distribution with the resultant acting at a height of H/3 up from the base of the wall, where H is the retained height of the wall. The passive pressure and bearing capacity can be increased by ⅓ in determining the seismic stability of the wall. Retaining walls should be provided with a backdrain to reduce the accumulation of hydrostatic pressures or be designed to resist hydrostatic pressures. Backdrains can consist of a 2-foot-wide zone of ¾-inch crushed rock. The crushed rock should be separated from the adjacent soils using a non- woven filter fabric, such as Mirafi 140N or equivalent. A perforated pipe should be installed at the base of the backdrain and sloped to discharge to a suitable storm drain facility, or weep holes should be provided. As an alternative, a geocomposite drainage system such as Miradrain 6000 or equivalent placed behind the wall and connected to a suitable storm drain facility can be used. The project architect should provide dampproofing/waterproofing specifications and details. Figure 7-1 presents typical conventional retaining wall backdrain details. Note that the guidance provided on Figure 7-1 is conceptual. A variety of options are available to drain retaining walls. Wall backfill should consist of granular, free-draining material having an expansion index of 20 or less. The backfill zone is defined by a 1:1 (h:v) plane projected upward from the heel of the wall. Expansive or clayey soil should not be used. Additionally, backfill within 3 feet from the back of the wall should not contain rocks greater than 3 inches in dimension. Backfill should be compacted to at least 90% relative compaction. Backfill should not be placed until walls have achieved adequate structural strength. Compaction of wall backfill will be necessary to minimize settlement of the backfill and overlying settlement sensitive improvements. However, some settlement should still be anticipated. Provisions should be made for some settlement of concrete slabs and pavements supported on backfill. Additionally, any utilities supported on backfill should be designed to tolerate differential settlement. Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 22 Figure 7-1. Typical Conventional Retaining Wall Backdrain Detail 7.7. Pipelines For level ground conditions, a passive earth pressure of 350 psf per foot of depth below the lowest adjacent final grade can be used to compute allowable thrust block resistance. A value of 150 psf per foot should be used below groundwater level, if encountered. A modulus of soil reaction (E’) of 1,500 psi can be used to evaluate the deflection of buried flexible pipelines. This value assumes that granular bedding material is placed adjacent to the pipe and is compacted to at least 90% relative compaction. Pipe bedding as specified in the “Greenbook” Standard Specifications for Public Works Construction can be used. Bedding material should consist of clean sand having a sand equivalent not less than 20 and should extend to at least 12 inches above the top of pipe. Alternative materials meeting the intent of the bedding specifications are also acceptable. Samples of materials proposed for use as Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 23 bedding should be provided to the engineer for inspection and testing before the material is imported for use on the project. The on-site materials are not expected to meet “Greenbook” bedding specifications. The pipe bedding material should be placed over the full width of the trench. After placement of the pipe, the bedding should be brought up uniformly on both sides of the pipe to reduce the potential for unbalanced loads. No voids or uncompacted areas should be left beneath the pipe haunches. Ponding or jetting the pipe bedding should not be allowed. Where pipeline inclinations exceed 15%, cutoff walls are recommended in trench excavations. Additionally, we do not recommend that open graded rock be used for pipe bedding or backfill because of the potential for piping erosion. The recommended bedding is clean sand having a sand equivalent not less than 20 or 2-sack sand/cement slurry. If sand/cement slurry is used for pipe bedding to at least 1 foot over the top of the pipe, cutoff walls are not considered necessary. The need for cutoff walls should be further evaluated by the civil engineer designing the pipeline. 7.8. Corrosivity Representative samples of the on-site soils were tested to evaluate corrosion potential. The test results are presented in Appendix D. The project design engineer can use the sulfate results in conjunction with ACI 318 to specify the water/cement ratio, compressive strength, and cementitious material types for concrete exposed to soil. It should be noted that the test results indicate relatively low resistivity, which may be corrosive. A corrosion engineer should be contacted to provide specific corrosion control recommendations. Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 24 8. INFILTRATION FEASIBILITY 8.1. Overview At this time, stormwater BMP locations have not been finalized. NOVA assumes that stormwater BMP facilities will be designed utilizing an underdrain. Two infiltration tests were conducted near the northwestern portion of the site for planning purposes. NOVA evaluated the site using guidance contained in the BMP Manual. Based on the calculated infiltration rates and restriction elements in Table D.1-1 of the BMP Manual (Figure 8-1 below), it is NOVA’s judgement that the site is not suitable for permanent stormwater infiltration due to the potential for groundwater levels within 10 feet below planned stormwater BMPs. Figure 8-1 outlines infiltration restriction considerations for proposed BMP facilities. The SWQMP preparer should review the restriction elements. Figure 8-1. Infiltration Restriction Considerations Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 25 8.2. Percolation Testing The percolation test wells were pre-soaked by filling the test holes with water to the ground surface level, and testing commenced within a 26-hour window. On the day of testing, two 25-minute trials were conducted in each test well. The pre-soak water percolated more than 6 inches into the soil within 25 minutes. Based on the results of the trials, water levels were recorded every 10 minutes for 1 hour. At the beginning of each test interval, the water level was raised to approximately the same level as the previous tests to maintain a near-constant head during each test period. Table 8-1 summarizes the percolation test conditions and infiltration rates. Table 8-1. Summary of Borehole Percolation Tests Test Location Test Depth (feet) Material at Test Depth Tested Infiltration Rate (in/hr, FS=2)1 P-1 5 Old paralic deposits: silty sand 2.39 P-2 5 Old paralic deposits: silty sand 2.12 Note 1: FS indicates ‘Factor of Safety’ As shown in Table 8-1, a factor of safety (FS) is applied to the infiltration rate (I) determined by the percolation testing. This factor of safety, calculated for this site as FS=2, considers the nature and variability of subsurface materials, as well as the natural tendency of infiltration structures to become less efficient with time. A default factor of safety of 2 is applied for BMPs utilizing an underdrain. The calculated infiltration rates at locations P-1 and P-2 after applying FS = 2 are 2.39 and 2.12 inches per hour, respectively. 8.3. Recommendation for No Infiltration As previously mentioned, due to the relatively high groundwater levels, it is NOVA’s judgment that the site is restricted by elements that cannot be reasonably resolved through site design changes. In our opinion, the site is not suitable for permanent stormwater infiltration. BMP facilities should be lined throughout with an impermeable geomembrane to reduce the potential for water-related distress to adjacent structures or improvements. A subdrain system should be installed at the bottom of BMP facilities. Additionally, BMP facilities should be kept at least 10 feet from structural foundations. Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 26 9. CLOSURE NOVA should review project plans and specifications prior to bidding and construction to check that the intent of the recommendations in this report has been incorporated. Observations and tests should be performed during construction. If the conditions encountered during construction differ from those anticipated based on the subsurface exploration program, the presence of personnel from NOVA during construction will enable an evaluation of the exposed conditions and modifications of the recommendations in this report or development of additional recommendations in a timely manner. NOVA should be advised of changes in the project scope so that the recommendations contained in this report can be evaluated with respect to the revised plans. Changes in recommendations will be verified in writing. The findings in this report are valid as of the date of this report. Changes in the condition of the site can, however, occur with the passage of time, whether they are due to natural processes or work on this or adjacent areas. In addition, changes in the standards of practice and government regulations can occur. Thus, the findings in this report may be invalidated wholly or in part by changes beyond NOVA’s control. This report should not be relied upon after a period of two years without a review by NOVA verifying the suitability of the conclusions and recommendations to site conditions at that time. In the performance of professional services, NOVA exercises the level of care and skill ordinarily exercised by members of the geotechnical profession currently practicing under similar conditions and in the same locality. The client recognizes that subsurface conditions may vary from those encountered at the boring locations and that the data, interpretations, and recommendations reported herein are based solely on the information obtained by NOVA. NOVA will be responsible for those data, interpretations, and recommendations, but shall not be responsible for interpretations by others of the information developed. Our services consist of professional consultation and observation only, and no warranty whatsoever, express or implied, is made or intended in connection with the work performed or to be performed by us, or by our proposal for consulting or other services, or by our furnishing of oral or written reports or findings. Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 27 10. REFERENCES American Concrete Institute, 2014, Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary, dated September. California Emergency Management Agency (Cal EMA), California Geological Survey, University of Southern California, 2009, Tsunami Inundation Map for Emergency Planning. California Department of Transportation (Caltrans), 2018, Standard Specifications. California Geological Survey (CGS), 2002, California Geomorphic Provinces Note 36, Electronic Copy, Revised December 2002. ______, 2008a, Geologic Map of the Oceanside 30’ x 60’ Quadrangle, California, Scale 1:100,000. ______, 2008b, Guidelines for Evaluating and Mitigating Seismic Hazards in California, Special Publication 117A, September 2008. ______, 2011, Susceptibility to Deep-Seated Landslides in California. ______, 2018, Earthquake Fault Zones, Special Publication 42, Revised 2018. ______, 2021, Landslide Inventory, at: https://maps.conservation.ca.gov/cgs/lsi/. ______, 2022, Fault Activity Map of California Website, https://maps.conservation.ca.gov/cgs/fam/, accessed in November. California State Water Resources Control Board, GeoTracker website, accessed October 2022. City of Carlsbad, 2021, Engineering Standards, Volume 5, Carlsbad BMP Design Manual (Post Construction Treatment BMPS), 2021 Edition, Dated September. Federal Emergency Management Agency, 2012, FIRM Flood Insurance Rate Map, San Diego County, Firm Panel 06073C0762G, https://msc.fema.gov/portal/search, accessed in October 2022. International Code Council, 2018, 2019 California Building Code, California Code of Regulations, Title 24, Part 2, Volume 2 of 2, Based on the 2018 International Building Code, Effective 1/1/20. KFA, 2023, First Floor Plan, Tooley Carlsbad, 945-1065 Carlsbad Village Dr., Carlsbad, CA 92008, Entitlement Set, Job No. 2022-004.00, May 9. Kennedy, M.P. and Tan, S.S., 2007, Geologic Map of the Oceanside 30’ x 60’ Quadrangle, California, California Geological Survey, Scale 1:100,000. Landslide Inventory, accessed August, 2021 at: https://maps.conservation.ca.gov/cgs/lsi/. Public Works Standards, Inc., 2021, “Greenbook” Standard Specifications for Public Works Construction, 2021 Edition. Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 28 Structural Engineers Association of California (SEAOC), 2022, OSHPD Seismic Design Maps: found at https://seismicmaps.org, accessed October. United States Geological Survey (USGS), 2022a, USGS Geologic Hazards Science Center, U.S. Quaternary Faults, accessed November. USGS, 1997, San Luis Rey Quadrangle, California – San Diego Co. 7.5-Minute Series (Topographic), Contour Interval 20 feet, Scale 1:24,000. Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 PLATES P-1 P-2 B-1 B-2 B-4 B-3 B-6B-5 B B' A A' af/top Qop Tsa af/top Qop Tsa Qop Tsa Qop Tsa ?? ? ? ? ? 0 50'100' NW E N S 4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575 944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710 NOVA CA R L S B A D V I L L A G E M I X E D - U S E 94 5 - 1 0 6 5 C A R L S B A D V I L L A G E D R I V E C A R L S B A D , C A L I F O R N I A GEOTECHNICAL MATERIALS SPECIAL INSPECTION DVBE www.usa-nova.com PROJECT NO.: DATE: DRAWN BY: REVIEWED BY: 2022210 NOV 2022 DTJ AN GEOTECHNICAL MAP DRAWING TITLE: SCALE:1"=50' PLATE NO.1 OF 2 SBE SDVOSB SLBE KEY TO SYMBOLS GEOTECHNICAL BORINGB-6 Qop OLD PARALIC DEPOSITS BOREHOLE PERCOLATION TESTP-2 Tsa SANTIAGO FORMATION GEOLOGIC CROSS-SECTIONBB' GEOLOGIC CONTACT,QUERIED WHERE UNCERTAIN? *BASE MAP: KFA, 2022 NOTE: ALL LOCATIONS APPROXIMATE af/top UNDIFFERENTIATEDFILL & TOPSOIL 50 A 0 100 50 100 150 200 250 300 350 400 450 EL E V A T I O N ( F E E T M S L ) HORIZONTAL DISTANCE (FEET) 0 500 PL PL TD=16' B-5 PROPOSED BUILDING PROPOSED BUILDING 50 A' 100 0 EL E V A T I O N ( F E E T M S L ) TD=20' B-3 TD=16' B-6 (PROJECTED 84' NORTHWEST)(PROJECTED 45' SOUTHEAST) (PROJECTED 88' NORTHWEST) Qop Qop TsaTsa af/top ?? ??????????? PROPOSED BUILDING 50 B 0 100 50 100 150 200 250 300 350 400 450 EL E V A T I O N ( F E E T M S L ) HORIZONTAL DISTANCE (FEET) 0 50 B' 100 0 EL E V A T I O N ( F E E T M S L ) PROPOSED BUILDING PROPOSED COMMERCIAL BUILDING B TD=16½' B-2(PROJECTED 26' SOUTHWEST) TD=19½' B-3 (PROJECTED 54' NORTHEAST) TD=16' B-6(PROJECTED 75' SOUTHWEST)Qop Qop TsaTsa af/top ??? ?????????? PROPOSED BUILDING 0 50'100' NW E N S 4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575 944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710 NOVA CA R L S B A D V I L L A G E M I X E D - U S E 94 5 - 1 0 6 5 C A R L S B A D V I L L A G E D R I V E C A R L S B A D , C A L I F O R N I A GEOTECHNICAL MATERIALS SPECIAL INSPECTION DVBE www.usa-nova.com PROJECT NO.: DATE: DRAWN BY: REVIEWED BY: 2022210 NOV 2022 DTJ AN GEOLOGICCROSS-SECTIONS DRAWING TITLE: SCALE:1"=50' PLATE NO.2 OF 2 SBE SDVOSB SLBE KEY TO SYMBOLS af/top UNDIFFERENTIATEDFILL & TOPSOIL GEOTECHNICAL BORINGB-6 Qop OLD PARALIC DEPOSITS Tsa SANTIAGO FORMATION GEOLOGIC CONTACT,QUERIED WHERE UNCERTAIN? NOTE: ALL LOCATIONS APPROXIMATE GROUND WATER Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 APPENDIX A USE OF THE GEOTECHNICAL REPORT Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 APPENDIX B BORING LOGS SUBSURFACE EXPLORATION LEGENDNOVA GEOTECHNICAL MATERIALS SPECIAL INSPECTION SBEDVBE SDVOSB 4373 Viewridge Ave., Suite BSan Diego, CA 92123P: 858.292.7575 www.usa-nova.com 944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710 MAJOR DIVISIONS TYPICAL NAMES GRAVEL MORE THAN HALFCOARSE FRACTIONIS LARGER THANNO. 4 SIEVE GRAVEL WITH15% OR MOREFINES CLEAN GRAVELWITH LESS THAN15% FINES CLEAN SAND SAND MORE THAN HALFCOARSE FRACTIONIS FINER THAN NO.4 SIEVE SIZE SAND WITH 15%OR MORE FINES WITH LESS THAN15% FINES SILTS AND CLAYS LIQUID LIMIT 50% OR LESS SILTS AND CLAYS LIQUID LIMIT GREATER THAN 50% HIGHLY ORGANIC SOILS GW GP GM GC SW SP SM SC ML CL OL MH CH OH PT WELL-GRADED GRAVEL WITH OR WITHOUTSAND POORLY GRADED GRAVEL WITH ORWITHOUT SAND SILTY GRAVEL WITH OR WITHOUT SAND CLAYEY GRAVEL WITH OR WITHOUT SAND WELL-GRADED SAND WITH OR WITHOUTGRAVEL POORLY GRADED SAND WITH OR WITHOUTGRAVEL SILTY SAND WITH OR WITHOUT GRAVEL CLAYEY SAND WITH OR WITHOUT GRAVEL SILT WITH OR WITHOUT SAND ORGRAVEL ELASTIC SILT WITH OR WITHOUT SANDOR GRAVEL FAT CLAY WITH OR WITHOUT SAND ORGRAVEL ORGANIC SILT OR CLAY OF HIGHPLASTICITY WITH OR WITHOUT SAND ORGRAVEL PEAT AND OTHER HIGHLY ORGANIC SOILS FI N E - G R A I N E D S O I L S CO A R S E - G R A I N E D S O I L S MO R E T H A N H A L F I S F I N E R T H A N N O . 2 0 0 S I E V E M O R E T H A N H A L F I S C O A R S E R T H A N N O . 2 0 0 S I E V E RELATIVE DENSITY OFCOHESIONLESS SOILS RELATIVE DENSITY VERY LOOSE LOOSE MEDIUM DENSE DENSE VERY DENSE SPT N60BLOWS/FOOT 0 - 4 4 - 10 10 - 30 30 - 50 OVER 50 CONSISTENCY OF COHESIVE SOILS CONSISTENCY VERY SOFT SOFT MEDIUM STIFF STIFF VERY STIFF HARD 0 - 2 2 - 4 4 - 8 8 - 15 15 - 30 OVER 30 NUMBER OF BLOWS OF 140 LB HAMMER FALLING 30 INCHES TO DRIVE A 2 INCH O.D.(1-3/8 INCH I.D.) SPLIT-BARREL SAMPLER THE LAST 12 INCHES OF AN 18-INCH DRIVE(ASTM-1586 STANDARD PENETRATION TEST).IF THE SEATING INTERVAL (1st 6 INCH INTERVAL) IS NOT ACHEIVED, N IS REPORTED ASREF. 0 - 0.25 0.25 - 0.50 0.50 - 1.0 1.0 - 2.0 2.0 - 4.0 OVER 4.0 LEAN CLAY WITH OR WITHOUT SAND OR GRAVEL ORGANIC SILT OR CLAY OF LOW TOMEDIUM PLASTICITY WITH ORWITHOUT SAND OR GRAVEL SLBE SPT N60BLOWS/FOOT POCKET PENETROMETERMEASUREMENT (TSF) BULK SAMPLE SPT SAMPLE ( ASTM D1586) MOD. CAL. SAMPLE (ASTM D3550) UNRELIABLE BLOW COUNTS GEOLOGIC CONTACT SOIL TYPE CHANGE * GROUNDWATER / STABILIZED GROUNDWATER SEEPAGE CORROSIVITY DIRECT SHEAR EXPANSION INDEX MAXIMUM DENSITY ATTERBERG LIMITS CONSOLIDATIONCN CR DS EI MD LAB TEST ABBREVIATIONS AL RESISTANCE VALUERV SIEVE ANALYSISSA SAND EQUIVALENTSE DE P T H ( F T ) N60 BL O W S P E R F O O T N 5 10 15 20 25 30 0 BU L K S A M P L E SUMMARY OF SUBSURFACE CONDITIONS (USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER) LA B T E S T S CA L / S P T S A M P L E SOIL DESCRIPTION DRILLING EQUP.:ELEVATION:GROUNDWATER DEPTH: MO I S T U R E (% ) SO I L C L A S S . (U S C S ) DR Y D E N S I T Y (p c f ) DRILLING METHOD:DATE DRILLED: SAMPLE METHOD:NOTES: 4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575 944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710 NOVA GEOTECHNICAL MATERIALS SPECIAL INSPECTION www.usa-nova.com SBEDVBE SDVOSB SLBE CARLSBAD VILLAGE MIXED-USE 945-1065 CARLSBAD VILLAGE DRIVE CARLSBAD, CALIFORNIA PROJECT: 2022210BY: GN REVIEWED BY: AN LOG OF BORING B-1 OCTOBER 20, 2022 ± 68 FT HAMMER: 140 LBS., DROP: 30 IN (AUTOMATIC) 8-INCH HOLLOW STEM AUGER CME 75 NOT ENCOUNTERED ETR~73.9%, N60 ~ 73.960*N~1.23*N 6 IN OF ASPHALT CONCRETE 14 BORING TERMINATED AT 16 FT. NO GROUNDWATER ENCOUNTERED. APPENDIX: B.1 FILL (af): CLAYEY SAND; BROWN, MOIST, MEDIUM DENSE, FINE GRAINED, CONSTRUCTIONDEBRIS (METAL, WIRES)SC 17 31 38 50 40 SM OLD PARALIC DEPOSITS (Qop): SILTY SAND; DARK BROWN, MOIST, MEDIUM DENSE, FINETO MEDIUM GRAINED, MICACEOUS YELLOWISH RED, DENSE WEAKLY CEMENTED TRACE BLACK MINERAL PRECIPITATE DEPOSITS, TRACE ROOTS INCREASE IN BLACK MINERAL PRECIPITATE DEPOSITS 28 34 50/3" 62/3" POORLY GRADED SAND; PALE BROWN, MOIST, DENSE, MEDIUM TO COARSE GRAINED, WEAKLY CEMENTED SA ALEI CR SANTIAGO FORMATION (Tsa): CLAYEY SANDSTONE; PALE BROWN, MOIST, VERY DENSE, FINE GRAINED, MICACEOUS, WEAKLY CEMENTED 5.4 100.8 SP DE P T H ( F T ) N60 BL O W S P E R F O O T N 5 10 15 20 25 30 0 BU L K S A M P L E SUMMARY OF SUBSURFACE CONDITIONS (USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER) LA B T E S T S CA L / S P T S A M P L E SOIL DESCRIPTION DRILLING EQUP.:ELEVATION:GROUNDWATER DEPTH: MO I S T U R E (% ) SO I L C L A S S . (U S C S ) DR Y D E N S I T Y (p c f ) DRILLING METHOD:DATE DRILLED: SAMPLE METHOD:NOTES: 4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575 944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710 NOVA GEOTECHNICAL MATERIALS SPECIAL INSPECTION www.usa-nova.com SBEDVBE SDVOSB SLBE CARLSBAD VILLAGE MIXED-USE 945-1065 CARLSBAD VILLAGE DRIVE CARLSBAD, CALIFORNIA PROJECT: 2022210BY: GN REVIEWED BY: AN LOG OF BORING B-2 OCTOBER 20, 2022 ± 72 FT HAMMER: 140 LBS., DROP: 30 IN (AUTOMATIC) 8-INCH HOLLOW STEM AUGER CME 75 13 FT ETR~73.9%, N60 ~ 73.960*N~1.23*N 4 IN OF ASPHALT CONCRETE 10 BORING TERMINATED AT 16½ FT. GROUNDWATER ENCOUNTERED AT 13 FT. APPENDIX: B.2 FILL (af): CLAYEY SAND; BROWN, MOIST, MEDIUM DENSE, FINE TO MEDIUM GRAINEDSC 12 40 32 SM TOPSOIL: SILTY SAND; DARK BROWN, MOIST, LOOSE TO MEDIUM DENSE, FINE TO MEDIUMGRAINED 24 30 POORLY GRADED SAND; LIGHT YELLOWISH RED, MOIST, MEDIUM DENSE TO DENSE, FINE TO MEDIUM GRAINED, WEAKLY CEMENTED, FRIABLESP RV POORLY GRADED SAND; OLIVE BROWN, WET, MEDIUM DENSE, FINE TO MEDIUM GRAINED, WEAKLY CEMENTEDSP 20 25 OLD PARALIC DEPOSITS (Qop): SILTY SAND; REDDISH BROWN, MOIST,MEDIUM DENSE,FINE TO MEDIUM GRAINED, MICACEOUS, WEAKLY CEMENTED DENSE, BLACK MINERAL PRECIPITATE DEPOSITS SILTY SAND; REDDISH BROWN, MOIST, MEDIUM DENSE TO DENSE, FINE TO MEDIUM GRAINED, MICACEOUS, WEAKLY CEMENTEDSM SM 6.6 121.6 DE P T H ( F T ) N60 BL O W S P E R F O O T N 5 10 15 20 25 30 0 BU L K S A M P L E SUMMARY OF SUBSURFACE CONDITIONS (USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER) LA B T E S T S CA L / S P T S A M P L E SOIL DESCRIPTION DRILLING EQUP.:ELEVATION:GROUNDWATER DEPTH: MO I S T U R E (% ) SO I L C L A S S . (U S C S ) DR Y D E N S I T Y (p c f ) DRILLING METHOD:DATE DRILLED: SAMPLE METHOD:NOTES: 4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575 944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710 NOVA GEOTECHNICAL MATERIALS SPECIAL INSPECTION www.usa-nova.com SBEDVBE SDVOSB SLBE CARLSBAD VILLAGE MIXED-USE 945-1065 CARLSBAD VILLAGE DRIVE CARLSBAD, CALIFORNIA PROJECT: 2022210BY: GN REVIEWED BY: AN LOG OF BORING B-3 OCTOBER 20, 2022 ± 68 FT HAMMER: 140 LBS., DROP: 30 IN (AUTOMATIC) 8-INCH HOLLOW STEM AUGER CME 75 14½ FT ETR~73.9%, N60 ~ 73.960*N~1.23*N 4 IN OF ASPHALT CONCRETE OVER 3 IN OF AGGREGATE BASE APPENDIX: B.3 OLD PARALIC DEPOSITS (Qop): SILTY SAND; YELLOWISH RED, MOIST, MEDIUM DENSE,FINE TO MEDIUM GRAINED, WEAKLY CEMENTED, MICACEOUS, TRACE BLACK MINERALPRECIPITATE DEPOSITS DARK BROWN, SOME CLAY SM2423 20 25 CLAYEY SAND; DARK YELLOWISH REDDISH BROWN, MOIST, MEDIUM DENSE, FINE TO MEDIUM GRAINEDSC SANTIAGO FORMATION (Tsa): CLAYEY SANDSTONE; PALE BROWN, WET, VERY DENSE, COARSE GRAINED, WEAKLY CEMENTED FINE TO COARSE GRAINED, MINOR IRON OXIDE STAINING 50/5" 62/5" POORLY GRADED SAND; PALE BROWN, VERY MOIST, MEDIUM DENSE, MEDIUM TO COARSEGRAINED, BLACK MINERAL PRECIPITATE DEPOSITSSP 30 37 28 34 BORING TERMINATED AT 19½ FT. GROUNDWATER ENCOUNTERED AT 14½ FT. 50/5" 62/5" DENSE 2.7 114.4 DE P T H ( F T ) N60 BL O W S P E R F O O T N 5 10 15 20 25 30 0 BU L K S A M P L E SUMMARY OF SUBSURFACE CONDITIONS (USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER) LA B T E S T S CA L / S P T S A M P L E SOIL DESCRIPTION DRILLING EQUP.:ELEVATION:GROUNDWATER DEPTH: MO I S T U R E (% ) SO I L C L A S S . (U S C S ) DR Y D E N S I T Y (p c f ) DRILLING METHOD:DATE DRILLED: SAMPLE METHOD:NOTES: 4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575 944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710 NOVA GEOTECHNICAL MATERIALS SPECIAL INSPECTION www.usa-nova.com SBEDVBE SDVOSB SLBE CARLSBAD VILLAGE MIXED-USE 945-1065 CARLSBAD VILLAGE DRIVE CARLSBAD, CALIFORNIA PROJECT: 2022210BY: GN REVIEWED BY: AN LOG OF BORING B-4 OCTOBER 20, 2022 ± 72 FT HAMMER: 140 LBS., DROP: 30 IN (AUTOMATIC) 8-INCH HOLLOW STEM AUGER CME 75 15 FT ETR~73.9%, N60 ~ 73.960*N~1.23*N 4 IN OF ASPHALT CONCRETE APPENDIX: B.4 OLD PARALIC DEPOSITS (Qop): SILTY SAND; DARK REDDISH BROWN, MOIST, LOOSE, FINETO MEDIUM GRAINED, MICACEOUS REDDISH BROWN SM 25 31 BROWN, FRIABLE SANTIAGO FORMATION (Tsa): CLAYEY SANDSTONE; LIGHT BROWNISH GRAY, WET, VERY DENSE, MEDIUM GRAINED, WEAKLY CEMENTED LIGHT YELLOWISH RED STAINING 80/8" 98/8" 21 17 7 9 BORING TERMINATED AT 19½ FT. GROUNDWATER ENCOUNTERED AT 15 FT. 50/5" 62/5" CLAYEY SAND; REDDISH BROWN, MOIST, DENSE, FINE TO MEDIUM GRAINED, MICACEOUS, SOME BLACK MINERAL PRECIPITATE DEPOSITSSC 3.8 113.2 DE P T H ( F T ) N60 BL O W S P E R F O O T N 5 10 15 20 25 30 0 BU L K S A M P L E SUMMARY OF SUBSURFACE CONDITIONS (USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER) LA B T E S T S CA L / S P T S A M P L E SOIL DESCRIPTION DRILLING EQUP.:ELEVATION:GROUNDWATER DEPTH: MO I S T U R E (% ) SO I L C L A S S . (U S C S ) DR Y D E N S I T Y (p c f ) DRILLING METHOD:DATE DRILLED: SAMPLE METHOD:NOTES: 4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575 944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710 NOVA GEOTECHNICAL MATERIALS SPECIAL INSPECTION www.usa-nova.com SBEDVBE SDVOSB SLBE CARLSBAD VILLAGE MIXED-USE 945-1065 CARLSBAD VILLAGE DRIVE CARLSBAD, CALIFORNIA PROJECT: 2022210BY: GN REVIEWED BY: AN LOG OF BORING B-5 OCTOBER 20, 2022 ± 64 FT HAMMER: 140 LBS., DROP: 30 IN (AUTOMATIC) 8-INCH HOLLOW STEM AUGER CME 75 13 FT ETR~73.9%, N60 ~ 73.960*N~1.23*N 4 IN OF ASPHALT CONCRETE APPENDIX: B.5 TOPSOIL: SILTY SAND; DARK BROWN, MOIST, MEDIUM DENSE, FINE TO MEDIUM GRAINED,MICACEOUSSM 26 32 SANTIAGO FORMATION (Tsa): CLAYEY SANDSTONE; PALE BROWN, WET, VERY DENSE, FINE TO MEDIUM GRAINED50/4"62/4" 42 34 19 23 BORING TERMINATED AT 16 FT. GROUNDWATER ENCOUNTERED AT 13 FT. AUGER CHATTER, YELLOWISH BROWN, WET, FINE TO COARSE GRAINED, SOME ROUNDED GRAVEL AND COBBLE OLD PARALIC DEPOSITS (Qop): SILTY SAND; REDDISH BROWN, MOIST, MEDIUM DENSE,FINE TO MEDIUM GRAINED, SLIGHTLY MICACEOUS, MODERATELY CEMENTEDBLACK MINDERALIZATION PRECIPITATE DEPOSIT SM SA ALEI CR REDDISH YELLOWISH BROWN, DENSE8.7 123.8 DE P T H ( F T ) N60 BL O W S P E R F O O T N 5 10 15 20 25 30 0 BU L K S A M P L E SUMMARY OF SUBSURFACE CONDITIONS (USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER) LA B T E S T S CA L / S P T S A M P L E SOIL DESCRIPTION DRILLING EQUP.:ELEVATION:GROUNDWATER DEPTH: MO I S T U R E (% ) SO I L C L A S S . (U S C S ) DR Y D E N S I T Y (p c f ) DRILLING METHOD:DATE DRILLED: SAMPLE METHOD:NOTES: 4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575 944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710 NOVA GEOTECHNICAL MATERIALS SPECIAL INSPECTION www.usa-nova.com SBEDVBE SDVOSB SLBE CARLSBAD VILLAGE MIXED-USE 945-1065 CARLSBAD VILLAGE DRIVE CARLSBAD, CALIFORNIA PROJECT: 2022210BY: GN REVIEWED BY: AN LOG OF BORING B-6 OCTOBER 20, 2022 ± 69½ FT HAMMER: 140 LBS., DROP: 30 IN (AUTOMATIC) 8-INCH HOLLOW STEM AUGER CME 75 11½ FT ETR~73.9%, N60 ~ 73.960*N~1.23*N 4 IN OF ASPHALT CONCRETE APPENDIX: B.6 23 28 SANTIAGO FORMATION (Tsa): CLAYEY SANDSTONE; PALE BROWN, MOIST, VERY DENSE, FINE GRAINED, SOME BLACK MINERAL PRECIPITATE DEPOSITS50/4"62/4" 12 15 22 18 BORING TERMINATED AT 16 FT. GROUNDWATER ENCOUNTERED AT 11½ FT. CLAYEY SAND; REDDISH BROWN, MOIST, MEDIUM DENSE, FINE TO MEDIUM GRAINED, BLACK MINERAL PRECIPITATE DEPOSITS, MICACEOUS, WEAKLY CEMENTED OLD PARALIC DEPOSITS (Qop): SILTY SAND; DARK TO REDDISH BROWN, MOIST, MEDIUMDENSE, FINE TO MEDIUM GRAINED, SLIGHTLY MICACEOUS, WEAKLY CEMENTEDSM SA ALEI YELLOWISH RED SC POORLY GRADED SAND; OLIVE BROWN, WET, DENSE TO VERY DENSE, MEDIUM TO COARSEGRAINED, WEAKLY CEMENTEDSP 5.7 114.4 DE P T H ( F T ) N60 BL O W S P E R F O O T N 5 10 15 20 25 30 0 BU L K S A M P L E SUMMARY OF SUBSURFACE CONDITIONS (USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER) LA B T E S T S CA L / S P T S A M P L E SOIL DESCRIPTION DRILLING EQUP.:ELEVATION:GROUNDWATER DEPTH: MO I S T U R E (% ) SO I L C L A S S . (U S C S ) DR Y D E N S I T Y (p c f ) DRILLING METHOD:DATE DRILLED: SAMPLE METHOD:NOTES: 4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575 944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710 NOVA GEOTECHNICAL MATERIALS SPECIAL INSPECTION www.usa-nova.com SBEDVBE SDVOSB SLBE CARLSBAD VILLAGE MIXED-USE 945-1065 CARLSBAD VILLAGE DRIVE CARLSBAD, CALIFORNIA PROJECT: 2022210BY: GN REVIEWED BY: AN LOG OF PERCOLATION BORING P-1 OCTOBER 20, 2022 ± 64½ FT HAMMER: 140 LBS., DROP: 30 IN (AUTOMATIC) 8-INCH HOLLOW STEM AUGER CME 75 NOT ENCOUNTERED ETR~73.9%, N60 ~ 73.960*N~1.23*N 4 IN OF ASPHALT CONCRETE BORING TERMINATED AT 5 FT AND CONVERTED TO A BOREHOLE PERCOLATION TEST. APPENDIX: B.7 FILL (af): SILTY SAND; DARK BROWN, MOIST, MEDIUM DENSE, FINE TO MEDIUM GRAINEDSM OLD PARALIC DEPOSITS (Qop): SILTY SAND; YELLOWISH RED, MOIST, MEDIUM DENSE, FINE TO MEDIUM GRAINED, WEAKLY CEMENTED BROWN SM 35 28 SA DE P T H ( F T ) N60 BL O W S P E R F O O T N 5 10 15 20 25 30 0 BU L K S A M P L E SUMMARY OF SUBSURFACE CONDITIONS (USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER) LA B T E S T S CA L / S P T S A M P L E SOIL DESCRIPTION DRILLING EQUP.:ELEVATION:GROUNDWATER DEPTH: MO I S T U R E (% ) SO I L C L A S S . (U S C S ) DR Y D E N S I T Y (p c f ) DRILLING METHOD:DATE DRILLED: SAMPLE METHOD:NOTES: 4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575 944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710 NOVA GEOTECHNICAL MATERIALS SPECIAL INSPECTION www.usa-nova.com SBEDVBE SDVOSB SLBE CARLSBAD VILLAGE MIXED-USE 945-1065 CARLSBAD VILLAGE DRIVE CARLSBAD, CALIFORNIA PROJECT: 2022210BY: GN REVIEWED BY: AN LOG OF PERCOLATION BORING P-2 OCTOBER 20, 2022 ± 64 FT HAMMER: 140 LBS., DROP: 30 IN (AUTOMATIC) 8-INCH HOLLOW STEM AUGER CME 75 NOT ENCOUNTERED ETR~73.9%, N60 ~ 73.960*N~1.23*N 4 IN OF ASPHALT CONCRETE OF 12 IN OF AGGREGATE BASE BORING TERMINATED AT 5 FT AND CONVERTED TO A BOREHOLE PERCOLATION TEST. APPENDIX: B.8 FILL (af): SILTY SAND; DARK BROWN, MOIST, MEDIUM DENSE, FINE TO MEDIUM GRAINEDSM OLD PARALIC DEPOSITS (Qop): SILTY SAND; YELLOWISH RED BROWN, MOIST, MEDIUMDENSE, FINE TO MEDIUM GRAINED, WEAKLY CEMENTEDSM Geotechnical Investigation Carlsbad Village Mixed-Use, Carlsbad, California NOVA Project No. 2022210 November 21, 2022 APPENDIX C LABORATORY TESTING Laboratory tests were performed in accordance with the generally accepted American Society for Testing and Materials (ASTM) test methods or suggested procedures. Brief descriptions of the tests performed are presented below: LAB TEST SUMMARY ·CLASSIFICATION: Field classifications were verified in the laboratory by visual examination. The final soil classifications are in accordance with the Unified Soils Classification System and are presented on the exploration logs in Appendix B. ·IN-PLACE MOISTURE AND DENSITY OF SOIL (ASTM D3550, D2216): In-place moisture contents and dry densities were determined for representative soil samples. This information was an aid to classification and permitted recognition of variations in material consistency with depth. The dry unit weight is determined in pounds per cubic foot, and the in-place moisture content is determined as a percentage of the soil's dry weight. The results are summarized in the exploration logs presented in Appendix B. ·GRADATION ANALYSIS (ASTM D6913): Gradation analyses were performed on representative soil samples in general accordance with ASTM D422. The grain size distributions of the samples were determined in accordance with ASTM D6913. ·ATTERBERG LIMITS (ASTM D4318): Tests were performed on selected representative fine-grained soil samples to evaluate the liquid limit, plastic limit, and plasticity index in general accordance with ASTM D4318. These test results were utilized to evaluate the soil classification in accordance with the Unified Soil Classification System. ·EXPANSION INDEX (ASTM D4829): The expansion indexes of selected materials was evaluated in general accordance with ASTM D4829. Specimens were molded under a specified compactive energy at approximately 50 percent saturation (plus or minus 1 percent). The prepared 1-inch thick by 4-inch diameter specimens were loaded with a surcharge of 144 pounds per square foot and were inundated with tap water. Readings of volumetric swell were made for a period of 24 hours. ·R-VALUE (CT 301 and ASTM D 2844): The resistance value, or R-Value, for near-surface site soils was evaluated in general accordance with California Test (CT) 301 and ASTM D2844. The sample was prepared and evaluated for exudation pressure and expansion pressure. The equilibrium R-Value is reported as the lesser or more conservative of the two calculated results. ·CORROSIVITY TEST (CAL. TEST METHOD 417, 422, 643): Soil pH and minimum resistivity tests were performed on representative soil sampleS in general accordance with test method CT 643. The sulfate and chloride contents of the selected samples were evaluated in general accordance with CT 417 and CT 422, respectively. Soil samples not tested are now stored in our laboratory for future reference and evaluation, if needed. Unless notified to the contrary, samples will be disposed of 90 days from the date of this report. 4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575 944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710 NOVA GEOTECHNICAL MATERIALS SPECIAL INSPECTION www.usa-nova.com SBEDVBE SDVOSB SLBE FIGURE: C.1PROJECT: 2022210BY: GN REVIEWED BY: AN CARLSBAD VILLAGE MIXED-USE 945-1065 CARLSBAD VILLAGE DRIVE CARLSBAD, CALIFORNIA CLASSIFICATION TEST RESULTS Gravel Sand Coarse FineMediumCoarseFine Silt or Clay NOVA GEOTECHNICAL MATERIALS SPECIAL INSPECTION 4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575 www.usa-nova.com 944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710 SBEDVBE SDVOSB SLBE Sample Location: Depth (ft): USCS Soil Type: Passing No. 200 (%): B-1 ½ - 2 SC 22 24 15 9 Atterberg Limits (ASTM D4318): Liquid Limit, LL: Plastic Limit, PL: Plasticity Index, PI: FIGURE: C.2PROJECT: 2022210BY: GN REVIEWED BY: AN CARLSBAD VILLAGE MIXED-USE 945-1065 CARLSBAD VILLAGE DRIVE CARLSBAD, CALIFORNIA CLASSIFICATION TEST RESULTS Gravel Sand Coarse FineMediumCoarseFine Silt or Clay NOVA GEOTECHNICAL MATERIALS SPECIAL INSPECTION 4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575 www.usa-nova.com 944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710 SBEDVBE SDVOSB SLBE Sample Location: Depth (ft): USCS Soil Type: Passing No. 200 (%): FIGURE: C.3PROJECT: 2022210BY: GN REVIEWED BY: AN CARLSBAD VILLAGE MIXED-USE 945-1065 CARLSBAD VILLAGE DRIVE CARLSBAD, CALIFORNIA B-5 2 - 5 SM 24 NP NP NP Atterberg Limits (ASTM D4318): Liquid Limit, LL: Plastic Limit, PL: Plasticity Index, PI: CLASSIFICATION TEST RESULTS Gravel Sand Coarse FineMediumCoarseFine Silt or Clay NOVA GEOTECHNICAL MATERIALS SPECIAL INSPECTION 4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575 www.usa-nova.com 944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710 SBEDVBE SDVOSB SLBE Sample Location: Depth (ft): USCS Soil Type: Passing No. 200 (%): FIGURE: C.4 B-6 ½ - 4 SM 22 Atterberg Limits (ASTM D4318): Liquid Limit, LL: Plastic Limit, PL: Plasticity Index, PI: PROJECT: 2022210BY: GN REVIEWED BY: AN CARLSBAD VILLAGE MIXED-USE 945-1065 CARLSBAD VILLAGE DRIVE CARLSBAD, CALIFORNIA NP NP NP CLASSIFICATION TEST RESULTS Gravel Sand Coarse FineMediumCoarseFine Silt or Clay NOVA GEOTECHNICAL MATERIALS SPECIAL INSPECTION 4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575 www.usa-nova.com 944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710 SBEDVBE SDVOSB SLBE Sample Location: Depth (ft): USCS Soil Type: Passing No. 200 (%): FIGURE: C.5 P-1 3½ - 5 SM 23 PROJECT: 2022210BY: GN REVIEWED BY: AN CARLSBAD VILLAGE MIXED-USE 945-1065 CARLSBAD VILLAGE DRIVE CARLSBAD, CALIFORNIA LAB TEST RESULTS NOVA GEOTECHNICAL MATERIALS SPECIAL INSPECTION 4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575 www.usa-nova.com 944 Calle Amanecer, Suite FSan Clemente, CA 92673 P: 949.388.7710 SBEDVBE SDVOSB SampleLocation Expansion Index Expansion Index (ASTM D4829) Sample Depth(ft.)ExpansionPotential SLBE ExpansionPotential Classification of Expansive Soil (ASTM D4829) Expansion Index 0-20 21-50 51-90 91-130 >130 Very Low Low Medium High Very High B-1 0½ - 2 Very Low Sample Location R-Value SampleDepth(ft.) R-Value (Cal. Test Method 301 & ASTM D2844) B-5 2 - 5 B-4 15 FIGURE: C.6 ½ - 2 B-6 ½ - 4 PROJECT: 2022210BY: GN REVIEWED BY: AN CARLSBAD VILLAGE MIXED-USE 945-1065 CARLSBAD VILLAGE DRIVE CARLSBAD, CALIFORNIA 0 Very Low 0 Very Low LAB TEST RESULTS Corrosivity (Cal. Test Method 417,422,643) SampleLocation Sample Depth pH Resistivity Sulfate Content Chloride Content (ppm)(%)(Ohm-cm)(ft.)(ppm)(%) Water-Soluble Sulfate Exposure (ACI 318 Table 19.3.1.1 and Table 19.3.2.1) Water-Soluble Sulfate (SO4)in Soil (% by Weight)Exposure Class Cement Type(ASTM C150)ExposureSeverity Max. W/C Min. fc'(psi) SO4 < 0.10 0.10 ≤ SO4 < 0.20 0.20 ≤ SO4 ≤ 0.20 SO4 > 2.00 N/A Moderate Severe Very Severe S0 S1 S2 S3 No type restriction II V V plus pozzolan or slag cement N/A 0.50 0.45 0.45 2,500 4,000 4,500 4,500 NOVA GEOTECHNICAL MATERIALS SPECIAL INSPECTION 4373 Viewridge Avenue, Suite BSan Diego, CA 92123P: 858.292.7575 www.usa-nova.com 944 Calle Amanecer, Suite FSan Clemente, CA 92673P: 949.388.7710 SBEDVBE SDVOSB SLBE ½ - 2 7.5 2400 39 53 0.0050.004B-1 FIGURE: C.7 2 - 5 7.7 4500 54 11 0.0010.005B-5 PROJECT: 2022210BY: GN REVIEWED BY: AN CARLSBAD VILLAGE MIXED-USE 945-1065 CARLSBAD VILLAGE DRIVE CARLSBAD, CALIFORNIA