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SDP 2022-0005; 2676 STATE STREET; PRELIMINARY GEOTECHNICAL INVESITGATION AND RECOMMENDATIONS; 2022-05-20
PRELIMINARY GEOTECHNICAL INVESTIGATION AND RECOMMENDATIONS PROPOSED NEW COMMERCIAL STRUCTURE AND REMODEL TO AN EXISTING STRUCTURE LOCATED AT 2676 STATE STREET, CALIFORNIA EDG Project No. 226762-1 May 20th, 2022 PREPARED FOR: Fabric Investments Attn: Scott Heath 2659 State Street #100 Carlsbad, California ENGINEERING DESIGN GROUP www.designgroupca.com 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 Date: May 20th, 2022 To: Fabric Investments Attn: Scott Heath 2659 State Street #100 Carlsbad, California 92008 Re: Proposed, new commercial structure and remodel to an existing structure located at 2676 State Street, Carlsbad, California. Subject: Geotechnical Investigation and Recommendations Report In accordance with your request and our signed proposal we have provided this preliminary geotechnical investigation and recommendations report of the subject site for the proposed commercial structure and the remodel of the existing commercial structure, with associated hardscape & landscape improvements. The findings of the investigation, earthwork recommendations and foundation design parameters are presented in this report. In general, it is our opinion that the proposed construction, as described herein, is feasible from a geotechnical standpoint, provided the recommendations of this report and generally accepted construction practices are followed. If you have any questions regarding the following report, please do not hesitate to contact our office. Sincerely, ENGINEERING DESIGN GROUP Steven Norris Erin E. Rist California GE#2590 California RCE #65122 ENGINEERING DESIGN GROUP www.designgroupca.com 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 Table of Contents 1.0 SCOPE ................................................................................................................................................ 2 2.0 SITE AND PROJECT DESCRIPTION ...................................................................................................... 2 3.0 FIELD INVESTIGATION ....................................................................................................................... 2 4.0 SUBSURFACE CONDITIONS ............................................................................................................... 2 5.0 GEOLOGY ........................................................................................................................................... 3 6.0 GEOLOGIC HAZARDS ......................................................................................................................... 3 7.0 GROUND WATER ............................................................................................................................... 4 8.0 PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS ................................................................ 4 9.0 GRADING AND EARTHWORK............................................................................................................. 5 10.0 SEISMIC DESIGN PARAMETERS ......................................................................................................... 8 11.0 SHALLOW FOUNDATIONS ................................................................................................................. 8 12.0 CORROSION AND VAPOR EMISSION ............................................................................................... 10 13.0 CONCRETE SLAB-ON-GRADE ........................................................................................................... 11 14.0 RETAINING WALLS........................................................................................................................... 13 15.0 FLEXIBLE PAVEMENT DESIGN .......................................................................................................... 13 16.0 INFILTRATION .................................................................................................................................. 14 17.0 SURFACE DRAINAGE ........................................................................................................................ 14 18.0 LABORATORY TESTING .................................................................................................................... 15 19.0 CONSTRUCTION OBSERVATION AND TESTING ............................................................................... 15 20.0 MISCELLANEOUS ............................................................................................................................. 16 FIGURES Site Vicinity Map .......................................................................................................................... Figure No. 1 Site Location Map ........................................................................................................................ Figure No. 2 Site Plan ....................................................................................................................................... Figure No. 3 Geotechnical Map & Cross-Section ............................................................................................. Figure No. 4 Test Pit Logs ....................................................................................................................... Test Pit Logs 1 – 2 APPENDICES References .................................................................................................................................... Appendix A General Earthwork and Grading Specifications ............................................................................ Appendix B Laboratory Results ........................................................................................................................ Appendix C Retaining Wall Drainage................................................................................................................Appendix D Fabric Investments Page No. 2 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 1.0 SCOPE This report gives our geotechnical recommendations for the proposed new commercial development to be located at 2676 State Street, Carlsbad, California. (See Figure No. 1, "Site Vicinity Map", and Figure No. 2, "Site Location Map") We understand the scope of work includes a new commercial structure and the remodel of an existing commercial structure, with associated hardscape & landscape improvements. The scope of our work conducted onsite to date has included a visual reconnaissance of the property and surrounding areas, review of geologic maps, a limited subsurface investigation of the subject property, review of preliminary architectural plans, laboratory tests and preparation of this report presenting our findings, conclusions, and recommendations. 2.0 SITE AND PROJECT DESCRIPTION The subject property is located at 2676 State Street, in City of Carlsbad, California. For the purposes of this report the lot is assumed to face west. The property is bordered to the east by a residential development, to the north and south by commercial properties, and to the west by State Street. The site area topography generally consists of coastal foothill terrain. At the time of this report the lot is developed with a one-story, commercial structure, carport structure, parking areas and associated hardscape improvements. Based upon our review of site topography, the lot consists of a generally flat area, with an overall elevation differential of approximately one foot across the lot. Based upon our review of the preliminary project plans, we understand the proposed development will consist of the construction of a new, two-story, commercial structure to be located at the rear (east) portion of the lot, the remodel of the existing commercial structure, and associated hardscape/landscape improvements. 3.0 FIELD INVESTIGATION Our field investigation of the property consisted of a site reconnaissance, site field measurements, observation of existing conditions on-site and on adjacent sites and a limited subsurface investigation of soil conditions. Our subsurface investigation consisted of the visual observation of two exploratory test pits in the general areas of proposed construction, soil measurements with pocket penetrometers, logging of soil types encountered, and sampling of soils for laboratory testing. The approximate location of the test pits is given in Figure No. 3, "Site and Approximate Location of Test Pits". Fabric Investments Page No. 2 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 4.0 SUBSURFACE CONDITIONS Our subsurface investigation consisted of the excavation of two exploratory test pits / hand auger borings, the visual observation and logging of soil types encountered, penetrometer measurements, and the sampling of soil profiles for laboratory testing. Laboratory testing included expansion potential, R-value and testing for sulfate content/corrosivity. Fill, and weathered profiles were encountered to approximate depths of between 4.5 and 6.5 feet below adjacent grade in our exploratory test pits. Soil types encountered within our exploratory test pits are described as follows: 4.1 Fill / Weathered Fill and weathered unsuitable materials were encountered to depths of up to 4.5 to 6.5 feet below adjacent grade in our exploratory test pits. These materials consist of reddish brown to dark brownish gray to dark brown, moist, medium dense, silty sands, and sandy silts. Construction debris was encountered within our test pits in the upper 24 inches and black odorous material in the 2.5 - 6 feet zone. In general, these materials are not considered suitable for the support of structures and structural improvements in their present state but may be utilized as re-compacted fill, if necessary, provided the recommendations of this report are followed. Unsuitable soil materials classify as SW – SC per the Unified Soil Classification System, and based on laboratory results, are considered to possess high potential for expansion. 4.2 Qop6-7 – Old Paralic Deposits – Pleistocene (as mapped per Kennedy, M.P., et.al., 2007) Paralic material was found to underlie the fill/weathered profiles material within the exploratory test pits. The encountered material consists of brown to light brown, moist, dense, silty coarse sands. These materials are considered suitable for the support of structures and structural improvements, provided the recommendations of this report are followed. These materials classify as SW - SM per the Unified Soil Classification System, and based on visual observation and our experience, are considered to possess a low potential for expansion. Detailed logs of our exploratory test pits, as well as a depiction of their locations, please see the Figures section attached herein. Fabric Investments Page No. 3 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 5.0 GEOLOGY The project site is located within the Peninsular Ranges Geomorphic Province of California. The Peninsular Ranges extend 125 miles from the Transverse Ranges and the Los Angeles Basin south to the Mexican Border and beyond. This Geomorphic province is bounded on the east by the Colorado Desert and the Gulf of California. The topography of the area in and around the subject site consists of coastal foothill terrain and relatively shallow drainages. The project site is underlain by topsoil/fill/weathered profiles and Pleistocene-age, old paralic deposits. 6.0 GEOLOGIC HAZARDS 6.1 FAULTS The nearest mapped active fault (Holocene) is the Rose Canyon Fault (Newport-Inglewood Fault zone) in the Offshore Zone of Deformation, located approximately 2 miles west of the subject site. Other major mapped faults in the region are the San Jacinto Fault and related branches within the San Jacinto zone and the Elsinore Fault and associated faults within the Elsinore zone. The subject site is approximately 45 miles west from the San Jacinto Fault zone and approximately 30 miles southwest to the Elsinore Fault zone Our review of geologic literature pertaining to the general site area indicates the subject site is not within a mapped Alquist-Priolo fault zone. It is our opinion that the site could be subjected to moderate to severe ground shaking in the event of a major earthquake along any of the faults in the Southern California region. The seismic risk at this site is similar to that of the surrounding developed area. 6.2 LIQUEFACTION, LATERAL SETTLEMENT, SUBSIDENCE Liquefaction of cohesionless soils can be caused by strong vibratory motion due to earthquakes. Research and historical data indicate that loose, granular soils underlain by a near-surface ground water table are most susceptible to liquefaction, while the stability of most silty sands and clays is not adversely affected by vibratory motion. Because of the dense nature of the soil materials underlying the site and the lack of near surface water, the potential for lateral spreading, liquefaction, subsidence or seismically induced dynamic settlement at the site is considered low. The effects of seismic shaking can be reduced by adhering to the most recent edition of the California Building Code and current design parameters of the Structural Engineers Association of California. Fabric Investments Page No. 4 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 6.3 TSUNAMI Tsunami are sea waves generated by submarine earthquakes, landslides, or volcanic activity. Submarine earthquakes are common along the edge of the Pacific Ocean and coastal areas are subject to potential inundation by tsunami. Most of the tsunamis recorded on the San Diego Bay tidal gauge have only been a few tenths of a meter in height. The possibility of a destructive tsunami along the San Diego coastline is considered low. Tsunami or storm waves (associated with winter storms), even in conjunction with high tides, do not have the potential for inundations of the site. 6.4 SLOPE STABILITY As part of the preparation of this report we have reviewed geologic maps of the subject area. Our review of geologic maps does not indicate landslide deposits at the area in and around the subject site. In consideration of the relative flat nature of the subject lot, we do not anticipate slope instability. 7.0 GROUND WATER Static ground water was not encountered during our limited subsurface investigation. However, perched groundwater conditions can develop, should be anticipated, and change over time, where no such condition previously existed and can have a significant impact. Waterproofing membrane shall be specifically detailed by waterproofing consultant. If groundwater conditions are encountered during site excavations, a slab underdrain system may be required. Trenches below slab should be detailed with perimeter and trench cut-off walls keyed into competent material. Please see our INFILTRATION and DRAINAGE sections for additional recommendations. 8.0 PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS Based upon our review of preliminary project plans, we understand the proposed improvements will include a new, two-story, commercial structure, the remodel of an existing commercial structure, and the construction of associated hardscape & landscape improvements. In general, it is our opinion that the proposed new structures and improvements, as discussed and described herein, are feasible from a geotechnical standpoint, provided the recommendations of this report and all applicable codes are followed. • Based upon our subsurface investigation, competent material is anticipated at approximate depths of 4.5 to 6.5 feet below existing grades. At area of proposed commercial structure, at rear (east) of lot, competent material was encountered at depths of 4.5 feet below existing grades. Fabric Investments Page No. 5 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS • In area of the new commercial structure, we anticipate the removal and re-compaction of the upper approximately 5 feet of material. In consideration of the expansion potential of underlaying materials, an 18-inch import cap is recommended. Where removal and re-compaction is conducted, we recommend new shallow foundations and slab-on-grade floors for the proposed new commercial structure. • New foundations shall extend 24 inches, founded in competent re-compacted material. New slab- on-grade shall be founded in competent re-compacted, import cap material. Foundations shall be founded in re-compacted, non-import cap material, to create potential groundwater cut-off walls. • We understand no additions to the existing commercial structure are proposed. At a minimum, where new loads are added to existing footings, footings should be adequately sized and detailed for new loads. Project structural engineer to confirm existing foundations are sufficiently sized and reinforced for loads. Additionally, any retrofit of current foundation system shall be coordinated with project structural engineer. • Based upon our review of the preliminary grading plans, existing asphalt, with the exception of the ADA areas, is anticipated to remain. It appears new asphaltic concrete (AC) pavement is anticipated at new ADA parking areas. • New driveway / parking area subgrade is anticipated to be removed and re-compacted in the upper 12 inches. Proposed driveway and parking areas are anticipated to be founded in competent re-compacted material. • Based upon our review of the preliminary grading plans, we anticipate adjacent property and improvements will not be negatively impacted from a geotechnical standpoint, provided the recommendations of this report, generally accepted construction practices, applicable codes, OSHA requirements, civil design elements are implemented and applicable city and/or county standards are followed. • Any changes in the proposed design should be reviewed by this office for any revisions to the recommendations herein. 9.0 GRADING AND EARTHWORK Based upon our review of the preliminary plans, we anticipate earthwork operations will include the Fabric Investments Page No. 6 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS removal and re-compaction of material in the upper approximately 5 feet with an 18-inch import cap in area of new commercial structure, the preparation of parking/driveway subgrade in areas of new pavement, and localized fine grading for drainage purposes. All grading shall be done in accordance with the recommendations below as well as Appendix B of this report and the standards of county and state agencies, as applicable. 9.1 Site Preparation Prior to any grading, the areas of proposed improvements should be cleared of surface and subsurface debris (including organic topsoil, vegetative and construction debris). Removed debris should be properly disposed of off-site prior to the commencement of any fill operations. Construction debris should not generally be mixed with fill soils. Holes resulting from the removal of debris, existing structures, or other improvements, should be filled, and compacted. 9.2 Removals In areas of new proposed additions, fill/weathered profiles found to mantle the site, are not suitable for the structural support of buildings or structural improvements in their present state. We anticipate the removal and re-compaction of unsuitable profiles in area of new commercial structure, in the upper approximately 5 feet. 9.3 Transitions All settlement sensitive improvements (including but not limited to new structure, etc.), should be constructed on a uniform building pad. We anticipate new footings to be founded in competent re- compacted material. Preliminary grading plans indicate no cut-fill transitions and based upon our subsurface investigation no undercutting is anticipated. If undercuts are necessary, undercuts should extend a minimum of 5 feet horizontally (or to a distance at least equal to depth of fill) beyond the footprint of the proposed structures (including exterior columns) and settlement sensitive improvements. Undercuts shall be made a minimum of 3 feet deep, or to a minimum depth of half the depth of deepest fill. Undercut bottoms may require sloping at a minimum 1% to daylight and may require the construction of a subdrain (reference Appendix B), to be determined in the field during construction as appliable. We anticipate building foundations will be founded on competent re-compacted material. This condition needs to be verified in the field by a representative of Fabric Investments Page No. 7 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS our firm prior to placement of steel or improvements during site grading operations. 9.4 Fills/Backfill All fill/backfill material should be cleaned of loose debris and oversize material (material more than 6 inches in diameter), be brought to approximately +2% of optimum moisture content, and re-compacted to at least 90 percent relative compaction (based on ASTM D1557 – latest edition). Fills should generally be placed in lifts not exceeding 6 - 8 inches in thickness. All fill/backfill requires testing for relative density every 2 vertical feet at a minimum. In consideration of the expansion potential of onsite soils, we recommend an import cap in the upper 18 inches of finish pad subgrade. Imported soils should have a very low potential for expansion (E.I. < 20), free of debris and organic matter. Prior to importing soils, they should be visually observed, sampled, and tested at the borrow pit area to evaluate soil suitability as fill. Onsite materials are suitable for re-use as fill material during grading operations provided, they are less than 18 inches below finish pad, free of contamination (construction debris and organics) and oversize material in excess of 6 inches in diameter. Utility trenches should be properly backfilled in accordance with the latest edition of Green Book standards. 9.5 Slopes In consideration of the generally flat nature of the lot, no slopes are anticipated. Where new slopes are constructed, permanent slopes may be cut to a face ratio of 2:1 (horizontal to vertical). Permanent fill slopes shall be placed at a maximum 2:1 slope face ratio. All temporary cut slopes shall be excavated in accordance with OSHA requirements and OSHA Alternative Sloping Plans and shall not undermine adjacent properties, public improvements, or any structures without proper shoring of excavation and/or structures. Subsequent to grading, planting or other acceptable cover should be provided to increase the stability of slopes, especially during the rainy season (October thru April). 9.6 Driveways and Flatwork In the areas of proposed driveways and exterior flatwork we recommend, the upper 12 inches of subgrade or finish grade shall be ripped a minimum of 12 inches, moisture conditioned to near optimum moisture content and compacted to 90% minimum relative compaction (ASTM D1557 – latest edition). (Please see our CONCRETE SLAB-ON-GRADE section for additional flatwork recommendations, and our Fabric Investments Page No. 8 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS INFILTRATION section for additional paver recommendations). 10.0 SEISMIC DESIGN PARAMETERS 10.1 Seismic Design Parameters, as outlined in the table below. Site Class D Seismic Design Category D ASCE 7-16 Seismic Design Parameters SS (g) 1.081 S1 (g) 0.391 SMS (g) 1.297 SDS (g) 0.865 ASCE 7-16 Acceleration Parameters PGA = MCEG peak ground acceleration 0.477 PGAM = Site modified peak ground acceleration 0.572 11.0 SHALLOW FOUNDATIONS The following design parameters may be utilized for new foundations founded on competent re- compacted material. 11.1 Footings bearing uniformly in competent material may be designed utilizing maximum allowable soils pressure of 2,000 psf. 11.2 Bearing values may be increased by 33% when considering wind, seismic, or other short duration loadings. 11.3 The parameters in the table below should be used as a minimum for designing new footing width and depth below lowest adjacent grade into competent material. Footing depths are to be confirmed in the field by a representative of Engineering Design Group prior to the placement of form boards, steel, and removal of excavation equipment. Fabric Investments Page No. 9 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS No. of Floors Supported Minimum Footing Width *Minimum Footing Depth Below Lowest Adjacent Grade 1 15 inches 24 inches 2 15 inches 24 inches 3 18 inches 24 inches *Footings are anticipated to be founded in competent material. 11.4 All footings founded into competent material should be reinforced with a minimum of two #4 bars at the top and two #4 bars at the bottom (3 inches above the ground). For footings over 30 inches in depth, additional reinforcement, and possibly a stemwall system will be necessary, and should be reviewed by project structural engineer prior to construction. 11.5 All isolated spread footings should be designed utilizing the above given bearing values and footing depths and be reinforced with a minimum of #4 bars at 12 inches o.c. in each direction (3 inches above the ground). Isolated spread footings should have a minimum width and depth of 24 inches. 11.6 The maximum expected total static settlement for the proposed structure supported on a conventional foundation system utilizing a maximum allowable soil bearing pressure of 2,000 psf (deriving support in competent re-compacted fill material), is estimated to be on the order of ½ to 1 inch. Differential settlement is not expected to exceed ½ inch over a distance of twenty (20) feet. 11.7 For footings adjacent to slopes a minimum of 10 feet horizontal setback in competent material or properly compacted fill should be maintained. A setback measurement should be taken at the horizontal distance from the bottom of the footing to slope daylight. Where this condition cannot be met, it should be brought to the attention of the Engineering Design Group for review. 11.8 All excavations should be performed in general accordance with the contents of this report, applicable codes, OSHA requirements and applicable city and/or county standards. 11.9 All foundation subgrade soils and footings shall be pre-moistened to 2% over optimum to a minimum of 18 inches in depth prior to the pouring of concrete. Fabric Investments Page No. 10 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 12.0 CORROSION AND VAPOR EMISSION 12.1 Resistivity and chloride testing of onsite samples from our subsurface investigation was conducted to evaluate corrosion potential to proposed improvements. Tests performed indicate that soils classify, according to ACI 318 standard, as category C1, and based upon laboratory results are considered mild to moderately corrosive to buried metals. Test results are included in Appendix C of this report. The project structural engineer to note increased concrete protection requirements for corrosive environments, as applicable. 12.2 Laboratory testing of onsite samples for water soluble sulfates, indicate soils classify, according to ACI 318 standard, as category S0, mildly to moderately corrosive due to sulfate attack to concrete structures. 12.3 In consideration of laboratory results and ACI standards, we recommend for moisture sensitive slabs, retaining walls and foundations (i.e., below grade walls/spaces, built interior environments, floor finishes) concrete with a maximum water to cement ratio of 0.45 resulting in a compressive strength of 4,500 psi minimum (no special inspection required for water to cement ratio purposes, unless otherwise specified by structural engineer). 12.4 For non-moisture sensitive areas, we recommend concrete with a minimum compressive strength of 2,500 psi. 12.5 Buried metals shall be protected, and a corrosion engineer should be consulted for appropriate mitigation recommendations. EDG is not an expert in corrosion protection. Design recommendations for the protection of improvements from corrosive environment shall be provided by the corrosion consultant. 12.6 Where onsite improvements propose the use of reclaimed water, onsite soils are to be considered highly corrosive to buried metals. Precautions should be taken to protect all buried metals. 12.7 Slab Underlayment: We recommend the following beneath proposed slab-on-grade floors. 12.7.a. For moisture-sensitive areas, we recommend a vapor barrier. 12.7.b. The slab underlayment for moisture-sensitive areas consists of a vapor barrier layer (15 mil) placed below the upper one-inch of sand. The vapor barrier shall meet the following minimum requirements: Permeance of less than 0.01 perm [grains/(ft²hr in/Hg)] as tested Fabric Investments Page No. 11 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS in accordance with ASTM E 1745 Section 7.1 and strength per ASTM 1745 Class A. 12.7.c. In areas of level slab on grade floors, we recommend a one-inch layer of coarse sand material, Sand Equivalent (S.E.) greater than 50 and washed clean of fine materials, should be placed beneath the slab in moisture-sensitive areas, above the vapor barrier. There shall be not greater than a 2-inch difference across the sand layer. 12.7.d. The vapor barrier should extend down the interior edge of the footing excavations a minimum of 6 inches. The vapor barrier should lap a minimum of 8 inches, sealed along all laps with the manufacturer’s recommended adhesive. Beneath the vapor barrier a uniform layer of 3 inches of pea gravel is recommended under the slab in order to more uniformly support the slab, help distribute loads to the soils beneath the slab, and act as a capillary break. 12.8 The project waterproofing consultant should provide all slab underdrain, slab sealers and various other details, specifications, and recommendations (i.e., Moiststop and Linkseal) at areas of potential moisture intrusion. Engineering Design Group accepts no responsibility for design or quality control of waterproofing elements of the building. 13.0 CONCRETE SLAB-ON-GRADE We anticipate new, concrete slab-on-grade floors will be placed on competent re-compacted, import material. Where new, concrete slab-on-grade floors and exterior improvements are proposed, we recommend the following as the minimum design parameters. 13.1 Interior concrete slab-on-grade: Minimum thickness of 5 inches and reinforced with #4 bars at 18 inches o.c. placed at the midpoint of the slab. Concrete driveways: Minimum thickness of 5 inches and reinforced with #4 bars at 18 inches o.c. placed at the midpoint of the slab, placed on 4 inches of Class II Base. Exterior flatwork / Parking areas: Minimum thickness of 4 inches and reinforced with #3 bars at 16 inches o.c. at the midpoint of the slab. 4 inches of Class II Base 13.1.a. Slump: Between 3 and 4 inches maximum. 13.1.b. Aggregate Size: ¾ - 1 inch. Fabric Investments Page No. 12 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 13.2 Adequate control joints should be installed to control the unavoidable cracking of concrete that takes place when undergoing its natural shrinkage during curing. The control joints should be well located to direct unavoidable slab cracking to areas that are desirable by the designer. 13.3 All required fills used to support slabs, should be placed in accordance with the GRADING AND EARTHWORK section of this report and the attached Appendix B, and compacted to 90 percent relative compaction (Modified Proctor Density, ASTM D-1557 – Latest Edition). 13.4 Concrete should be poured during cool (40 – 65 degrees) weather if possible. If concrete is poured in hotter weather, a set retarding additive should be included in the mix, and the slump kept to a minimum. 13.5 All subgrade soils to receive concrete slabs and flatwork are to be pre-soaked to 2 percent over optimum moisture content, to a minimum depth of 18 inches. 13.6 Exterior concrete flatwork, due to the nature of concrete hydration and minor subgrade soil movement, are subject to normal minor concrete cracking. To minimize expected concrete cracking, the following additional recommendations should be implemented: 13.6.a. Exterior concrete flatwork should be poured with a 10-inch-deep thickened edge. Flatwork adjacent to top of a slope should be constructed with an outside footing to attain a minimum of 7 feet distance to daylight. 13.6.b. Exterior concrete flatwork should be constructed with tooled joints creating concrete sections no larger than 225 square feet. For sidewalks, the maximum run between joints should not exceed 5 feet. For rectangular shapes of concrete, the ratio of length to width should generally not exceed 0.6 (i.e., 5 ft. long by 3 ft. wide). Joints should be cut at expected points of concrete shrinkage (such as male corners), with diagonal reinforcement placed in accordance with industry standards. 13.6.c. Isolation joints should be installed at exterior concrete where exterior concrete is poured adjacent to existing foundations. 13.6.d. Drainage adjacent to exterior concrete flatwork should direct water away from the improvements. Concrete subgrade should be sloped and directed to the collective subdrain system, such that water is not trapped below the flatwork. Fabric Investments Page No. 13 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 13.7 The recommendations set forth herein are intended to reduce cosmetic nuisance cracking. The project concrete contractor is ultimately responsible for concrete quality and performance and should pursue a cost-benefit analysis of these recommendations, and other options available in the industry, prior to the pouring of concrete. 14.0 RETAINING WALLS No retaining walls are anticipated as part of the proposed development. Where plans change and retaining walls are required, specific retaining wall details shall be brought to the attention of Engineering Design Group for specific recommendations and minimum design parameters. 15.0 FLEXIBLE PAVEMENT DESIGN We understand new flexible pavement parking areas are proposed in limited areas of proposed new ADA parking as part of the anticipated development. We have provided a flexible pavement section for the proposed areas to include new asphaltic concrete (AC) pavement. The proposed new driveway section was designed utilizing the Caltrans Method and a Traffic Index of 4 for parking areas & 5 for drive aisles, to reflect parking areas and commercial driveway. Based upon laboratory results, an R-Value of 15 was utilized for our calculations. Below we have provided options for pavement sections. Pavement Section - R-value = 27 Assumed TI 4 5 Traffic Type Parking Spots Drive Aisles Option 1 - (6" AC) Asphalt 6 6 Class II Base 3 5 Option 2 - (4" AC) Asphalt 4 4 Class II Base 5 9 Prior to the placement of base material, subgrade shall be scarified to a depth of 12 inches, moisture conditioned and compacted to 90 percent minimum relative compaction, as determined in accordance with ASTM D1557 – latest edition. Driveway subgrade shall be inspected by a representative of Engineering Design Group prior to the placement of base. Base material, as outlined in the table above, shall be placed above compacted subgrade, moisture conditioned and compacted to 95 percent minimum relative compaction, as determined in accordance with ASTM D1557 – latest edition. Fabric Investments Page No. 14 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 16.0 INFILTRATION Our review of preliminary plans indicates no bioretention/infiltration facilities are proposed at the time of this report. In consideration of expansion potential of underlying soil materials, we do not recommend infiltration. Where bioretention facilities are necessary they shall be lined. Based upon our review of preliminary grading plans, permeable pavers are not proposed on the project site. In general, where pervious pavers are included in project plans, permeable paver subgrade adjacent to the building, shall be sloped away at 2% should be lined with an impervious liner a minimum horizontal distance of 5 feet from building. Permeable paver subgrade shall be sloped 2% minimum to a perforated subdrain, gravel filled (1cf/ft), wrapped in a filter fabric, permeable pavers shall be detailed with reinforced concrete edge restraints that extend minimum 4 inches below reservoir depth, and horizontal restraints. In addition to the above details, specific paver detailing should be detailed and constructed per the minimum recommendations of the specific paver manufacturer as well as the Interlocking Concrete Paver Institute including minimum bedding specifications, base and subgrade requirements, installation tolerances, and drainage, etc. Where runoff and storm water are directed over permeable pavements and water is anticipated to flow through pavers into an aggregate base near and adjacent to foundations, basements or other structures, additional detailing shall include systems to control and to prevent subsurface flow beneath the building. Generally, these systems, detailed as part of the specific building construction plans, may include the cut-off walls and underdrains. Proper surface drainage and irrigation practices will play a significant role in the future performance of the project. Please note in the Corrosion and Vapor Emission section of this report for specific recommendations regarding water to cement ratio for moisture sensitive areas should be adhered. The project architect and/or waterproofing consultant shall specifically address waterproofing details. 17.0 SURFACE DRAINAGE Adequate drainage precautions at this site are imperative and will play a critical role on the future performance of the proposed improvements. Under no circumstances should water be allowed to pond against or adjacent to tops of slopes and/or foundation walls. The ground surface surrounding proposed improvements should be relatively impervious in nature, and slope to drain away from the structure in all directions, with a minimum slope of 2% for a horizontal distance of 10 feet (where possible). Area drains or surface swales should then be provided in low spots to accommodate runoff and avoid any ponding of water. Any french drains, backdrains and/or slab Fabric Investments Page No. 15 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS underdrains shall not be tied to surface area drain systems. Roof gutters and downspouts shall be installed on the new and existing structures and tightlined to the area drain system. All drains should be kept clean and unclogged, including gutters and downspouts. Area drains should be kept free of debris to allow for proper drainage. Over watering can adversely affect site improvements and cause perched groundwater conditions. Irrigation should be limited to only the amount necessary to sustain plant life. Low flow irrigation devices as well as automatic rain shut-off devices should be installed to reduce over watering. Irrigation practices and maintenance of irrigation and drainage systems are an important component to the performance of onsite improvements. During periods of heavy rain, the performance of all drainage systems should be inspected. Problems such as gullying, or ponding should be corrected as soon as possible. Any leakage from sources such as water lines should also be repaired as soon as possible. In addition, irrigation of planter areas, lawns, or other vegetation, located adjacent to the foundation or exterior flat work improvements should be strictly controlled or avoided. 18.0 LABORATORY TESTING Laboratory tests were performed on samples of onsite material collected during our subsurface investigation. Test results are attached as Appendix C. 19.0 CONSTRUCTION OBSERVATION AND TESTING The recommendations provided in this report are based on subsurface conditions disclosed by the investigation and our general experience in the project area. Interpolated subsurface conditions should be verified in the field during construction. The following items shall be conducted prior/during construction by a representative of Engineering Design Group in order to verify compliance with the geotechnical and civil engineering recommendations provided herein, as applicable. The project structural and geotechnical engineers may upgrade any condition as deemed necessary during the development of the proposed improvement(s). 19.1 Review of final approved grading and structural plans prior to the start of work for compliance with geotechnical recommendations. 19.2 Attendance of a pre-grade/construction meeting prior to the start of work. 19.3 Observation of keyways, subgrade, and excavation bottoms. Fabric Investments Page No. 16 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 19.4 Testing of any fill placed, including retaining wall backfill and utility trenches. 19.5 Observation of footing excavations prior to steel placement and removal of excavation equipment. 19.6 Field observation of any "field change" condition involving soils. 19.7 Walk through of final drainage detailing prior to final approval. The project soils engineer may at their discretion deepen footings or locally recommend additional steel reinforcement to upgrade any condition as deemed necessary during site observations. Engineering Design Group shall, prior to the issuance of the certificate of occupancy, issue in writing that the above inspections have been conducted by a representative of their firm, and the design considerations of the project soils report have been met. The field inspection protocol specified herein is considered the minimum necessary for Engineering Design Group to have exercised due diligence in the soils engineering design aspect of this building. Engineering Design Group assumes no liability for structures constructed utilizing this report not meeting this protocol. Before commencement of grading the Engineering Design Group will require a separate contract for quality control observation and testing. Engineering Design Group requires a minimum of 48 hours’ notice to mobilize onsite for field observation and testing. 20.0 MISCELLANEOUS It must be noted that no structure or slab should be expected to remain totally free of cracks and minor signs of cosmetic distress. The flexible nature of wood and steel structures allows them to respond to movements resulting from minor unavoidable settlement of fill or natural soils, the swelling of clay soils, or the motions induced from seismic activity. All the above can induce movement that frequently results in cosmetic cracking of brittle wall surfaces, such as stucco or interior plaster or interior brittle slab finishes. Data for this report was derived from surface and subsurface observations at the site and knowledge of local conditions. The recommendations in this report are based on our experience in conjunction with the limited soils exposed at this site. We believe that this information gives an acceptable degree of reliability for anticipating the behavior of the proposed improvement; however, our recommendations are professional opinions and cannot control nature, nor can they assure the soils profiles beneath or adjacent to those observed. Therefore, no warranties of the accuracy of these recommendations, beyond the limits Fabric Investments Page No. 17 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS of the obtained data, is herein expressed or implied. This report is based on the investigation at the described site and on the specific anticipated construction as stated herein. If either of these conditions is changed, the results would also most likely change. Man-made or natural changes in the conditions of a property can occur over a period. In addition, changes in requirements due to state-of-the-art knowledge and/or legislation are rapidly occurring. As a result, the findings of this report may become invalid due to these changes. Therefore, this report for the specific site, is subject to review and not considered valid after a period of one year, or if conditions as stated above are altered. It is the responsibility of the owner or his/her representative to ensure that the information in this report be incorporated into the plans and/or specifications and construction of the project. It is advisable that a contractor familiar with construction details typically used to deal with the local subsoil and seismic conditions be retained to build the structure. If you have any questions regarding this report, or if we can be of further service, please do not hesitate to contact us. We hope the report provides you with necessary information to continue with the development of the project. FIGURES FIGURE 1 Vicinity Map Site Location Project: Fabric / 2676 State St. Address: 2676 State Street, Carlsbad, California EDG Project No: 226762-1 ENGINEERING DESIGN GROUP 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 FIGURE 2 Site Map Site Location Project: Fabric / 2676 State St. Address: 2676 State Street, Carlsbad, California EDG Project No: 226762-1 ENGINEERING DESIGN GROUP www.designgroupca.com 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 FIGURE 3 Site and Approximate Location of Exploratory Test Pits Test Pits Not to Scale T1 T2 Project: Fabric / 2676 State St. Address: 2676 State Street, Carlsbad, California EDG Project No: 226762-1 ENGINEERING DESIGN GROUP www.designgroupca.com 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 0+00.00 50.0 48 _g;:_ -----/;J ."Ii I LI 1,-1-.00--------I .00-- 46 44 42 -~~ ------I 40.0 J8 J6 J4 J2 . - . 00-- . 00-- .00-- JO.O _g;: =-28 25.~ """ -u , . .,, ..... ----- 0+00.00 . I . . I I " I I 0+25.00 ~ TP-2 t' L I) l'l ~ 0+50.00 Qaf/ Qop EXISTING BUILDING TO REMAIN GEOTECH MAP 0 20 40 LI _._ _ _.1 ___ 1 Feet SCALE: 1 INCH=20 FEET PROPOSED BUILDING TP-1 1 +00.00 PROPOS~h E CARPORT~~ RIJ/1 nJNr. BE REMOVE> ~-,A --· ,, ?---~ ---f--! ~---__ ,, 0+75.00 1 +00.00 1 +25.00 SECTION A-A SCALE: 1 "=20'-0" ~ ' ; -I 1~~ 4 n I I" I ~ L.....J 1 +50.00 1+75.00 n 1+93. ~ I- I I I I I I I 1+93. LEGEND I Oaf I Artificial Fill/ Weathered Material IOopl TP-2 ~ JOB NAME: Old Paralic Deposits (Mapped per Kennedy 2007) Test Pit Property Line FABRIC INVESTMENTS JOB ADDRESS: 2676 STATE STREET, CARLSBAD, CA 92008 JOB NO.: DATE: 226762-1 5-17-2022 FIGURE NO.: 4 ENGINEERING DESIGN GROUP 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 www.designgroupca.com Project Name: Fabric Investments TEST PIT LOG NO. 1 EDG Project 226762-1 Number: Location: See Figure 3 -Location of Test Pits Sheet 1 of 1 Date(s) Total Depth: Groundwater Excavated: 4/20/2022 6.0' Level: Not Encountered Logged By: ER/ RM/ AB Approx. Surface Backfilled Elev. Finished Grade -36' (date) Same Day Excavation Method: Hand Dug / Hand Auger Soil Type Depth Material Description and Notes ucsc Sample FILL, WEATHERED MATERIALS A 0-4.5 Brown to dark brown to black, moist, medium dense to stiff, silty sand and SW-CL --- sandy silts to sandy clays. Mild to moderate organic odor at 2-4.5 ft. PARALIC DEPOSITS (as ma~~ed ~er Kenned)!'., M.P.1 Tan, S.S., et. al., B 4.5-6.0' 2007) SW-SM --- Brown to dark yellowish brown, moist, dense, silty sand/sandy silt GRAPHIC REPRESENTATION FT. B.A.G. FG \lE:,Hl:;::, l .. . . . .. : --,(1'1\z.llk 1 , -. . . ' . . A) ,, "·: 2 ' ' ' 1/1//;fl/ 3 . . I' 4 ~-:..:· 77 :; > . . I ·-;~ 5 i-:--:-"~ 6 ~ ~ 7 8 Project Name: Fabric Investments TEST PIT LOG N O. 2 EDGProject 226762-1 Number: .. Location: See Figure 3 -Location of Test Pits Sheet 1 of 1 Date(s) Total Depth: Groundwater Excavated: 4/20/2022 8.0' Level: Not Encountered Logged By: ER/RM/AB Approx. Surface Backfilled Elev. Finish,~d Gradi:: -36' (date) Same Day Excavation Method: Hand Dug / Hand Auger Soil Type Depth Material Description and Nohs ucsc Sample FILL, WEATHERED MATERIALS A 0-6.5' Brown to dark brown to black, moist, medium dense to stiff, silty sand and sandy silts to sandy clays. Construction debris in the upper 3 feet. Mild to SW-CL --- moderate organic odor at 3-6.5 ft. PARALIC DEPOSITS {as maQQed Qer Kenned~, F/1.P.1 Tan, S.S., et. al.1 B 6.5-8.0' 2007) ~; Brown to dark brown, moist, dense, silty sand/sandy silt. SW-SM --- GRAPHIC REPRESENTATION FT. B.A.G. FG ina1tt. ' . -u1~1tr~ . C • . -.. . 1 ~ ~ <:: ~ ,.i. (~~~ ' ' 2 ~--·····-' ' .·' I ._'@ 3 ' ·. ' ,. .. ' . -~-~ 4 ,½ 5 6 77~ 7 J..J_!. "• .. ~· . 8 ~- APPENDIX A REFERENCES 1. California Geological Survey, Probabilistic Seismic Hazards Mapping Ground Motion Page. 2. California Department of Conservation, Division of Mines and Geology, Fault Rupture Zones in California, Special Publication 42, Revised 1990. 3. California Department of Conservation, Division of Mines and Geology, DMG Open-File Report 95-04, Landslide Hazards in the Northern Part of the San Diego County Metropolitan Area, San Diego County, California – Landslide Hazard Identification Map No. 35 – Oceanside and San Luis Rey Quadrangle (Plate 35A), dated 1995. 4. Coleman Architect, Preliminary Plans for 2676 State Street, Carlsbad, undated. 5. Day, Robert W. 1999. Geotechnical and Foundation Engineering Design and Construction. McGraw Hill. 6. Greensfelder, R.W., 1974 Maximum Credible Rock Acceleration from Earthquakes in California Division of Mines and Geology, Map Sheet 23. 7. Kennedy, Michael M.P., Tan, S.S., et. al., Geologic Map of the Oceanside 30’x60’ Quadrangle, California, dated 2007. 8. Lee, L.J., 1977, Potential foundation problems associated with earthquakes in San Diego, in Abbott, P.L. and Victoria, J.K., eds. Geologic Hazards in San Diego, Earthquakes, Landslides, and Floods: San Diego Society of Natural History John Porter Dexter Memorial Publication. 9. Pasco Laret Suiter & Associates, Drainage and Grades Plan for 2676 State Street, Carlsbad, CA 92008 – APN: 203- 101-01, received 10. Ploessel, M.R. and Slossan, J.E., 1974 Repeatable High Ground Acceleration from Earthquakes: California Geology, Vol. 27, No. 9, P. 195-199. 11. State of California, Fault Map of California, Map No. 1, Dated 1975. 12. State of California, Geologic Map of California, Map No. 1, Dated 1977. 13. Structural Engineers Association of Southern California (SEAOSC) Seismology Committee, Macroseminar Presentation on Seismically Induced Earth Pressure, June 8, 2006. 14. U.S. Army Corps of Engineers, Coast of California Storm and Tidal Waves Study, Shoreline Movement Data Report, Portuguese Point to Mexican Border, dated December 1985. 15. U.S. Army Corps of Engineers, Coast of California Storm and Tidal Waves Study, Coastal Cliff Sediments, San Diego Region (CCSTWS 87-2), dated June 1985. 16. Van Dorn, W.G., 1979 Theoretical aspects of tsunamis along the San Diego coastline, in Abbott, P.L. and Elliott, W.J., Earthquakes and Other Perils: Geological Society of America field trip guidebook. 17. Various Aerial Photographs. APPENDIX B General Earthwork and Grading Specifications 1.0 General Intent These specifications are presented as general procedures and recommendations for grading and earthwork to be utilized in conjunction with the approved grading plans. These general earthwork and grading specifications are a part of the recommendations contained in the geotechnical report and shall be superseded by the recommendations in the geotechnical report in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new recommendations which could supersede these specifications or the recommendations of the geotechnical report. It shall be the responsibility of the contractor to read and understand these specifications, as well as the geotechnical report and approved grading plans. 2.0 Earthwork Observation and Testing Prior to commencement of grading, a qualified geotechnical consultant should be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report and these specifications. It shall be the responsibility of the contractor to assist the consultant and keep him apprised of work schedules and changes, at least 24 hours in advance, so that he may schedule his personnel accordingly. No grading operations should be performed without the knowledge of the geotechnical consultant. The contractor shall not assume that the geotechnical consultant is aware of all grading operations. It shall be the sole responsibility of the contractor to provide adequate equipment and methods to accomplish the work in accordance with the applicable grading codes and agency ordinances, recommendations in the geotechnical report and the approved grading plans not withstanding the testing and observation of the geotechnical consultant If, in the opinion of the consultant, unsatisfactory conditions, such as unsuitable soil, poor moisture condition, inadequate compaction, adverse weather, etc., are resulting in a quality of work less than recommended in the geotechnical report and the specifications, the consultant will be empowered to reject the work and recommend that construction be stopped until the conditions are rectified. Maximum dry density tests used to evaluate the degree of compaction shouls be performed in general accordance with the latest version of the American Society for Testing and Materials test method ASTM D1557. 3.0 Preparations of Areas to be Filled 3.1 Clearing and Grubbing: Sufficient brush, vegetation, roots and all other deleterious material should be removed or properly disposed of in a method acceptable to the owner, design engineer, governing agencies and the geotechnical consultant. The geotechnical consultant should evaluate the extent of these removals depending on specific site conditions. In general, no more than 1 percent (by volume) of the fill material should consist of these materials and nesting of these materials should not be allowed. 3.2 Processing: The existing ground which has been evaluated by the geotechnical consultant to be satisfactory for support of fill, should be scarified to a minimum depth of 6 inches. Existing ground which is not satisfactory should be overexcavated as specified in the following section. Scarification should continue until the soils are broken down and free of large clay lumps or clods and until the working surface is reasonably uniform, flat, and free of uneven features which would inhibit uniform compaction. 3.3 Overexcavation: Soft, dry, organic-rich, spongy, highly fractured, or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, should be overexcavated down to competent ground, as evaluated by the geotechnical consultant. For purposes of determining quantities of materials overexcavated, a licensed land surveyor / civil engineer should be utilized. 3.4 Moisture Conditioning: Overexcavated and processed soils should be watered, dried back, blended and / or mixed, as necessary to attain a uniform moisture content near optimum. 3.5 Recompaction: Overexcavated and processed soils which have been properly mixed, screened of deleterious material and moisture-conditioned should be recompacted to a minimum relative compaction of 90 percent or as otherwise recommended by the geotechnical consultant. 3.6 Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical), the ground should be stepped or benched. The lowest bench should be a minimum of 15 feet wide, at least 2 feet into competent material as evaluated by the geotechnical consultant. Other benches should be excavated into competent material as evaluated by the geotechnical consultant. Ground sloping flatter than 5:1 should be benched or otherwise overexcavated when recommended by the geotechnical consultant. 3.7 Evaluation of Fill Areas: All areas to receive fill, including processed areas, removal areas and toe-of-fill benches, should be evaluated by the geotechnical consultant prior to fill placement. 4.0 Fill Material 4.1 General: Material to be placed as fill should be sufficiently free of organic matter and other deleterious substances, and should be evaluated by the geotechnical consultant prior to placement. Soils of poor gradation, expansion, or strength characteristics should be placed as recommended by the geotechnical consultant or mixed with other soils to achieve satisfactory fill material. 4.2 Oversize: Oversize material, defined as rock or other irreducible material with a maximum dimension of greater than 6 inches, should not be buried or placed in fills, unless the location, materials and disposal methods are specifically recommended by the geotechnical consultant. Oversize disposal operations should be such that nesting of oversize material does not occur, and such that the oversize material is completely surrounded by compacted or densified fill. Oversize material should not be placed within 10 feet vertically of finish grade, within 2 feet of future utilities or underground construction, or within 15 feet horizontally of slope faces, in accordance with the attached detail. 4.3 Import: If importing of fill material is required for grading, the import material should meet the requirements of Section 4.1. Sufficient time should be given to allow the geotechnical consultant to observe (and test, if necessary) the proposed import materials. 5.0 Fill Placement and Compaction 5.1 Fill Lifts: Fill material should be placed in areas prepared and previously evaluated to receive fill, in near-horizontal layers approximately 6 inches in compacted thickness. Each layer should be spread evenly and thoroughly mixed to attain uniformity of material and moisture throughout. 5.2 Moisture Conditioning: Fill soils should be watered, dried-back, blended and/or mixed, as necessary to attain a uniform moisture content near optimum. 5.3 Compaction of Fill: After each layer has been evenly spread, moisture-conditioned and mixed, it should be uniformly compacted to no less than 90 percent of maximum dry density (unless otherwise specified). Compaction equipment should be adequately sized and be either specifically designed for soil compaction or of proven reliability, to efficiently achieve the specified degree and uniformity of compaction. 5.4 Fill Slopes: Compacting of slopes should be accomplished in addition to normal compacting procedures, by backrolling of slopes with sheepsfoot rollers at increments of 3 to 4 feet in fill elevation gain, or by other methods producing satisfactory results. At the completion of grading, the relative compaction of fill out to the slope face would be at least 90 percent. 5.5 Compaction Testing: Field tests of the moisture content and degree of compaction of the fill soils should be performed at the consultant’s discretion based on file dconditions encountered. In general, the tests should be taken at approximate intervals of 2 feet in vertical rise and/or 1,000 cubic yards of compacted fill soils. In addition to, on slope faces, as a guideline approximately one test should be taken for every 5,000 square feet of slope face and /or each 10 feet of vertical height of slope. 6.0 Subdrain Installation Subdrain systems, if recommended, should be installed in areas previously evaluated for suitability by the geotechnical consultant, to conform to the approximate alignment and details shown on the plans or herein. The subdrain location or materials should not be changed or modified unless recommended by the geotechnical consultant. The consultant however, may recommend changes in subdrain line or grade depending on conditions encountered. All subdrains should be surveyed by a licensed land surveyor / civil engineer for line and grade after installation. Sufficient time shall be allowed for the survey, prior to commencement of filling over the subdrains. 7.0 Excavation Excavations and cut slopes should be evaluated by a representative of the geotechnical consultant (as necessary) during grading. If directed by the geotechnical consultant, further excavation, overexcavation and refilling of cut areas and/or remedial grading of cut slopes (i.e. stability fills or slope buttresses) may be recommended. 8.0 Quantity Determination For purposes of determining quantities of materials excavated during grading and/or determining the limits of overexcavation, a licensed land surveyor / civil engineer should be utilized. SIDE HILL STABILITY FILL DETAIL FINISHED SLOPE FACE PROJECT 1 TO 1 LINE FROM TOP OF SLOPE TO OUTSIDE EDGE OF I< EY OVERBURDEN OR UNSUITABLE MATERIAL EXISTING GROUND -- SURFACE~ -------- ,,,...---.,,,,,. / ,.,,.,... / .,,...,,.. / .,,...,,.. / __ ,.,,.,... / ..,,,-- ,,,,,., ✓ / / FINISHED CUT PAO / / :;;,!. ---------- :::COMPACTED-:--_-:::-:::-::-:::~ F!J.._Lj:-:'.:-- ~ ·-----------I -------------------------PAO OVEREXCAVATION DEPTH ANO RECOMPACTION MAY BE RECOMMENDED BY THE GEOTECHNICAL CONSUL TANT BASED ON ACTUAL FIELD CONOIT-IONS-.ENCOUNTERED. ( COMPETENT BEDROCK OR MATERIAL AS EVALU~TEO BY THE GEOTECHNICAL CONSULTANT NOTE: Subdrain details and key width recommendations to be provided based on exposed subsurface conditions STABILITY FILL / BUTTRESS DETAIL OUTLET PIPES ,4• ~ NONPERFORATEO PIPE, 100' MAX. O.C. HORIZONTALLY, 30' MAX. O.C. VERTICALLY -~-=-~ KEY DEPTH --::COl,il'A-CI::J --=---==~~~~==~~~:-~:~~::~=~~=.-.... -. ..---- 2 ~\\I MIN. f ---------_21'-~~-====~~~~~- ll~I I KEY WIDTH j AS NOTED ON .GRADING PLANS 15' MIN. e• MIN. 31,4•-1-112· CLEAN GRAVEL (3ft~/ft. MIN. ... 9J NON-PERFORAT OVERLAP PIP~::-==--:~~=!ijii~;;,,:Jj --FIL TEA FABRIC ENVELOPE (MIRAFI 140N OR APPROVED EQUIVALENT)* . see T-CONNECTION DETAIL 4• ~ PERFORATED PIPE 4• MIN. BEDDING SUBDRAIN TRENCH DETAIL NOTES: SEE SUBDRAIN TRENCH DETAIL LOWEST SUBDAAIN SHOULD BE SITUATED AS LOW AS POSSIBLE TO ALLOW SUITABLE OUTLET r-----,. 1 O' MIN. PERFORATED I t · I EACH SIDE PIPE~• CAP NON-PER FORA OUTLET PIP T-CO.NNECTION DETAIL * IF CAL TRANS CLASS 2 PERMEABLE MATERIAL IS USED IN PLACE OF 314•-1-112• GRAVEL, FILTER FABRIC MAY BE DELETED SPECIFICATIONS FOR CALTRANS CLASS 2 PERMEABLE MATERIAL U.S. Standard Sieve Size l" 3/4" 3/8" No. 4 No. 8 No. 30 No. SO No. 200 % Passing 100 90-100 40-100 25-40 18-33 5-15 0-7 0-3 Sand Equiva1ent>7S For buttress dimensions, see geotechnical report/plans. Actual dimensions of buttress and aubdrain may be changed by the geotechnical consultant based on field conditions. SUBDAAIN INSTALLATION-Subdraln pipe should be Installed with perforations down as depicted. At locatlon, recommended by the geotechnical consultant, nonperforated pipe should be Installed SUBORAIN TYPE-Subdraln type should be Acrylon trlle Butadlene Styrene (A.B.S.), Polyvinyl Chloride (PVC) or approved equivalent. Class 125,SDR 32.5 should be used for maximum fill depths of 35 feet. Claaa 200, SOR 21 1hould be used for maximum fill depth• of 100 feet. KEY AND BENCHING DETAILS FILL SLOPE ~':.~~~~~ 6~ ~L~:: \\\~~!!! TO COMPl!TENT MATERI ~:;!.l.~~~::- EXIST1NG GROUND SURFAC 2' MIN.L15' MIN~ KEY ILOWEST--7 OEPTH BENCH (KEY) BENCH ACTEO=-:~ FILL-OVER-CUT SLOPE ILL~-----=- EXISTING ~ GROUND SURF ACE ) --------- --LO-WEST ...--MIN. BENCH D~~fH (KEY) CUT SLOPE (TO BE EXCAVATEO PRIOR TO FILL PLACEMENT) //~ CUT-OVER-FILL SLOPE PROJECT 1 TO 1 LINE FROM TOE OF SLOPE TO COMPETENT MATERIAL EXISTING / / GROUND / / SURFACE~// K // ~l~.?' / I,, 1.,, ..... / -::,JI CUT SLOPE (TO BE EXCAVATED PRIOR TO FILL PLACEMENT) NOTE: Back drain may be recommended by the geotechnical consultant based on actual field conditions encountered. Bench dimension recommendations may also be altered based on field conditions encountered. ROCK DISPOSAL DETAIL PIN&aH GRADE OVERSIZE WINDROW DETAIL -------------------------------------------- -------------------------------------------- TYPICAL PROFILE ALONG WINDROW 1) Rock with maximum dimensions greater than 6 inches should not be used within 10 feet vertically of finish grade (or 2 feet below depth of lowest utility whichever is greater), and 15 feet horizontally of slope faces. 2) Rocks with maximum dimensions greater than 4 feet should not be utilized in fills. 3) Rock placement, flooding of granular soil, and fill placement should be observed by the geotechnical consultant. 4) Maximum size and spacing of windrows should be in accordance with the above details Width of windrow should not exceed 4 feet. Windrows should be staggered vertically (as depicted). 5) Rock should be placed in excavated trenches. Granular soil (S.E. greater than or equal to 30) should be flooded in the windrow to completely fill voids around and beneath rocks. APPENDIX C Fabric Investments 2676 State Street, Carlsbad, California Job No. 226762-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS LABORATORY RESULTS Method Cal-Trans Analyte Result Reporting Limit Units Dilution Method SULFATE 45.9 n/a ppm 1 CT 417 CHLORIDE 3.6 n/a ppm 1 CT 422 p.H. 8.28 n/a pH units 1 CT 643 RESISTIVITY 7290 n/a ohms.com 1 CT 643 ND=None detected – us/cm = micro-Siemens per centimeter - ppm-parts per million (10,000ppm=1% by weight) ENGINEERING DESIGN GROUP www.designgroupca.com 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 10-3988L Lab Number:33373 EDG (10-3988)Date Sampled:4/21/2022 DV Date Tested:5/13/2022 LAB WORK SHEET EXPANSION INDEX TEST Initial Final WET WEIGHT (g)311.5 407.8 DRY WEIGHT (g)276.4 329.4 % MOISTURE (%)12.7 23.8 WEIGHT OF RING & SOIL (g)738.5 WEIGHT OF RING (g)367.4 WEIGHT OF SOIL (lbs.)0.8181 VOLUME OF RING (ft.3)0.0073 WET DENSITY (pcf)112.5 DRY DENSITY (pcf)99.8 % SATURATION (%)50.0 EXPANSION READING DATE TIME: INITIAL READING INCH 0.0444 VERY LOW 0-20 LOW 21-50 MEDIUM 51 -90 FINAL READING HIGH 91-130 0.1402 VERY HIGH 130> EXPANSION INDEX 96 NOTES: Equipment ID: 2D EI at saturation between 48-52% Measured EI:95.8 Measured Saturation:50.0 EI at 48-52% Saturation:96 Job Name:EDG - Fabric Job Number: Sampled By: Tested By: Soil Location:TP-1 @ 0-4' ASTM D 4829 TEST RESULTS Soil Description:Grey CL A Universal Engineering Sciences Company i i 10-3988L Lab Number:33373 EDG (10-3988)Date Sampled:4/21/2022 DV Date Tested:5/13/2022 LAB WORK SHEET EXPANSION INDEX TEST Initial Final WET WEIGHT (g)320.7 389.1 DRY WEIGHT (g)283.5 319.1 % MOISTURE (%)13.2 21.9 WEIGHT OF RING & SOIL (g)725.7 WEIGHT OF RING (g)364.6 WEIGHT OF SOIL (lbs.)0.7961 VOLUME OF RING (ft.3)0.0073 WET DENSITY (pcf)109.5 DRY DENSITY (pcf)96.7 % SATURATION (%)48.1 EXPANSION READING DATE TIME: INITIAL READING INCH 0.0502 VERY LOW 0-20 LOW 21-50 MEDIUM 51 -90 FINAL READING HIGH 91-130 0.1489 VERY HIGH 130> EXPANSION INDEX 99 NOTES: Equipment ID: 2B EI at saturation between 48-52% Measured EI:98.7 Measured Saturation:48.1 EI at 48-52% Saturation:99 Job Name:EDG - Fabric Job Number: Sampled By: Tested By: Soil Location:TP-2 @ 4-5' ASTM D 4829 TEST RESULTS Soil Description:Greyish Brown CL A Universal Engineering Sciences Company i i Date: Date: Date: Date: 4.5 39 psi 652 460 204 THICK 0.56 0.71 0.88 crv 41 26 8 PRESS 0.7 0.36 0.2 0.59 727.4 727.4 727.4Tare (g) Dry Weight / Tare (g) 1927.5 1927.5 1927.5 1897.5 1897.5 1897.5 0.0011 0.0006 2550 Specimen/ Mold No.1 3 2 Compactor Air Pressure, ft.lbs.350 250 4/21/2022 0.70 0.36 0.20 204 0.56 0.71 0.88 460 0.0021 E.D.G. REPORT OF RESISTANCE 'R' VALUE-EXPANSION PRESSURE 4/21/2022 E.D.G. (Fabric)33373 Wet Weight / Tare (g) Water Added, ml 90 100 200 Initial Moisture, %2.6 2.6 2.6 110 Moisture at Compaction, %10.3 3290 3260 11.1 12.0 Wt. Of Briquette and Mold, g 3271 2094 2095 121.8 Wt. Of Mold, g 2108 Height of Briquette, in 2.53 2.59 2.59 Wt. Of Briquitte,g 1163 1196 1165 5.44 133 60 Displacement Stabilometer PH @ 1000 lbs 73 98Stabilometer PH @ 2000 lbs 37 45 Laboratory Manager R' Value Dry Density, pcf 4.26 4.35 41 126.4 126.0 26 Cover Thickness by Expansion Pressure-Feet Expansion From Graph: Erik Campbell Expansion Press, Thick-ft Exudation Pressure, psi TI Expansion R-value 15Exudation 39Expansion 15 Expansion Pressure Stabilometer Thickness - ft 652 8 8150 Corrected 'R' Value Exudation Pressure, lbs 8 5750 41 Test Procedure: 26 Not Submitted Greyish Brown (SC/CL) Cal 301 Soil Description: Project Name: Sample Location: Project Number.:10-3988 5/17/2022 5/20/2022 Lab No.: Sampled By: Submitted By: Tested By: Reviewed By:Erik Campbell Larry Sachs E.D.G. 0 10 20 30 40 50 60 70 0100200300400500600700800 CO R R E C T E D R V A L U E EXUDATION PRESSURE, LBS/IN2 R VALUE @ 300 LBS/IN2 0 0.5 1 1.5 0 0.5 1 1.5 / V V A Universal Engineering Construction Testing & Engineering, Inc. Sciences Company Inspection I Testing I Geotechnical I Environmental & Construction Engineering I Civil Engineering I Surveying I I I I V I/ / / / / / r, V '1 ./ V \. / ' / :l. ... ~ ~ APPENDIX D ADDEDUM LETTERS llll ENGINEERING DESIGN GROUP 2121 MONTIEL ROAD PHONE: {760) 839-7302 SAN MARCOS, CALIFORNIA 92069 FAX: {760) 480-74n CONC OR CMU----,__,.'----+-....,,__ RET WALL FER FLAN l DETAILS I-IYOROTITE WATER- STOFS AT COLO- JOINTS FER f"FR INSTALLATION INSTFi!LICTIONS SL.Al3 l VAPOR 1!3ARRIER FER FLAN l DETAILS MINIMUM WATEREfsQOFING SPECIFICATIONS (NOT TO SCALE) r.i\ FOAM UV PROTECTION BOARD FER \.V MANI.FACTURER'S SPECIFICATION GRACE FROCOR FLUID-APPLIED WATERFROCf=ING INSTALLED FER MANI.FACTURER'S SPECIFICATIONS l EXTEND E3EI-IINO CEMENTITOUS BACl<ER BOARD. f"i\ GRACE I-IYOROOUCT 22,J 0 INSTALLED FER MANI.FACTURER'S SFECIFICA TIONS OYER FLUID-APPLIED WA TERFROCf=ING (l) TEFNINATION f3AR FER MANLFACTURER'S SFECIFICA TIONS FILTER FAl3RIC WI 6" MIN LAP 314" GRA\iEL (I SF I FT) 4" DIA t=EFiFORATED DRAIN LINE (SCI-I 4,; OR EQJIVJ t=EFiFORATIONS ORIENTED DOILN IS MINIMUM GRADIENT TO SUITABLE OUTLET - EXACT PIPE LOCATION TO E3E OETEFiHINED er SITE CONSTRAINTS ® 4" TALL CONCRETE CANT • FTG I WALL CONNECTION (IK)ER WATERFROCf=INGJ. SLOPE TO 13ACI<. EDGE C1= FOOTING. ® ca-tPACTEO l3ACl<FILL ~ MIN RELATl\iE ca-tPACTION IN ALL OTI-IER AREAS U.O.N. 6 11 MAX LIFTS. ONLY LIGI-ITUEIGI-IT I-IANO-OFERA TED EQJIFMENT SI-IALL E3E USED WITI-IIN 3 FEET C1= Tl-IE 13ACI<. FACE C1= WALL. ADDENDUM LETTERS EDG Project No. 226762-1 Date: August 17th, 2022 To: Fabric Investments c/o: Scott Heath 2659 State Street #100 Carlsbad, California 92008 Re: Proposed new commercial structure, and remodel to existing structure located at 2676 State Street, Carlsbad, California Subject: Addendum No. 1 – Alternative Foundation Recommendations Ref: 1. “Preliminary Geotechnical Investigation and Recommendations Proposed New Commercial Structure and Remodel to an Existing Structure Located at 2676 State Street, Carlsbad, California”, prepared by Engineering Design Group, Project No. 226762-1, dated May 20th, 2022. 2. Wankner Architecture + Landscape Designs, Updated Preliminary Site Plan, received 8- 1-2022. We have prepared this addendum to our original report, (Reference No. 1) to provide alternative foundation recommendations, for the proposed commercial development to be located at 2676 State Street, in the City of Carlsbad (Reference No. 2), California. 1. ALTERNATIVE FOUNDATION RECOMMENDATIONS As an alternative to a 5-foot removal and re-compaction, we have provided the following alternative foundation recommendations. • OPTION 1 – Extend deepened foundations to competent material, anticipated at approximately 5 feet below existing grades (in area of rear building at east portions of lot) and 6 feet (at western portions of lot), extending into competent material a minimum of one foot, and the removal and re-compaction of the upper 2 feet of slab-on-grade subgrade, with the upper 18 inches consisting of an import cap, (material with low potential for expansion), as described in our original report (Reference No. 1). Under this option, new foundations, are anticipated to be locally deepened and founded into competent material, and slab-on-grade floors are anticipated to be founded in competent, re- compacted, import cap material with low expansion potential. We recommend stiffener footings, (a minimum of 12” x 12”), such that concrete spans are limited to 12 feet 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 EDG Project No. 226762-1 horizontally. • OPTION 2 – Foundations deepened & slabs designed as structural slabs, founded with a deep, caisson-type foundation and grade-beam system. Concrete floors under this option, shall be designed as structural floors spanning over unsuitable soil profiles. An import cap of 18 inches is anticipated below structural floors. If you have any questions regarding this report, please do not hesitate to contact our office. Sincerely, ENGINEERING DESIGN GROUP Steve Norris Erin Rist Geotechnical Engineer GE 2590 Licensed Civil Engineer C 65122 Certified Engineering Geologist EG 2263 EDG Project No. 226762-1 Date: December 5th, 2022 To: Fabric Investments c/o: Scott Heath 2659 State Street #100 Carlsbad, California 92008 Re: Proposed new commercial structure, and remodel to existing structure located at 2676 State Street, Carlsbad, California Subject: Addendum No. 2 – Updated Recommendations and Response to Comments Ref: 1. “Preliminary Geotechnical Investigation and Recommendations Proposed New Commercial Structure and Remodel to an Existing Structure Located at 2676 State Street, Carlsbad, California”, prepared by Engineering Design Group, Project No. 226762-1, dated May 20th, 2022. 2. Addendum No. 1 – Alternative Foundation Recommendations, “Proposed new commercial structure, and remodel to existing structure located at 2676 State Street, Carlsbad, California”, dated August 17th, 2022. 3. Geotechnical Report Review, City of Carlsbad – Land Development Engineering, Tyra HQ2, 2676 State Street (1st Review), dated October 21, 2022. 4. W A L DESIGNS - Wankner Architecture + Landscape Designs, Construction Documents Set for TYRA HQ2 – 2676 State Street, Carlsbad, CA 92008, dated 12/06/2022. We have prepared this addendum to our original report and addendum No. 1 (References No. 1 and No. 2, respectively) to provide additional information and to respond to City comments (Reference No. 3), regarding the proposed commercial development to be located at 2676 State Street, in the City of Carlsbad, California (Reference No. 4). The responses to City comments are incorporated into this addendum. SUBSURFACE CONDITIONS The original subsurface investigation exposed a range of fill, and weathered soil profiles in the upper 4.5 to 6.5 feet in our exploratory test pits. These materials consisted of a range of brown to ENGINEERING DESIGN GROUP www.designgroupca.com 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 EDG Project No. 226762-1 reddish brown to dark brown to black, with traces of gray and dark grayish brown, medium dense to medium stiff, silty sands & sandy silts to clayey sands and sandy clays. Laboratory testing of clayey sand & sandy clay profiles indicated they possess high potential for expansion, as indicated in our original report. Per the Unified Soil Classification System, soil profiles encountered at these locations classify as SW to CL. No additional subsurface exploration was done as part of this addendum. SEISMIC DESIGN PARAMETERS As provided in the original geotechnical report, the following table outlines Seismic Design Parameters. Additional parameters have been included in this Addendum. Site Class D* Seismic Design Category D* ASCE 7-16 Seismic Design Parameters SS (g) 1.081 S1 (g) 0.391 SMS (g) 1.297 SDS (g) 0.865 ASCE 7-16 Acceleration Parameters PGA = MCEG peak ground acceleration 0.477 PGAM = Site modified peak ground acceleration 0.572 Fa = Site amplification factor at 0.2 second 1.2 Fv = Site amplification factor at 1.0 second -* *Using code values provided in the table above rather than performing a ground motion hazard analysis, requires the exception identified in ASCE Section 11.4.8 be utilized in the structural design. Structural design for the subject property should be performed in accordance with the most up-to-date version of ASCE 7-16, Section 11.4.8 – ‘Exemption’ 2. ADDITIONAL VALUES The proposed scope of work has generally remained the same as that of the one described in our original geotechnical report. No retaining walls are anticipated as part of proposed development. EDG Project No. 226762-1 If a new scope is proposed and new retaining walls are included as part of proposed development, Engineering Design Group shall provide additional recommendations and minimum design parameters. Below are additional values, which include passive pressure and coefficient of friction. Passive soil resistance may be calculated using an equivalent fluid pressure of 300 pcf. This value assumes that onsite soil is competent, or it has been properly compacted. A coefficient of friction of 0.28 between the soil and concrete footings may be utilized to resist lateral loads in addition to the passive earth pressures above. SHALLOW FOUNDATIONS As presented in our original geotechnical report, footings bearing uniformly in competent material, may be designed utilizing a maximum allowable soil pressure of 2,000 psf. During our original subsurface investigation, various penetrometer readings were taken within our test pits. Readings from our tests, indicate onsite soils posses an unconfined compressive strength of between 2.0 and 3.0 tons per square foot. Based upon onsite testing, observation of onsite soils, and our engineering experience, a conservative value of 2,000 psf for bearing capacity was provided in our original report. Additional laboratory testing of onsite samples was conducted as part of the preparation of this addendum, which included shear strength, and proctor. Please see attachments for additional laboratory results. EXPANSIVE SOIL CONDITIONS Weathered materials that overlain the site were analyzed as part of our original subsurface investigation. Laboratory results indicate clayey soil profiles tested, possess expansion potential in the high range, as described in our original geotechnical report. Recommendations for slab-on-grade floors presented in our ‘original Geotechnical Report’ and in ‘Addendum No.1 – Alternative Foundation Recommendations’, include the removal of onsite soils, 18 inches below areas of proposed slabs, and the placing of import material (in the upper 18 inches) in area of slab-on-grade subgrade. Import material shall consist of soil with low potential for expansion (E.I.<20). Foundations shall be deepened into and placed on competent paralic deposits, as described in Addendum No.1. Based on our experience, visual observation, and engineering judgment, paralic deposits posses a low potential for expansion. It is our opinion, the slab-on-grade floors proposed will meet the requirement of Section 1808.6 for the following reasons: the removal of expansive soil in areas below slab-on-grade floors (Section 1808.6.3), and, proposed foundations are to be deepened, and founded through expansive soil profiles, into competent paralic materials. EDG Project No. 226762-1 TEMPORARY VERTICAL CUTS, TEMPORARY SLOPES, AND SHORING Addendum No. 1 (Reference No. 2), provides ‘alternative foundation recommendations’ to those provided in the original geotechnical report (Reference No. 1). The alternative foundation recommendations include the deepening of all new foundations into competent paralic materials, the removal and re-compaction of the upper 2 feet of slab-on-grade subgrade, of which, the upper 18 inches would consist of an import cap (material with low expansion potential, E.I.<20). This alternative recommendation was provided in lieu of the original recommendation, which consisted of an approximately 5 feet removal and re-compaction in the area of the proposed new structure, described in our original geotechnical report. In consideration of the ‘alternative foundation recommendations’ provided in Addendum No. 1, as described above, we no longer anticipate vertical cuts along north and east property lines. We do not anticipate the need for temporary shoring or associated temporary slopes. It is ultimately the responsibility of the owner and/or his representative (i.e., contractor) to ensure the construction process, including the excavation of footings, adheres to local, state, and construction industry safety standards. FLEXIBLE PAVEMENT DESIGN An R-value of 15 was utilized for our calculations. The table below provides pavement sections, as provided in original geotechnical report. Pavement Section - R-value = 15 Assumed TI 4 5 Traffic Type Parking Spots Drive Aisles Option 1 - (6" AC) Asphalt 6 6 Class II Base 3 5 Option 2 - (4" AC) Asphalt 4 4 Class II Base 5 9 CONSTRUCTION OBSERVATION AND TESTING The following additional items shall be conducted prior/during construction by a representative of Engineering Design Group to verify compliance with the geotechnical recommendations provided in the Addenda (No.1 and No. 2), and in our original report (Reference No.1), as applicable. These recommendations are in addition to those provided in Section 19.0 of our original report. • Observation of temporary excavations. (As applicable) • Observation of hardscape and pavement subgrade. EDG Project No. 226762-1 If you have any questions regarding this report, please do not hesitate to contact our office. Sincerely, ENGINEERING DESIGN GROUP Steve Norris Geotechnical Engineer GE 2590 Certified Engineering Geologist EG 2263 Attachments: Figure 4 – Updated Geotech Map Figure 5 – Cross Section A-A’ and Section B-B’ Laboratory Results 12-6-2022 FIGURE NO.: Feet 0 20 40 ·-ci J '" J J ~ A? I J " } C >: C) ') 'MLl/?AIN I t. i a..; "' ~( ~:0 "' J d~ .,,/ -~1 // I: l.iT<' / LI A1N t X TQ I J1,N -' I ~ / E:XIS,, TO REMAIN (FF= 37.16) t:.: 1-i..:.10.fr %,LfJINGTn 'ltM/llN I/ r"\-"\ ,, ~ J1 T,Wt TL V hFMn,/1., **BACKGROUND IMAGE: DRAINAGE AND GRADES PLAN -TYRA HQ2, PREPARED BY PASCO LARET SUITER & ASSOC/ATES, DATED 09/19/22. GEOTECH MAP SCALE: 1 INCH=20 FEET / '37 ,9 T ,',/ lij)" ') 31 2c:i1/tdJ,F ..... 13; <t 8W@ /-GI LEGEND XIST/NG CARPORT TO BE REMOVED --t<8b9 1/Vl r-11 bl ,IV pi Fe 1 t OPIV .jJFS ;;c/(8) /' ' VV@r "') f''b3 WI --(J739,W[U!r ') Ji28W@F0 I· _ ;;:i~cu, < ---,12-'¥', ~. I / i; ,.F~ , ---~~:t~~~~iF:NCc '" - ---IJhl '/ -~ I ,P 76 TW) / '1';;orwlwr::~1 13; r /-u1 I (?1 Ob owl~ c...:'I JOB NAME: ~ RI/ & Weathered Material *Old Para/ic Deposits ( as Mapped per Kennedy 2007) Location of Exploratory Test Pit Property Line Existing Contours SECTION VIEW ONLY Geologic Contact Limits Area of Slab Subgrade Removal & Re-Compaction. (Including upper 1 B inches of Low E.I. import material) (Diagonal Hatch) Test Pit Location (Sand Hatch) FABRIC INVESTMENTS JOB ADDRESS: 2676 STATE STREE~ CARLSBAD., CA 92008 JOB NO.: DATE: ENGINEERING DESIGN GROUP www.designgroupca.com 226762-1 4 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 12-6-2022 FIGURE NO.: Feet 0 20 40 Ir. (E) CARPORT TO BE REMOVE ~-----r~=-=---=:::------_ -----i_::-..=i------:---------i------,--------,-------~r------------r---~=====~==;::::~==~==t:==:::::;r---r----.-50. 00 STATE T PROP XISTIN ACC STRC. _ lt., iv# GRADE 40.00 30.00 ,(l±.____j~======t=======tt!=~====l============l=====~=:::!!~=t=====t===:l========t====~-±-25,00 0+25.00 0+50.00 P~L XISTIN STRUCTURE ~ TO REMAIN f : Qal\: -· · ,_ " APPROXIMATE EXISTING AN PROPOSED GRADES APPROXIMATE AND PROJECT£ LOCATION OF TEST PIT 1 0+75.00 1+25.00 1+50. 00 1 + 75. 00 / I SECTION A-A' PROPOSED BUILDING FF=J7.2 PL f < I 1 kc.AN,- ' DOTINGS TO BE DEEPENED INTO COMPETENT PARALIC MATERIALS. (FOOTING DESIGN PER STRUCTURAL) ROPOSED FOOTINGS TO BE DEEPENED INTO COMPETENT PARALIC MATERIALS. AREA OF REMEDIAL GRADING (FOOTING DESIGN, INCLUDING DIMENSIONS, SLAB-ON-GRADE SUBGRADE BY PROJECT STRUCTURAL ENGINEER). SECTIONS A-A' ANO B-B' JOB NAME: LEGEND @ill 100P6-10I Fill & Weathered Material *Old Paralic Deposits ( as Mapped per Kennedy 2007) Location of Exploratory Test Pit Property Line _ (37.l_ _ Existing Contours SECTION VIEW ONLY Geologic Contact Limits Area of Slab Subgrade Removal & Re-Compaction. (Including upper 18 inches of Low E.I. import material) (Diagonal Hatch) Test Pit Location (Sand Hatch) FABRIC INVESTMENTS JOB ADDRESS: 2676 STATE STREET, CARLSBAD, CA 92008 SCALE: 1 INCH=20 FEET **BACKGROUND IMAGES: DRAINAGE AND GRADES PLAN -TYRA HQ2, PREPARED BY PASCO LARET SUITER & ASSOCIATES, DATED 09/19/22. JOB NO.: DATE: ENGINEERING DESIGN GROUP www.designgroupca.com 226762-1 5 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 SHEAR STRENGTH TEST - ASTM D3080 Job Name: Project Number:4814.1003988.0000 Lab Number:34114 Sample Location:Tested By: Sample Description: Fabric Sample Date: Test Date: 12/6/2022 Dark Brown (SM) Remolded to 90%Angle Of Friction:33.4 Cohesion: Engineering Design Group (Fabric) 660 psf Initial Dry Density (pcf):128.8 Initial Moisture (%):9.9 Final Moisture (%):13.6 L.S. 12/17/2022 0 0.5 1 1.5 2 2.5 3 3.5 40.1 1 10 100 ST R A I N ( i n c h e s ) TIME (minutes) PRECONSOLIDATION 0 1000 2000 3000 4000 5000 0 2 4 6 8 10 12 14 16 18 20 SH E A R S T R E S S ( p s f ) STRAIN (%) SHEARING DATA 0 1000 2000 3000 4000 5000 0 1000 2000 3000 4000 5000 SH E A R I N G S T R E S S ( p s f ) VERTICAL STRESS (psf) FAILURE ENVELOPE dr=0.08 mm./min VERTICAL STRESS 1000 psf 3000 psf 5000 psf I v--. \ I l I .__ V" -' / i V \ / " ...... 1/ I I-I 0 I J 1, I I c@) A Universal Engineering Sciences Company J.G.Date: J.G.Date: EDG Date: N/A Sample Description: 200 150 100 50 1 2 3 4 Dry X 4100 4165 4119 3984 Moist 2020 2020 2020 2020 2080 2146 2100 1965 X 208.0 215.0 223.0 210.5 184.0 194.0 205.0 197.0 0.0 0.0 0.0 0.0 Drop: 13.0 10.8 8.8 6.9 137.7 142.0 139.0 130.1 121.8 128.2 127.8 121.7 X Procedure A Soil Passing No. 4 (4.75 mm) Sieve Mold : 4 in. (101.6 mm) diameter Layers : 5 (Five) Blows per layer : 25 (twenty-five) May be used if No.4 retained =/< 25% Procedure B Soil Passing 3/8 in. (9.5 mm) Sieve Mold : 4 in. (101.6 mm) diameter Layers : 5 (Five) Blows per layer : 25 (twenty-five) May be used if 3/8" retained =/< 25% Procedure C Soil Passing 3/4 in. (19.0 mm) Sieve Mold : 6 in. (152.4 mm) diameter Layers : 5 (Five) Blows per layer : 56 (fifty-six) May be used if 3/4" retained =/< 30% Plus 3/4" Plus 3/8" Plus #4 OVERSIZE FRACTION Total Sample Weight (g):16792.5 Percent Retained N/A N/A Weight Retained (g) Wt. of Container (g) Depth (ft.) TEST NO. Wt. Comp. Soil + Mold (g) Hammer Weight: Wet Wt. of Soil + Cont. (g) Dry Wt. of Soil + Cont. (g) Dark Brown (SM) Preparation Method: Project Name: Project Number: Lab Number: Sample Location: 12/6/2022 EDG - Fabric Tested By : Calculated By : Sampled By: 12/15/2022 12/15/2022 Mold Volume (ft.3):0.03330 Mechanical Rammer Manual Rammer Moisture Added (ml) Net Wt. of Soil (g) Wt. of Mold (g) 10.0 lb. Optimum Moisture Content (%) Optimum Moisture Content (%) Maximum Dry Density (pcf) PROCEDURE USED 128.8 9.9 Rock Correction Applied per ASTM D 4718 197.5 1.2 4814.1003988.0000 34114 Fabric LABORATORY COMPACTION OF SOIL (MOD.) ASTM D 1557 Maximum Dry Density (pcf) 18 in. Dry Density (pcf) Moisture Content (%) Wet Density (pcf) 110.0 115.0 120.0 125.0 130.0 0.0 5.0 10.0 15.0 20.0 Dr y D e n s i t y ( p c f ) Moisture Content (%) SP. GR. = 2.65 SP. GR. = 2.70SP. GR. = 2.75 34114 - Proctor C EnginHiing © A Uliivil,r:1<11 kloneos Coml)(lny I I I I I I ' I I I I \ /' N I' I ' I I \ \ \I\ .,,...,,.... I\' A' _.,,.. v ~ ' V _,,,.. 1./" \\ \ \ \ \ \ \ ,1\ \ \ "'\ I\, \. \ \ \ \' E3 E3 ' \ I\ \ [\ \ \ \ \ I\' \. \ \\ I\ \' \ \\ I\ I\' \ \\ EDG Project No. 226762-1 Date: January 17th, 2023 To: Fabric Investments c/o: Scott Heath 2659 State Street #100 Carlsbad, California 92008 Re: Proposed new commercial structure, and remodel to existing structure located at 2676 State Street, Carlsbad, California Subject: Addendum No. 3 – Updated Recommendations and Response to Comments Ref: 1. “Preliminary Geotechnical Investigation and Recommendations Proposed New Commercial Structure and Remodel to an Existing Structure Located at 2676 State Street, Carlsbad, California”, prepared by Engineering Design Group, Project No. 226762-1, dated May 20th, 2022. 2. Addendum No.1 – Alternative Foundation Recommendations, “Proposed new commercial structure, and remodel to existing structure located at 2676 State Street, Carlsbad, California”, dated August 17th, 2022. 3. Addendum No. 2 – Updated Recommendations and Response to Comments, “Proposed new commercial structure, and remodel to existing structure located at 2676 State Street, Carlsbad, California”, dated December 5th, 2022. 4. Geotechnical Report Review, City of Carlsbad – Land Development Engineering, Tyra HQ2, 2676 State Street (2nd Review), dated December 27, 2022. 5. W A L DESIGNS - Wankner Architecture + Landscape Designs, Construction Documents Set for TYRA HQ2 – 2676 State Street, Carlsbad, CA 92008, dated 12/06/2022. We have prepared this addendum to our original report and addenda (References No.1 through No. 3) to provide additional information and to respond to City comments (Reference No. 4), regarding the proposed commercial development to be located at 2676 State Street, in the City of Carlsbad, California (Reference No. 4). The responses to City comments are incorporated into this addendum. 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 EDG Project No. 226762-1 TEMPORARY VERTICAL CUTS FOR FOOTING EXCAVATIONS In consideration of the proposed depth of temporary excavations necessary for the construction of the proposed foundations, as described in our previous reports (References No. 1 through No. 3), and in response to City comments regarding specific excavation recommendations, we have provided the following options: • OPTION 1 - TEMPORARY SHORING In areas were proposed footing excavations are adjacent to neighboring properties or existing improvements; and temporary back-cuts are not possible, a temporary shoring system is anticipated. If the shoring system chosen incorporates piles or sheets, we do not recommend piles or sheets to be driven in, as vibrations during construction operations may damage improvements on adjacent properties. • OPTION 2 - SLOT-CUTTING AND SLURRY As an alternative to a temporary shoring system, excavations for proposed foundations may be performed in sections. In consideration of the depth to competent material and new improvements proposed adjacent to property lines, the following is recommended under this option. o The excavation of sections of up to 10 horizontal feet maximum is recommended. o Excavations for new footings shall extend at least one foot into competent materials, AND a concrete slurry mix shall be added up to a depth of 36 inches as measured from below existing grade to top of concrete slurry mix. (If this option is chosen for additional, smaller, accessory structures proposed at the site, concrete slurry up to 30 inches may be used). o Concrete slurry mix shall have a minimum of 2,500 psi and a fast-setting additive shall be included. o Immediately after excavation operations for each individual horizontal slot, the pouring of concrete slurry shall occur. Excavations over 3 feet in depth shall not stay open for extended periods or overnight. If rain events are in the forecast, excavation operations shall not be performed. TEMPORARY SHORING If option 1 above is chosen, the shoring designer must consider the support of adjacent underground utilities and/or structures and the effects of shoring deflection on supported improvements including existing road improvements, walls, and structures. For shoring design, we recommend the following as the minimum recommendations. Shoring designer shall include, EDG Project No. 226762-1 and upgrade shoring design recommendations as applicable, based upon final shoring system utilized. • The design embedment of the shoring pile toes shall be maintained during the excavation activities. The toes of the deepened piles shall be designed to take into account any required excavations necessary for excavation activities, foundations, drainage and/or utility systems. • Surcharge pressures should be added to this earth pressure for surcharges within a distance from the top of the shoring up to the height of the shoring. The surcharge for vehicular traffic within 10 feet of the shoring wall should be a uniform lateral pressure applied to the top 10 feet of the wall. (In consideration of the adjacent driveway areas at some locations). • The above earth pressures are actual with no increase in factor of safety. Shoring designer shall add appropriate factor of safety. • In the event that construction traffic or traffic loads is anticipated within the surcharge zone of the shoring, temporary shoring shall be designed for shoring height as outlined in AASHTO. • Some means of monitoring the performance of the shoring system should be incorporated. The monitoring should consist at a minimum of the establishment of monitoring points along existing adjacent settlement sensitive improvements, periodic surveying of lateral and vertical locations of the tops and bottoms of the solider piles. • Prior to the start of construction all conditions on adjacent sites should be photo documented. • During the installation of lagging, the excavation below the lagging shall not extend more than 1 foot below the bottom of lagging at any time. Time between lagging excavation and lagging placement should be as short as possible and should not remain unlagged overnight. • Where voids develop behind the shoring, voids shall be filled with slurry, or other acceptable material, such that the lagging is fully engaged. Voids shall be filled following every installation of lagging. • Where lagging is to be left in place it should be treated, and the upper one foot of lagging removed. • Shoring lagging shall extend to the bottom of the excavation. • Seams in the lagging shall be maintained so as not to allow the piping of granular material or create an impenetrable barrier so has not to allow the drainage of water. EDG Project No. 226762-1 OSHA SOIL TYPE Soil profiles that mantle the site, in the upper 4.5 to 6.5 feet are considered to classify as OSHA Type B soil. Temporary cuts necessary for the excavation of footings, in areas where this is possible, may be sloped at a maximum of 1:1 (H:V). Recommendations provided in our original report and addenda shall be followed if not superseded by updated recommendations. If you have any questions regarding this report, please do not hesitate to contact our office. Sincerely, ENGINEERING DESIGN GROUP Steve Norris Geotechnical Engineer GE 2590 Certified Engineering Geologist EG 2263