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Home My WebLink AboutAMEND 2017-0020; GRAND PACIFIC PALISADES RESORT; GEOTECHNICAL INVESTIGATIONS; 2017-11-20Geotechnical Engineering Services GEOTECHNICAL INVESTIGATION Hilton Tapestry Resorts Expansion 5803 Armada Drive Carlsbad, California Material Inspection and Testing Environmental Services • • 01 l·llT' I,()( \Tf(l',S OH\\!;!· Cot 'd\ ( 0/H'Ol{ \ IT Im\ V II 'c11,1' I I ,'j l'.ili:1:1 \'sl'l1lll S1111,· \ \1uh,·ui;. ( .·\ ,;:s,1r1 I ,:I I l 11 ;_:, _''-1'-/-' f·:/\ ; 1-1 I\< .. ' -~•)'' i S\\ l>!l·LO hll'Ll<:l \I ('Ot '\ 1 \ ,. n ''J_, f,·1rh -.;q11;11, • • • • • • • • - --- -- l's·! S."'":; r: YJ'J<l !·:\\ """ i ,, <•)'",11 ht ,,11 L\IP!l{I Huitd11L' .:.\ {)('/1.\/h.t \\Pl·.\ll'HU l)\'-,l' \ I( ll ."'i ,, 1>11-1.n IW.;r, nu 11 '·' 11 llil~'I 1111: ,·, 111 (;eotechnical Engineering Construction Inspection Materials Testing Environmental GEOTECHNICAL INVESTIGATION Hilton Tapestry Resorts Expansion 5803 Armada Drive Carlsbad, California Prepared For: Grand Pacific Palisades Hotel, LP 5900 Pasteur Court, Suite 200 Carlsbad, California 92008 Prepared By: MTGL,lnC . 6295 Ferris Square, Suite C San Diego, California 92121 November 20, 2017 MTGLProjectNo.1916A12 MTGLLogNo.17-1619 ' -<f:CFIVED DE[ 0 6 2017 CITY Or' CARL~BAu ni I\NNlt\lf~ DIVISION • • • • • • • • • • • • • • • • .. .. • • • - - • - .. .. .. • .. ()I{\ '-<,I COi 'n ('1HW11k\ll H!{\\,("ll ,. Su11,_' \ .. .. -.. .. - .. -.. -.. - • - • .. • -.. .. • .. .. .. - \11,:lt,·:iH. ( .\ \J_;:,-;1 ii, I ,_'I -,, I l hi' ~<i•J<J ]·_1\ ~1-1-,,~.2>f.'l s,, DtH,O l\li'l'KI\I ('OI "\l"\ 1-,.:,;_, f ,·n1·_ "q11:1k Su1l,: l. J ,·I ;-,_,;-, i;" ~ci•J'' ! .i \ ,,;-.;\ ,; ; ·: "lq,,l I I ; . .;1,i \1:11dun l',11-k\1->; OC/1 \/hl ,,11E\Ll'HH: l)f'.-,1' \ l ( ·11 :,.,111 i. i') I _2<11 •I I '..; \ ", IJJJ-l :i I l)ISI' \ H 'H \\\1\\ 11Li·_,\i11,·c·1,n1 November 20, 2017 Grand Pacific Palisades Hotel, LP 5900 Pasteur Court, Suite 200 Carlsbad, California 92008 Attention: Mr. Houston Arnold Geotechnical Engineering Construction Inspection Materials Testing Environmental MTGLProjectNo. 1916A12 MTGL Log No. 17-1619 Subject: GEOTECHNICAL INVESTIGATION Hilton Tapestry Resorts Expansion 5803 Armada Drive Carlsbad, California Dear Mr. Arnold: In accordance with your request and authorization we have completed a Geotechnical Investigation for the subject site. We are pleased to present the following report which addresses both engineering geologic and geotechnical conditions including a description of the site conditions, results of our field exploration and laboratory testing, and our conclusions and recommendations for grading and foundations design . Based on our investigation, the site will be suitable for construction, provided the recommendations presented herein are incorporated into the plans and specifications for the proposed construction. Details related to geologic conditions, seismicity, site preparation, foundation design, and construction considerations are also included in the subsequent sections of this report. We appreciate this opportunity to be of continued service and look forward to providing additional consulting services during the planning and construction of the project. Should you have any questions regarding this report, please do not hesitate to contact us at your convenience . Respectfully submitted, MTGL,Inc. 4(,~ Sam E. Valdez, RCE 56226, GE 2813 Vice President\ Engineering Page i of iii .. --.. .. -.. ,. .. .. .. • .. -.. - --.. .. - --• • • .. • .. • .. • .. • .. • • .. - Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad. California TABLE OF CONTENTS MTGL Project No. 1916A12 MTGLLogNo.17-1619 1.00 INTRODUCTION ...................................................................................................................... 1 1.01 PLANNED CONSTRUCTION .......................................................................................................... I 1.02 SCOPEOFWORK ........................................................................................................................ l 1.03 SITE DESCRIPTION ...................................................................................................................... 1 1.04 FIELD INVESTIGATION ................................................................................................................ 2 1.05 LABORATORYTESTING .............................................................................................................. 2 1.06 PERCOLATION TESTING .............................................................................................................. 3 2.00 FINDINGS .................................................................................................................................. 4 2.01 REGIONAL GEOLOGIC CONDIDONS ............................................................................................ 4 2.02 SITE GEOLOGIC CONDIDONS ..................................................................................................... 4 2.03 GROUNDWATER CONDIDONS ..................................................................................................... 5 2.04 FAULTING AND SEISMICITY ......................................................................................................... 5 2.05 LIQUEFACTION POTENTIAL .......................................................................................................... 5 2.06 LANDSLIDES ................................................................................................................................ 6 2.07 TSUNAMI AND SEICHE HAZARD .................................................................................................. 6 3.00 CONCLUSIONS ........................................................................................................................ 7 3.01 GENERALCONCLUSIONS ............................................................................................................ 7 3.02 EARTIIQUAKE ACCELERATIONS\ CBC SEISMIC PARAMETERS .................................................. 7 3.03 EXPANSION POTENTIAL .............................................................................................................. 8 4.00 RECOMMENDATIONS .......................................................................................................... 9 4.01 EXCAVATION CHARACTERISTICS/SHRINKAGE ........................................................................... 9 4.02 SETILEMENT CONSIDERATIONS ................................................................................................. 9 4.03 SITE CLEARING RECOMMENDATIONS ....................................................................................... 10 4.04 SITE GRADING RECOMMENDATIONS -STRUCTURES ................................................................ 10 4.05 SITE GRADING RECOMMENDATIONS-CUTIFILL TRANSIDON ................................................. 11 4.06 SITE GRADING RECOMMENDATIONS -HARDSCAPE ................................................................ 11 4.07 COMPACTION REQUIREMENTS ................................................................................................. 11 4.08 FILL MATERIALS ...................................................................................................................... 11 4.09 SLOPES ..................................................................................................................................... 12 4.10 FOUNDATIONS .......................................................................................................................... 12 4.11 CONCRETE SLABS ON GRADE AND MISCELLANEOUS FLATWORK ........................................... 13 4.12 PREWETTING RECOMMENDATION ............................................................................................ 14 4.13 CORROSIVITY ........................................................................................................................... 14 4.14 RETAINING W ALLS ................................................................................................................... 15 4.15 FOUNDATION SETBACKS .......................................................................................................... 16 4.16 Bro RETENTION BASIN ............................................................................................................. 17 4.17 CONSTRUCTION CONSIDERATIONS ........................................................................................... 17 4.17.1 MOISTURE SENS/TN£ SOll,S/WEATHER RELATED CONCERNS ............................................... 17 4.17.2 DRAINAGE AND GROUNDWATER CONSIDERATIONS .............................................................. 18 4.17.3 TEMPORARY EXCAVATIONS AND SHORING ........................................................................... 18 Page ii of iii 5 Fcrrif> Square. Suite C San Diego. CA 92121 (858) '.117-3999 .. .. .. -.. .. .. .. -- • .. .. .. .. .. .. .. .. - • .. • .. .. .. .. .. .. .. .. --- Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California MTGLProjectNo. 1916Al2 MTGLLogNo. 17-1619 4.17.4 UTIUTYTRENCHES ............................................................................................................. 20 4.17.5 SITE DRAlNAGE ................................................................................................................... 21 4.18 GE0TECHNICAL OBSERVATION/TESTING OF EARTHWORK OPERATI0NS ................................. 21 5.00 LIMITATIONS ........................................................................................................................ 22 ATTACHMENTS: Figure 1 -Site Location Map Figure 2 -Site Plan Figure 3 -Retaining Wall Drainage Detail Appendix A -References Appendix B -Field Exploration Program Appendix C -Laboratory Test Procedures Appendix D -Percolation Test Appendix E -Standard Earthwork and Grading Specifications Page iii of iii 5 Ferri~ Square. Suite C San Diego, CA 92121 (858) 537-3999 .. .. --.. .. • -.. -.. .. .. • .. 11 • .. .. • .. .. .. • .. • .. ... - • .. .. .. • --.. .. Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California MTGL Project No. 19!6Al2 MTGL Log No. 17-1619 1.00 INTRODUCTION In accordance with your request and authorization, MTGL, Inc. has completed a Geotechnical Investigation for the subject site. The following report presents a summary of our findings, conclusions and recommendations based on our investigation, laboratory testing, and engineering analysis . 1.0 I Planned Construction It is our understanding that one three-story hotel building is planned to be constructed between the existing Karl Strauss restaurant and hotel in an area that is currently occupied with grass landscaping and hardscape. The hotel building pad is anticipated to have a finish grade elevation that is close to existing elevations of 155 feet ms!. Other improvements at the site are to include retaining walls and associated underground utilities. 1.02 Scope of Work The scope of our geotechnical services included the following: • Review of geologic, seismic, ground water and geotechnical literature . • Logging, sampling and backfilling of two exploratory borings drilled with a 6-inch diameter solid-stem auger limited access drill rig to a maximum depth of 45½ feet below existing grades. Appendix B presents a summary of the field exploration program . • Laboratory testing of representative samples (See Appendix C) . • Geotechnical engineering review of data and engineering recommendations . • Performing of two (2) percolation tests in the proposed development area . • Preparation of this report summarizing our findings and presenting our conclusions and recommendations for the proposed construction . 1.03 Site Description The project is located at 5803 Armada Drive, Carlsbad, California, see Site Location Map, Figure 1. There is an existing Hilton hotel resort at the site. The area where the proposed hotel building is to be located is a landscaped area east of an existing hotel building. A conference building and Karl Strauss restaurant border the area on the northern and eastern sides. A retaining wall and walkway border the area on the south. The Site Plan, Figure 2, shows the proposed development area . Page 1 of 22 5 Ferris Square. Suite C San Diego, CA 92121 (858) 517-3999 -,. .. -.. -----.. -.. • .. .. • .. .. .. .. .. .. .. -• -• .. .. • • .. ---.. Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California MTGL Project No. 1916A12 MTGLLogNo. 17-1619 The site was previously graded in the 1990s and developed into a hotel resort in the late 1990s (Leighton and Associates. Inc., 1997). The area is relatively flat with an elevation of 155 to 156 feet above mean sea level (ms!). A retaining wall located south of the site was constructed to raise the area to current grade. 1.04 Field Investigation Prior to the field investigation, a site reconnaissance was performed by an engineer from our office to mark the borings, as shown on the Site Plan, and to evaluate the boring locations with respect to obvious subsurface structures and access for the drilling rig. Underground Service Alert was then notified of the marked location for utility clearance . Our subsurface investigation consisted of drilling test borings utilizing a limited access drill rig equipped with a 6-inch diameter solid stem auger. See Appendix B for further discussion of the field exploration including logs of test borings . Borings were logged and sampled using Modified California Ring (Ring) and Standard Penetration Test (SPT) samplers at selected depth intervals. Samplers were driven into the bottom of the boring with successive drops of a 140-pound weight falling 30 inches. Blows required driving the last 12 inches of the 18-inch Ring and SPT samplers are shown on the boring logs in the "blows/foot" column (Appendix B). SPT was performed in the borings in general accordance with the American Standard Testing Method (ASTM) D1586 Standard Test Method. Representative bulk soil samples were also obtained from our borings and test pits . Each soil sample collected was inspected and described in general conformance with the Unified Soil Classification System (USCS). The soil descriptions were entered on the boring logs. All samples were sealed and packaged for transportation to our laboratory . I.OS Laboratory Testing Laboratory tests were performed on representative samples to verify the field classification of the recovered samples and to determine the geotechnical properties of the subsurface materials. All laboratory tests were performed in general conformance with ASTM or State of California Standard Methods. The results of our laboratory tests are presented in Appendix C of this report . Page 2 of 22 .:'i Ferri~ Square, Suite C San Diego, CA 92121 (858) 537~3999 ---.. .. -.. .. -.. -.. • • • • • • • • -- --- .. .. .. .. .. -.. - - Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad. California 1.06 Percolation Testing MTGL Project No. 1916Al2 MTGLLogNo. 17-1619 Percolation testing was conducted m general accordance with the guidelines presented in the Design Manual for Onsite Wastewater Treatment Systems, 2010 Edition of the County of San Diego Department of Environmental Health, Land and Water Quality Division. Two (2) test holes were drilled to about 5 feet below existing grade within the fill soils. The holes were pre-socked overnight and the tests were performed on November 14, 2017. The results indicate an infiltration rate of 0.956 inches per hour for P-1 and 0.638 inches per hour for P-2. Appendix D presents the results of the Percolation Testing . Page 3 of22 5 Fenis Square, Suite C San Diego. CA 92121 (858J 537-3999 --.. .. -.. -.. .. -.. -.. ... ---- -------.. ... .. .. -- ----- Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad. California 2.00 FINDINGS 2.01 REGIONAL GEOLOGIC CONDIDONS MTGL Project No. 1916A12 MTGLLogNo.17-1619 The site is located in the coastal portion of the Peninsular Range Province of California. This area of the Peninsular Range Province has undergone several episodes of marine inundation and subsequent marine regression throughout the last 54 million years, which has resulted in the deposition of a thick sequence of marine and nonmarine sedimentary rocks on the basement rock of the Southern California Batholith. Gradual emergence of the region from the sea occurred in Pleistocene time, and numerous wave-cut platforms, most of which were covered by relatively thin marine and nonmarine terrace deposits, formed as the sea receded from the land. Accelerated fluvial erosion during periods of heavy rainfall, coupled with the lowering of the base sea level during Quaternary times, resulted in the rolling hills, mesas, and deeply incised canyons which characterize the landforms in the general site vicinity today. 2.02 SITE GEOLOGIC CONDIDONS As observed during this investigation, and our review of geotechnical maps, the site is underlain at depth by Quaternary-aged Old Paralic Deposits, Unit 2-4 Undivided (QoP2-4) and Tertiary-aged Santiago Formation (Tsa). Previously placed engineered fill materials were encountered above the formational materials. Logs of the subsurface conditions encountered in our borings are provided in Appendix B. Generalized descriptions of the materials encountered during this investigation are presented below. Previously placed fill soils were encountered in the borings and extended up to 8½ feet below existing grade. As observed in our borings the fill materials consisted of reddish brown Silty Sand (SM) that was fine to coarse grained, moist to wet, and medium dense. In general, the fill soils are not considered suitable for support of proposed loading in their current condition. Recommendations are presented in this report for remedial grading of existing fill materials . Quaternary-aged Old Paralic Deposits, Unit 2-4 Undivided (Qorz-4) [formerly Terrace Deposits] was encountered in the borings at depths that ranged from existing seven (7) to 8Y2 feet below existing grade. As observed in our explorations, the Old Paralic Deposits consisted of Silty Sandstone 'SM', Poorly Graded Sandstone with Silt 'SP-SM', and Poorly Graded Sandstone 'SP'. Colors ranged from reddish brown, light brown, orangish brown, yellowish brown, and gray. The sandy materials were fine to coarse grained, moist, and weakly to moderate cemented. In general, the Old Paralic Deposits are considered suitable for support of structural loading in their current condition. Page 4 of 22 5 Ferris S4uarc. Suite C San Diego, CA 92121 (858) :\17-3999 -,. ---,. -----• .. .. .. .. .. -------.. .. .. -.. .. -.. .. -... .. ,. Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California MTGLProjectNo.1916Al2 MTGL Log No. 17-1619 Tertiary-aged Santiago Formation was encountered below the Old Paralic Deposits. The Santiago Formation material encountered consisted of light brown, fine grained Silty Sandstone 'SM' that was moist and weakly cemented. Gravel was encountered in the borings at the contact between the Old Paralic Deposits and Santiago Formation. In general, the sandy materials of the Santiago Formation are considered suitable for support of structural loading in their current condition; however, there are highly expansive clayey portions of the formation that require special handling during construction. 2.03 Groundwater Conditions Groundwater was not encountered in the borings drilled for this investigation. Based on the relative density of the formational materials at the site there is a high potential for perched water to appear along the contact between the fill soils and the formational materials. It should be recognized that excessive irrigation, or changes in rainfall or site drainage could produce seepage or locally perched groundwater conditions within the soil underlying the site . 2.04 Faulting and Seismicity Active earthquake faults are very significant geologic hazards to development in California. Active faults are those which have undergone displacement within the last approximately 11,000 years. Potentially active faults show evidence of displacement within the last approximately 1.6 million years. The site is not located within an Alquist-Priolo Earthquake Fault Zone and there are no known active faults mapped through the site, therefore, surface rupture of an active fault is not considered to be a significant geologic hazard at the site . Potential seismic hazards at the site are anticipated to be the result of ground shaking from seismic events on distant active faults. The nearest known active fault is the Rose Canyon fault zone, which is located about 4.5 miles west of the site. A number of other significant faults also occur in the San Diego metropolitan area suggesting that the regional faulting pattern is very complex. Faults such as those offshore are known to be active and any could cause a damaging earthquake. Other active faults within the region include the Coronado Banks fault zone, approximately 20.4 miles southwest of the site, and the Elsinore fault zone, approximately 23.1 miles northeast of the site. The San Diego metropolitan area has experienced some major earthquakes in the past, and will likely experience future major earthquakes . 2.05 LIQUEFACTION POTENTIAL Page 5 of22 S Fcnis Square, Suite C San Diego, CA 92121 (85HJ 537-3999 ----.. .. - ---- ------ • ---.. ---- -.. .. 11 ------.. Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California MTGL Project No. 1916Al2 MTGLLogNo. 17-1619 Liquefaction is a phenomenon where earthquake induced ground vibrations increase the pore pressure in saturated, granular soils until it is equal to the confining, overburden pressure. When this occurs, the soil can completely lose its shear strength and become liquefied. The possibility of liquefaction is dependent upon grain size, relative density, confining pressure, saturation of the soils, and strength of the ground motion and duration of ground shaking. In order for liquefaction to occur three criteria must be met: underlying loose, coarse-grained (sandy) soils, a groundwater depth of less than about 50 feet and a nearby large magnitude earthquake. Given the relatively dense nature of the subsurface soils, and the absence of a groundwater table, the potential for liquefaction at the site is considered to be negligible. 2.06 LANDSLIDES Evidence of ancient landslides was not found at the subject site. Recommendations are provided in the following sections of the report which will help to reduce the potential for future slope instabilities. 2.07 TSUNAMI AND SEICHE HAZARD The site is not located within an area mapped by the California Geological Survey as subject to inundation by tsunami. Given the location of the site at an elevation of approximately 155 feet ms!, the inundation hazard posed by tsunami is considered to be low. Seiches are not considered to be a hazard due the absence of above-ground tanks or reservoirs located immediately up gradient from the site. Page 6 of 22 5 Fcnis S4uare. Suite C San Diego, CA 92 l 21 (858) 537-3999 ----- -----... -- • -.. -.. ... ... ----- • ... .. .. • • -.. --.. Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad. California 3.00 CONCLUSIONS 3.01 GENERAL CONCLUSIONS MTGL Project No. 1916Al2 MTGLLogNo. 17-1619 Given the findings of the investigation. it appears that the site geology is suitable for the proposed construction. Based on the investigation, it is our opinion that the proposed development is safe against landslides and settlement provided the recommendations presented in our report are incorporated into the design and construction of the project. Grading and construction of the proposed project will not adversely affect the geologic stability of adjacent properties. The nature and extent of the investigation conducted for the purposes of this declaration are, in our opinion, in conformance with generally accepted practice in this area. Therefore, the proposed project appears to be feasible from a geologic standpoint. There appears to be no significant geologic constraint onsite that cannot be mitigated by proper planning, design, and sound construction practices. Specific conclusions pertaining to geologic conditions are summarized below: • Due to proximity of the site to regional active and potentially active faults, the site could experience moderate to high levels of ground shaking from regional seismic events within the projected life of the building. A design performed in accordance with the current California Building Code and the seismic design parameters of the Structural Engineers Association of California is expected to satisfactorily mitigate the effects of future ground shaking . • The potential for active (on-site) faulting is considered low . • The potential for liquefaction during strong ground motion is considered low . • The potential for landslides to occur is considered low if the remedial recommendations presented herein are incorporated. • The on-site fill materials are considered not suitable for structural support in their present condition. Recommendations are presented in the following sections for remedial grading at the site. • The proposed structures may be supported by a conventional shallow foundation system if the undocumented fill materials are mitigated as recommended . 3.02 EARIBQUAKE ACCELERATIONS \CBC SEISMIC PARAMETERS The 2016 California Building Code seismic design parameters were obtained from the USGS website using a project location of latitude 33.124° North and a longitude of 117.314° West. Based upon the anticipated grading requirements at the site a Site Class C was used for the project. The 2016 Seismic Design Parameters are presented below: Page 7 of22 5 Fenis S4uare, Suite C San Diego, CA 92121 (858) 537-3999 Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California Ground Motion Value Parameter Ss 1.135g S1 0.437g Site Class C SMs 1.135g SM1 0.595g Sos 0.757g Soi 0.397g 3.03 EXPANSION POTENTIAL MTGL Project No. 1916Al2 MTGL Log No. 17-1619 While not encountered in our investigation, there is a potential or highly expansive claystone materials to be encountered within the Santiago Formation. The claystones have a very high expansion potential and are not considered suitable for support of any new loads. Recommendations are provided in this report for mitigation of these highly expansive clayey materials if they are encountered. The fill materials observed at the site have a very low expansion potential and are considered suitable for use as engineered fill. Page 8 of 22 6295 Fem; S4uare. Suite C San Diego, CA 92121 (858) 537-3999 .. • .. .. .. • .. • - • .. • .. .. .. • -.. --.. -.. • .. --.. .. ·• .. ---.. -- Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad. California 4.00 RECOMMENDATIONS MTGL Project No. 1916A12 MTGL Log No. 17-1619 Our recommendations are considered minimum and may be superseded by more conservative requirements of the architect, structural engineer, building code, or governing agencies. The foundation recommendations are based on the expansion index and shear strength of the onsite soils. Import soils, if necessary should have a very low expansion potential (Expansion Index less than 20) and should be approved by the Geotechnical Engineer prior to importing to the site. In addition to the recommendations in this section, additional general earthwork and grading specifications are included in Appendix E . 4.0 I EXCAVATION CHARACTERISTICS/SHRINKAGE Our exploratory borings were advanced with little difficulty within the fill soils and no oversize materials were encountered in our subsurface investigation. Our exploratory borings were advanced with some effort within the weakly to moderately cemented formational materials. Accordingly, we expect that all earth materials will be rippable with conventional heavy-duty grading equipment with experienced operators and that oversized materials are not expected . Shrinkage is the decrease in volume of soil upon removal and recompaction expressed as a percentage of the original in-place volume, which will account for changes in earth volumes that will occur during grading. Bulking is the increase in volume of soil upon removal recompaction expressed as a percentage of the original in-place volume. Our estimate for shrinkage of the onsite fill soils are expected to range from 5 to 10 percent. Our estimate for bulking of the formational materials is estimated to range from 5 to IO percent. It should be noted that bulking and shrinkage potential can vary considerably based on the variability of the in-situ densities of the materials in question . 4.02 SETTLEMENT CONSIDERATIONS Based on the proposed grading recommendations, we anticipate that properly designed and constructed foundations that are supported on compacted fill materials will experience a total static settlement of up to 1.0 inch with differential settlements of ½ an inch. As a minimum, structures supported by shallow conventional foundations should be designed to accommodate a total settlement of at least 1.0 inch with differential settlements of½ an inch over a horizontal distance of 40 feet. Page 9 of 22 5 Fenis S4uarc, Suite C San Diego, CA 92121 (858) 537-3999 ·-.. .. .. -.. - • .. .. - • .. .. .. -- ·• .. ·• .. • .. .. -.. .. -.. .. .. .. - "'" -.. Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California 4.03 SITE CLEARING RECOMMENDATIONS MTGL Project No. 1916A12 MTGLLogNo.17-1619 All surface vegetation, trash, debris, asphalt concrete, portland cement concrete and underground pipes should be cleared and removed from the proposed construction site. Underground facilities such as utilities may exist at the site. Depressions resulting from the removal of foundations of existing buildings, buried obstructions and/or tree roots should be backfilled with properly compacted material. All organics, debris, trash and topsoil should be removed from the grading area and hauled offsite. 4.04 SITE GRADING RECOMMENDATIONS -STRUCTURES Remedial grading for new building at the site should include removal of all previously placed fills to expose undisturbed formational materials (Old Paralic Deposits, Unit 2-4). Based on information from the borings, removals may extend to about 8½ feet below existing grade. The bottom of the removals should then be evaluated by the geotechnical engineer or geologist to see if further remedial grading is warranted. The horizontal limits of the removals should extend to at least 5 feet beyond the building footprint. Once formational materials have been exposed and approved, the undocumented fill materials ( with an expansion index of less than 50 and with no deleterious materials) may be placed as compacted fill. Prior to fill placement, the exposed excavation bottom should be scarified to a depth of 8 to 12 inches, moisture conditioned and re-compacted. The materials should be compacted to at least 90 percent of the maximum dry density as determined by ASTM Test Method D1557 at a moisture content that is slightly above optimum moisture content. If encountered, the highly expansive claystone materials of the Santiago Formation should not underlie new structures. Remedial grading should include complete removal of all expansive claystone materials beneath the structure. The claystone materials should be properly disposed of off-site . Page 10 of22 5 Fenis Square, Suite C San Diego, CA 92121 (858} 537-3999 • .. • .. • • .. .. .. • .. .. .. .. .. .. .. .. -.. ---• .. ,. .. .. .. -.. .. .. .. .. -.. Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad. California 4.05 SITE GRADING RECOMMENDATIONS CUT/FILL TRANSIDON MTGL Project No. 1916A12 MTGLLogNo.17-1619 After remedial grading to remove all previously placed fill has been performed, there is a potential within the building footprint to have a transition where footings rest both on undisturbed formational materials and compacted fill. This 'cut/fill' transition could result in adverse differential settlement. To mitigate the cut/fill transition we recommend that the formational deposits within the cut portion of the building pad be over-excavated to a depth equal to one-half of the maximum fill depth (but not less than 3 feet) of the fill portion of the building pad. The depths are those measured from the bottom of the proposed footings. The over-excavated cut soils may then be placed as compacted fill. The purpose of the cut/fill mitigation is to provide a uniform fill mat of at least three (3) feet beneath all of the footings . 4.06 SITE GRADING RECOMMENDATIONS HARDSCAPE Hardscape areas should have the upper two (2) feet of previously placed fills removed and re- compacted as engineered fill. If dense formational materials are encountered prior to reaching the two feet, then the over-excavation may be terminated at the dense formational materials. Prior to re-compaction of soils, the exposed excavation bottom should be scarified to at least 8 to 12 inches, moisture conditioned, and compacted. The materials should be compacted to a minimum of 90 percent of the maximum density at a moisture content that is slightly above optimum. Processing for hardscape areas should extend a minimum of two (2) feet outside the hardscape limits. 4.07 COMPACTION REQUIREMENTS All fill materials should be compacted to at least 90 percent of maximum dry density as determined by ASTM Test Method D 1557. Fill materials should be placed in loose lifts, no greater than 8 inches prior to applying compactive effort. All engineered fill materials should be moisture- conditioned and processed as necessary to achieve a uniform moisture content that is slightly above optimum moisture content and within moisture limits required to achieve adequate bonding between lifts . 4.08 FILLMATERIALS Removed and/or over-excavated soils may be reused as engineered fill except for expansive soils ( expansion index greater than 50) and soils containing detrimental amounts of organic material, trash and other debris . Page 11 of22 5 Fenis S4uarc, Suite C San Diego, CA 92 I :! 1 (858J s:n~J999 - - -- • ---.. -.. ---.. - --- • ---.. .. .. ---.. Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California MTGL Project No. 1916Al2 MTGL Log No. 17-1619 hnported materials shall be free from vegetable matter and other deleterious substances, shall not contain rocks or lumps of a greater dimension than 4 inches, shall have an expansion index of less than 20, and shall be approved by the geotechnical consultant. Soils of poor gradation, expansion, or strength properties shall be removed off-site. 4.09 SLOPES Grading at the site may include construction of a minor fill slope. We recommend that slopes be inclined no steeper than 2: 1 (horizontal to vertical). Fills over sloping ground should be constructed entirely on prepared bedrock. In areas where the existing ground surface slopes at more than a 5: 1 gradient, it should be benched to produce a level area to receive the fill. Benches should be wide enough to provide complete coverage by the compaction equipment during fill placement. Slopes constructed at 2: 1 or flatter should be stable with regard to deep seated failure with a factor of safety greater than 1.5, which is the generally accepted safety factor. However, all slopes are susceptible to surficial slope failure and erosion, given substantial wetting of the slope face. Surficial slope stability may be enhanced by providing proper site drainage. The site should be graded so that water from the surrounding areas is not able to flow over the top of the slopes. Diversion structures should be provided where necessary. Surface runoff should be confined to gunite-lined swales or other appropriate devises to reduce the potential for erosion. It is recommended that slopes be planted with vegetation that will increase their stability. Ice plant is generally not recommended . 4.10 FOUNDATIONS The recommendations and design criteria are "minimum" in keeping with the current standard-of- practice. They do not preclude more restrictive criteria by the governing agency or structural considerations. The project structural engineer should evaluate the foundation configurations and reinforcement requirements for actual structural loadings. The foundation design parameters assume that remedial grading is conducted as recommended in this report, and that all the buildings are underlain by a relatively uniform depth of compacted fill with a low expansion potential (Expansion Index less than 50). Conventional shallow foundations are considered suitable for support of the proposed structure provided that remedial grading to remove undocumented fill materials and mitigation of cut/fill transitions are performed . Page 12 of22 5 Fcnis Square, Suite C San Diego, CA 92121 (858) 5:17-3999 ------ -- --- ----- ------ • .. • .. .. -.. ---- Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad. California MTGL Project No. 1916Al2 MTGLLogNo. 17-1619 Allowable Soil Bearing: Minimum Footing Width: Minimum Footing Depth: Coefficient of Friction: Passive Pressure: 3,000 lbs/ft2 (allow a one-third increase for short-term wind or seismic loads). The allowable soil bearing may be increase 500 lbs/ft2 for every 12-inch increase in depth above the minimum footing depth and 250 lbs/ft2 for every 12-inch increase in width above the minimum footing width. The bearing value may not exceed 5,000 lbs/ft2 24 inches 24 inches below lowest adjacent soil grade 0.35 350 psf per foot of depth. Passive pressure and the friction of resistance could be combined without reduction 4.11 CONCRE1E SLABS ON GRADE AND MISCELLANEOUS FLATWORK Interior slab-on-grade should be designed for the actual applied loading conditions expected. The structural engineer should size and reinforce slabs to support the expected loads utilizing accepted methods of concrete design, such as those provided by the Portland Cement Association or the American Concrete Institute. A modulus of subgrade reaction of 150 pounds per cubic inch (pci) could be utilized in design. Based on geotechnical consideration, interior slab for conventional slab-on-grade design should be a minimum of 5 inches and should be reinforced with at least No. 4 bars on I 8 centers, each way. Actual reinforcement should be designed by the project structural engineer based upon medium expansion potential. Structural slabs should be designed by the structural engineer and should span from foundation supports. Concrete slabs constructed on soil ultimately cause the moisture content to rise in the underlying soil. This results from continued capillary rise and the termination of normal evapotranspiration. Because normal concrete is permeable, the moisture will eventually penetrate the slab. Excessive moisture may cause mildewed carpets, lifting or discoloration of floor tiles, or similar problems . To decrease the likelihood of problems related to damp slabs, suitable moisture protection measures should be used where moisture sensitive floor coverings, moisture sensitive equipment, or other factors warrant. A commonly used moisture protection in southern California consists of about 2 inches of clean sand covered by at least 10 mil plastic sheeting. In addition, 2 inches of clean sand are placed over the plastic to decrease concrete curing problems associated with placing concrete directly on an impermeable membrane. However, it has been our experience that such systems will transmit from Page 13 of22 5 Fcnis S4uarc. Suite C San Diego, CA 92 ! 21 (858J s:n.J999 --- -- -----... -.. ,. .. .. ----------.. .. .. .. .. .. - , .. -- Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad. California MTGL Project No. 1916A12 MTGLLogNo.17-1619 approximately 6 to 12 pounds of moisture per 1,000 square feet per day. This may be excessive for some applications, particularly for sheet vinyl, wood flooring, vinyl tiles, or carpeting with impermeable backing that use water soluble adhesives. If additional moisture protection is needed, then a Stego Wrap moisture barrier, or equivalent, may be used in lieu of 10 mil plastic sheeting. The Stego Wrap should be installed per the manufacturers' recommendations. Concrete is a rigid brittle material that can withstand very little strain before cracking. Concrete, particularly exterior hardscape is subject to dimensional changes due to variations in moisture of the concrete, variations in temperature and applied loads. It is not possible to eliminate the potential for cracking in concrete; however, cracking can be controlled by use of joints and reinforcing. Joints provide a pre-selected location for concrete to crack along and release strain and reinforcement provides for closely spaced numerous cracks in lieu of few larger visible cracks. Crack control joints should have a maximum spacing of 5 feet for sidewalks and 10 feet each way for slabs . Differential movement between buildings and exterior slabs, or between sidewalks and curbs may be decreased by doweling the slab into the foundation or curb. Exterior concrete slabs on the expansive site soils may experience some movement and cracking . Exterior slabs should be at least 4 inches thick and should be reinforce with at least 6x6, W2.9/W2.9 welded wire fabric or No. 4 bars spaced at 18 inches on center, each way, supported firmly at mid-height of the slab. 4.12 PREWETIINGRECOMMENDATION The soils underlying the slab-on-grade should be brought to a minimum of 2% and a maximum of 4% above their optimum moisture content for a depth of 12 inches prior to the placement of concrete. The geotechnical consultant should perform insitu moisture tests to verify that the appropriate moisture content has been achieved a maximum of 24 hours prior to the placement of concrete or moisture barriers. 4.13 Corrosivity Corrosion series tests consisting of pH, soluble sulfates, soluble chlorides, and minimum resistivity were performed on selected samples of the on-site soils. Soluble sulfate levels for the on-site fill soils indicate a negligible sulfate exposure for concrete structure. As such, no special considerations are required for concrete placed in contact with the on-site soils. However, it is recommended that Type II cement to be used for all concrete . Page 14 of 22 '.) Penis Square. Suite C San Diego, CA 92121 (858) 537-3999 Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, Califo rnia MTGL Project No. 1916A 12 MTGL Log No. 17-16 19 Based on the soluble chloride levels the on-site soils have a degree of corrosivity to metals that is negligible. Based on the pH and Resistivity, the on-site soils have a degree of corrosivity to fe rrous metals that is corrosive. The actual corrosive potential is determined by many factors in addition to those presented herein. MTGL, Inc. does not practice corrosion engineering. Underground metal conduits in contact with the soil need to be protected. We recommend that a corrosion engineer be consul ted. 4.14 RETAJNING WALLS Embedded structural walls should be designed for lateral earth pressures exerted on the walls. The magnitude of these earth pressures will depend on the amount of deformation that the wall can yield under the load. If the wall can yield sufficiently to mobilize the full shear strength of the soils, it may be designed for the active condition. If the wall cannot yield under the applied load, then the shear strength of the soil cannot be mobilized and the earth pressures will be higher. These walls such as basement walls should be designed for the at rest condition. If a structure moves towards the retained soils, the resul ting resistance developed by the soil will be the passive resistance. For design purposes, the recommended equivalent fluid pressure for each case for walls constructed above the static groundwater table, backfilled with low expansive soils, and where remedial grading has been performed is provided below. Retainjng wall backfill should be compacted to at least 90% relative compaction based on the maximum density defined by ASTM D1 557. Retaining structures may be designed to resist the following lateral earth pressures. • Allowable Bearing Pressure -3,000 psf • Coefficient of Friction (Soil to Footing) -0.35 • Passive Earth Pressure -equivalent fluid weight of 300 pcf (Maximum of 2,000 pcf) • At rest lateral earth pressure -60 pcf • Acti ve Earth Pressures -equivalent fluid weights: Slope of Retained Equivalent Fluid Weight Material (pct) Level 40 2: l (H:V) 55 Page 15 of 22 6295 Fenis S4uare. Suite C San Diego. CA 921 :! I (858) 537-3999 .. .. .. • • • • -.. - • .. -- • .. .. -.. - • .. -.. • -.. • - • -.. -.. -.. Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California MTGLProjectNo.1916A12 MTGL Log No. 17-1619 It is recommended that all retaining wall footings be embedded at least 24 inches below the lowest adjacent finish grade. In addition, the wall footings should be designed and reinforced as required for structural considerations . Lateral resistance parameters provided above are ultimate values. Therefore, a suitable factor of safety should be applied to these values for design purposes. The appropriate factor of safety will depend on the design condition and should be determined by the project Structural Engineer. If any super-imposed loads are anticipated, this office should be notified so that appropriate recommendations for earth pressures may be provided . Retaining structures should be drained to prevent the accumulation of subsurface water behind the walls. Back drains should be installed behind all retaining walls exceeding 3.0 feet in height. A typical detail for retaining wall back drains is presented as Figure 3. All back drains should be outlet to suitable drainage devices. Walls and portions thereof that retain soil and enclose interior spaces and floors below grade should be waterproofed and damp-proofed in accordance with the 2016 CBC . For retaining walls exceeding 6 feet in height we recommend that a seismic retaining wall design be conducted by the structural engineer. For seismic design we used a peak site acceleration of 0.45g calculated from the modified seismic design parameters (Ss/2.5). For a retained wall condition, such as the planned basement levels, we recommend a seismic load of 18H be used for design. The seismic load is dependent of the retained wall height where H is the height of the wall, in feet, and the calculated triangular loads result in pounds per square foot exerted at the base of the wall and zero at the top of the wall. 4.15 FOUNDATION SETBACKS As a minimum, structural foundations should be setback from any descending slope at least 8 feet. Screen-wall foundations should have a minimum setback of 5 feet. The setback should be measured horizontally from the bottom outside edge of the footing to the slope face. The horizontal setback can be reduced by deepening the foundation to achieve the recommended setback distance projected from the footing bottom to the slope face. It should be recognized that the outer few feet of all slopes are susceptible to gradual down-slope movements due to slope creep. This will affect hardscape such as concrete slabs. We recommend that settlement sensitive structures, including concrete slabs, not be constructed within 5 feet of the slope top without a specific review by the geotechnical consultant. Page 16 of22 5 Fcnis Square. Suite C San Diego, CA 9212 J (8.'i8) 517-3999 .. 11 .. .. .. • • .. - • .. • .. .. .. .. .. ,. - - - • • - • .. .. .. .. - Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California MTGLProjectNo.1916Al2 MTGLLogNo. 17-1619 Utility trenches, swimming pools, and biorentention basins that are adjacent to foundations should not extend into the footing influence zone defined as the area within a line projected at a I: 1 (horizontal to vertical) drawn from the bottom edge of the footing . 4.16 Bro RETENTION BASIN Any bio retention basin proposed for the site should be designed by the project civil engineer using the information presented in this report. We recommend that the bio retention basin be lined with an impermeable barrier on the sides and bottom to prevent any water from migrating laterally into the foundations of the existing structures or onto the existing descending slope. A subdrain should be provided beneath the basin. Prior to discharge into the storm drain pipe, a seepage cutoff wall should be constructed at the interface between the subdrain and storm drain pipe. The concrete cutoff wall should extend a minimum of 6 inches beyond the perimeter of the gravel packed subdrain system . We performed two percolation tests at the site. The percolation tests were conducted in the undocumented fill soils that exist on the site. Remedial grading has been recommended which would result in the news fill soils being denser than the existing fills and subsequently less permeable. The Old Paralic Deposits which exist beneath the fill soils are not permeable. Because of these conditions we do not consider the site suitable for infiltration of storm water runoff. 4.17 CONS'IRUCTION CONSIDERATIONS 4.17 .1 MOISTURE SENSIDVE Son,s/WEATIIER RELATED CONCERNS The upper soils encountered at this site may be sensitive to disturbances caused by construction traffic and to changes in moisture content. During wet weather periods, increases in the moisture content of the soil can cause significant reduction in the soil strength and its support capabilities. In addition, soils that become excessively wet may be slow to dry and thus significantly delay the progress of the grading operations. Therefore, it will be advantageous to perform earthwork and foundation construction activities during the dry season. Much of the on-site soils may be susceptible to erosion during periods of inclement weather. As a result, the project Civil Engineer/Architect and Grading Contractor should take appropriate precautions to reduce the potential for erosion during and after construction . Page 17 of22 5 Ferris Sq_uare. Suite C San Diego, CA 92121 (858) 537-.3999 -.. .. .. - - • - • .. .. -.. ,. .. .. -- • - • -.. • • • • • • • -.. - Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad. California 4.17 .2 DRAINAGE AND GROUNDWATER CONSIDERATIONS MTGLProjectNo. 1916A12 MTGL Log No. 17-1619 Groundwater was not encountered in the borings drilled for this investigation. It should be noted, however, that variations in the ground water table may result from fluctuation in the ground surface topography, subsurface stratification, precipitation, irrigation, and other factors that may not have been evident at the time of our exploration. Seepage sometimes occurs where relatively impermeable and/or cemented formational materials are overlain by fill soils . We should be consulted to evaluate areas of seepage during construction . Water should not be allowed to collect in the foundation excavation, on floor slab areas, or on prepared subgrades of the construction area either during or after construction. Undercut or excavated areas should be sloped to facilitate removal of any collected rainwater, groundwater, or surface runoff. Positive site drainage should be provided to reduce infiltration of surface water around the perimeter of the building and beneath the floor slabs. The grades should be sloped away from the building and surface drainage should be collected and discharged such that water is not permitted to infiltrate the backfill and floor slab areas of the building . 4.17.3 TEMPORARY EXCAVATIONS AND SHORING Short term temporary excavations in existing soils may be safely made at an inclination of 1: 1 (horizontal to vertical) or flatter. If vertical sidewalls are required in excavations greater than 3 feet in depth, the use of cantilevered or braced shoring is recommended. Excavations less than 3 feet in depth may be constructed with vertical sidewalls without shoring or shielding. Our recommendations for lateral earth pressures to be used in the design of cantilevered and/or braced shoring are presented below. These values incorporate a uniform lateral pressure of 72 psf to provide for the normal construction loads imposed by vehicles, equipment, materials, and workmen on the surface adjacent to the trench excavation. However, if vehicles, equipment, materials, etc. are kept a minimum distance equal to the height of the excavation away from the edge of the excavation, this surcharge load need not be applied . Page 18 of 22 5 Ferris Square, Suite C San Diego, CA 92121 (858) 517-3999 -- --.. .. .. - - .. .. .. • - - -- • ,. - • -- Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California MTGL Project No. 1916Al2 MTGLLogNo.17-1619 H P ~ 30 H nsf 72 nsf P =25H sf P Total -72 psi+ 30 H psi P Total= 72 sf+ 25 H s! SHORING DESIGN: LATERAL SHORING PRESSURES Design of the shield struts should be based on a value of 0.65 times the indicated pressure, Pa, for the approximate trench depth. The wales and sheeting can be designed for a value of 2/3 the design strut value. STRUTS (lyp.) SHIELD (typ.) UNDISTURBED SOIL BEDDING Pa = 30 H'" psi HEIGHT OF SHIELD, H,h = DEPTH OF TRENCH, D1 , MINUS DEPTH OF SLOPE, H1 TYPICAL SHORING DETAIL Placement of the shield may be made after the excavation is completed or driven down as the material is excavated from inside of the shield. If placed after the excavation, some over- excavation may be required to allow for the shield width and advancement of the shield. The shield may be placed at either the top or the bottom of the pipe zone. Due to the anticipated thinness of the shield walls, removal of the shield after construction should have negligible effects on the load factor of pipes. Shields may be successively placed with conventional trenching equipment. Page 19 of 22 5 Penis Square. Suite C San Diego, CA 92121 (858J 537-W99 - - - -- .. ---.. --- - - M - ------ - - Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California MTGL Project No. 1916Al2 MTGL Log No. 17-1619 Vehicles, equipment, materials, etc. should be set back away from the edge of temporary excavations a minimum distance of 15 feet from the top edge of the excavation. Surface waters should be diverted away from temporary excavations and prevented from draining over the top of the excavation and down the slope face. During periods of heavy rain, the slope face should be protected with sandbags to prevent drainage over the edge of the slope, and a visqueen liner placed on the slope face to prevent erosion of the slope face. Periodic observations of the excavations should be made by the geotechnical consultant to verify that the soil conditions have not varied from those anticipated and to monitor the overall condition of the temporary excavations over time. If at any time during construction conditions are encountered which differ from those anticipated, the geotechnical consultant should be contacted and allowed to analyze the field conditions prior to commencing work within the excavation. All Cal/OSHA construction safety orders should be observed during all underground work. 4.17.4 UTILITYTRENCHES All Cal/OSHA construction safety orders should be observed during all underground work. All utility trench backfill within street right of way, utility easements, under or adjacent to sidewalks, driveways, or building pads should be observed and tested by the geotechnical consultant to verify proper compaction. Trenches excavated adjacent to foundations should not extend within the footing influence zone defined as the area within a line projected at a 1: 1 (horizontal to vertical) drawn from the bottom edge of the footing. Trenches crossing perpendicular to foundations should be excavated and backfilled prior to the construction of the foundations. The excavations should be backfilled in the presence of the geotechnical engineer and tested to verify adequate compaction beneath the proposed footing. Utilities should be bedded and backfilled with clean sand or approved granular soil to a depth of at least I-foot over the pipe. The bedding materials shall consist of sand, gravel, crushed aggregate, or native, free draining soils with a sand equivalence of not less than 30. The bedding should be uniformly watered and compacted to a firm condition for pipe support. The remainder of the backfill shall be typical on-site soil or imported soil which should be placed in lifts not exceeding 8 inches in thickness, watered or aerated to near optimum moisture content, and mechanically compacted to at least 90% of maximum dry density (ASTM D1557). Page 20 of 22 5 Ferris S<.juare, Suite C San Diego, CA 92121 (858) 537-3999 --- ---- -- - -- -- -.. .. - --- - Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California 4.17.5 SITE DRAINAGE MTGL Project No. 19l6A12 MTGLLogNo. 17-1619 The site should be drained to provide for positive drainage away from structures in accordance with the building code and applicable local requirements. Unpaved areas should slope no less than 2% away from structure. Paved areas should slope no less than 1 % away from structures. Concentrated roof and surface drainage from the site should be collected in engineered, non- erosive drainage devices and conducted to a safe point of discharge. The site drainage should be designed by a civil engineer. 4.18 GEOTECHNICAL OBSERV A TI ON/TESTING OF EARTHWORK OPERA TIO NS The recommendations provided in this report are based on preliminary design information and subsurface conditions as interpreted from the investigation. Our preliminary conclusion and recommendations should be reviewed and verified during site grading, and revised accordingly if exposed Geotechnical conditions vary from our preliminary findings and interpretations. The Geotechnical consultant should perform Geotechnical observation and testing during the following phases of grading and construction: • During site grading and over-excavation. • During foundation excavations and placement. • Upon completion of retaining wall footing excavation prior to placing concrete. • During excavation and backfilling of all utility trenches • When any unusual or unexpected Geotechnical conditions are encountered during any phase of construction. Page 21 of 22 5 Ferrif> S4uarc. Suite(' San Dicgn, CA 92121 (858) 537-3999 --- - - -.. -.. .. • --- .... .. .. --------- -.. Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California 5.00 LIMITATIONS MTGL Project No. 1916Al2 MTGLLogNo.17-1619 The findings, conclusions, and reconuuendations contained in this report are based on the site conditions as they existed at the time of our investigation, and further assume that the subsurface conditions encountered during our investigation are representative of conditions throughout the site. Should subsurface conditions be encountered during construction that are different from those described in this report, this office should be notified inuuediately so that our reconuuendations may be re-evaluated. This report was prepared for the exclusive use and benefit of the owner, architect, and engineer for evaluating the design of the project as it relates to geotechnical aspects. It should be made available to prospective contractors for information on factual data only, and not as a warranty of subsurface conditions included in this report. Our investigation was performed using the standard of care and level of skill ordinarily exercised under similar circumstances by reputable soil engineers and geologists currently practicing in this or similar localities. No warranty, express or implied, is made as to the conclusions and professional advice included in this report . This firm does not practice or consult in the field of safety engineering. We do not direct the Contractor's operations, and we are not responsible for their actions. The contractor will be solely and completely responsible for working conditions on the job site, including the safety of all persons and property during performance of the work. This responsibility will apply continuously and will not be limited to our normal hours of operation . The findings of this report are considered valid as of the present date. However, changes in the conditions of a site can occur with the passage of time, whether they are due to natural events or to human activities on this or adjacent sites. In addition, changes in applicable or appropriate codes and standards may occur, whether they result from legislation or the broadening of knowledge. Accordingly, this report may become invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and revision as changed conditions are identified. Page 22 of 22 :'i Ft!rris Square. Suite C San Dkgn, CA 92121 (858) 537-3999 - -.. - FIGURES - - - -.. - • ... ,. .. • .. .. -.. l'.\ND 1ilfiger arlsbad Outlet \nn Taylor ,zumiez Rubio s Coastal Grill cks B El ,vron 6 \irport Rd -0 Cl) lands en Cl) 0 CJ ~ 3e11 G) z 0 ;1 (I) The Flower Fields ~ Palomar Airport Rd 0 Carl s Jr 7-Eleven Q State of California Maintenance Stations REFERENCE: Google Maps, November 17, 2017. 1vn;1"11 ,~ n 1u.:,t\.. 6 e Wok 'N' Bowl Ramen ~ G, Karl Strauss Brewing Com ny Dino Island " SEA LIFE Aquariur Grand Pacific A Palisades Resort & ., ' ct> (.Q 0 Cl ::, 0. ~ SITE Palomar Airport Rd @ill @ill Palomar Airport Rd E1 Wells Fargo Bank 0 starbucks Go g le c ro "O (0 § <( • , ---• ' , ~ NOSCALE SITE LOCATION PLAN PROJECT NO. 1916A12 MTGL, INC Log No. 17-1619 FIGURE 1 EXISllNC 8UILOINC WISH flOOR = !6aJO \ 1os. B-2 ~ASS AREA~~ lIDill P-2T MOIi' STRIP \ ;._B_-1 ~AZ Ali'EA\ .P-1 l £X!SllNC BU/LO/NC /'!NISH flOOR = !55. !9 1" = 20' KEY: ~-2 ~ Boring Number and approximate location • P-1 REFERENCE: Topographic Survey provided by Excel Engineering, dated September 1, 2017. Percolation Number and approximate location SITE PLAN PROJECT NO. 1916A12 MTGL, INC Log No. 17-1619 FIGURE 2 ---.. .. .. --.. • -.. .. --.. ... -- -----.. ---- Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad. California MTGL Project No. 1916Al2 MTGLLogNo. 17-1619 Retaining wall Wall waterproofing per architect's specifications Provide open cell head joints or outlet drain at 50 feet on center to a ~ suitable drainage device ""' Finished Grade Compacted fill Wall footing SPECIFICATIONS FOR CLASS 2 PERMEABLE MATERIAL (CAL TRANS SPECIFICATIONS) Sieve Size % Passing 1" 100 3/4" 90-100 3/8" 40-100 No.4 25-40 No.8 18-33 No.30 5-15 No.SO 0-7 No.200 0-3 <1 4 ~ <1 4 ,¼ 0 0 0 0 0 /2 0 0 _o. Soil backfill, compacted to 90% relative compaction* Filter fabric envelope (Mirafi 140N or approved equivalent) •• Minimum of 1 cubic foot per linear foot of 3/4" crushed rock ~--3" diameter perforated PVC pipe (schedule 40 or equivalent) with perforations oriented down as depicted minimum 1 % gradient to suitable outlet. * Based on ASTM D1557 0 If class 2 permeable material (See gradation to left) is used in place of 3/4" -1 1/2" gravel. Filter fabric may be deleted. Class 2 permeable material compacted to 90% relative compaction. • RETAINING WALL DRAINAGE DETAIL Figure 3 5 Fenis Square, Suite C San Diego, CA 9212 ! (858) 537-.1999 --- "" ------.. • -.. -.. APPENDIX A --REFERENCES - - -.. -... .. .. - ----.. .. -- .. - - - -- ------ • ---.. - --- - - -- Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad. California APPENDIX A REFERENCES MTGLProjectNo. 1916A12 MTGL Log No. 17-1619 Anderson, J.G., Rockwell, T.K., Agnew, D.C (1989). Past and Possible Future Earthquakes of Significance to the San Diego Region, Earthquake Spectra, Vol. 4, No. 2, pp 299-335. California Building Standards Commission (2016). 2016 California Building Code, July 2016. California Division of Mines and Geology, 1997, Fault-Rupture Hazard Zones in California, Special Publication 42. California Emergency Management Agency (2009). Tsunami Inundation Map For Emergency Planning, Encinitas Quadrangle, June I. California Geological Survey, 2008, Guidelines for Evaluating and Mitigating Seismic Hazards in California, Special Publication 117. Excel Engineering (2017). Topographic Survey, Field Survey Performed August 16, 2017, dated September I, 2017. Kennedy, Michael P. and Siang Tan (2005). Geologic Map of the Oceanside 30' x 60' Quadrangle, California, USGS Digitally Prepared. Leighton and Associates (1997). Geotechnical Investigation, Proposed Carlsbad Ranch Hotel and Timeshare Resort, Lot 14 of Tract No. 92-7, Carlsbad Ranch, Carlsbad, California, Project No. 4971101-001, May 5. Seed, H.B. and Whitman, R.V., 1970, Design of Earth Structures for Dynamic Loads in ASCE Specialty Conference, Lateral Stresses in the Ground and Design of Earth-Retaining Structures. U.S. Geologic Survey (2017). Design Maps Summary Report, http://geohazards.usgs.gov/ U.S. Geologic Survey (2008). 2008 National Seismic Hazard Maps -Source Parameters. Page A-1 5 Ferri~ Square, Suite C San Diego, CA 92121 (858) .Y"7-3999 --- ------- .. --APPENDIXB -FIELD EXPLORATION PROGRAM .. -.. -.• --- - .. ----... .. -•• --- , .. --.. -----.. -.. -- ---.. -.. ---.. --- ---.. ---- Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad. California APPENDIXB FIELD EXPLORATION PROGRAM MTGLProjectNo. 1916Al2 MTGL Log No. 17-1619 The subsurface conditions for this Geotechnical Investigation were explored by excavating two exploratory borings. The exploratory borings were excavated using a 6-inch diameter solid-stem- auger to a maximum depth of 45½ feet below existing grade. The approximate locations of the borings are shown on the Site Plan (Figure 2). The field exploration was performed under the supervision of our engineer who maintained a log of the subsurface soils encountered and obtained samples for laboratory testing. All drive samples were obtained by SPT or California Tube Sampler. Subsurface conditions are summarized on the accompanying Logs of Borings. The logs contain factual information and interpretation of subsurface conditions between samples. The stratum indicated on these logs represents the approximate boundary between earth units and the transition may be gradual. The logs show subsurface conditions at the dates and locations indicated, and may not be representative of subsurface conditions at other locations and times. Identification of the soils encountered during the subsurface exploration was made using the field identification procedure of the Unified Soils Classification System (ASTM D2488). A legend indicating the symbols and definitions used in this classification system and a legend defining the terms used in describing the relative compaction, consistency or firmness of the soil are attached in this appendix. Bag samples of the major earth units were obtained for laboratory inspection and testing, and the in-place density of the various strata encountered in the exploration was determined The exploratory borings were located in the field by using cultural features depicted on a preliminary site plan provided by the client. Each location should be considered accurate only to the scale and detail of the plan utilized. The exploratory borings were backfilled in accordance with State of California regulations which incorporated compacting soil cuttings and bentonite chips. Page B-1 95 Fcnis Square. Suite C San Diego. CA 92121 (858J .'B7-3999 Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California MTGL Project No. 1916Al2 MTGL Log No. 17-1619 UNIFIED SOIL CLASSIFICATION SYSTEM (1.) GRAVELS Clean Gravels (less GW Well-graded gravels, gravel-sand mixtures. ~ (l'J > are more than half of than 5% fines) Ii ttle or no fines ·-·-(1.) 0 Cl')·- "'-;;i "' coarse fraction larger Poorly-graded gravels, gravel-sand mixtures, "2 ·c: 8 Gravels with fines GP c B N than #4 sieve little or no fines .§ E ~ SANDS Clean Sands (less Silty Gravels. poorly-graded gravel-(1.) ~c..... c'tS GM :c ~ 0 -5 are more than half of than 5% fines) sand-silt mixtures ·;;; '-N '- "' --(1.) ·s 0 -oil coarse fraction larger Clayey Gravels, poorly-graded gravel- (1.) u /I l!l Sands with fines GC u than #4 sieve sand-clay mixtures ·e "' Well-graded sands, gravelly sands, a. SW ~ little or no fines (1.) ~ SP Poorly-graded sands, gravelly sands, E little or no fines V) SIL TS AND CLAYS (1.) V) Silty Sands, poorly-graded sands--5 -;;i Liquid Limit SM -~ ·c: gravel-clay mixtures (1.) B (1.) Less than 50 > "' > Clayey Sands, poorly-graded sand-(1.) E -~ SC izi .... "' gravel-silt mixtures -e og Inorganic clays of low to med plasticity. "' ~N ML -0 -'*I: C /I C gravelly, sandy. silty, or lean clays "' ~ V) "' :-;: ..c Inorganic clays of low to med plasticity, u:i 0 -CL Vl .... gravelly, sandy. silty, or lean clays (1.) :j -0 -(1.) -;;i 8 -~ E OL Organic silts and clays <d "' of low olasticity N ~-~ ci (1.) SILTS AND CLAYS Inorganic silts, micaceous or diatomaceous z C Liquid Limit MH u: fine sands or silts Greater than 50 Inorganic clays of high plasticity, CH fat clavs OH Organic silts and clays of medium to high olasticity Highly Organic Soils PT Peat. humus swamp soils with high organic content GRAIN SIZE SIZE PROPORTION Descriotion Sieve Size Grain Size Aooroximate Size Trace -Less than 5% Boulders >12" >12" Larner than basketball-sized Few -5% to I 0% Cobbles 3"-12" 3"-12" Fist-sized to basketball-sized Little -15% to 20% Gravel Coarse ¾"-3" ¾"-3" Thumb-sized Some -30% to 45% Fine #4 -¾" 0.19" -0.75" Peat-sized to thumb-sized Most! y -50% to I 00% Coarse #10 -#4 0.079" -0.19" Rock salt-sized to oea-sized MOISTURE CONTENT Sand Medium #40-#10 0.017" -0.079" Sul!ar-sized to rock salt-sized Dry -Absence of moisture Fine #200 -#40 0.0029" -0.017" Flour-sized to sugar-sized Moist -Damo but not visible Fines Passing #200 <0.0029" Flour-sized or smaller Wet -Visible free water CONSISTENCY FINE GRAINED SOILS RELATIVE DENSITY COARSE GRAINED SOILS Apparent SPT Mod CA Sampler Apparent Densitv <Blows/Foot) (Blows/Foot) Densitv Very Soft <2 <3 Very Loose Soft 2-4 3-6 Loose Firm 5-8 7-12 Medium Dense Stiff 9-15 13-25 Dense Very Stiff 16-30 26-50 Very Dense Hard >30 >50 Page B-2 SPT <Blows/Foot) <4 4-10 11-30 31-50 <50 Mod CA Sampler <Blows/Foot) <5 5-12 13-35 36-60 <60 6295 Ferris Square. Suite C San Diego. CA 92121 (858) 537-3999 BORING NO. 1 Logged by: SEV Date Drilled: 10/30/2017 Method of Drilling: 6-inch diameter solid-stem auger limited access Elevation: 155' msl I-w w i1:' ;e-;:::-u.. ...J ...J a: a. a. 0 ~ '=-w :1: :iii: !:. w ::c a. < < > a: DESCRIPTION LAB TESTS I-Cl) Cl) Cl) I-::> I-a. == w ~ iii Cl) w 0 > ...J z 5 0 ...J ii: ::> w III 0 III 0 :1: Grass: Heavily irrigated. .... 1 '---FILL: Silty Sand (SM), reddish brown, fine to coarse, moist to wet, medium dense. Maximum Density & .... 2 Optimum Moisture, pH, Resistivity, ... 3 Sulfate, Chloride - 4 16 CAL 123 7.5 ... ... 5 ... 6 12 SPT -... 7 ... 8 - 9 26 CAL 110 8.8 ... -OLD PARALIC DEPOSITS, Unit 2-4, Undivided (Q0 p2-4): Silty Sandstone 'SM', .... 10 -orangish brown and gray, fine to coarse grained, moist, weakly to moderately cemented. .... 11 28 SPT Slightly clayey. -.... 12 .,_ 13 '-14 '-15 ..__ '-16 47 CAL -113 7.8 .... 17 .... 18 ... 19 -20 '---Reddish brown and gray. .... 21 26 SPT -... 22 -23 .. 24 '-25 ..__ ... 26 49 CAL ..__ 110 6.4 .... 27 .... 28 .... 29 .... 30 A 6295 Ferris Square, Suite C PROJECT NO. 1916A12 SanDiego,CA92121 LOG OF BORING PAGE B-1a (858) 537-3999 BORING NO.1 (Continued) Logged by: SEV Date Drilled: 10/30/2017 Method of Drilling: 6-inch diameter solid-stem auger limited access Elevation: 155' msl I-w w i:L ~ i=' u. ..J ..J a: a. a. 0 ~ !!:. w :ii: :ii: !:. w ::c a. ca: ca: >-a: DESCRIPTION LAB TESTS I-Cl) Cl) Cl) I-::, a. == w ~ in I- w ~ Cl) 0 0 ..J z 0 ..J a: ::, w aJ 0 aJ 0 :; (Continued) No. 200 Wash -31 24 SPT OLD PARALIC DEPOSITS, Unit 2-41 Undivided (O0p2-4): Poorly Graded .,__ -32 Sandstone with Silt 'SP-SM', light brown, gray, and yellow, fine to coarse grained, moist, weakly to moderately cemented. -33 (7.5% Passing No. 200 Sieve) -34 ... 35 .,__ ... 36 52 CAL .,__ 103 8.9 ... 37 ... 38 -----------------·------·------------------------------------------------------------------------------------ ... 39 Silty Sandstone 'SM', reddish brown and gray, fine to coarse grained, moist, moderately cemented. -40 .,__ ,.... 41 90-11" SPT Gravels. .,__ ,.... 42 ,.... 43 .,__ SANTIAGO FORMATION (Tsa): Silty Sandstone 'SM', light brown, fine grained, No. 200 Wash 44 80-11½' SPT moist, weakly cemented. /16.3% Passino No. 200 Sieve) ,.... -45 Total Depth: 44 feet Groundwater not encountered -46 Backfilled on 10/30/2017 -47 ... 48 ... 49 ... 50 ... 51 ,.... 52 ... 53 ... 54 I-55 -56 I-57 ... 58 I-59 ... 60 A 6295 Ferris Square, Sutte C PROJECT NO. 1916A12 SanDiego,CA92121 LOG OF BORING PAGE B-1b L-il i'1~f tilri. (858) 537-3999 BORING NO. 2 Logged by: SEV Date Drilled: 10/31/2017 Method of Drilling: 6-inch diameter solid-stem auger limited access Elevation: 155' msl I-w w i:L ~ [ u. .J .J a: C. C. 0 a., w :: :: !:!:.. w J: C. <( <( >-a: DESCRIPTION LAB TESTS I-fl) fl) fl) I-:::> C. 3: w ~ U) I-fl) w 0 > .J z 5 0 .J a: :::> w ID 0 ID 0 :: Grass: Heavily irrigated. ... 1 FILL: Silty Sand (SM), brown, fine to coarse, moist to wet, medium dense. ... 2 Expansion Index 3 25 CAL 111 8.9 ... -... 4 5 26 CAL 119 7.2 Direct Shear ... -... 6 - 7 19 CAL 120 9.8 Consolidation ... ,_ 8 ,___ OLD PARALIC DEPOSITS, Unit 2-4, Undivided (Q0 p24): Silty Sandstone 'SM', mottled reddish brown, yellow, and gray, fine to coarse grained, moist, weakly 9 29 CAL cemented. -,___ ... 10 -- ... 11 Weakly to moderately cemented. 38 SPT (22.2% Passing No. 200 Sieve) No. 200 wash --... 12 ... 13 Slightly clayey. ,_ 14 ,_ 15 - 16 45 CAL 108 5.2 ,_ - ,_ 17 -----------------·------·-----------------------------------------------------------------------------------,_ 18 Poorly Graded Sandstone 'SP', gray and yellowish brown, fine grained, moist, ... 19 weakly cemented. -20 ,___ ... 21 22 SPT ,___ ... 22 -23 ... 24 ,_ 25 ,___ ··-·sg·· -----·ffo-·------------------------------------------------------------------------------------ 26 CAL 6.2 -,___ Silty Sandstone 'SM', reddish brown, fine to coarse grained, moist, moderately ... 27 cemented. ... 28 ... 29 ,_ 30 ~ 6295 Ferris Square, Suite C LOG OF BORING PROJECT NO. 1916A12 San Diego, CA 92121 PAGE B-2a . (858) 537-3999 BORING NO. 2 (Continued) Logged by: SEV Date Drilled: 10/31/2017 Method of Drilling: 6-inch diameter solid-stem auger limited access Elevation: 155' msl t w w L2 -.:-..J ..J :,!! a: 0. 0. (.) ~ !:!:. w :E :E !:, w :c 0. < < > a: DESCRIPTION LAB TESTS I-tn tn tn I-:::> I-0. 3: w ~ iii tn w 0 ~ ..J z 5 0 ..J a: :::> w III 0 III 0 :E (Continued) ... 31 26 SPT OLD PARALIC DEPOSITS, Unit 2-4, Undivided (O0p2-4): Silty Sandstone 'SM', ... 32 reddish brown, fine to coarse grained, moist, weakly cemented . -33 -34 -35 ---------1-------·------·------------------------------------------------------------------------------------ ... 36 50 CAL 105 7.0 Poorly Graded Sandstone with Silt 'SP-SM', light brown, fine grained, moist, weakly cemented. ,_ 37 ... 38 ... 39 -40 -Gravel. -41 78-9" ~ ,_ 42 SANTIAGO FORMATION (Tsa): Silty Sandstone 'SM', light brown, fine to coarse grained , moist, weakly cemented . ... 43 .,.. 44 - "" 45 60 SPT ... 46 Total Depth: 45½ feet .,.. 47 Groundwater not encountered Backfilled: 10/31/2017 ... 48 .,.. 49 -50 -51 -52 -53 -54 ... 55 ... 56 -57 -58 -59 -60 .. 6295 Ferris Square, Suite C PROJECT NO. 1916A12 SanDiego,CA92121 LOG OF BORING PAGE B-2b AlU ,\ i I t-h.. (858) 537-3999 PERCOLATION NO. 1 Logged by: SEV Date Drilled: 11/13/2017 Method of Drilling: 3½-inch diameter hand auger Elevation: 155' msl t w w U:-~ .=-.J .J 0 a: Q. Q. ~ !:!::. w :i: :i: e:. w J: Q. <( <( > a: DESCRIPTION LAB TESTS I-(/) (/) (/) I-:J I-Q. ;= w ~ cii (/) w 0 > .J z 0 C .J ir :J w ID C ID C :i: ,_ 1 FILL: Silty Sand (SM), reddish brown, fine to coarse, moist to wet, medium dense. ,_ 2 ,_ 3 ,_ 4 ,_ 5 ,_ 6 ,_ 7 ,_ 8 ,_ 9 ,_ 10 ,_ 11 ,_ 12 ,_ 13 -14 ,_ 15 -16 ,_ 17 ,-18 -19 ,-20 ,_ 21 ,_ 22 ,_ 23 ,-24 ,-25 -26 ,_ 27 ,_ 28 ,_ 29 ,_ 30 A 6295 Ferris Square, Suite C PROJECT NO. 1916A12 SanDiego,CA92121 LOG OF BORING PAGE 8-3 ..l\111114 • f tt.. (858) 537-3999 ,., PERCOLATION NO. 2 Logged by: SEV Date Drilled: 11/13/2017 Method of Drilling: 3½-inch diameter hand auger Elevation: 155' msl I-w w r2 -;:::-LL ...J ...J -;!?_ a: 0.. 0.. 0 ~ !:!:. w ~ ~ !:. w J: 0.. ct ct > a: DESCRIPTION LAB TESTS I-(/) (/) (/) I-::, 0.. 3: w ~ iii I- w > (/) 0 ...J z 0 C ...J ii: ::, w Ill C Ill C ~ -1 FILL: Silty Sand (SM), brown, fine to coarse, moist to wet, medium dense. ,-2 -3 -4 -5 ,-6 ,-7 ,-8 ,-9 -10 -11 1-12 1-13 1-14 -15 -16 -17 1-18 ,_ 19 1-20 ,-21 ,-22 -23 -24 ._ 25 ,-26 ,-27 ,-28 -29 -30 ~ 6295 Ferris Square, Suite C PROJECT NO. 1916A12 SanDiego,CA92121 LOG OF BORING PAGE 8-4 (858) 537 .3999 APPENDIXC LABO RA TORY TEST PROCEDURES APPENDIXC LABO RA TORY TESTING PROCEDURES 1. Classification 2. Soils were classified visually, generally according to the Unified Soil Classification System. Classification tests were also completed on representative samples in accordance with ASTM D422 for Grain Size. The test resultant soil classifications are shown on the Boring Logs in Appendix B. In-Situ Moisture/Density The in-place moisture content and dry unit weight of selected soil samples were determined using relatively undisturbed samples from the Cal Tube Sampler. The dry unit weights and moisture contents are shown on the Boring Logs in Appendix B. 3. Percent Passing No. 200 Sieve Particle size determinations for the percentage of sample passing the No. 200 sieve were performed in general accordance with the laboratory procedures outlined in ASTM test Method Dl 140. The results are shown on the Boring Logs in Appendix B. 4. Maximum Density Maximum density tests were performed on a representative bag sample of the near surface soils in accordance with ASTM Dl557. Test results are presented on the table below. Sample Description Maximum Dry Optimum Moisture Location Density (pcf) Content(%) B-1 at 1' to 5' Silty Sand (SM) -Reddish Brown 132 9.0 5. Direct Shear Direct Shear Tests were performed on an in-place sample of site soils in accordance with ASTM D3080. The test results are presented in Figure C-1. Page C-1 6295 Fen-is Square. Suite C San Diego. CA 92121 (858) 537-3999 Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California 6. Expansion Index MTGL Project No. 1916Al2 MTGL Log No. 17-1619 Expansion Index testing was completed in accordance with the standard test method ASTM D4829. Test results are presented below. Sample Description Expansion Index Expansion Location (El) Index B-2 at 2' to 4 ' Silty Sand (SM) -Brown 0 Very Low 7. Corrosion Chemical testing was performed on a representative sample to determine the corrosion potential of the onsite soils. Testing consisted of pH, chlorides (CTM 422), soluble sulfates (CTM 417), and resistivity (CTM 643). Test results are as follows: Sample pH Chlorides Sulfates Resistivity Location (oom) (ppm) (ohm-cm B-1 at 1' to 5' 7.3 99 276 1,700 8. Consolidation Consolidation tests were performed on representative, relatively undisturbed samples of the underlying soils to . determine compressibility characteristics in accordance with ASTM D2435. Test results are presented on Figure C-2. Page C-2 6295 FcrTis Square. Suilc C San Diego, CA 92121 (858) 537-3999 H ;,1:?~::; -=~= :::. :r:: -47 -,---+ ....... ---... --.... + .... ........ o ~-·-•··+ ........ _ ....... t ....... . I •• 0 2000 4000 6000 Normal Stress. psf ---r-..._ - -+ +-------...... -- T+.- T t:: i -• +-... "1' • . ~--'--... -.. .. .. .. --+---i ! t + i I I + + t . -+ .... ---, •I .. • • + • f t .,_ ---+-'t' t I ~--+ t' ' .... ....-.... ,.. ...... 8000 10000 6000 .. . -.... t -+ ~ -~-. -!-+ I Sample No. 1 2 -. . . -. .. T . . --· I . . ... r t . . -----t ' t + . --t Water Content,% 7.2 7.2 5000 ... --+-T . I t -. ... + t Dry Density, pcf 118.6 118.9 . --. .....,_ -. . +-.J._ -+ . . . . -t • . 1 t + ~ Saturation, % 48.3 49.1 --. t ------t --+ + • l-•• I I •• • •• ·r 12000 3 7.-4 117.5 48.1 f----• --+--,+ --. ' 4000 ·c Void Ratio 0.3948 0.3910 0.4076 .... V) . + --+ • . + -• + a. ' i-I I I ... ,-~ -+. -T vi ;. + l-~ I ----V) . !'"/'"' l + I I ' !!:? ·-- u5 3000 1~ -t . . . + ... • . ; ... .... . I • + • t" + --<1l (I) + I . . -; . + ' .c -. . +---. ~ I -+ + -(/J 2000 W; --+-----t ' .... •-+ . '. --. --t -+ . . • + ;::/ r"t.' + ---+ -. I 1000 I t . -I . . ..._ __ -. + -. + ' . t l . -. -• -~-+ T ---..... t 1 • . -+ . ' I ?" .... _..__, 0 0 5 10 15 20 Strain,% Sample Type: Description: Silty Sand (SM) -Brown Assumed Specific Gravity= 2.65 Remarks: Figure C-l 3 2 1 Diameter, in. 2.42 2.42 2.42 Heiaht, in. 1.00 1.00 1.00 Water Content,% 14.5 14.1 14.4 Dry Density, pct 119.6 120.5 119.6 0 Saturation, % 100.0 100.0 100.0 (I) ~ < Void Ratio 0.3830 0.3729 0.3830 Diameter, in. 2.42 2.42 Heiaht, in. 0.99 0.99 Normal Stress, psf l000 2000 Fail. Stress, psf 1274 1684 Strain,% 4.6 6.1 Ult. Stress , psf 886 1415 Strain,% 14.6 14.7 Strain rate, in./min. 0.010 0.010 Client: Project: HILTON TAPESTRY Sample Number: B2 Depth: 4' Proj. No.: 19l 6-Al2 Date Sampled: DIRECT SHEAR TEST REPORT MTGL, Inc. San Dieao. CA 2.42 0.98 4000 33 12 5.6 2974 14.7 0.0 10 CONSOLIDATION TEST REPORT -0.2 \ 0.0 0.2 0.4 0.6 C § cil E o.a 2l Q) 0.. 1.0 \ ' \ '-.. I\ " - ~ :\ ' \ 1, ' ~ i\ ' ~ :\ V ~ ~i Water A~d "\ ' \ 1.2 ....___ ............... \ ............ ...._ 1.4 1.6 1 8 100 DRY DENSITY MOISTURE (pcf) CONTENT, (%) INITIAL 119.7 9.8 FINAL 13.8 -... ...... i""'l ~ 1000 Pressure. p, psf ~ SUMMARY OF TEST RESULTS SATURATION VOID SPECIFIC OVERBURDEN Pc (%) RATIO GRAVITY (psf) (psf) 67.6 0.182 2.65 2053 100.0 0.365 Depth: 6' Sample Number: 82 Material Description: Silty Sand (SM) -Brown Remarks: uses: MTGL, Inc. Client: Project: HILTON TAPESTRY San Die o CA Project No.: 1916-Al2 \ -\ !SWELL PRESS Cc (psf) 0.03 AASHTO: Figure C-2 • .. • • - • - • • - APPENDIXD PERCOLATION TEST -.. • --- - Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California APPENDIXD PERCOLATION TEST MTGL Project No. 1916Al2 MTGLLogNo. 17-1619 Two percolation tests were conducted in general accordance with the guidelines presented in the Design Manual for Onsite Wastewater Treatment Systems (March 22, 2010 Edition) of the County of San Diego Department of Environmental Health Land and Water Quality Division. The percolation holes were drilled with a 3¼-inch auger to a depth of five (5) feet below existing grade . The Site Plan, shows the approximate location of the percolation tests. The holes were presoaked overnight and the test was performed on November 14, 2017. The percolation test results are presented on Figures D-1 and D-2. Water was added during the percolation tests to help maintain a constant level of water within the infiltration zone. The infiltration rate was estimated using the Porchet Method with the percolation test data. The results of the percolation study indicates an infiltration rate of 0.956 in/hr for P-1 and 0.638 81/hr for P-2. Page D-1 5 Fc1Tis Square, Suit..: C San Diego, CA 92121 (858) 537-3999 PERCOLATION DATA SHEET - Project Name: Hilton Tapestry Job No.: 1916A12 Tested By: SEV Test Hole No: P-1 Date Excavated: 11/13/2017 Date Tested: 11/14/2017 ... Depth of Test Hole: 60Inches Soil Classification: Silty Sand 0: 3.25 Inches Check for Sandy Soil Criteria Tested By: Date: Presoak: SANDY SOIL CRITERIA TEST • .. Trial Time Initial Final Change in No. Time Interval Water Level Water Level Water Level (min.) (inches) (inches) (inches) .. -ii 1 I I 0:00 I I I 0.00 I 2 0:00 0.00 .. Use Normal Sandy (Circle One) Soil Criteria .. .. .. Reading Time Total Initial Final Change in Percolation Time Interval Elapsed Time Water Leve1<1> Water Level Water Level Rate Number (min.) (hrs:min) (inches) (inches) (inches) (min/inch) 1 7:04 0:30 0:30 10.25 28.75 18.50 1.62 7:34 2 7:34 0:30 1:00 5.00 23.50 18.50 1.62 8:04 3 8:04 0:30 1:30 1.50 20.00 18.50 1.62 8:34 4 8:34 0:30 2:00 5.25 20.75 15.50 1.94 9:04 5 9:04 0:30 2:30 4.50 20.50 16.00 1.88 9:34 -.. 6 9:34 0:30 3:00 4.00 19.00 15.00 2.00 10:04 -7 10:04 0:30 3:30 4.25 19.25 15.00 2.00 10:34 8 10:34 0:30 4:00 3.00 17.75 14.75 2.03 11 :04 Average (of last 2) = 2.02 111 Water added to test hole after reading. Infiltration Rate (Porchet Method}: Ho= 56.38 IIH 60 r Hf= 41.50 II 11 (in/hr)= 0.956 II I,= Lit (r+2Havg) IIH = 14.88 (Last 2 readings) Hava;:: 48.94 Project No. 1916A12 Log No. 17-1619 FIGURE D-1 --PERCOLATION DATA SHEET Project Name: Hilton Tapestry Job No.: 1916A12 Tested By: SEV Test Hole No: P-2 Date Excavated: 11/13/2017 Date Tested: 11/14/2017 .. Depth of Test Hole: 62Inches Soil Classification: Silty Sand !<I: 3.25 Inches -Check for Sandy Soil Criteria Tested By: Date: Presoak: SANDY SOIL CRITERIA TEST - ·• Trial Time Initial Final Change in No. Time Interval Water Level Water Level Water Level (min.) (inches) (inches) (inches) - I 1 I I 0:00 I I I 0.00 I 2 0:00 0.00 • Use Normal Sandy (Circle One) Soil Criteria - • - Reading Time Total Initial Final Change in Percolation Time Interval Elapsed Time Water Leve1<1> Water Level Water Level Rate Number (min.) (hrs:min) (inches) (inches) (inches) (min/inch) .. 1 7:06 7:36 0:30 0:30 3.75 19.50 15.75 1.90 2 7:36 8:06 0:30 1:00 8.00 17.50 9.50 3.16 3 8:06 8:36 0:30 1:30 3.50 15.00 11.50 2.61 -4 8:36 0:30 2:00 3.00 14.25 11.25 2.67 9:06 5 9:06 9:36 0:30 2:30 6.50 15.25 8.75 3.43 6 9:36 10:06 0:30 3:00 3.25 13.50 10.25 2.93 -7 10:06 0:30 3:30 2.00 13.25 11.25 2.67 10:36 8 10:36 11 :06 0:30 4:00 2.25 13.00 10.75 2.79 Average (of last 2) = 2.73 ('I Water added to test hole after reading. Infiltration Rate (Porchet Method): Ho= 59.88 IIH 60 r Hf= 48.88 II I, (in/hr)= 0.638 II I,= Ill (r+2Ha,g) IIH = 11.00 (Last 2 readings) Havn = 54.38 Project No. 1916A 12 Log No. 17-1619 FIGURE D-2 APPENDIXE STANDARD GRADING SPECIFICATIONS Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California APPENDIXE MTGL Project No. 1916Al2 MTGL Log No. 17-1619 GENERAL EARTHWORK AND GRADING SPECIFICATIONS GENERAL These specifications present general procedures and requirements for grading and earthwork as shown on the approved grading plans, including preparation of areas to be filled, placement of fill, installation of subdrains, and excavations. The recommendations contained in the attached geotechnical report are a part of the earthwork and grading specifications and shall supersede the provisions contained herein 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. EARTHWORK OBSERVATION AND TESTING Prior to the start of grading, a qualified Geotechnical Consultant (Geotechnical Engineer) shall be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report and these specifications. It will be necessary that the Consultant provide adequate testing and observation so that he may determine that the work was accomplished as specified. It shall be the responsibility of the Contractor to assist the Consultant and keep them apprised of work schedules and changes so that he may schedule his personnel accordingly. It shall be the sole responsibility of the Contractor to provide adequate equipment and methods to accomplish the work in accordance with applicable grading codes or agency ordinances, these specifications and the approved grading plans. Maximum dry density tests used to determine the degree of compaction will be performed in accordance with the American Society for Testing and Materials Test Method (ASTM) Dl557. PREPARATION OF AREAS TO BE FILLED Clearing and Grubbing: All brush, vegetation and debris shall be removed or piled and otherwise disposed of. Page E-1 5 Ferris Squme. Suitt: C San Diego. CA 9212 I (R"i8) 537-3999 -.. • • • Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California MTGL Project No. 1916Al2 MTGLLogNo.17-1619 Processing: The existing ground which is determined to be satisfactory for support of fill shall be scarified to a minimum depth of 12 inches. Existing ground, which is not satisfactory, shall be overexcavated as specified in ~he following section. Overexcavation: Soft, dry, spongy, highly fractured or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, shall be overexcavated down to firm ground, approved by the Consultant. Moisture conditioning: Overexcavated and processed soils shall be watered, dried-back, blended, and mixed as required to have a relatively uniform moisture content near the optimum moisture content as determined by ASTM D1557. Recompaction: Overexcavated and processed soils, which have been mixed, and moisture conditioned uniformly shall be recompacted to a minimum relative compaction of 90 percent of ASTMD1557 . Benching: Where soils are placed on ground with slopes steeper than 5: 1 (horizontal to vertical), the ground shall be stepped or benched. Benches shall be excavated in firm material for a minimum width of 4 feet. FILL MATERIAL General: Material to be placed as fill shall be free of organic matter and other deleterious substances, and shall be approved by the Consultant. Oversize: Oversized material defined as rock, or other irreducible material with a maximum dimension greater than 12 inches, shall not be buried or placed in fill, unless the location, material, and disposal methods are specifically approved by the Consultant. Oversize disposal operations shall be such that nesting of oversized material does not occur, and such that the oversize material is completely surrounded by compacted or densified fill. Oversize material shall not be placed within 10 feet vertically of finish grade or within the range of future utilities or underground construction, unless specifically approved by the Consultant. Import: If importing of fill material is required for grading, the import material shall meet the general requirements . Page E-2 5 Fenis S4.uare. Suit1: C San Diego, CA 92121 (858) 5.17-3999 - Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad. California FILL PLACEMENT AND COMPACTION MTGL Project No. 1916Al2 MTGLLogNo. 17-1619 Fill Lifts: Approved fill material shall be placed in areas prepared to receive fill in near-horizontal layers not exceeding 6 inches in compacted thickness. The Consultant may approve thicker lifts if testing indicates the grading procedures are such that adequate compaction is being achieved with lifts of greater thickness. Each layer shall be spread evenly and shall be thoroughly mixed during spreading to attain uniformity of material and moisture in each layer. Fill Moisture: Fill layers at a moisture content less than optimum shall be watered and mixed, and wet fill layers shall be aerated by scarification or shall be blended with drier material. Moisture conditioning and mixing of fill layers shall continue until the fill material is at uniform moisture content at or near optimum. Compaction of Fill: After each layer has been evenly spread, moisture conditioned, and mixed, it shall be uniformly compacted to not less that 90 percent of maximum dry density in accordance with ASTM D1557. Compaction equipment shall be adequately sized and shall be either specifically designed for soil compaction or of proven reliability. to efficiently achieve the specified degree of compaction. Fill Slopes: Compacting on slopes shall be accomplished, in addition to normal compacting procedures, by backrolling of slopes with sheepsfoot rollers at frequent increments of 2 to 3 feet as the fill is placed, or by other methods producing satisfactory results. At the completion of grading, the relative compaction of the slope out to the slope face shall be at least 90 percent in accordance with ASTM D1557. Compaction Testing: Field tests to check the fill moisture and degree of compaction will be performed by the consultant. The location and frequency of tests shall be at the consultant's discretion. In general, these tests will be taking at an interval not exceeding 2 feet in vertical rise, and/or 1,000 cubic yards of fill placed. In addition, on slope faces, at least one test shall be taken for each 5,000 square feet of slope face and/or each 10 feet of vertical height of slope. SUBDRAIN INSTALLATION Subdrain systems, if required, shall be installed in approved ground to conform to the approximate alignment and details shown on the plans or herein. The subdrain location or materials shall not be changed or modified without the approval of the Consultant. The Consultant, however, may recommend and, upon approval, direct changes in subdrain line, grade or materials. All subdrains should be surveyed for line and grade after installation and sufficient time shall be allowed for the surveys, prior to commencement of fill over the subdrain. Page E-3 5 Ferris Square, Suite C s,m Diego. CA 92121 (858) 537-3999 -- Hilton Tapestry Resort Expansion -Geotechnical Investigation Carlsbad, California EXCAVATION MTGL Project No. 1916Al2 MTGL Log No. 17-1619 Excavations and cut slopes will be examined during grading. If directed by the Consultant, further excavation or overexcavation and refilling of cut areas, and/or remedial grading of cut slopes shall be performed. Where fill over cut slopes are to be graded, unless otherwise approved, the cut portion of the slope shall be made and approved by the Consultant prior to placement of materials for construction of the fill portion of the slope. Page E-4 5 Fen-is Squan.:. Suite C San Diego. CA 921~1 (858) 537-3999 Corporate: Phone: 714.632.2999 -FAX: 714.632.2974 2992 E. La Palma Ave, Suite A, Anaheim, CA 92806 Dispatch: 800.491.2990 San Diego/Imperial County: Phone: 858.537.3999 -FAX: 858.537.3990 6295 Ferris Square, Suite C, San Diego, CA 92121 Dispatch: 800.491 .2990 Inland Empire: Phone: 951 .653.4999 -Fax: 951 .653.4666 14467 Meridian Pkwy., Bldg. 2-A, Riverside, CA 92518 Dispatch: 800.491.2990 Indio: Phone: 760.342.4677 -Fax: 760.342.4525 44917 Golf Center Parkway, Suite 1, Indio, CA 92201 Dispatch: 800.491.2990 PROJECT LISTINGS: Highways; Streets; Airfield Paving; Parking Lots; Garages; Vehicle Maintenance; Park- ing Decks; Commercial Buildings; Shop- ping Centers; Educational Facilities; Classrooms; Office Buildings; Industrial Parks; Hospitals & Medical Facilities; Utilities; Gas, Water, Electric; Auditoriums & Theaters; Postal Facilities; Housing