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Home My WebLink AboutSDP 2022-0004; AQUAZONE LEGOLAND PLAY STRUCTURE; PRELIMINARY GEOLOGICAL/GEOTECHNICAL INVESTIGATION; 2022-02-28ll'.§7j Civil Engineering Design Group CIVIL & STRUCTURAL February 28, 2022 ProjectNo.0205022 TO: Mr. Ali Bemanian Pacific Play Systems, Inc. 3288 Grey Haw Court Carlsbad, CA 92010 Via Email: ab@pacificplayinc.com SUBJECT: Preliminary Geologica1/Geotechnical Investigation Proposed Playground Installation Legoland -One Legoland Drive, Carlsbad, CA 92008 Dear Mr. Bemanian: In accordance with your request, we have performed a preliminary geological/ geotechnical investigation within the Legoland park. The project will consist of the conversion of the Aquazone Wave Racer attraction to a playground and picnic area. This investigation included a geological reconnaissance, site inspection and subsurface soil exploration of the subject development area on the subject property on February 22, 2022, accompanied by us, personnel from the Pacific Play Systems, Inc. and Legoland. The purpose of our inspection was to identify features that could indicate the presence of geological hazards and soil foundation issues affecting the filling of an existing pool within the subject property and provide recommendations to support the foundation of the proposed future playground equipment on the same area. In general, we found the property suitable for the proposed project provided that the recommendations contained herein are adhered to. We are presenting herein our findings and recommendations. This report has been prepared for the exclusive use of the stated client and his design consultants for specific application to the project described herein. Should the project be changed in any way, the modified plans should be submitted to our firm for review to determine their conformance with our recommendations and to determine if any additional subsurface investigation, laboratory testing and/ or additional recommendations are necessary. Our professional services have been performed, our findings obtained, and our recommendations prepared in accordance with generally accepted engineering principles and practices. This warranty is in lieu of all other warranties, expressed or implied. MAY O 9 2022 1930 Watson Way, Suite A, Vista, CA 92081 Phone 760-599-8566 Fax 760-599-8901 ( ( l~j Civil Engineering Design Group CIVIL & STRUCTURA If you should have any questions after reviewing this report, please do not hesitate to contact our office. This opportunity to be of professional service is sincerely appreciated. Respectfully submitted, Civil Engineering Design. Group 9' {?5), 7-;, Massood Gaskari, P.E. 1930 Watson Way, Suite A, Vista, CA 92081 Phone 760-599-8566 Fax 760-599-8901 TABLE OF CONTENTS ( PROJECT DESCRIPTION ................................................................................................ 1 SCOPE OF WORK ............................................................................................................ 1 FINDINGS .......................................................................................................................... 2 SITE DESCRIPTION .................................................................................................... 2 GEOLOGY ..................................................................................................................... 3 DESCRIPTION OF SITE SUBSURFACE CONDITIONS ........................................ 4 SEISMIC DESIGN PARAMETERS ................................................................................. 5 GEOTECHNICAL HAZARDS ........................................................................................ 6 CONCLUSIONS AND DISCUSSIONS .......................................................................... 9 RECOMMENDATIONS ................................................................................................. 10 EARTH WORK AND GRADING ............................................................................ 10 General ....................................................................................................................... 10 Fill Suitability ............................................................................................................ 10 Observation of Grading ........................................................................................... 11 Site Preparation ....................................................................................................... 11 Compaction and Method of Filling ...................................................................... 12 Temporary Cut Slopes ............................................................................................. 12 Excavation Characteristics ...................................................................................... 12 Surface Drainage ..................................................................................................... 12 Erosion Control ........................................................................................................ 13 DESIGN PARAMETERS FOR EARTH RETAINING STRUCTURES ................ 14 ( Active Pressure for Retaining Walls ...................................................................... 14 Retaining Wall Foundations ................................................................................... 15 Waterproofing and Drainage .................................................................................. 1,2 Backfill ........................................................................................................................ 15 FIELD INVESTIGATION ............................................................................................... 18 LABO RA TORY TESTS AND SOIL INFORMATION ................................................ 18 LIMIT A TIONS ................................................................................................................. 18 REFERENCES .................................................................................................................. 20 TABLES Table I Mapped Spectral Acceleration Values and Design Parameters Page 6 Table II Equivalent Fluid Weights for Calculating Lateral Earth Pressures Page 14 ( ( ( FIGURES FigureNo.1 FigureNo.2 Figure No. 3 Figure No. 4A Figure No. 4B Figure Nos. SA-5D APPENDICIES ATTACHMENTS Site Location and Topographic Map Regional Geologic Map Regional Fault Activity Map Plot Plan and Site Geologic/Geotechnical Map Grading Plan and Site Geologic/Geotechnical Map Boring Logs Appendix "A"-Standard Grading Specifications Appendix 11B11 -Unified Soil Classification Chart REPORT OF PRELIMINARY GEOLOGICAI/GEOTECHNICAL INVESTIGATION Proposed Playground Legoland One Legoland Drive, Carlsbad, CA 92008 PROJECT DESCRIPTION The following report presents the results of a preliminary geological/ geotechnical investigation performed for the conversion of the Aquazone Wave Racer attraction to a playground and picnic area within the Legoland theme park in Carlsbad California. The attraction is currently abandoned and partially demolished. When operational the attraction consisted of a shallow pool with two "racer" concrete loading pads that were connected to main park with metal bridges. The racers attached to and revolved around the concrete loading pads. The loading docks consisted of circular concrete platforms. The features associated with the Aquazone Wave Racer have been abandoned, demolished and/or removed. The pool void area was approximately 4 feet deep and has recently been backfilled with granular soil to facilitate the construction of a playground and picnic area. The playground will feature several Playcraft play structures, 10' x 10' cantilever shade umbrellas, and a rubberized surface placed over aggregate base. A layout of the proposed playground improvements is presented in the below plan. The play structures will be supported with metal post and pipe supports embedded in concrete pier foundations. Playcraft recommends a minimum pier embedment of 30 inches below the pavement subgrade elevation and minimum diameter of 18 inches for post supports. A minimum pier embedment of 18 to 30 inches below the pavement subgrade elevation and minimum diameter of 12 inches for the support pipes. Playcraft specifies the piers be embedded in "undisturbed soil". ( ( The scope of this study was limited to surface reconnaissance, research of readily available geologic and geotechnical literature pertinent to the site, subsurface exploration, laboratory testing, engineering and geologic analysis of the field data, and preparation of this report. More specifically, the intent of this study was to: • Identify the surface conditions of the site pertaining to the proposed development on the subject property • Based on our experience with similar sites in the area, identify the engineering properties of the various strata that may influence the proposed grading and construction including the allowable soil bearing pressures, expansive characteristics, and settlement potential. • Describe possible geotechnical factors that could have an effect on the site grading and construction. • Provide mapped spectral acceleration parameters relative to the 2019 CBC. • Address potential grading and construction difficulties that may be encountered due to soil conditions, groundwater, and provide recommendations concerning these problems. • Recommend an appropriate foundation system for the proposed filled surface of the pools and develop soil engineering design criteria for the recommended foundation design of the proposed playground. • Recommend grading measures for the subject pools and for the future playground construction. • Present our opinions in this written report, which includes, in addition to our findings and recommendations, one site plan showing the location of our subsurface excavations. ( SITE DESCRIPTION AND HISTORY February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page2 The project site is located within the 128-acre Legoland theme park, California. Legoland is located at One Legoland Drive in the City of Carlsbad. The park is bounded on the north by commercial developments and Cannon Drive, on the east by The Crossings Drive, on the south by Palomar Airport Road, and on the west by Legoland Drive. Development on the Legoland theme park reportedly occurred during the late 1990s; the park officially opened in 1999. Prior to construction the park area was crossed by a major south draining canyon, which was filled to create the current condition. The subject site was located on the east wall of the canyon and was likely developed with only minor grading. The project site encompasses a level area of about 8,500 square feet near the southeast portion of the park area. Figure No. 1 (attached) shows the regional site vicinity and the approximate location of the Aquazone Wave Racer attraction within the Legoland Theme Park. Satellite photography of the Legoland is presented on the following page with a "blowup" view of the project area; the Aquazone Wave Racer attraction shown in the photograph has since been abandoned and has been partially demolished. A ground level photograph of the abandoned Aquazone Wave Racer site is provided below. The photograph was taken during demolition operations and shows the pool bottom concrete pavement was partially removed during demolition process. Portions of the pool bottom remained and have since been covered with imported backfill soil. February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page3 February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page4 A reported estimated 4 to 5 feet of fill was placed on the site to backfill the pool and demolition void. Approximately 4 to 4½ feet of backfill was encountered as reported in our test boring logs shown on Figure Nos. SA through 5D. Excavating refusal was reached in all borings on dense aggregate or remained concrete slab. FINDINGS GEOLOGY The site is within the Coastal Plains Physiographic Province of San Diego County within the Peninsular Ranges Geomorphic Province of California. The near-surface material observed on the subject development site on the Legoland property in Carlsbad consists of undocumented artificial fill. The fill in the vicinity of the site is reportedly underlain by bedrock materials consisting of late to middle Pleistocene-aged old paralic deposits, Units 2-4 (Kennedy and Tan, 2005, 2007, map unit Qopz-4) or terrace deposits (map unit Qt, Tan and Kennedy, 1996), underlain by middle Eocene-aged Santiago Formation (map unit Tsa) as mapped by Kennedy and Tan (2005, 2007, Figure No. 2) and reported by Leighton and Associates (1996). Kennedy and Tan (2007, p. 7) described the old paralic deposits as "Poorly sorted, moderately permeable, reddish-brown, interfingered strandline, beach, estuarine and colluvial deposits composed of siltstone, sandstone and conglomerate." Leighton and Associates (1996) described this material in their test pits near the site as terrace deposits, consisting of reddish brown, silty fine to coarse sand. They described the underlying Santiago Formation as primarily olive green-gray, sandstone to claystone. The site is not in an Earthquake Hazard Zone according to CDMG (1991). The site will be affected by seismic shaking due to earthquakes on major local and regional active faults throughout the southern California region. The northwesterly trending Newport-Inglewood-Rose Canyon fault zone is the nearest active fault system, of which the nearest fault strand is located about 6 miles southwest of the site (Figure No. 3). Other regional active faults, the Elsinore, San Jacinto and San Andreas fault zones, are about 24, 52, and 78 miles northeast, respectively, from the site. The attached Plot Plan and Site Geologic/ Geotechnical Map (Figure No. 4) and was prepared from review of published geologic maps, unpublished project literature, and recent field mapping using an architectural site plan as a base map. February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page5 DESCRIPTION OF SITE SUBSURFACE CONDITIONS Subsurface conditions on the site are described individually below in order of increasing age. Also refer to the test boring logs attached as Figure Nos. SA through SD for more detailed information on subsurface conditions. Artificial Fill (Qaf): Approximately 4 to 4½ feet of artificial fill soil was encountered in all four (4) test borings on the site. These materials consist of primarily light to medium brownish gray, medium-to coarse-grained, gravelly silty sand manufactured sand that was surfically loose and becoming medium dense to dense with depth. The fills were placed to backfill the void produced by the demolition of the Aquazone Wave Racer feature and pool. No documentation exists regarding placement and compaction of the manufactured sand/ aggregate fill soil underlying the proposed development site. Therefore, the fill is undocumented and considered unsuitable for foundation support of the proposed post supports. Old Paralic Deposits (Qop2-4; or Terrace Deposits, Qt): Old paralic or terrace deposits were not encountered in our soil test borings but are anticipated to lie underneath the undocumented fill below about the 5-foot depth. Leighton and Associates (1996) described these deposits in an excavation near the site as "Reddish brown, slightly damp, very dense, silty fine to coarse sand." Santiago Formation (Tsa): The Santiago Formation was not encountered in our soil test borings but is anticipated to lie underneath the undocumented fill and old paralic deposits (if present) below about the 5-foot depth. Leighton and Associates (1996) described the Santiago Formation in an excavation near the site as "Olive green-gray, moist, medium dense to dense sandstone to claystone 4 to 6 inches thick, cobble layer at contact with Qt [terrace deposit]." SEISMIC DESIGN PARAMETERS We have determined the mapped spectral acceleration values for the site utilizing U.S. Seismic Design Maps (2019 CBC) from the USGS website (OSHPD, 2022). We have also provided values for the current ASCE 7-16 Standard (Table 1). Due to the stiff or dense consistency reported in the underlying old paralic (or terrace) February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page6 ( deposits and the Santiago Formation, Site Class C is considered applicable for the seismic design. The values generated by the Design Map Report are provided in the following table: The analysis included the following input parameters for the ASCE 7-16 Standard: Design Code Reference Document: ASCE 7-16 Standard Site Soil Classification: Site Class C Risk Category: II Site Coordinates: 33.12758°N, -117.31034°W TABLE I Site Coefficients and Spectral Response Acceleration Parameters (ASCE 7-16 Standard) Ss S1 Fa Fv Sms Sm1 Sds 1.052 0.381 1.2 1.5 1.263 0.571 0.842 Sdt 0.381 Application to the criteria in Tables I for seismic design does not constitute any kind of guarantee or assurance that significant structural damage or ground failure will not occur if ever seismic shaking occurs. The primary goal of seismic design is to protect life, not to avoid all damage, since such design may be economically prohibitive. GEOTECHNICAL HAZARDS No geotechnical hazards of sufficient magnitude to preclude the remedial construction at the site, as we presently understand it, are known to exist. GROUND SHAKING A likely geologic hazard to affect the site is ground shaking as a result of movement along one of the major active fault zones mentioned above. The maximum bedrock ( accelerations that would be attributed to a maximum probable earthquake February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page7 occurring along the nearest fault segment that could affect the site are summarized c· in Table I on Page 5 of this report. ( Probable ground shaking levels at the site could range from slight to moderate, depending on such factors as the magnitude of the seismic event and the distance to the epicenter. It is likely that the site will experience the effects of at least one moderate to large earthquake during the life of the proposed remedial development. LIQUEFACTION AND LIQUEFACTION INDUCED SETTLEMENTS Liquefaction is defined as the transformation of a granular material from a solid state into a liquid state with vibration (most commonly seismic shaking) in the presence of water. It is a phenomenon that tends to occur in areas with shallow groundwater and where the soils are composed of loosely compacted granular materials. During an earthquake, saturated, cohesionless soil particles tend to decrease in volume (condense), because the vibration causes smaller particles to shift and fill in the voids (pores) between larger soil particles normally filled with water. As the soil condenses, less space is left for water, causing an increase in pore water pressure. If the pore water pressure increases sufficiently, the soil loses its strength and transforms into a liquid state. Liquefiable conditions, when present, can lead to damage of overlying structures caused by loss of bearing, settlement, or subsidence of the soil. The subject pools and playground development site is underlain with loose to dense gravelly silty sand of artificial fill reportedly underlain by materials of the old paralic or terrace deposits reportedly underlain by sandstone and claystone of the Santiago Formation. No groundwater was encountered in the soil test borings to the maximum explored depth of approximately 4½ feet. Therefore, the fill and reported natural formational materials underlying the subject development site are considered to have a low susceptibility to liquefaction or liquefaction induced settlements. LATERAL SPREADING Due to the absence of shallow groundwater, mostly medium dense to dense fill soil, stiff or dense formational materials underlying the site, and lack of significant slopes on the site, the potential for lateral ground spreading is considered low in these materials. FLOODING The site is on an upland terrace and not within a floodplain; therefore, the potential for flooding at the site is considered nil. February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page8 ( TSUNAMIS AND SEICHES Tsunamis are great sea waves produced by submarine earthquakes or volcanic eruptions. It is thought that the wide continental margin of the coast acts to diffuse and reflect the wave energy of remotely generated tsunamis. The site is located outside of the boundaries of the tsunami inundation area as defined by the Tsunami Inundation Maps for Emergency Planning for the Oceanside, San Luis Rey and Encinitas Quadrangles (State of California, 2009). Seiches are periodic oscillations in large bodies of water such as lakes, harbors, bays, or reservoirs. The site is not near any large bodies of water, and therefore the potential for seiches affecting the site is considered nil. GROUNDWATER Groundwater was not observed in any of the soil test hand-auger borings to the maximum explored depth of approximately 4½ feet. The depth to regional groundwater is anticipated to be greater than about 20 feet. Local perched groundwater conditions may occur on the site and are usually due to landscape irrigation or excessively heavy rainfall. LANDSLIDE POTENTIAL As part of this study, we reviewed the publication, "Landslide Hazards in the Northern Part of the San Diego Metropolitan Area" by Tan and Giffen (1995). The 1995 reference is a comprehensive study that classifies San Diego County into areas of relative landslide susceptibility. The subject site is located in" Area 3-1." Land within Area 3-1 is considered to be generally susceptible to slope failures. "Slopes within this area are at or near their stability limits due to a combination of weak materials and steep slopes (many slope angles exceed 15 degrees). Although most slopes within Subarea 3-1 do not currently contain landslide deposits, they can be expected fail, locally, when adversely modified." (Tan and Giffen, 1995, p. 3).However, the existing ground in proposed pools and playground area is nearly level; therefore, the potential for a slope failure is considered low. No evidence of deep-seated landslides was detected in the site vicinity on published topographic maps (U.S.G.S., 2018) and aerial photographs (Google Earth, 2022), reported on published geologic maps or in the consultant reports by Leighton and Associates (1996, 2011),and none were observed during our site reconnaissance. February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page9 ( r \ CONCLUSIONS AND DISCUSSIONS Our general conclusions and summary findings regarding the area of the proposed playground on the subject Legoland property and proposed remediation options are summarized below. Specific recommendations for site preparation and foundation design follow this section. • The demolished Aquazone pool (future playground) site has been recently backfilled with up to 4.5 feet of fill soils that consist of good quality manufactured sand with some aggregate-sized particles. The fills are underlain at depth with competent sedimentary formational deposits and/ or controlled fill materials. • We were not provided with any documentation regarding the backfill placement and "certification" of proper compaction. Therefore, this backfill is considered "undocumented" and cannot be used for support of structural improvements unless documentation can be provided. • The construction plans by Pacific Play Systems (2022) propose post supports be embedded in concrete piers. The plans specify a minimum pier embedment of 3-feet below the pavement subgrade. The plans also specify the piers shall bear on "undisturbed" soil. As stated above the undocumented, recent backfill shall not be used to support structural improvements. Therefore, it is recommended the pier supports extend through the pool and demolition backfill section and be founded on the original ground below the bottom of the removed pool. Also, if a portion of the old pool bottom is encountered the pier may be supported on the existing buried slab with no additional soil penetration. • The circular concrete pad, loading platforms still remain. It is our opinion these platforms are suitable to support any of the playground structures that encroach onto this area. Therefore, if any playground structures will be located over the concrete platform it may be possible to anchor the structure to the concrete in lieu of a deepened pier foundation. If such is the case the structural engineer shall provide details for the attachment. • The upper one foot of the pavement subgrade should be processed and recompacted prior to placing the aggregate base. • From the information we have been provided it appears large portions of the bottom of the pool have been removed (See photograph on Page 3). This has created a large earthen bottom to allow for drainage through the subsoil. February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page 10 ( An impervious basin like a continuous pool can cause a backup of accumulated groundwater analogous to a bathtub filled with soil. • Alternately, in lieu of deepened pier foundations, areas of the playground that require foundation support may be regraded. All undocumented fills shall be removed from this area and recompacted. Supports placed in documented fill may be standard design dimensions. RECOMMENDATIONS We are providing two options for remedy of the foundation support for the proposed playground structures as summarized below. Detailed specifications and guidance are included in the Earthworks and Grading section of this report. Re-compaction of Undocumented Fill Option One option is the removal and proper re-compaction of the undocumented backfill in the areas that require foundation support. Removals shall extend at least 5 feet beyond the perimeter of the Playcraft play structure foundations. Specifications for materials and fill placement are provided in the following Earthworks and Grading section of this report. Embedment of Foundation Support into Original Ground Option A second option may be the deepening of the foundation for the support posts into the competent original soils underlying the recently placed backfill. The deepened footing may also terminate and bear on remaining portions of the pre-existing pool slab. An adequate depth of embedment shall be determined by the geotechnical engineer and/ or structural engineer. The depth of embedment should be verified in the field by the geotechnical engineer or engineering geologist. EARTHWORK& GRADING General Any grading should conform to the guidelines presented in this report, Sections 1804 and Appendix "J" of the 2019 California Building Code, the minimum requirements of the City of Carlsbad or County of San Diego, and the Recommended Grading Specifications and Special Provisions (Appendix A) (-· attached hereto, except where specifically superseded in the text of this report. February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page 11 ( Prior to grading, a representative of Civil Engineering Design Group should be present at the preconstruction meeting to provide additional grading guidelines, if necessary, and to review the earthwork schedule. The below earthwork recommendations, generally, only apply if remedial grading is performed to remove and recompact the existing pool backfill and "certify" the placement. Fill Suitability On-site excavated soil materials may be used as compacted fill material or backfill. The on-site materials are anticipated to possess a very low expansion potential. Any potential import soil sites should be evaluated and approved by the Geotechnical Consultant prior to importation. At least two working days of notice of a potential import source should be given to the Geotechnical Consultant so that appropriate testing can be accomplished. The type of material considered most desirable for import is a non-detrimentally expansive granular material with some silt or clay binder. Observation of Grading Observation and testing by the soil engineer is essential during the grading operations. This observation can range from continuous to an as-needed basis, based on the project situation. This allows the soil engineer to confirm the conditions anticipated by our investigation, to allow adjustments in design criteria to reflect the actual field conditions exposed, and to determine that the grading progresses in general accordance with the recommendations contained herein. Site Preparation Site preparation should begin with the removal of any vegetation and other deleterious materials from the portion of the site that will be graded and that will receive improvements. This should include all root balls from the trees removed and all significant root material. The resulting materials should be disposed of off- site. After clearing and grubbing, site preparation should continue with the removal all existing loose backfill from areas that will be graded or that will support settlement-sensitive improvements. Removals are expected to range from approximately 4 to 5 feet but may be thicker in localized areas. Where possible, the removals should extend laterally a minimum of 5 feet beyond the area of the proposed play structure or to a distance equal to the depth of removals (whichever is greater). All removal areas should be approved by a representative of the geotechnical consultant prior to the placement of additional fill or improvements. February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page 12 C C Prior to placing any fill soils or constructing any new improvements in areas that have been cleaned out to receive fill, the exposed soils should be scarified to a depth of approximately 6 to 12 inches, be moisture conditioned, and compacted to at least 90 percent relative compaction. The below earthwork recommendations, generally, only apply if remedial grading is performed to remove and recompact the existing pool backfill and "certify" the placement. Compaction and Method of Filling Any structural fill placed at the site should be compacted to a minimum relative compaction of at least 90 percent of its maximum dry density as determined by ASTM Laboratory Test D1557. Fills should be placed at or slightly above optimum moisture content, in lifts six to eight inches thick, with each lift compacted by mechanical means. Fills should consist of approved earth material, free of trash or debris, roots, vegetation, or other materials determined to be unsuitable by our soil technicians or project geologist. All material should be free of rocks or lumps of soil in excess of six inches in maximum width. Temporary Cut Slopes We do not anticipate long-term temporary cut slopes exceeding 5 feet in height and, therefore, specifications for temporary cuts are not provided at this time. However, typically temporary cuts must be inclined at a 1:1 (horizontal to vertical) inclination (unless excavated into bedrock-Type A soils). It should be noted that the contractor is solely responsible for designing and constructing stable, temporary excavations and may need to shore, slope, or bench the sides of trench excavations as required to maintain the stability of the excavation sides where friable sands or loose soils are exposed. The contractor's "responsible person", as defined in the OSHA Construction Standards for Excavations, 29 CFR, Part 1926, should evaluate the soil exposed in the excavations as part of the contractor's safety process. In no case should slope height, slope inclination, or excavation depth, including utility trench excavation depth, exceed those specified in local, state, and federal safety regulations. Actual safe slope angles should be verified by the geotechnical consultant at the time of excavation. Surface Drainage Surface drainage should be implemented per Section 1804 of the California Building Code, as a guideline. in general, the ground immediately adjacent to foundations shall be sloped away from the building at a slope of not less than one unit vertical in 20 units horizontal (5-percent slope) for a minimum distance of 10 ( feet (3048 mm) measured perpendicular to the face of the wall. If physical February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page 13 ( obstructions or lot lines prohibit 10 feet (3048 mm) of horizontal distance, a 5- percent slope shall be provided to an approved alternative method of diverting water away from the foundation. Where needed, drainage should be directed to suitable disposal areas via non- erodible devices such as paved swales, gunited brow ditches, and storm drains. Pad drainage should be designed to collect and direct surface water away from proposed structures and the top of slopes and toward approved drainage areas. For such devices a minimum gradient of two percent should be maintained away from the structures. Erosion Control In addition, appropriate erosion-control measures shall be taken at all times during construction to prevent surface runoff waters from entering footing excavations, ponding on finished building pad or pavement areas, or running uncontrolled over the tops of newly constructed cut or fill slopes. Appropriate Best Management Practice (BMP) erosion control devices should be provided in accordance with local and federal governing agencies. DESIGN PARAMETERS FOR EARTH RETAINING STRUCTURES Active Pressure for Retaining Walls Lateral pressures acting against masonry and cast-in-place concrete retaining walls can be calculated using soil equivalent fluid weight. The equivalent fluid weight value used for design depends on allowable wall movement. Walls that are free to rotate at least 0.5 percent of the wall height can be designed for the active equivalent fluid weight. Retaining walls that are restrained at the top (such as basement walls) or are sensitive to movement and tilting should be designed for the at-rest equivalent fluid weight. Values given in the table below are derived from Section 1610.lof the CBC and are in terms of equivalent fluid weight and assume a triangular distribution. The provided equivalent fluid weight values assume typical onsite manufactured sands s are used for wall backfill. February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page 14 ( C TABLE II Equivalent Fluid Weights (efw) For Calculating Lateral Earth Pressures (Using Non-detrimentally Expansive Backfill) LEVEL BACKFILL "Average" Conditions Backfill (SM-SC) Active 30 pc£ At-Rest 60 pc£ Retaining Wall Foundations Retaining wall foundations shall be designed by the structural engineer based on the appropriate parameters provided in this report. Waterproofing and Drainage In general, retaining walls should be provided with a drainage system adequate to prevent the buildup of hydrostatic forces and waterproofed as specified by the project architect. Also refer to American Concrete Institute ACI 515.R (A Guide to the Use of Waterproofing, Damp Proofing, Protective and Decorative Barriers Systems for Concrete). Positive drainage for retaining walls should consist of a vertical layer of permeable material positioned between the retaining wall and the soil backfill. Such permeable material may be composed of a composite drainage geosynthetic or a natural permeable material such as crushed rock or clean sand at least 12 inches thick and capped with at least 12 inches of backfill soil. The gravel should be wrapped in a geosynthetic filter fabric. Provisions should be made for the discharge of any accumulated groundwater. The selected drainage system should be provided with a perforated collection and discharge pipe placed along the bottom of the permeable material near the base of the wall. The drainpipe should discharge to a suitable drainage facility. If lateral space (due to property line constraints) is insufficient to allow installation of the gravel-wrapped "burrito" drain, a geocomposite system may be used in lieu of the typical gravel and pipe subdrain system. TenCate's Mira Drain (and similar products) provide a "low- profile" drainage system that requires minimal lateral clearance for installation. Mira DRAIN and similar products may also be incorporated into a waterproofing system and provide a slab drainage system (Please note that supplemental manufacturer's details will be required to provide a waterproofed system). February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page 15 ( Backfill All backfill soils should be compacted to at least 90% relative compaction. Soil with an expansion index (EI) of greater than 50 should not be used as backfill material behind retaining walls. The wall should not be backfilled until the masonry has reached an adequate strength. Oversize rock cannot be placed within 10 feet of the reconstructed slope face. FOUNDATIONS Based on the findings of our investigation, it is our opinion the support posts may be supported by the proposed concrete pier footings provided that they be founded in competent original ground or certified compacted fill. The on-site materials generally possess a low expansive potential and therefore, consideration for heaving soils is included in our recommendations. Dimensions and Embedment Pier foundations shall be designed to minimum specifications as detailed by the Playcraft plans. Playcraft recommends a minimum pier embedment of 30 inches below the pavement subgrade elevation and minimum diameter of 18 inches for post supports. A minimum pier embedment of 18 to 30 inches below the pavement subgrade elevation and minimum diameter of 12 inches for support pipes. Playcraft specifies the piers be embedded in "undisturbed soil". In addition, if remedial grading is not performed, the foundations will need to be deepened. The foundations shall also extend through the undocumented backfill section and be embedded on competent "original" ground materials at a depth of approximately 4 to 5 feet below the existing grade. Deepened pier foundations may also terminate if the pool slab is encountered. Design pier diameters may be used for deepened footings. Soil Bearing Value A bearing capacity of 2000 psf may be assumed for footings when founded a on firm natural ground or properly compacted fill. This bearing capacity may be increased by one-third, when considering wind and/ or seismic loading. Lateral Load Resistance Lateral loads against foundations may be resisted by friction between the bottom of the footing and the supporting soil, and by the passive pressure against the footing. The coefficient of friction between concrete and soil may be considered to be 0.4. The passive resistance may be considered to be equal to an equivalent fluid February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page 16 ( ( weight of 100 pounds per cubic foot as assigned to the portion of the footing extending through undocumented fill. A value of 325 pounds per cubic foot may be used for footing embedded entirely in documented and properly compacted fill. These values assume the footings are poured tight against undisturbed soil. If a combination of the passive pressure and friction is used, the friction value should be reduced by one-third. Foundation Reinforcement Reinforcement requirements for foundations should be provided by a structural engineer. Anticipated Settlements Based on our experience with the soil types on the subject site, the soils should experience settlement in the magnitude of less than 0.5 inches under proposed structural loads. It should be recognized that minor hairline cracks normally occur in concrete slabs and foundations due to shrinkage during curing and/ or redistribution of stresses and some cracks may be anticipated. Such cracks are not necessarily an indication of excessive vertical movements. Plan Review The finalized, structural and grading plans (if available) should be submitted to this office for review to ascertain that the recommendations provided in this report have been followed and that the assumptions utilized in its preparation are still valid. Additional or amended recommendations may be issued based on this review. FIELD INVESTIGATION Four (4) test borings were placed near the areas of the playground on the property using a 4-inch diameter hand auger. The excavations were placed specifically in areas where representative soil conditions were expected and/ or where the proposed remedial grading and construction will be located. Our investigation also included a visual site reconnaissance. The excavations were visually inspected and logged by our field geologist, and samples were taken of the predominant soils throughout the field operation. The logs of the exploratory borings are presented on Figure Numbers SA through 5D (respectively). The soils are described in accordance with the Unified Soils Classification. In addition, a verbal textural description, the moist color, the February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page 17 apparent moisture and the density or consistency are provided. The density of the granular fill is given as loose to dense. Bulk samples of disturbed soil were collected in bags from the test borings. Representative disturbed bulk samples were obtained from the fill soilsfrom the test borings and were transported to the laboratory for testing. LABORATORY TESTS AND SOIL INFORMATION A brief description of the field tests performed is presented below: CLASSIFICATION: Field classifications were verified in the laboratory by visual examination. The final soil classifications are in accordance with the Unified Soil Classification System. ,------LIMITATIONS i ~~--------------------------------_J The recommendations presented in this report are contingent upon our review of final plans and specifications. Such plans and specifications should be made available to the Geotechnical Engineer and Engineering Geologist so that they may review and verify their compliance with this report and with Appendix A and the 2019 California Building Code. It is recommended that Private Eyes Engineers be retained to provide soil-engineering services during the construction operations. This is to verify compliance with the design concepts, specifications or recommendations and to allow design changes in the event that subsurface conditions differ from those anticipated prior to start of construction. The recommendations and opinions expressed in this report reflect our best estimate of the project requirements based on an evaluation of the subsurface soil conditions encountered at the subsurface exploration locations and on the assumption that the soil conditions do not deviate appreciably from those encountered. It should be recognized that the performance of the foundations and/ or cut and fill slopes may be influenced by undisclosed or unforeseen variations in the soil conditions that may occur in the intermediate and unexplored areas. Any unusual conditions not covered in this report that may be encountered during site development should be brought to the attention of the Geotechnical Engineer so that he may make modifications if necessary. This office should be advised of any changes in the project scope or proposed site grading so that we may determine if the recommendations contained herein are February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page 18 appropriate. It should be verified in writing if the recommendations are found to be appropriate for the proposed changes or our recommendations should be modified by a written addendum. The findings of this report are valid as of this date. Changes in the condition of a property can, however, occur with the passage of time, whether they are due to natural processes or the work of man on this or adjacent properties. In addition, changes in the Standards-of-Practice and/ or Government Codes may occur. Due to such changes, the findings of this report may be invalidated wholly or in part by changes beyond our control. Therefore, this report should not be relied upon after a period of two years without a review by us verifying the suitability of the conclusions and recommendations. In the performance of our professional services, we comply with that level of care and skill ordinarily exercised by members of our profession currently practicing under similar conditions and in the same locality. The client recognizes that subsurface conditions may vary from those encountered at the locations where our borings, surveys, and explorations are made, and that our data, interpretations, and recommendations are based solely on the information obtained by us. We will be responsible for those data, interpretations, and recommendations, but shall not be responsible for the interpretations by others of the information developed. Our services consist of professional consultation and observation only, and no warranty of any kind whatsoever, express or implied, is made or intended in connection with the work performed or to be performed by us, or by our proposal for consulting or other services, or by our furnishing of oral or written reports or findings. It is the responsibility of the stated client or their representatives to ensure that the information and recommendations contained herein are brought to the attention of the structural engineer and architect for the project and incorporated into the project's plans and specifications. It is further their responsibility to take the necessary measures to ensure that the contractor and his subcontractors carry out such recommendations during construction. The firm of Private Eyes Engineers shall not be held responsible for changes to the physical condition of the property, such as addition of fill soils or changing drainage patterns, which occur subsequent to the issuance of this report. Our firm will not be responsible for the safety of personnel other than our own on the site; the safety of others is the responsibility of the Contractor. The Contractor should notify the Owner if he considers any of the recommended actions presented herein to be unsafe. February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page 19 ( ( REFERENCES California Division of Mines and Geology (CDMG+), 1991, Earthquake Hazard Zones (formerly Alquist-Priolo Special Studies Zone) Map of the La Jolla 71/2-minute quadrangle, scale 1:24,000. California Emergency Management Agency, 2009, Tsunami Inundation Map for Emergency Planning, State of California -County of San Diego, Encinitas Quadrangle, dated June 1, 2009, scale 1:24,000. California Emergency Management Agency, 2009, Tsunami Inundation Map for Emergency Planning, State of California -County of San Diego, Oceanside and San Luis Rey Quadrangles, dated June 1, 2009, scale 1:24,000. Google Earth, 2022, photo imagery. Jennings, C.W., and Bryant, W.A., 2010, Fault Activity Map of California: California Geological Survey, Geologic Data Map No. 6, scale 1:750,000. + Currently called California Geological Survey (CGS) as of 2001 February 28, 2022 Proposed Playground Area Page 20 Legoland, Carlsbad, CA ( Kennedy, M.P., and Tan, S.S., (digital version 2005, paper version 2007, Geologic Map of the Oceanside 30' x 60' Quadrangle, California: California Geologic Survey, Regional Geologic Map Series, Map 2, scale 1:100,000. Leighton and Associates, 1996, Supplemental Geotechnical Investigation, Lego Family Park, Carlsbad Ranch, Carlsbad, California, Project No. 4960151- 001, dated July 23, 1996. Leighton and Associates, 2011, Updated Geotechnical Investigation, Proposed Legoland California Hotel, Carlsbad, California, Project No. 960151-034, dated May 2, 2011. Office of Statewide Health Planning and Development (OSHPD), 2022, Seismic Design Maps, website: https:/ / seismicmaps.org. Pacific Play Systems, Inc., 2022, Construction drawings, Playground Installation, Legoland, One Legoland Drive, Carlsbad, CA 92008, 3 sheets, dated January 11, 2022. REFERENCES (Continued) Tan, S.S., and Giffen, D.G., 1995, Landslide Hazards in the Northern Part of the San Diego Metropolitan Area, San Diego County, California, Landslide Hazard Identification Map No. 35: California Division of Mines and Geology Open File Report 95-04 pp. 1-6, Plate 35A-Oceanside and San Luis Rey Quadrangles. Tan, S.S., and Kennedy, M.P., 1996, Geologic Maps of the Northwestern Part of San Diego County, California: California Division of Mines and Geology Open-File Report 96-02, 2 plates, map scales 1:24,000. U.S. Geological Survey, 2018, Topographic map of the Encinitas 7.5-minute quadrangle, California, scale 1:24,000. U.S. Geological Survey, 2018, Topographic map of the San Luis Rey 7.5-minute quadrangle, California, scale 1:24,000. February 28, 2022 Proposed Playground Area Legoland, Carlsbad, CA Page 21 0 KILOMETERS 2 1000 500 0 METERS 1000 2000 0.5 0 N MILES 1000 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 l FEET CONTOUR INTERVAL 20 FEET NORTH AMERICAN VERTICAL DATUM OF 1988 Modified Excerpts of the Topographic Maps of the Encinitas and San Luis Rey Quadrangles, San Diego County, California: U.S. Geological Survey, 2018, scale 1:24,000. Figure No. 1 : Site Location and Topographic Map One Legoland Drive, Carlsbad, CA EXPLANATION OF LOCAL GEOLOGIC MAP UNITS: ·~ .. i Old paralic deposits, Units 2-4 (late to middle Pleistocene)~ ......... / Qoa " ► '--t---7 . '--:"°-'-•-·-·~--· ...... \~', / / / \ Santia go Formation (middle E ocene) 2 3 Teo \ 4 5 6 7 MILES I .5 0 2 3 4 5 6 7 KJLOMETERS 11111 --- Contour Interval 50m Figure No. 2: Regional Geologic Map ~ ~ Kt N l Excerpt of the Geologic Map of the Oceanside 30' x 60' Quadrangle, California: Database, by M.P. Kennedy and S.S. Tan, 2005: California Geological Survey, scale 1:100,000. One Legoland Drive, Carlsbad, CA -'-_,,,,, • .;_•··I , , ~'r~l l\le ,,f~?':;',,.e~"-/~ ~,.,:: _ji'--:.--z-.. (/;~ :__ \. 4',.~ ~~ Follbrook .. , -e,., . 1063ft __ .,. ~~~ (\,_ ._ / ·• / ) ...--,-·P~laRtt " ~ \ \ ,, r • ' --.. -, , I , I 1 ---'-. ··• ...... '\_ ~\ \ .... \, : I I \ ,..,,17 (i J. --.... \ \ \ ~ / \ '-,-. I \ T : .. , , . 6' _. '--I'', ~ '\ i ( ~ '• 70 C~'.; _ . \ f \ ~', t -:· , ~ N '-' '-..' ' \. \ \ \ ,\ \', \ ~ 'l •, 4 0 "-. , 10ml 0 . 1 '-. , f J _ ,~ /~LaJ~4'1:- ---,,.. -, , • 1-<earvato,,. .,.. .f".-.... \ -; • VaUey I 1\ -'o _,, _..,..t...'(,-\' 1 ~ Center --' -• • •. 1\ ~ f • ; Vista ~ ', ;' ~'\\ ., ~ ii') r ! .. ----'. ' ~ I . I ' '• \\ Carlsbad -. . _ -y, -f, -, ( ''h '-. -~ r ' . San "' • 1 ._, I II ' \~\ \ •, , , • ' ~-1.lrcos , ti I i l f ' ' ,t '. ', "'..:! ':~-~"' ...,_ E scondl do· ~ ' .,;, ,l, 1-i >, :.:i. ~ ITE -., ... "> > I\\ -~· • , . ,. t.-"' J •\,, \_ ~~ ~ ,. . -.. -~-/ ~\ ,· . -.,~ ·-;-~--1' J \'., :-1,. (/1 _.,t;-' / ',\1 Q 1 . , \ V c -• , \. . I I 1,\\ , ,." -~. \. Encmitos 7 't , ._..,.. ~Romona / / \ o".; ', \ ''I" ii. ·--67 : -/ ''Z ~I , ,'\~ \ = c' '-. I!!,, --/ ,,i "' ~ f / ,,ti .. ,,,,. l._ El HERE.'. Delorme; USGS_. faGA. ';_~-~:.~~DA, NPS I CalitomiJ G... 1 ~,1.1 Excerpt from Fault Activity Map of California by Charles W. Jennings and William A. Bryant (201 O) SUMMARY EXPLANATION Fault traces on land are indicated by solid lines where well located, by das11ed lines where approximately located or inferred, and by dotted lines where concealed by younger rocks or by lakes or bays. Fault traces are queried where continuation or existence is micertain. --------·------- FAULT CLASSIDCATIOl'i COLOR CODE (Indicating Recency ofMonment) Historic Fault (last 200 years) i----I Late Quaternary fault (during past 700,000 years). Holocene fault {dwing past 11,700 years) without historic record. Pre-Quaternary fault (older that 1.6 million years) or fault without recognized Quaternary displacement. _________ ,__ __ , Quaternary fault (age tmdifferentiated) Figure No. 3: Regional Fault Activity Map One Legoland Drive, Carlsbad, CA ~)] 7 111 ,.'i I ) o'I I :f' I J\\! ----;.:.::.~ ~: -l/1/ I.. •• _-..r-·.:: ! -,-.::--,:::,• ·--...... >--.:-..; ~ ,\ \ \ t\ 1\ , · ~-,, ,-,, Qal I (ljlbp2 \ , I _I '---, ,. A -----=--1 S10 S 1 01 -s,o 1c1, B3 I I I '~-<J, \ '\ \ 1V N 1:: \ AS-BUILT SCALE: 1 / 16" = 1 '-0" 0 1Q _ __2_Q 30 FEET LEGEND: Qaf = Artificial Fill (Latest Holocene) Qop2-4 = Old Paralic Deposits, Units 2-4 (Pleistocene) Tsa = Santiago Formation (Eocene) Note: Geologic unit in parentheses and italics is B4 concealed -Soil test hand-auger boring ~ '\. --=:::::--_.._ \. ......._~ ............. ... ,,\ ......... .........__ ~ "Y/ ~-~-\~-./ ''---i I\ \ 1_.~.,1 ~.)l f l ~~'~10 .. ::-:::?} t. I l-~!:::i I \ • I ----, ";: ~1_ ~~. •a1 I ~-·,--, I\\ \ ':'.:). II J \ II ---........_II ,,. -1_ / t I 1 -..... ---~ ~I =~::'7 --~ Base map for playground site taken ~rom plot plan prepared by Pacific Play jsystems, Inc., dated January 11, 2022 Figure No. 4A: ii \':-\ ~ r "~ Plot Plan and Site Geologic/Geotechnical Map One Legoland Drive, Carlsbad, C{' ) /' ,,,,. /J ------,:;:('!EA~) -';';~ -n1~r J§,,., ,,., ,,., ---,,., .,..,,,,,. (71 / / / ------ ,l\ I Base map-{Qr playground site is excerpt ~ ----__ _, 1 from gradingplarf prepared by Lego land I; I //,,,-.---_.,.. - '; I / / ~ -- , I I __ , ;;:,,, _::::::..-:-'·~is. ~...... ' "m.M"jf'/ i i t t U .t-.:,_VJ';.~--~--~,,:.._~ " , \\/ W' '~ L -,tt-' ~ , . , , 0 ' , ,,. ~ --, ' ' ' '-'-"°'' ' \\ / , / ;_ ;::p,r, ~ -"--,lr--,~, '-'-\~\ ",' '~i( ( Y, ->'' ,,,,., ~ ' ' , / L ' ' '" ,, \ ~-,, ''-'''" .-------~\,_ I '( '-'-..1~1 '\. ---~✓"" '-~"' _-..;.'.'\'\\ '--'\ "J; ':J~-\.1 M. \ \ -:J. ;l ,59.22 I '\ :'\ \ fl\ '\ \,._\ •. ~ M . I \, ,<t-\ \\ --....... "fo.25 \-ff:, \::-ii I Al O'\ 1I -' °'-----.... -. ./~' ............____ I Q~~1~ ------ --', Carlsbad; dated May 10, 1999 Q 10 20 FEET --- ' -' '\ ' ' '\ 30 ------CD N la a:;-TEST 130RING NO. 1 -~ I ~ -:,e z -C. 0 1i ~ >-~~ Surface Elevation: 156±' Date: 2/22/2022 LoggedBy: SEJ !. Cl) ! t: .... Cl) I.J. , ~ e Cl) i5 6 Ill I ~ ~ tR ::) Excavation Method: 4" diameter hand auger i Q ~ s ..J >-I Ill a= • Q DESCRIYilON OF SUBSURFACE CONDffiONS GM/ FILL (Qaf): Gravelly Silty Sand ( crushed rock), medium-to coarse--SM grained, light brownish gray, angular gravels mostly½ to 1 ½", slightly ·1 moist, loose to medium dense @ ~ 1 ', medium to dark brownish gray, moist, medium dense 2 -@~2', very moist, medium dense to dense - 3 4 - @ 4.5', practical excavating refusal EXCAVATION BOTTOM= 4.5 FEET 5 -No water; no caving - 6 -I I I - 7 - - 8 - - 9 - - 10 - - 11 - - 12 - ( • One Legoland Drive ~ :~~~~.;.~~~i~.r! Carlsbad, CA FIGURE NO. 5A la -I ~ se. -e;. 'C ~ cf II) ! -e II) = ! IQ i 0 Q :S -:i :, I &Cl • 1 2 3 4 5 c6 7 8 9 10 11 u • It' k! z -0 >-e~ t: Cl) v. i5 5 Ill 18 :, Q ~ >-Cl: Q GM/ SM TEST BORING NO. 2 Surf.tee Elevation: 156±' Date: 2/22/2022 I.oggedBy: SEJ Excavation Method: 4" diameter hand auger DESCRIPTION OF SUBSURFACE CONDmONS FILL (Qaf): Gravelly Silty Sand ( crushed rock), medium-to coarse- grained, light to medium brownish gray, angular gravels mostly ½ to 1 ½", slightly moist, loose to medium dense @ ~ l ', brownish gray, moist, medium dense to dense @ ~3 ', moist to very moist @ 4.3 ', practical excavating refusal EXCAVATION BOTTOM= 4.3 FEET No water; no caving -PEE Private Eyes Engineers One Legoland Drive Carlsbad, CA FIGURE NO. 5B ( la Ii:' TEST BORING NO. 3 i ~ l le ! --'G ~ >-~~ Smface Elevation 156±' Date 2/22/2022 Logged By: SEJ -~ II) ! t: ..... Ill v . -t e I i5 6 <II I !!l ig:::1 Excavation Method: 4" diameter hand auger 0 0 Q a Q ; ..i ~ >-; ID a: • Q DESCRIPTION OF SUBSURFACE CONDmONS -GM/ FILL (Qat): Gravelly Silty Sand ( crushed rock), medium-to coarse- SM grained, light to medium brownish gray, angular gravels mostly ½ to 1 -1 ½", slightly moist to moist, loose to medium dense -@ ~ 1.5 ', brownish gray, moist, medium dense to dense 2 - -@ ~2.5', medium to dark grayish brown, moist to very moist 3 - - 4 -@ 4.3 ', practical excavating refusal -EXCAVATION BOTTOM= 4.3 FEET 5 -No water; no caving - 6 - -I I I 7 - - 8 - - 9 - - 10 - - 11 - - 12 - C • One Legoland Drive PEE ~~~-t&~i;.r! Carlsbad, CA FIGURE NO. 5C ia I -~ ~ -t,;,. 11 Ill ~ II) ~ -t a II) = ~ IQ ; 0 Q ~ ..i ~ ::, I Ill • 1 2 3 5 ( 6 7 8 9 10 11 12 G;' ~ ► t: II) i5 Q ► ! z TEST BORING NO. 4 0 e~ V. Smf.tee Elevation: 156±' Date 2/22/2022 Logged By: SEJ Ej Ill i ::a Excavation Method: 4" diameter hand auger a DESCRIPTION OF SUBSURFACE CONDmONS ~~/ FILL (Qaf): Gravelly Silty Sand ( crushed rock), medium-to coarse- grained, light to medium brownish gray, angular gravels mostly ½ to 1 ½", slightly moist to moist, loose to medium dense @ ~ 1.5 ', brownish gray, moist, medium dense to dense @ ~2.3 ', medium to dark grayish brown, moist to very moist @ 4.1 ', practical excavating refusal EXCAVATION BOTTOM= 4.1 FEET No water; no caving PEE Private Eyes Engineers One Legoland Drive Carlsbad, CA FIGURE NO. 5D