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Home My WebLink AboutPIP 05-13; VIASAT LOT 4; UPDATE OF REPORT OF GEOTECHNICAL INVESTIGATION; 2005-09-09w CHR.ISTIAN WHEELER ENGINEER.ING September 9, 2005 RREEF CWE 2040295.05 2131 Palomar Airport Road, Suite 100 . Carlsbad, California 92008 Attention: SUBJECT: References: Rich Ruz)'lo UPDATE OF REPORT OF GEOTECHNICAL INVESTIGATION, LINCOLN NORTHPOINTE DEVELOPMENT, LOT 4, EL CAMINO REAL, CARLSBAD, CALIFORNIA. 1) "Report of Geotechnical Investigation, Buildings 4a & 4b, Lincoln Northpointe Deyelopment, El Camino Real, Carlsbad, California," prepared 0' Christian \"'\,11eeler Engineering, Report No, 2040295.04, dated July 19,2004. 2) Site Plan, Proposed Shell Building Deyeloped By: RREEF/VIASAT, North Pointe Tech Center, RreefLot 4, El Camino Real, Carlsbad, California, 0' Smith Consulting Architects, dated August 12,2005. Ladies and. Gentlemen: In accordance '.vith the request of Smith Consulting Architects, we have reyiewed the r.evised project plans .. and prel?ared this report to prO\·ide updated geotechnical recommendations, if necessary, for the currently proposed project. The proposed construction that was addressed by the referenced report \vas to consist of constructing two, two-story office buildings on the subject lot, along with the associated parking and driveways. One building was to be 34,500 square feet in area and the other was to be 22,500 square fect in area. W'e understand that rather than constructing these two separate office buildings, the project will now consist of the constluction of a single, 60,OOO-squarc;-foot office building. The currently proposed building is also expected to be of concrete tilt-up construction with conventional spread foundations and on-grade concrete floor slabs. 4 9 25M ere u r y S t r e e t.. San Die go, C A 9 2 1 1 1 + 8 5 8 -4 9 6 -9 7 6 0.. FAX8 '; 8 -4 9 6 -9 7 5 8 C\'(!E 2040295.05 September 9, 2005 Page No. 2 Based on our review of the referenced site plan and of our referenced geotechnical report, it is our opinion that the conclusions and recommendations remain applicable to the revised project. It should be noted, though, that the site preparation for the proposed building will need to be performed in accordance with the recommendations presented for Building 4b in the referenced report. To reiterate, it was 'recommendedthat the existing soils be removed to a minimum depth of five (5) feet below the building pad, be well mixed, and be replaced as uniformly compacted fill, at a moisture content of at least 3 percent above optimum. The removal should extend to a minimum distance of ten (10) feet outside the perimeter. of the building and th~ bottom of the excavation should be sloped at least two (2) percent from the center to the four outside edges of the excavation. If you have any questions after reviewing this report, please do not hesitate to contact our office. This opportunity to be of professional service is sincerely appreciated, Respectfully submitted, CHRISTIAN WHEELER ENGINEERING G4/J/£ Charles H. Christian, R.G.E. #00215 ~,~. Curtis R. Burdett, C.E.G. #1090 CHC:CRB:scc cc: (6) Smith Consult,1nt Architects, Att: Scott Cairns, 12220 El Ca~n(j Real"Suite 200, San Diego, CA 92130 .. J :.1 I' J I' I 'I I I 'I' ,I I I I I I 'I I I II CHRJSTIAN WHEELER. ENGINEER.ING REPORT OF GEOTECHNICAL INVESTIGATION PROPOSED BUILDINGS 4a & 4b LINCOLN NORTHPOINTE DEVELOPMENT EL CAMINO REAL CARLSBAD, CALIFORNIA SUBMITTED TO: 'RREEF 2131 PALOMAR AIRPORT ROAD, SUITE 100 CARLSBAD, CALIFORNIA 92008' SUBMITTED BY: CHRISTIAN WHEELER ENGINEERING 4925 MERCURY STREET SAN DIEGO, CALIFORNIA 92111 4925 M.ercury Street" San Diego, CA 92111 .. 858-496-9760" FAX 858-496-9758 ,I J ~ ~ ~ ~ ,I ~ " ,I ,I ~I j !'I I '( I; I I' I I July 19, 2004 RREEF' w CHRISTIAN WHEELER ENGINEER-ING CW'E 2040295.04 2131 Palomar Airport Road, Suite 100 Carlsbad, California 92008 Attention: SUBJECT: Reference: Rich Ruzylo REPORT OF GEOTECHNICAL INVESTIGATION, BUILDINGS 4a & 4b, LINCOLN NORTHPOINTE DEVELOPMENT, EL CAMINO REAL, CARLSBAD, CALIFORNIA. 1) "Geotechnical Investigation for Hughes Project, Carlsbad, Califort)ia," prepared I?J Robert Prater Associates, dated March 27, 1997. 2) "Supplemental Geotechnical Investigation for Lincoln Northpointe, Carlsbad, California," prepared f?y Robert Prater Associates, dated December 2, 1997. 3) "Report of Grading Observations and Testing, Lincoln Northpointe, Carlsbad Tract 98-07, EI Camino Real, Carlsbad, California," prepared 1:;' Christian \'\'he"eler Engineering, dated May 26, 1999. Ladies and Gentlemen: In accordance with tlle request of Smith Consulting Architects and our Proposal dated March 24, 2004, tllls report has been prepared to update the referenced geotechnical reports to reflect the proposed development of Lot 4 of Carlsbad Tract 98-07. This lot was originally graded as part of tlle Lincoln Northpointe development, located west of El Camino Real and soutll of Palomar Airport Road, in Carlsbad, California. As part of our scope of surfaces, we have completed a supplementary geotechnical investigation for the subject lot. \\Te are presenting herewitll our findings and recommendations. In general;our findings indicate that the subject lot is suitable for the proposed construction, provided the recommendations provided herein are followed. \\Te have determined that the lot is underlain by Tertiary-age 4925 Mercury Street + .San Diego, CA 92111 + 858-496-9760 + FAX 858-496-9758 C\VE 2040295.04 July 19, 2004 Page No. 2 deposits of the Delmar Fonnation that are overlain by a relatively thin layer of fill in the western portion ot the lot. The near surface soils of the Delmar Formation in the northerly portion of the site were found to be moderately to highly expansive while the near surface soils in southerly half of the site were found to be very highly expansive. As such special foundation and slab recommendations are provide in the attached report. In addition, recommendations are presented to undercut the building pad for Building 4b, mix the excavated . . soils and replace them at an elevated moisture content. Undercutting of the subgrade soils in the southerly half of the site is also recommended. The thin cap of fill material, 1 to 1.5 feet thick, is considered unsuitable in its present condition to sUpp9rt fill and/ or sett1e~ent sensitive improvements. As such, any fill material not removed by the planned or 'recommended grading will need to be removed and replaced as structural fill. The site is located in an area that is relatively free of geologic hazards that will have a significant effect on the proposed development. The most significant geologic hazard that could affect the site is ground shaking due to seismic activity along one of the regional actiye faults. However, construction in accordance with the . requirements of the most recent edition of the Uniform Building Code and the local governmental agencies . should provide a level of life-safety suitable for the type of development proposed. If you have any questions after reviewing this report, please do not hesitate to contact our office. This opportunity to be of professional service is sincerely appreciated. Respectfully submitted, CHRISTIAN WHEELER ENGINEERING Charles H. Christian, R.G.E. #00215 Oj~ Curtis R. Burdett, C.E.G. #1090 CI:iC:CRB:scc:wm . . . cc: (6) Smit11 Consultant Architects, Att: Scott Cairns, 12220 EI Camino Rea~ Suite 200, San Diego, CA 92130 , , , I I , , , I , , , , , , , ~. , , TABLE OF CONTENTS PAGE Introduction and Project Description .............................................................................................................................. ; ..................... 1 Project Scope ............................................................................................................................................................................................. 2 Findings .......................................................................................................................................................................................... : .......... 3 Site Description ........................................................................... ; ..................................................... ~ .................................................. 3 General.Geology and Subsurface Conditions ................................................................................................................................. 3 Geologic Setting and Soil Description ........................................................... ~ ............................................................... 3 .L\rtificial Fill ................................ ~ ........................................................ ~ ........................................................................................ 3 Dehnar Formation ....................................................................................................................................................................... 4 Groundwater .............................................................................. : ................. : .................................................................... 4 Tectonic Setting ............................................................................................................................................................... 4 Geologic Hazards ................................................................................................................................................................................. 5 . Ground Shaking ................................................................................................... ~ ............................................................ 5 Conclusions ................................................................................................................................................................... ~ ............... : ......... :. 5 Recommendations .................................................................................................................................................... : ..................... ~ ........ 6 Grading and ·Earthwork ............................................................................................................................. : ......................... : .............. 6 General ................................................................ ~ ............................................................................................................. 6 Observation of Grading ............................................................................. : ................. ~ ............................ : ....... ~ ............. 6 Clearing and Grubbing ................................................................................................................... : ................................. 6· Site Gradin.g ............................................................................... ~ .............................................. : ....................................... 6 Processing of Fill Areas ................................................................................................................................. : ................. 7 . Compaction and 1fethod of Filling ........................................................................................................... , ................... 7 Surface Drainage .......... , .......................... : .................................................................................................................... ,: .. 8 . Foundations ........................................................................................................................................................................................... 8 General ................................................................................................ : ............................................................................. 8 Conventional Foundations .......................................................................................... :.: .................... : ........................... 8 Bearing Capacity ................................................. , ................................................ , ........................................................ : .. 8 . Footing Reinforcing .................................................................................................................................... : ......... ; ......... 8 Lateral Load Resistance .................................................................................................................................. : ............... 8 Settlement Characteristics .............................. ; ............................................................................................................... 9 Expansive Characteristics ............................................................................................... ~ ......... ~ ..................................... 9· Foundation Plan Review ............................. , ........................................................................................... : ....................... 9 Foundation Excavation Observation .................................. : .............. · .......................................................................... 9 Seismic Design Parameters ...................................................................................................................... , ....... ~ ................................... 9 On-Grade Slabs ............................................................................................................................................................... , ......... : ........ 10 General ..................................................................................... : ........................................................... : .......................... 10· Interior Floor Slabs ................................................................................................................................................... · .... 10 J\;foisture Protection for Interior Slabs .................................... ; ............. ; ...... : ...... ~ ...................................................... 10 Exterior Slabs ................................................................................. ~ ....................................... : ....................................... 1 0 Soluble Sufates .................................................................................................................. : ........................................... : ................. , ... 11 Preliminary Pavement Section .. ; ................................. : .................................................................................................................... 11 Traffic Index ................................................................................................... : ..... ~ ....... : ......................... ; ....................... 11 R-V alue Test ..................................................... ; ................................... : .............. , .......................................................... 11 . Preliminary Structural Section ............................... ; ............................................................. · ........ : ........................ : ....... 11 . Lixnitations ............................................................................................................................................................................................... 12 Review, Observation and Testing ..................................................................................................................................................... 12 Uniformity of Conditions ......................................................................................................................... ~ ........................................ 12 Change in Scope ................................................................................................................ ~ ..... ; ............................................ : ..... : .. : .... 13 TJrIle Lixnitations .... : .................................................................................................................................. : ........................................... 13 Professional Standard ................................................................................ : .......................... : ............................... : ..................... , ........ 13 Client's Responsibility ........................................................................................................................................ : ................................ 13 Field Explorations ................................................................................................. l ...................................... : ....... : ........................ ~ ........ 14 Laboratory Testing ................... : .............................................. ; ......................... ~ ..................... ; .............................................................. 14 C\'{lE 2040295.04 Proposed Buildings 4A & 4B, Lincoln Northpointe Development El Camino Real, Carlsbad, California TABLES Table I Table II FIGURES F:igure 1 PLATES Plate 1 Plates 2-7 ATTACHMENTS Maximum Ground Acceleration, Page 5 Seismic Design Parameters, Page 10 Site Vicinity Map, Follows Page 1 Site Plan Boring Logs APPENDICES . Appendix A References Appendi.'{ B Recommended Grading Specifications -General Provisions C\VE ~040295.04 Proposed Buildings 4,-\ & 4B, Lincoln Northpointe Development EI Camino Real, Carlsbad. California f , , , CHRJSTIAN WHEELER. ENGINEER.ING REPORT OF GEOTECHNICAL INVESTIGATION PROPOSED BUILDINGS 4a & 4b LINCOLN NORTHPOINTE DEVELOPMENT EL CAMINO REAL CARLSBAD. CALIFORNIA INTRODUCfIONAND PRO]ECf DESCRIPTION 1bis report presents the results of a geotechnical investigation for two proposed two-story office buildings to be constructed on Lot 4 of the Lincoln Northpointe development, Carlsbad Tract 98-07, El Camino Real, in the city of Carlsbad, Ca:lifornia. Figure Number 1 presented on the following page provides a vicinity map showing the location of the property. 1bis lot is within the Lincoln Northpointe development, located west of El Camino Real and south of Palomar Airport Road, in Carlsbad, California. We understand that it is proposed to construct two, two-story office buildings on the subject lot, along with the associated parking and driveway~. One buUding will be 34,500 square feet in area and the other will be 22,500 square feet in area. We expect that the buildings will be of concrete tilt-up construction with conventional spread foundations and on-grade concrete floor slabs. , Grading is expected to consist orcuts and fills of less than about five feet from the existing grades. To aid in the preparation of this report, we were provided with a site plan prepared by Smith Consultant Architects, dated June 2, 2004. A copy of the site plan was modified to show our geologic mapping and is included herewith as Plate Number L 1bis report has been prepared for the exclusive use ofRREEF and their design consultants for specific application to the project described herein.' Should the project be changed in any way, the modified plans should be submitted to Christian \'Vheeler Engineering for review to determine their conformance with our recommendations and to determine if any additional subsurface investigation, labora'tory testing and/or recommendations are necessary. O~r professional services have been performed, our findings obtained and our recommendations prepared in accordance with generally accepted engineering principles and practices. This warranty is in lieu of all other warranties, express or implied. 4925 Mercury Street .. San Diego, CA 92111 .. 858-496-9760 .. FAX 858-496.9758 I , , , , , I , , '""' ~ _11 , I ;; l' North CWE2040295 SITE VICINITY MAP (Adapted from Thomas Brothers Maps) PROPOSED BUILDINGS 4A & 4B LINCOLN NORTHPOINTE DEVELOPMENT EL CAMINO REAL CARLSBAD. CALIFORNIA July 2004 Figure 1 I I , , " .. , , , , , , , , , '!:II , ~ ~ ~ ,I I C\VE,2040295.04 July 19, 2004 Page No. 2 PROJECT SCOPE Our geotechnical investigation consisted of surface reconnaissance, subsurface exploration, obtaining representative soil samples, laboratory testing, analysis of the field and laboratory data and review of relevant geologic literature. Our scope of service did not include assessment of hazardous substance contamination, recommendations to prevent floor slab 'moisture intrusion or the formation of mold within the structure, or any other services not specifically described in the scope of services presented ~elow. Mote specifically, the intent of this investigation was to: a) Explore the subsurface conditions of the site to the depths influenced by the pr~posed cons truction; b) Evaluate, by laboratory tests, the engineering properties of the, various' strata that may inOuence the proposed development, including bearing capacities, expansive characteristics and settlement potential; c) " Describe the general geology at the site including possible geologic hazards that could have an effect 'on the site development, and provide the seismic design parameters as required by the most recent edition of the Uriiform Building Code; d) Develop soil engineering criteria for site preparation and grading; e) Recommend an appropriate foundation system for the type of strilctures anticipated and develop soil engineering design criteria for the'recommended foundation design; f) Provide recommendations' for structural pavement sections; g) Present our professional opinions in this report, which includes in addition to our conclusions and recommendations, a plot plan, exploration logs and a summary. of the laboratory test results Although tests for the presence of soluble sulfates within the soils that may be in contact with reinforced concrete were performed as part of the scope of our services, it should be understood Christian \v1J1eeler Engineering does not practice corrosion engineering. If such an analysis is considered necessary, we recommend that the client retain an engineering firm that specializes in this field to cons~lt witll them on this , , , , , , , , , , , ~ , ..,.. J , , ~ C\VE 2040295.04 July 19,2004 Page No. 3 matter. The results of these tests 'should only b~ used as ~ guideline to detennine if additional testing and analysis is necessary. Additionally, our approved scope of service did not include assessments of hazardous substance contamination, the formation of mold within the proposed structure, or any. other services not specifically described. FINDINGS SITE DESCRIPTION The subject lot is a vacant, rectangular-shaped lot, identified as Lot 4 of the Lincoln Nor~pointe development, Carlsbad Tract 98-07. The lot is located to the west ofEl Camino Real and to the south of Palomar Airport Road, in the city of Carlsbad, California. The lot is bordered on the'east by El Camino Real, and on the nQrth, south and east by paved driveways. The lot ~as originally graded into a relatively' level pad in 1999. The gradinK of the subject lot involved cutting down the eXisting'gra~es by about 10 to 12.feet. The grading operation was observed and testing was performed by Christian \'V'heeler Engineering. The as.:.gradecl . . . Geotechnical report is identified by Report No. 198.064.11, and was dated May 26, 1999; Topographically, the site is relatively level. Vegetation on-site consists of grass and low bushes. GENERAL GEOLOGY AND SUBSURFACE CONDITIONS GEOLOGIC SETTING AND SOIL DESCRIPTION: The subject lods located in the Co~stal Plains' Physiographic Province of San Diego County. Based on the results of our subsurface explorations and review of . pertinent, readily available geologic literature, the lot was detennined to be underlain by Tertiary-age derosits the Delmar Formation that are overlain by a relatively thin layer of fill in the western portion of the lot. Each.of the encountered soil units is discussed below. ARTIFICIAL FILL: A relatively thin layer of fill was encountered within our exploratory boringS, B-1, B-S, and B-6. The £ill layer extended to a depth of only about 1 to 1.5 feet below existing site grades. We expect that the fill material consists of disturbed "cut" soils associated with. the rough grading of the site, and are relatively minor in extent The fill material generally consisted of medium brown, clayey sand, .(SC) that was typically moist and loose to medium dense in consistency. The existing fill is expected to possess a "low" to "moderate" Expansion Index and moderate settl~ment potential. The fill is considered unsuitable in its present condition to support settlement-sensitive improvements. , I , , , , , , , , I , , , ~ I C\,{'E 2040295.04 July 19, 2004 Page No. 4 DELMAR FORMATION (Td): Tertiary-age deposits of the Dehnar Fonnation were encountered at the surface within our exploratory borings B-2 through B-4, and below the fill within borings B-1, 13-5, and B-6. TIlls fonnation underlies the entire site. The materials of the Dehnar Fonnation typically consist of interfingered light grayish-brown, silty sand (S~1), medium reddish-brown, clayey sand (sq, medium grayish-brown, sandy clay (CL), and light reddish-brown, sandy silt (ML). These materials were typically damp to moist and dense to very dense in the sandy portion, and stiff to very stiff in the clayey portion. The materials of the Dehnar Formation were found to possess a "medium" to ''very high" R,--pansion Index and high strength parameters. These materials are considered suitable in th~ present " condition to support setdement-sensitive improvements. GROUNDWATER: Groundwater was not encountered in ,any of our exploratory borings ami" we 'do not anticipate that any groundwater-related problems will be encountered either during or after the proposed construction. TECTONIC SETTING: It should be noted that much of Southern California, ,including th~ San,Diego County area, is characterized by a series of Quaternary-age fault zone~ that consist of several individual, en echelon faults that generally strike in a northerly to northwesterly direction. Some of these fault zones (and the individual faults within dle zone) are classified as "active" according to the criteria of the California Division of Mines and Geology. , Active fault zones are those that have shown conclusive evidence of faulting during the Holocene Epoch (the most recent 11,000 years). The Division of Mines and Geology, used the tenn "potentially active" on Earthquake Fault Zone maps until 1988 to refer to all Qua~ernary-a~e Qast 1.6 million years) £'lults for the purpose of evaluation for possible zonation in accordance ~th the Alquist-Priolo Earthq~ake Fault Z~mlrig Act and identified all Quaternary-age faults as "potentially active" except for certain faults that wer~ presumed to be inactive based on direct geologic evidence of inactivity during all of Holocene time or longer. Some faults considered to be "potentially active" would be considered to be "active" but lack specific criteria used by the , State Geologist, such as sl1fidentfy adive and well-defined. Faults older than Quatemary-age are not specifically defmed in Special Publication 42, Fault RuptUre Hazard Zones in California, published by the California Division of Mines and Geology. However, it is generally accepted that faults showing no movement during the Quaternary period may be considered to be "inactive". A review of available geologic maps indicates that a portion of the Rose Canyon Fault Zone is located' approximately 11 kilometers southwest of the site. Other active fault zones in the region that could possibly affect the site include the Coronado Bank and San Clemente Fault Zones to the SOUdlW~St, the Elsinore" I , , , , , , , , , , , , I , , e!I , e!i CWE 2040295.04 July 19, 2004 Page No. 5 Earthquake Valley, San Jacinto, and San Andreas Fault Zones to d1e norilieast, and d1e Newport-Ing\e\vood and Palos Verdes Fault Zones to d1e noriliwest. GEOLOGIC HAZARDS GROUND SHAKING: A likely geologic hazard.to affect the site is ground shaking as a result of movement along one of ilie major active fault zones mentioned above. The maximum ground ac:;celerations d1at would be attributed to a maximum probable earthquake occurring along the nearest fault segments of se~ected fault zones that could affect ilie site are summarized in Table I presented below. TABLE I: MAXIMUM GROUND ACCELERATIONS Fault Zone Distance Max. Magnitude Maximum Ground Earthquake Acceleration Rose Canyon" llkm 6.9 Magnitude 0.24g: Newport-Inglewood 16km 6.9 Magnitude 0.19 g Coronado Bank 36km 7.4 lvfagnitude O.13g Elsinore Gulian) 37km 7.1 ~1agnitude 0.11 g Eariliquake Valley 64km 6.5 Magnitude O.OSg Palos Verdes 6Skm 7.1 Magnitude 0.07 g Probable ground shaking levels at ilie site could range from slight to moderate, depending on such factors as the magnitude of the seismic event and ilie distance to ilie epicenter. It is likely iliat the site will experience ilie effects of at least one moderate to large eariliquake during ilie life of the proposed improvements. CONCLUSIONS " In general, our ftndings indicate iliat the subject lot is suitable for the proposed construction, provided ilie " recommendations provided herein are followed We have determined that the lot is underlain by Terti~-3ge " " deposits of ilie Delmar Fonnation iliat are overlain by a relatively iliin layer of @l material in ilie western portion of ilie lot. The near surface soils were detennined to have moderate to very high expansion potential, -. .' . . wiili the very highly expansive soils in ilie souilierly portion of ilie site where building 4b is proposed. In " " consideration of dus, it is recommended iliat ilie existing soils in ilie area of Buil~g 4b be removed to a depth of five feet, be well mixed wlth ilie less expansive" soils, and be replaced at an elevated moisture conten t. Both buildings mn also require strengthened foundations and thickened; more heavily reinforced floor slabs. C\"V.E 2040295.04 July 19, 2004 Page No. 6 The thin layer of fill material is considered unsuitable in its present condition to support fill and/or settlement , , sensitive improvements. As such, any,fill material not removed by the planned grading will need to be removed and replaced 'as structural fill. The site is located in an area that is relatively free of geologic hazards that will have a significant effect on the proposed development. The most significant geologic hazard that could affect the site is ground shaking due to seismic activity along one of the regional active faults. However, construction in accordance with the requirements of the most recent edition of the Uniform Building Code and the local governmental agencie~' should provide a level of life-safety suitable for the type of development proposed. RECOMMENDATIONS GRADING AND EARTHWORK GENERAL: All grading should conform to the guidelines presented in Appendix Chapter A33 of the Uniform Building Code, the minimum requirements of the city of Carlsbad, and the recommended Grading Specifications and Special Provisions attached hereto, except where specifically superseded in the text of this report. Prior to grading, a representative of Christian \"VheeIer Engineering sh~uld be present at the pre- construction meeting to provide additional grading guidelines, if necessary, and to review the earthwork schedule. , , OBSERVATION OF GRADING: Continuous observation by the Geotechnical Consultant is essential during the site preparation and grading operitions to co~ftnn conditions anticipated by our in~estigation, to allow adjustments in design criteria to reflect actual field conditions exposed, and to determine that the grading proceeds in general accordance with the recommendations contained herein. CLEARING AND GRUBBING: Site preparation should begin with the removal of all ~egetation and other deleterious materials from the site. This should include all significant ~oot material. The 'resulting materials should be disposed of off-site in a legal dumpsite. It should be noted that discing of the vegetation into the surficial soils is not an acceptable form of removal. SITE GRADING: Site grading will consist of cuts and fills of up to about three feet from existing site grades. Any o'f the existing fill material that is not removed by the planned grading, or the building pad undercut recommended hereinafter, will need to be removed to expose the Delmar Formation material and , , I , , , , , , , , I I I , C\'{i'E 2040295.04 July 19,2004 Page No. 7 replaced as structural fill. The bottom of the excavations should be approved by our project geologist, engineer, or technician supervisor prior to placing fIlls or constructing improvements. In the area of Building 4b, it is recommended that the existing soils be removed to a min~um depth of fIve (5) feet below the building pad, be well mixed, and be replaced as uniformly compacted fill, at a moisture content of at least 3 percent· above optimum. The purpose of this recommendation is to reduce the expansive potential of the clayey soils that underlie the southerly portion of the building pad. The removal. should extend to a minimum distance of ten (10) feet outside the perimeter of the building. The bottom of.- the ex.cavation should be sloped at least two (2) percent from the center to the four outside edges of the excavation. This recommendation is made in order to reduce the possibility of irrigation water seeping into the fill and migrating under the building along the contact with the fill and formational soils. In addition to overexcavating the soil~ below the pad for Building 4b, we recommend that the'subgrade soils on the south, east .and west sides of Building 4b also be overexcavated to a depth of two (2) feet below the 'pavement subgrade and be 'replaced at a moisture content of at least three (3) feet above optimum moisture content. This recommendati~n is also made in order to reduce the expansive potential of the clayey soils tha~ underlie the 'proposed pavements. PROCESSING OF FILL AREAS: Prior to placing any new f1ll s<?ils in ~rea's that have been cleaned out to receive f1ll and approved by the Geotechnical Consultant or his representative, the exposed soils sha'uld be scarifIed to a depth of 12 inches, moisture conditioned, and compacted to at least 90 percent relative compaction. No other special ground preparation is anticipated at this time. COMPACTION AND METHOD OF FILLIN:G: All structural f1ll placed at the site should b~ compa<:t~d to a relative compaction of at least 90 per~ent of its maximum laboratory dry de~sity as determined by ASThf .. Laboratory Test D1557-91. Fills should be placed at or slighdy above optimum moisture content, in lifts six to ~ght inches' thick, with each lift compacted by mechanical means. Fills shoul~ consist of approved earth materia~ free of trash or debris, roots, vegetation, or other materials determined to be unsuitable by the Geotechnical Consultant. Fill material should be free of rocks or lumps of soil in exc.ess of twelve inches in . . . maximum dimension. However, in the upper two' feet of pad grade, no rocks or lumps of soil ~ excess of si.'i: inches f!hould be allowed. Utility trench backfill within fIve feet of the proposed buildings and beneath all concrete flatWork should be compacted to a minimum of 90 percent of its maximum dry density. All aggregate base material si1Quld be compacted to at least 95 percent of its maximum dry density as determined by ASThI Test D1557-91. In I• .. I , I , , I , I , J , , , , , , p , CWE 2040295.04 July 19, 2004 Page No·. 8 addition, just prior to placing the aggregate base material the subgrade soils should be ·scarified to a depth of 12 inches, m~isture conrutioned to near optimum moisture content, and compacted. to at least 95 percent of its maximum dry density. SURFACE DRAINAGE: The ground around the proposed buildings should be graded so that surface water flows rapidly away from the buildings without ponding: In general, we recommend that the ground adjacent to" the buildings slopes away at a gradient of at least two percent. Densely vegetated areas where runoff can be. impaired should have a minimum gradient of five percent within the first five feet from the . .. structure. Gutters and downspouts should discharge to controlled drainage systems. FOUNDATIONS GENERAL: It is our opinion that the proposed tilt-up struc·tures may be supported by conventi~nal continuous and spread footings. The following recommendations are considered the minimum based on soil conditions and are· not intended to be lieu of structural considerations. All foundations should be· designed by a . qualified structural engineer. CONVENTIONAL FOUNDATIONS: Conventional continuous and spread footings supporting the proIJosed structures should be founded at least 24 inches below the· lowest adjacent finished grade'. . Continuous f(lotings should have a minimum width of 1~ inches. Horizontal dimensions of isolated footings .. should be at least 24 inches by 24 inches. BEARING CAPACITY: Conventional footings with the above nlinimum diinensions may be designed for an allowable soil bearing pressure of 2,500 pou~ds per square foot. Thi~ val~e may be increased by 700 pounds per square foot for each additional foot of embedment depth and 350 pounds per square foot for each . additional foot of ·width, up to a ma..ximum of 4,000 ps£ This value may be ~creased by one-third for . combinations of temporary loads such as those due to wind or seismic loads. FOOTING REINFORCING: Reinforcement requirements for foundations should be provided by the project structural engineer. However, based on the existing soil conditions, we .recoinmend that the minimum reinforcing for continuous footings consist of at least two No.5 bars positioned thre: inches. above the bottom of the footing and two No.5 bars positioned two inches below the top of th~ footing. LATERAL LOAD RESISTANCE: Lateral loads a~st foundations may be resisted by friction between the bottom of the footing and the supporting soil, and by the passive pressure against the footing. The CWE 2040295.04 July 19, 2004 Page No. 9 coefficient of friction between concrete and soil may be considered to be 0.35. The passive resist~nce may be considered to be equal to an equivalent fluid weight of 300 pounds per cubic foot. This assumes the footings . are cast tight against undisturbed soils. If a combination of the passive pressure and friction· is used, the, friction value should be reduced by one-third. 'SETTLEMENT CHARACTERISTICS: The anticipated total and differential settlement is expected to be less than about 1 inch and i ,inch in 40 feet, respectively, provided the recommendations prese'nted in this report are followed. It should be recognized that minor cracks normally occur in concrete slabs and foundations due to shrinkage during curing or redistribution ,of stresses, therefore some cracks may be anticipated. Such cracks are not necessarily an indication of excessive ver~cal movements. EXPAN~IVE CHARACTERISTICS: The anticipated foundation soils are e-xpected to have a "medium" to "very high" expansion potential. The recommendations presented in this report reflect this condition. FOUNDATION PLAN REVIEW: The foundation plans should be submitted to this office for review in order to ascertain that the recommendations of this report have been implemented, and that no additional recqmmendations are needed due to changes in the anticipated construction. FOUNDATION EXCAVATION OBSERVATION: All foundation excavations should be observed by the Geotechnical Consultant pri<?r to placing reinforcing steel or constructing fQrrri.s ,~ order ~o determine if , ,the foundation recommendations presented herein are complied with. All footing excavations should be excavated neat, level and square. All loose or unsuhable material should be removed prior to the placement of concrete. SEISMIC DESIGN PARAMETERS Based on our Detenninistic Seismic Hazard Analysis~ the Ma~um Ground Acceleration at the ~ite is approximately 0.24 g. For structural design purposes, a damping ratio not greater than 5 percent of critical : dampening, and Soil Prome Type Sc are recommended (UBC Table 16-J)., Based on the site's location at approximately 11 kilometers from the Rose Canyon Fault Zone (Type B Fault), Near Source Factors Na equ~l to 1.0 and N~ equal to 1.0 are also applicable. These values, along ,vith other seismically relate~ design parameters from the Uniform Building Code (UBC) 1997 edition, Volume II, Chapter 16, utilizing a Seismic Zone 4 are presented in the following table. C\"\lE 2040295.04 July 19, 2004 Page No. 10 TABLE II: SEISMIC DESIGN PARAMETERS UBC Chapter 16 Seismic Recommended Table No. Parameter Value 16-1 Seismic Zone Factor Z 0040 16-J Soil Pro@e-Type SC 16-Q Seismic Coefficient C. OAON. 16-R Seismic Coefficient C,. 0.56 N,. 16-S Near Source Factor N. 1.0 16-T Near Source Factor Nv 1.0 16-U Seismic Source Type B ON-GRADE SLABS , ' GENERAL: It is our understanding that the floor system for the proposed buildings will c6nsjs,t of concrete slabs-on-grade. The following recommendations are considered the ~uin slab requir~ments based on the soil conditions and are not intended to be in lieu of structural considerations. INTERIOR FLOOR SLABS: The minimum floor slab thickness sh,ould b~ 'five inches (actual) and all floor 'slabs should he reinforced with at least No.4 reinforcing bars placed at 12 inches on center each way. Slab reinforcement should be supported on chairs such that' the reinfo~cing bars are p'ositioned at mid-h~lght in the floor slab. The slab reinforcement should extend into the perimeter foundations at least si. ... inches. MOISTURE PROTECTION FOR INTERIOR SLABS: It should be noted that it 1s-the industry standard that interior on-grade concrete slabs be underlain by a moisture retarder. \Ve suggest that the, subslab moisture retarder consist of at least a two-inch-thick blanket of one-Cjliarter-inch pea gravel ?r clean coarse sand overlain by a layer of 10-mil visqueen. The'visqueen should'be overlain by a two-inch-thlck ia);er of coarse, clean sand that has less than 'ten percent and five percent passing 'the No. 100 and No. 200 sieve~. Our experience indicates that dlis moisture barner should allow the transmission 9ffrom about six to tWelve pounds of moisture per 1000 'square feet per day through the on-grade slab. This may b~ an excess amount of moisture for some types of floor covering. If addi,tional protection is considered necessary, the concl;ete mix can be designed to help reduce the permeability of the concrete and thps moisture emi~sion upward~ through' the floor slab. EXTERIOR SLABS: Exterior slabs should have a mininlUtn thickness of five inches. Reinforcement and control joints should be constructed in exterior concrete flatwork to reduce the potential for cracking and movement. Joints should be placed in exterior concrete flatwork to help control the location'of shrinkage cracks. Spacing of control joints should be in accordance with the American Concrete Institute I C\VE 2040295.04 July 19, 2004 PageNo.ll specifications. It should be noted that the presences of expansiye soils makes it likely that some heaving of exterior slabs and other exterior improvements may occur, and that some of the light exterior concrete may need to be replaced within the first one or two years after the buildings are completed. This is generally much less expensive that removing and replacing the expansive soils in the upper 3 to 4 feet with nondetrimental expansive soils. SOLUBLE.SUFATES The water soluble sulfate content was determined for representative soil samples from the site ill accordapce with California Test Method 417. Soil with a soluqle sulfate content ofO.lO-0.20 % as S04 is c~nsidered moderate. Soil with a soluble sulfate content ofless than 0.1 % as S04is considered to be negligible and no . . special recommendations are needed. The results· of the tests indicate that the representative soil samples had ·a soluble sulfate content of 0.049 % and 0.046 % as S04, which i§ considered "negligible". PRELIMINARY PAVEMENT SECTION TRAFFIC INDEX: We assume that the proposed buildings will be for commercial office use. Based on this, we have assumed a Traffic In<:Jex of 5.0 for the driveways and general automobile parking areas. PRELIMINARY R-V ALUE TEST: For preliminary recommendations, an R-value test was performed on a sample obtained from the near surface soils in boring B-3. The sample'~ R-Value ~as determined to be 23. However, the soils in the area of Building 4b are very highly expansive and are expected to have an R-Value on the .order of 5 or less. We recommend that when the site grading is completed, representiti~e samples· of the subgrade soil be obtained and tested for their R-Value so th.at final pavement design recommendations can be provided. PRELIMINARY STRUCTURAL SECTION: Based on the preliminary parameters described.above; it . was determined tha~ the minimum structural pavement section for asphalt concrete pavement should consist of the following section: Areas north ofBuildi~g·4b . 3.0 Inches of Asphalt Concrete· pavement, over 6.0 Inches of Crushed Aggregate Base I , , [ . , I " C\VE 2040295.04 July 19, 2004 Areas on south, east and west sides of Building 4b 3.0 Inches of Asphalt Concrete pavement, over 10.0 Inches of Crushed Aggregate Base , Page No. 12 Concrete pavement should be constructed in front of the trash dumpster storage areas where the trash trucks will stop and pick up the dumpsters. The concrete pavement should be at least 6 inches' thick. Prior to placing the base material or concrete pavement, the subgradesoils,should be scarified to a depth of 12 inches, moisture conditioned and compacted to at least 95 percent of its maximum dry density. The Crushed, Aggregate Base material should conform to the r«,;quirements set forth in Section 200-22 of the Standard Specifications for Public \Vorks Construction. Concrete pavements construction shoqld comply with the requirements set forth in Sections 201-1.1.2 and 302-6 of the Standard Specifications for Public Works Construction (Concrete Class 520-A-2500). All paving'methods and materials should ,conform with good engineering and paving practices and to the requirements of the City of Carlsbad. , " LIMITATIONS REVIEW, OBSERVATION AND TESTING The recommendations presented in this report are contingent upon our review of final plans and specifications. . , . S~ch plans and specifications should be made available to the Geotechnical Engineer and Engineenng Geologist so that they may review and verify their compliance with this report and with, the Uniform Building Code. , It is recommended that Christian \'{Iheeler Engineering be retained to provide continuous soil engineering services during the earthwork operations. This is to verify compliance with the design concepts, specifications, ot recommend~tions and to allow design changes hi the event that subs~rface conditions differ from those anticipated prior to start of construction. , UNIFORMITY OF CONDITIONS The'recommendati?ns and opinions expressed in this report reflect our bestest1mate'of the projec~ requirements based on an evaluation of the subsurface soil conditions encountered at the subsurface exploration locations and on the 'assumption that the soil conditions do not deviate appreciably from tho~e ~ncountered, It should be recognized that the performance of the foundati~ns and/or cut and fill slopes may be influenced by , undisclosed or unforeseen variations in the soil conditions that may occur in the intennediate and unexplored areas. Any unusual conditions not covered in this report that may be encountered during sit,e development CWE 2040295.04 July 19, 2004 Page No. 13 should be brought to the attention of the Geotechnical Engineer so that he may make modifications if necessary. CHANGE IN SCOPE 11us office should be advised of any changes in the project scope or proposed site grading so that we may detennine if the recommendations contained herein are appropriate. It should be verified in writing if the reconlmendations are found to be appropriate for the proposed changes or our recomtnendations. should be modified by a written addendum. TIME LIMITATIONS The futdings .of this report are ~alid as of this date. Changes in the condition of a property can, however, qccur with the passage o~ time, whether they are due to natural processes or the work of man on thi~ or adjacent ) properties. In addition, changes in the Standards-of-Practice and/or Government Codes may occur. Due to such changes, the findings of this report may be invalidated wholly or in part by changes beyond our control. Therefore, this report should not be relied upon after a period of two years without a review by us verifying the suitability of the conclusions and recommendations. PROFESSIONAL STANDARD In.the performance of our professional services, we comply with ~at level of care and skin ordinarily exercised . . : 'by members of our profession currendy practicing under sinlliar conditions and in the same locality. The client . , recognizes that subsurface conditions may vary from those encountered at the locations w~ere our borings, surveys, and explorations are made, and that.our data, interpretations, and recommendations are based solely on the information obtained by us. \Ve will be responsible for those data, interpretations, and reconimendations, but shall not be' responsible for the interpretations by others of the informl!-tion developed. Our services consist of professional consultation and observation only, and no warranty of any kind whatsoever, express or implied, is made or intended in connection with the work performed or to be performed by us, or by our proposal for consulting or other services, or by our furnishing of oral or written reports or findings. CLIENT'S RESPONSIBILITY It is the responsibility of the client, or their design consultants, to ensure that the information and recommend~tions contained herein are brough~ to the attention of the structural engineer and arclutect for the , , , I , , C\X1E 2040295.04 July 19, 2004 Page No. 14 project and incorporated into the project's plans and specifications. It i~ further their responsibilitY' to take the necessary measures to insure that the contractor and his subcontractc;>rs carry out such recommendations during construction. FIELD EXPLORATIONS Six subsurface ~xplorations were made at the locations indicated on the attached Ph,te'Number 1 onJune 18, 2004. These explorations consisted of borings drilled using an auger drill rig. The fieldwork was conducted under the observation of our engineering geology personnel. The explorations were carefully logged when made. The boring logs are presented on the following Plate Numbers 2 through 7. The soils are described in accordance with the Unified Soils Classification System. In addition, a verbal textural description, the wet color, the apparent moisture and the density' or consistency are provided. The density of granular soils is given 'as very loose, loose, medium dense, dense or very dense. The consistency of silts or clays is given as either very soft, soft, mediul? stiff, stiff, very stiff, or hard. ' Relatively undisturbed drive samples were collected using a modified California sampler. The sampler, with an external diameter of 3.0 inches, is lined with i-inch long, thin, brass rings withinside diimeters of approximately 2.4 inches. The sample barrel was driven into the ground with the weight of a 14U .. pouncl , ' hammer falling 30 inches in general accordance with ASTM D 3550 .. 84. The driving, weighds permitted t6 fall freely. The number of blows per foot of driving, or as indicated, are presented on the boring logs as an index to the relative resistance of the sampled materials. The samples were removed fr~m the sample barrel in the brass rings, and sealed. Bulk samples of the encountered earth materials were also collected Samples were transported to our laboratory for'testing. The fieldwork'i.vas conducted under the direction of our engineering geology personnel. LABORAT.ORY TESTING Laboratory tests were perfonned in accordance with the generally accepie~fAmerican Society' for Testing and Materials (ASTM) test methods or suggested procedures. A brief description of the tests perfonned is, presented below: a) CLASSIFICATION: Field classifications w~re verified in the laboratory by visual examination. The final soil classifications are in accordance with the Unified Soil Classification System. , , C\'V'E 2040295.04 July 19, 2004 Page No. 15 'b) MOISTURE-DENSITY: In-place moisture contents and dry densities were determined for representative soil samples. This information was an aid to classification and permitted recognition of variations in material consistency with depth. The 'dry unit weight is determined ill pounds per cubic foot, and the in-place moisture content is determined as a percentage of the soil's dry weight. The results are summarized in the boring logs. c) DIRECT SHEAR TEST: A direct shear test was performed on a representative sa~ple of the fill to detennine the failure envelope based 'on yield shear strength. The 'shear box was designed to accommodate a sample having a diameter of 2.375 inches or 2.50 inches and a height of 1.0 inch. The sample~ were saturated and tested at different vertical loads. The shear stress,was ~pplied at a constant rate of strain of approximately 0.05 inch per nUnute. The results o,f these tests, are presented below. Sample Number: Sample Type: Angle of Intern~ Friction: ' Cohesion: Sample Number: Sample Type: Angle ofInternai Friction: Cohesion: Boring B-1 @ 2' Natural 26· 300 psf Boring B-6 @ 2.5' Natural 34· 400 psf' , d) EXPANSION INDEX TEST: An Expansion Index test on a remolded sample was perfqrmed on a representative sample of the soil present at finish grad'e. The test was performed on the portion of the sample passing the #4 standard sieve. The sample was brought to optimum moisture content and then dried back to a constant mo~sture content for 12 ~ours at 230 + 9 degrees Fahrenheit. The specimen was then compacted in a 4-inch-diameter mold in two equal layers by means of a tamper, then trimmed to a final height of 1 inch, and brought to a saturation of approximately 50 percent. The specimen was placed in a consolidometer~th porous stones,at the top ,and bottom, a total normal load of 12.63 pounds wits 'placed (144.7 psf), and the samples , were allowed to consolidate for a period of 10 minutes. The sample was saturated, and the change in vertical movement was recorded until the rate of expansion beca~e nominal.' The expansion index is reported below as the total vertical displacement times 1000. I ,. -; . , , , ,1 \ . , , , , I , C\'QE 2040295.04 July 19, 2004 Page No. 16' Sample Number: Boring B-2 @ 0'-4' Initial Moisture: 13.9% Initial Dry Density: 103.1 pcf Final Moisture Content 26.2% Expansion Index: 88 (Medium) Sample Number: Boring B-6 @ 1'-4' Initial Moisture: 13.0% Initial Dry Density: 103.3 pcf Final Moisture Content 30.~% Expansion Index: 145 (High) e) GRAIN SIZE DISTRIBUTION: The grain size distributions were'de~ermined from representa~ve soil samples in accordance with ASThf D422. The result of this test is presented below. Sample Number: Boring B-6 @ 1'-4' Sieve Size Percent Passing #4 100 #8 100 #16 100 #30 99 #50 99 #100 94 #200 86 0.05mm 85 O.OOSmm ·52 0.001 mm 23 . f) SOLUBLE SULFATES: The soluble sulfate content was determined for two samples of soil likely to be present at the foundation level. The soluble sulfate content was deterffiinea in: . accordance with California Test Method 417. The results are presented below. Boring B-3 @ 0'-4' Boring B-6 @ 1'-4' , , I I , , I , f I f l , , , . LOG OF TEST'BORING NUMBER B-1 Date Excavated: 6/18/2004 Logged by:' STH Equipment: CME55 Project Manager: CHC ~ Existing Elevation: Depth to Water: N/A Finish Elevation: Drive Weight: 1401bs./30" -z-. c.? Z· 0 ~ r--. ~ ~ Q,) ~ ~ H ~ 0 ~ '-' U ~ ~ 0C/.l ~ I-j ~ ffi t: ~~ :r: SU1-:nvfARY OF SUBSURFACE CONDITIONS ~ S ~. z ~ ~ ~ P=l C/.l ::> O~ 0 ffi H ~ P=l 0 <: ~ .j C/.l p.... Q Artificial Fill (QaO: Medium brown, moist, loose to medium dense, 2 CL't\'EY S.\ND DS' Del Mar Formation (Td): Light grayish-brow~, moist, dense to very Light to medium orangish-brown, moist, dense to very dense, 14:5 110.3 6 . CLn'EY SAND (sq, fine to·mediuin-grained. 8 At 8 feet becomes light grayish-brown, damp. 10~~ __________________________________________________ -+~+--+~~~1~24~~1~16~.8~ __ ~ Boring terminated at 10 feet. 12 14 16 18 20 ~~---------------------------------------------------------------------------~---~~---~---~------~---~ 'JI":~ f/J CHR.ISllAN WHEELER. BY: ENGINEERING OBNO.: BUILDING 4 OF NORTH P'OINTE EI Camino Real, Carlsbad, California HF DAlE: July 2004 2040295 PU1ENO.: 2 ,..------------,---------, , , LOG OF TEST BORING NUMBER B-2 I I I I I I I , , f J J , Date Excavated: 6/18/2004. CME55 Equipment Existing Eleyation: Finish Elevation: 'Z' Q) <2 '-" ¥S ~ ~ 2 . 4 6 8 ~ 8 U I-! ::r:: p.. ~ C,? SUMMARY OF SUBSURFACE CONDITIONS Del Mar Fonnatiori ad): Light to medium orangish-gray, moist, dense to very dense, CL\ l"EY SAND (sq, [Ule to medium-grained. Expansion Index= 88 (1fedium) At 4 feet becomes damp. Logged by: STH Project Manager: . CHC Depth to Water: N/ A Drive Weight: 140 lbs./30" ~ ,....., ~ ::!:: ~ ~ ~ t ~ ~ Z ;:J (/) ~ H -< 0 U) ~ Q 71 16.3 104.0 Cal 78 17.6 1)2.4 ~ Oci} f-if-i ~.~ ~. ~. E.I Cal 10~-+ ____________________________ ~ ____________ ~~+-~~4---r---+-~ Boring terminated at 10 feet. 16 18 20 ~~----------------------------------------------~--~~~~--~~~--~ .~~ 'ft "'. CHR.ISTIAN WHEELER. BY: . ENGINEER.ING OBNO.: BUILDING 4 OF NORT.H POINTE EI Camino Rea], Carlsbad, California HF DATE: July 2004 2040295 PUTENO.: 3 , , , I I , LOG OF TEST BORING NUMBER B-3 Date Excavated: 6/18/2004 CMESS Equipment: Existing Elevation: Finish Elevation: SU11MARY OF ?UBSURFACE CONDITIONS .Del Mar Fonnation (Td): Light to medium orangish-brown, moist, dense, CL\YEY S~\ND (SC). . ' Light orangish-gray, moist, very stiff, S.lliDY CLAY (CL). Boring terminated at 10 feet. 12 14 16 ,18 Logged by: Project Manager: Depth to Water: Drive Weight: STH CHC N/A 140Ibs./30" 67 17.7 1120 95 19.0 1l0.2 Cal 50/4" J~~~ tfi BUILDING 4 OF ,NORTH POINTE EI Camino Real, Carlsbad, California "'- CHR.ISllAN WHEELER. BY: HF July 2004 ENGINEEltlNG JOB NO.: 2040295 PL-\TENO.: 4 55 LOG OF TEST BORING NUMBER B-4 Date Excavated: 6/18/2004 CMES5 Equipment: Existing Elevation: Finish Elevation: SUM1"fARY OF SUBSURFACE CONDITIONS Del Mar Formation (fd): Light grayish-bro~, moist, dense, SILTY SAND (S11), fme-grained. Mediwn orangish-brown, moist, dense, CLA l'EY SAND (SC). Light orangish-gray, moist, stiff to very stiff, SANDY SILT (1ll.). Boring terminated at 10 feet. 12 14 16 18 Logged by: STH Project Manager: CHC Depth to Water: N/ A Drive Weight: 140Ibs./30" Cal 38 1 B.2 108.3 Cal 50/5" , , , , , , , , , BUILDING 4 OF NORTH POINTE El Camino Real, Carlsbad, California I." !/J [ CHR.lSl1AN WHEELER. BY: HF DATE: July 2004 I '--____ E_N_G_I_N_E_E _R._I_N_G ______ ..JoJ:....::O;...B....:N~O_. _: _-.--_2_0_40_2_9_S __ --'-P_LA_TE_N_' _0_.: ____ 5 ___ ---' 1'1'-, ~ , 4:,': :;...:.* • LOG OF TEST BORING NUMBER B-5 Date Excavated: 6/18/2004 CME55 Equipment: Existing Elevation: Finish Elevation: ~ CI) cE '-'" ::r:: H ~ 0 2 4 6 8 L')' g U H :r: p.. ~ () SU11MARY OF SUBSURFACE CONDITIONS Artificial Fill (Oaf): Medium brown, moist, loose to medium CL<\YEY S.-\ND Del Mar Formation (Td): Medium grayish-brown, moist, stiff to SANDY CL-\ Y Light brownish-gray, damp, dense to very dens~, SILTY S.:\ND (S1£), flne-grained. Logged by: Project Manager: Depth to \'{later: Drive Weight: ~ ~ ~ ~ -< CI) ,STH CHC N/A 1401bs./30" ---~ ~ ~ 'ga Rc H ~ Z 0 , CI) H ~, 0 ~ Q' 58 21.3 110.1 13.2 118.3 ~ ~ Cal 10~~~--------------------------------------~-------+~~~~~--~---4--~ Boring tenninated at 10 feet. 12 14 16 18 20,~~ ________________________________________________ -L~L-~ __ -L __ ~--~--~ .. ~~~ 'Il ". CHR.ISTIAN WHEELER. EN(;INEERING BY: lOBNO.: BUILDING 4 OF NORTH POINTE 'EI Camino Real, Carlsbad, 'California !iF DATE: July 2004 2040295 PLATE Nq.: 6 LOG OF TEST BORING NUMBER B-6 Date Excavated: 6/18/2004 Logged by: STH Equipment: CME55 Project Manager: CHC Existing Elevation: Depth to Water: N!A Finish Elevation: Drive Weight: 1401bs./30" 'Z' c..? 9 ~ ,...... ~ Q) ~ .1:l ~ ~ '-' U ~ ,~ H ~ :::r:: SU1llifARY OF SUBSURFACE CONDITIONS W i3 tI) p.. ~ H ~ I:iI ~ en Q H c..? ,~ 0 ~ Artificial Fill (QaO: Medium brown, moist, loose. CLAYEY 2 SA Del Mar Fonnation (Td): ,:Medium grayish-brown, moist, very stiff, 60 14.6 115.2 OS SANDY CLAY (CL). Expansion Index= 145 (Very High) E.l 4 Cal 45 18.1 110.5 6 8 Cal ,50/4" 10F-~-----------------------------------------------+--+--r~~--~---+--~ 12 16 18 20 Boring terminated at 10 feet. J'!j ~fI CHRJSllAN WHEELER. ENGINEER.ING BY: TOBNO.: BUILDING 4 OF NORTH PO'INTE EI Camino Real, Carlsbad, California HF D.ATE: July 2004 2040295 PLATE NO.: 7 C\V'E 2040295.04 July 19, 2004 "Appendix A, Page A-I REFERENCES Anderson,J.G.; Rock-well, R.K. and Agnew, D.c., 1989, Past and Possible Future Earthquakes of Significance to the San Diego Region, Earthquake Spectra, Volume 5, No.2, 1989. Boore, David M.,Joyner, William B., and Fumal, Thomas E., 1997, ''Empirical Near-Source Attenuation Relationships for Horizontal and Vertical C9mponents of Peak Ground Acceiera~on, ~eak Ground Velocity, and Pseudo-Absolute Accderation Response Spectra", in Seismological Research Letters, Volume 68, Number 1,January/February 1997. , , "Geo~echnical Investigation for Hughes Project, Carlsbad, California," prepared I?J Robert Prater Associates, dated March 27, 1997. "Supplemental Geotechnical Investigation for Lincoln Northpointe, Carlsbad; California," prepared 'I?J Robert Prater Associates, dated December 2,1997. "Report of Grading Observations and Testing, Lincoln Northpointe, Carlsbad Tract 98-07, EI Camino Rea!, Carlsbad, California, prepared I?J Christian \Vheeler Engineering, dated May 26, 1999. Califolnia Division of 11ines and Geology, 1998, Maps of Known Active Fault,Near Source~Z~nes in California 'and Adjacent Portions of Nevada. , Jennings, C.W., 1975, Fault Map of California, California Division of Mines and' Geol~gy, Map No.1, Scale 1:750,000. Kern, P., 1989, Earthquakes and Faults in San Diego Cotinty, Pickle Press, 73 pp. United States Department of Agriculture, 1970, Soil Survey, San Diego Area, California. Wesnousk]" S.G.,.1986, "Earthquakes, Quaternary Faults, and Seismic Hazards in California", in ' Journal of Geophysical Research, Volume 91, No. B12, pp 12,587 to'12,631, November1986. , , , I I I I I I I , • '-: , f ~' - CWE 2040295.04 July 19, 2004 'Appendix B-1 , RECOMMENDED GRADING SPECIFICATIONS -GENERAL PROVISIONS GENERAL INTENT PROPOSED BUILDINGS 4A & 4B LINCOLN NORTHPOINTE DEVELOPMENT EL CAMINO REAL CARLSBAD. CALIFORNIA The intent of these specifications is to establish procedures for clearing, compacting natural ground, preI>aring areas to be filled, and placing and compacting-fill soiIs-to the, lines and grades shown on the, accepted plans. The recommendations contained in the preliminary'geotechnical investigation report arid/or th~ attached Special Provisions are a part of the Recommended Grading Specifications and shall s~persede the provisions contained hereinafter in the case of conflict. These specifications 'shall only be used in 'conjunction with the geotechnical report for which they are a pa'rt. No deviation from these specifi~ations will be allowed, except where specified in the geotechnical report or in other written communicatiqn signed by the Geotechnical Engineer. OBSERVATION AND TESTING Christian \X'heeler Engineering shall be retained as the Geotechnical Engineer t9 obs~rve and test the earthwork in accordance with these specifications. It will be necessary that ,the Geotechnical Engineer or his representative provide adequate observation so that he may provide his opinion as to whether or not ,the . . .' work was accomplished as specified. It shall be the responsibility of the contractor to assist the Geotechnical Engineer and to keep him appraised of work schedules, changes and new information and pata so that h~ , , , ,', may provide these opinions. In the event ,that any unusual conditio1?-s not covered by'the special pr.ovisions , o~ preliminary geotechnical report are encountered during the,grading operation,s, the Geotechnical Engineex; shall be contacted for further recommendations. If, In the opinion of the Geotechnical Engineer, substandard conditi?ns are encountered, such as' questionable or unsuitable soil, unacceptable moisture c;:ontent, inadequate' compaction, adverse weather"etc;" ' construction should be stopped until the conditions are remedied or corrected or he,shall r~col?mend 'rejection of this work. CWE 2040295.04 July 19, 2004 Appendix B-2 Tests used to determine the degree of compaction should be performed in accordance with the following American Society for Testing and 1viaterials test methods: Maximum Density & Optimum Moisture Content -ASTM D-1557-91 Density of Soil In-Place -ASTM D-1SS6-90 or ASTM D-2922 All de'nsities shall be expressed in terms of Relative Compaction as determined by the foregoing ASTM 'testing procedures. PREPARATION OF AREAS TO ,RECEIVE FILL All vegetation, brush and debris derived from clearing operations shall be removed, 'and legally disposed 'of. All areas disturbed by site grading should be left in a neat and finished appearance, free from unsighdy debris. After clearing or benching the,natural ground, the areas to be filled shall be scarified to a depth of 6 inches, brought to the proper moisture content, compacted and tested for the specified minimum degree of , ' compaction. All loose soils in excess of 6 inches thick should be removed to firm natural ground which is defined as natural soil which possesses an in-situ density of at least 90 percent ,of its maximum dry density. ,\Vhen the slope of the natural ground receiving fill exceeds 20 percent (S horizontal units to 1 vertical unit), , - the original ground shall be stepped or benched. Benches shall be cut to a firm competent formati.onal soil. The lower bench shall be at least 10 feet wide or 1-1/2 tinles 'the equipment width, ~hichever is greater, and shall be sloped back into the hillside at a gradient of not less than two (2) percent. All other ~enches sho~ld ,be at least 6 feet wide. The horizontal portion of each bench shall be compacted prior to receiving fill as specified herein for compacted natural ground. Ground slopes flatter than 20 percent shall be benched when considered necessary by the Geotechnical Engineer. Any abandoned buried structures encountered during'grading operations must b,e totally removed. All underground utilities to be abandoned beneath any proposed structure should be removed from within 10 feet of the structure and properly capped off. The resulting depressions fro~ the above described procedure should be backftlled with acceptable soil that is compacted to the requirements of the· Geotechnical Engineer. This includes, but is not limited to, septic tanks, fuel tanks, sewer lines or leach lines, storm drains and water lines. Any buried structures or utilities not to be abandoned should be brought to the attention of the Geotechnical Engineer so that he may determine if any special recommendation will be necessary. I ,I . 1 I I I C\XIE 2040295.04 July 19, '2004 AI?pendix B-3 All water wells which will be abandoned should be backfilled and capped in accordance to the requkements set forth by the Geotechnical Engineer. The top of the cap should be at least 4 feet below fini~h grade or 3 feet below the bottom of footing whichever is greater. The type of cap will depend on the diameter of the well and should be determined by the Geotechnical Engineer and/or a qualified Structural Engineer. FILL MATERIAL Materials to be placed in the fill shall be approv~d by the Geotechnical Engineer and shall be free of . vegetable matter and other'deleterious substances. Granular soil shall contain sufficient fine material to fill. the voids. The definition and disposition of oversized rocks and expansive or detrimental soils are covered in the geotechnical report or Special Provisions. ExpaQsive soils, soils of poor gradation, or soikwith low . str~ngth characteristics may be thoroughly mixed with other soils to provide satisfactory fill material, but only ·with the explicit consent of the Geotechnical Engineer. Any import material shall be approved by the Geotechnical Engineer before being brought to the site. PLACING AND COMPACTION OF FILL Approved fill material shall be placed in areas prepared to receive fill in layers not to' exceed' 6 in~hes in compacted thickness. Each layer shall have a uniform moisture content in the range that will allow the . compaction effort to be efficiently applied to achieve the specified degree of compaction. Each layer sha~ be' uniformly compacted to the specified minimum degree of compaction wit~ equipment of adequate size to economically compact the layer. Compaction 'equipment should either be specifically designed for so~ . compaction or of proven reliability. The minimum degree of compaction to be achieved is specified in either the Special Provisions or the recommendations contained in the preliminary geotechnical investigation' . report. \'(lhen the structural fill material includes rocks, no rocks will be allowed to nest and ~ll voids must be carefully' [tIled with soil such that the minimuin degree of compaction recommended in the ~peciai . Provisions is achieved. The maximum size and spacing of rock pe~mitted in structural fills and in non': structural fills is discussed in the geotechnical report, when applicable . Field observation and compaction te~ts to estimate the degree of c9!J1paction of the fill will ~e taken by the Geotechnical Engineer or his representative. The location and frequency of the tests' shall be at the G.eotechnical Engineer's discretion. Whe'n the compaction test indicates that a particular layer is at less than I I I I ,I I I I I I I I I·' I I I I·, I C\X'E 2040295.04 July 19, 2004 .App.endix B - 4 the required degree of compaction, the layer shall be reworked to the satisfaction of the Geotechnical Engineer and until the desired relative compaction has been obtained. Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Co~paction by sheepsfoot roller shall be at vertical intervals of not greater-than four feet. In addition, fill slopes at a ratio of two hori~ontal to one vertical or flatter, should be trackrolled. Steeper fill slopes shall be over-built and cut- back to finish contours after the slope has been constructed. Slope compaction operations shall result in all fill material six or more inches inward from the finished face of the slope having a relative compaction of at least 90 percent of maximum dry density or the degree of compaction specified in the Speciai Provisions se~tion of this specification. The compaction operation: on the slopes shall be con,tinued until the Geotechnical Engineer is of the opinion that the slopes will be surficially stable. , Density tests in the slopes will be made by the Geotechnical Engineer during construction of the slop~s to . determine if the required compaction is being achieved. \Vhere failing tests occur or other field problems arise; the Contractor will be notified that day of such conditions by written communication' from the Geotechnical Engineer or his representative in the form of a daily field report. If the method of achieving the required slope compaction selected by the Contractor f~ils to produce the necessary results, the Contractor shall rework or rebuild such slopes until the requ~ed degree of compaction is obtained, at no cost to the Owner or Geotechnical Engineer. ,CUT SLOPES The Engineering Geologist shall inspect cut slopes excavated in rock or lithified formational material d'uring the grading operations at intervals determined at his discretion. If any conditions not antiCipated in the pre~nary report such as perched water, seepage, lenticular or confined strata of a'potentially adverse nature, unfavorably inclined bedding, joints or fa~lt planes are encountere~ during gr~ding, t.bese co~ditio~s . , , shall be analyzed by the Engineering Geologist and Geotechnical Engineer to detertni~e if mitigating measures are necessary. Unless otherwise specified in the geotechnical report, no cut slopes shall be' excavated higher or steeper than that allowed by the ordinances of the !,=qptrolling governmental ag~ncy. I I i I . t, f: I' f; , • "'1.. .... ,~~ . ~~ I,., ? :1 i ,I ,I I I "I I 'I 1 I I 'I I I I C\XJE 2040295:04 July 19, 2004 Appendix B--S ENGINEERING OBSERVATION Field observation by the Geotechnical Engineer or his repre~entative shall be ~ade d~ring the filling and' compaction operations so that he can express his opinion regarding the con'for~ance of the grading With acceptable standards of practice. Neither the presence of the Geotechnical Engineer or his representative or th~ observation and testing shall release the Grading Contractor from his duty to compact all fill material to the spe'cified degree of compaction. SEASON LIMITS Fill shall 'not. be placed during 'unfavo~able ~eather conditions. \Yhen ~ork is interrupted by heavy rain" filling operations shall not be resumed until the proper moisture content and d,ensity of the fill materials can , , be achieved. Damaged site conditions resulting from weather or acts of God shall be repaired before acceptance of work. RECOMMENDED GRADING SPECIFICATIONS -SPECiAL PROVISIONS RELATIVE COMPACTION: The rcinimum degree of c,o'mpaction to be o~taitie"d in compacted natUral , " ground, compacted fill, and compacted backfill shall be at least 90 perceQt" F~r ,~treei: and parking.1ot subgrade, the upper twelve inches should be compacted to a~ least 95 percent relative compaction. E~P ANSIVE SOILS: Detrimentally expanslv~ soil is defined as cl~yey soil which has a~ expansion inde~ of. 50 or greater when tested in accordan\:e'with the Ameridm Soq.ety of Testing Materials (AST'.M) Laboratory , Test '04829-95. , ,OVERSIZED MATERIAL: Oversized fill material is generally defi~ed herein as rocks or lumps of ~oil '. . . , . . , ove~ six,inches in diameter. Oversized materials should not be pla~eci in fill unless recom~e~datio~s Of , , ' placement of such material is provided by the Geotechnical Engineer. 'At least 40 percent, of-the fill soils, . _. . . .' shall pass through a No.4 U.S. Standard Sieve. TRANSITION LOTS: Where transitions between cut and, fill occur wit1~in' the propol?ed,build1ng pad~ the , . ' cut portion sho~ld be undercut a miq4num of one fo'ot below the base of the proposed fqotings and, : . - , recompacted as structural backf~. In certain cases that would be addressed in the ge,otechnical report, , sp'e~ial footing reinforcement or a combination of special footing reinforcement and undercutting may be required. , , , :-"'''---''\ , to .-8-6 Td Td 180· LEGEND APPROXIMATE BORING LOCATION DELMAR FORMATION -------------------------------- Christian Wheeler Engineering Job NOfnbefl2040295 ~ Date;6(r~2g={54 - Plate No.1 m!)JECT~:Ofm-i ::1-en c o o ...c .:t= E Cf) _:_e-~ .......... ·.I.~ ... L. (I) ..... c (I) U .s:: g~ .... • (1)-..... 0 c-l 0 a. .s:: t:: 0 Z 1; I L-. ~ ~ f 0::: ~ I -. ... ...,... r:~~ ..... ....,,0** "n ...... <-c <:-..$ot ....... 0.. < .. -_<z .. 0 ..... 0" < ZU -. ~c < <. u'" .. .. .. < wu ... au ----------- 1 -----------------------------------------------------------,