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HomeMy WebLinkAboutCT 80-33; PALOMAR AIRPORT BUSINESS PARK PHASE II; GEOTECHNICAL INVESTIGATION; 1977-09-19September 19, 1977 218-3, 1822 • ROBERT PRATER ASSOCIATES Consulting Sot!. Foundation & Geologicol Engineers Palomar Airport Business Park 6231 Yarrow Drive~ Suite C "-Carlsbad, California 92008 Attention: Mr. Bernard W. Gi Imore Re: Geotechnical Investigation Palomar Airport Business Park -Phase" Carlsbad, California Gentlemen: In accordance with your request I we have performed a detailed geotechnical. investi- gation for the subject project. The accompanying report presents the resu.lts of olJr field investigation, laboratory tests, and engineering analysis. The soil and foundation conditions are discussed and recommendations for the geotechnical engineering aspects of the project are presente~:!. If you have any questions concerning our findings, 'please call. Very truly yours, ROBERT PRATER ASSOCIATES Robert Prater, C. E. RP:jsr cc: Addressee (4) Wi IIdan Associates, Attn: Mr. Henry Worley (2) 11585 Sorrento Volley Rood, Suite 101, Son Diego, California 92121 • (714) 453-5605 I ~ I I I I [J I I 1 I I n -I I - l D U I; • • GEOTECHNICAL INVESTIGATION For PALOMAR AIRPORT BUSINESS PARK -PHASE" Carlsbad, California To PALOMAR AIRPORT BUSINESS PARK 6231 Yarrow Drive, Suite C Carlsbad, Cali£ornia September 1977 Letter of Transmittal Title Page Tab I e of Contents INTRODUCTION SCOPE SITE CONDITIONS A. Surface B. Subsurface • C. Groundwater D. Seismicity TABLE OF CONTENTS CONCLUSIONS AND RECOMMENDATIONS A. Earthwork 1. . Clearing and Stripping 2. Preparation for Filling 3. Excavation 4. Materials for Fill .5. Expansive Soils ·6 •. Slopes 7. Compaction 8. Trench Backfill 9. Drainage 10. Construction Observation B. Foundations 1. Footings 2 •. Reinforced Concrete Box Culvert 3. Slabs-an-Grade 4. lateral loads c. Pavements Figure 1 -Site Plan Figure 2 -Recommendations fat Fi "ing on Sloping Ground APPENDIX A -FIELD INVESTIGATION Figure A-I -Key to Exploratory Test Pit Logs Exploratory Test Pit logs 1 through 14 APPENDIX B -LABORATORY TESTING Figures 8-1 and B-2 -Plasticity Chart and Data Figure 8-3 -Gradation Test Data Figures 8-4 and 8-5 -Compaction Test Results Figures 8-6 and 8-7 -Direct Shear Test Data • APPENDIX C -GUIDE SPECIFICATIONS -SITE EARTHWORK Page No. 1 1 2 2 3 3 4 4 4 4 4 5 5 6 6 6 7. 7 7 8 8 8 9 A-1 B-1 C-1 u ~ u • • • • d • • • • • U I • • • D 0 , ;. INTRODUCTION • GEOTECHNICAL INVESTIGATION FOR PALOMAR AIRPORT BUSINESS PARK -PHASE II CARLSBAD, CALIFORNIA In this report we present the results of our geotechnical investigQtion for the Phase II portion Of the 330-acre Palomar Airport Business Park located on the south side of Palomar Airport Road opposite Palomar Airport in CarlsbadJ Califor:nia. Our predeces- sor firm previously performed,detailed geotechnical investigations for the existing Phase I portion of the business park and fQr the PT& T improvements along the alignment of Camino Vida Roble within the Phase" portion of the park. Our predecessor firm also provided earthwork observation and testing services in connection with t-hese projects. The purpose of this investigation was to,evaluate in detail the subsurface conditions at the site and to provide recommendations concerning the geotechnical engineering aspects of the Phase /I development. It is our understanding that the Phase II portion of the business park will most likely be developed in ol"1e and two-story concrete tilt-up structures with slah-on-grade, floors similar to those already constructed in the Phose I portion of the pork. Extensiy~ earthwork will be required to atfain the design finish site grades. Cuts of up to about 40 feet and fjlls of up to about 50 feet are presently pldnned. The lots will probably not be finish' graded d~ring the initial earthwork operations; large areas encompassing several 10tswHl be graded smoothly for drainage to within about plvs or minus 2 feet of the onticipated finish lot grades. Finish grading of lots to satisfy the specific needs of a given building and parking area will be undertaken as individual lots are developed. As indicated on the improvement plans for Camino Vida Roble prepared by Rick Engineering Company, a reinforced concrete box culvert will be constructed beneath Camino Vida Roble at the approximate location indicafed on the Site Plan, Figure 1. 'SCOPE The scope of work performed for this investigation included a site reconnaissance, sub- surface exploration, laboratory testing, engineering analysis of the field and laboratory data, and the preparation of this report. The data obtained and the analyses perfo'rmed were for the purpose of providing design and construction criteria for fhe required srte earthwork, bui Iding foundations and slab-on-grade construction. SITE CONDITIONS A. Surface The Phase" portion of the site is irregular in shape and 'bounded by Palomar Airport Road to the northwest, on S. D. G. 8. E. right-oF-way to the soufhwest, and by the Phase I por- IJ • 218-3 Page 2 tion of the business park to the east. The terrain is generally moderotely rolling with ground su:rface elevations ranging from a low of about el. 170 at the western extremity of the site to a high of about el. 310 in the northeast portion of the site adjacent to Palomar Airport Road. Su~face vegetation generally consists of a moderate to heavy growth of brush and chaparral. A few trees are present in the lower lying areas. A large stockpile of topsoil from the Phase I grading operation is present on the south side of Camino Vida Roble in the southeast portion of the Phase" development area. B. Subsurf(]ce A subsurface investigatian was performed at the site on August" 22, 1977 using a Case 580B backhoe. Fourteen exploratory test pits were excavated to g maximum depth of 14 feet at the approximate locations shown on the Site' Plan., Fig,ure 1. Logs of the test pits and details regarding the field investigation are presented in Appendix A. Details of the laboratory testing and the laboratory test results are pres~nted in Appendix B. It should be pointed out that the elevations referred to on the test pit logs are only approximate and were roughly estimated utilizing the ground surface contours shown on the preliminary grading plan provided by Wi IIdan Associates. The soils 'encountered in the exploratory test pits consisted predominantly of residual surface so'ils, colluvial soifs and formational sedimentary soils. Residual surface soils, generally . less than 2 feet thick and ranging in composition from silty sand to potentially expansive sandy cloy, were encountered on ridges and hillstdes at the upper elevations overlying the formational soils. The formational soils encountered over the majority of the site consisted of sandstones and siltstones. Due to the denseness and cementation of some of the formational materials encountered, refusal to penetration was met in expJoratory backhoe Test Pits 3 and 14 at depths of 5.0 and 5.5 feet, respectively. Most of the proposed cuts wi" be in formationa'i soi Is which possess gooq. strength characterist ics with regard to slope stability. The sandstone formational soils are non-expansive and of good pavement subgrade qual ity. Colluvial soils consisting of loose to medium dense silty sands were encountered to a depth of about 6.5 feet in Test Pit 9 which was located near the boUom of a ravine. The soils encountered in Test Pit 12 located in the low lying area of the southeastern portion of the site consisted of about 4 feet of loose sandy and clayey si-Its overlying very stiff to hard silty clay which possesses a high potential for expansion. The test pit logs and related information depict subsurface conditions only at the specific locations shown on the site plan and on the particular date designated on the logs. Sub:- surface condifions at other locations may differ from conditions occurring at these test pit locations. Also, the passage of time may result in a change in fhe subsurface c~nditions due to environmen~al changes. c. Groundwater Free groundwater was not encountered in any of the exploratory test pits excavated at the site and no groundwater seepages were observed. It must be noted, however, that 11 • • I I JI I I I I [] I 1 I 1 ~ U • 218-3 Page 3 fl uctuations in the level of groundwater may occur due to variations in surface topography, ~ubsurface stratification, rainfcil·1 and other possible fqctors which may not have been evident at the time of our field investigation • D. Seismicity Based on our reconnaissance and review of available published information, there are no active faults known to exist qf the site and the nearest known major active faults are the Elsi-nore and San Jacinto Fault Zones located approximately 24 and 46 miles nort-heast of the site, respectively. Although research on earthquoke prediction has greatly increased in recent years, seis- mologists have not yet reached the point where they ca.n predict when and where an earthqudk~ will occur. Nevertheless, on the basis of current technology, it is reasonable to assume that the proposed structures will be subject to at least one moderate earthquake during their design lives. During such an earthquake; the danger from fault offset through the site is remote but strong shaking of the site is likely to occur •. CONCLUSIONS AND RECOMMENDATIONS From a soil and foundation engineering standpoint i the site is suitable for construction of the proposed Phase II portion of the business park provid.ing the conclusions and recommen- dations of this report ,?re incorporated into the design and construction of th~ project. The primary feature of concern qt the site is the moderate to high expansion potential of some of the more clayey soils enco,untered in the exploratory test pits. We donlt anticipate, however, that expansive soils will be encountered to anysigniHcant degree on the higher ' lots comprising the northern portion of the site. Substantial quantities of expansive soils are most likely to be exposed over large areas in the cuts comprising the lower-Iyi'hg lots bordering the north side of Camino Vida Roble. Where expansive soils are exposed at or near th~ finish subgrade level of building .pads, the proposed buildings and slabs-on-grade could be subject to damage due to heave of the expansive materials. Therefore, on those building pads where such a condition exists, it wi" be necessary to 1) extend the building foundations somewhat deeper than would normally be required, and 2) provide a mat of non-expansive fill beneath all slabs-on- grade. In order to minimize the necessity of special design features and problems associated with expansive materials in fill areas, the site grading work should be planned and corried out so as to assure that all fi lis are capped with a layer of non-expansive sandstone fi II. In cut areas where the natural subgrade is comprised of expansi-ve soils, it wi II be necessary to overex~avate the expansive soils within building areas and replace them with non-expansive sandstone fill. Witbregard to pavements, substantially thicker pavement sections will be requited where clayey soils ore exposed at or near the finish subgrade surface than will be required in those areas where sandstone (natural or as fill) is present. ," o • A. Earthwork 1. Clearing and Stripping 218-3 ·Page 4 All areas to be graded-should be cleared of debris, brush, chaparral, designated trees, and associated roots. The cleared materials should be disposed of off-site. Any grqding planned for the area presently occupi ed by the topsoil stockpile on the southside of . Camino Vida Roble in the southeast portion of the si.te will require that the st9ckpHe first be relocated. After clearing, any cultivated areas as well as all other areas supporting a growth of surface grass and weeds should be stripped to a sufficient depth to remove all surface vegetation. Over much of the site little or no surface vegetation other than heavy brush and chapbrral is present. In these areas, stripping will not be required assuming that the clearing operation accomplishes removal of the brush and chaparral. 2. Preparation for Filling After the site has been cleared, stripped, and prior to placing fill, the exposed sl,lbgrade soils should be scarified to a ~epth of 6 inches, moisture conditioned, and compacted to the requirements for structural fill. In general, the surface soils in r9vines and draws ar~ loose to depths of only severcil inches and as a result, the normdl scarification and recom- paction process should be adequate to effectively stabili ze these soils. However, base.d on our experience in connection with the mass grading op~rations for the adjacent Phase I portion of the business park, we anticipate that isolated pqckets of loose, saturated colluvial soils wi II likely be exposed during the Phase II site grading work. The necessity for remov- ing and r~compacting those isolated pockets should be determined by the soil engi,neer in the field during construction. Fills constructed on natural slopes having an inclination ~teeper than 5 horizontal to 1 . vertical should be keyed and benched into firm natural ground below any loose surface soils as iilustrated on Figure 2. 3. Excavation Based on the results of our exploratory test pits, and our experiences with similar m~teria's, it is our opinion that fhe on-site soils and formational materials can be excavated utilizing ordinary heavy earthmoving equipment. Some heavy ripping could, however, be required in the deeper cut areas.of the site where IQyers of cemented formational materials may be encountered. . 4. Materials for Fill All existing on-site soils are in general suiJable for reuse as fill. Fill material should not, however I contain rocks or lumps larger than 6 inches in greatest dimension with not mote ':,. 11 II • • .' • II • .' • • • D • • • • q q • 218-3 Page 5 than 15 :percent larger than 2.5 inches. The use of potentially expansive soiJ as fill should conform to the requirements of Item A.5., "Expansive Soils. II Ail material for use as fill should be subject to approval by the soil engineer's field representative. The existing topsoil stockpile located in the southeast portion of the site may be reused as fill in the lower portions of the deeper site fills. However, any concentrations of organic material should be selectively removed and d'isposed of off.:'site.' The method of placement and suitability of the mah;rials should be subject to the soil engineer's approval. 5. Expansive Soi Is Potentially expansive soils taken from the required site excavations shol)'d be used as fill only up to within 2 feet of the design finish grades in street pavement oreas and on lots; the upper 2 feet of fill should be ,comprised of non-expansive sandy filf material. The determination as to which materials are expansive and which are not shoul~ be mode in the field during construction by the soil engineer's represer:ltative. Based on the limited information provided by our field explorat,ion work, it would at this stage b~ impossible to predict the octu'al conditions that will exist on each and eVery building lot (in cut) at the proposed design finish grades. A more accurate determination of the expansive soil conditions on individual lots in cut can be' made subsequent to the " rough site grading work. Priorlo constructing buildings, however, 'each individual building lot shourd be evaluated in order to accurately ,det'ermine the extent and severity of any expansive soils that may be present at or near the finish lot grades. 6. Slopes Based on the results of oLir exploratory test pits, laboratory tests, and stdbilHy analyses, it is our opinion that the proposed cut slopes and fill slopes up to 50 feet in height wHi be safe against mass instability if constructed to an inclination no steeper than 1.5 horizontal tol vertical. ' It is essential that tbe soil engineer's representative tnspect the matedals exposed in the proposed cuts during the excavation work to check for any signs of potentially unstable areas and to verify that the materials encountered throu'ghout the excavations correspond to those anticipated from our exploratory test pits. Fill slopes should be constructed so as to assure that a minimum degree of compaction of 90 percent is attained to within 18 inches of the finished slope face and that a minimum degre,e of compaction of 85 percent is attained in the outer 18 inches. This may be accompl:ished by "backrolling" with a sheepsfoot roller or other suitable equipment in 5 to 8 foot vertical increments as the fill is raised. Placement of fill near the tops of slopes should be carried out in such a manner as to assure that loose, uncompacted soi,ls are. not sloughed over the tops and allowed to accumulate on the slope face. The on-site sandy soils and formational sandstones will be quite susceptible to erosion where exposed on slopes. Therefore, the pro~ect plans pnd spe(:ifications should contain >. 218-3 Page 6 all necessary features and construction requirements to prevent erosion of the slopes both 'during and after construction. Slopes and other exposed ground surfaces should be appro- priately planted with a protective ground cover. It should be the grading contractor's obligation to take all measures deemed necessary during grading to provide erosion control devices in order .to protect slope area~ dnd adja-: cent properties from storm damage and flood hazard originating on this project. It should be made the contrqctor's responsibility to maintain, slopes in their as-graded form until all slopes are in satisfactory compliance with the job specificat,;ons, all berms have been properly constructed, and all associated drainage devices meet the requirements of .the civi I eng i neer. . 7. Compaction All structural fill should be compacted to a minimum degree of compaction of 90 percent based upon ASTM Test Designation D1557-70. The upper 6 inches of subgrade soils beneath pavements should be compacted to a .minimum degree 6f compaction of 95 percent. Fill material should be spread and compacted in uniform hori:zontal·lifts not exceeding 8 inches in uncompac;:ted thickness. . Bas'ed on the results of the laboratory tests we estimate that the on-site formational materials will undergo no shrinkage due to compaction and may in fact result in on overal'l increase'in volume in the compacted state relat'ive to the natural in-place density. However~ due to the presence of residual surface soils and colluvial soils which may be subject to significant shrinkage upon compaction, we feel that on over-all average shrinkage factor of between -3 and +3 percent would be reaspnable for planning purposes. 8. Trench Backfill Pipeline trenches should be backfilled with compacted fill. Backfill material should be placed in lift thicknesses ~ppropriate to the type of compaction equipment utilized and compacted to a minimum degree of compaction of 85 percent by mechanical means. In all slab-q/'l-grade and pavement are'as, the upper portion of the backfiH to a depth equal to 1.5 tImes the trench width, but not less than 3 feet, should be compacted to a minimum degree of compaction of 90 percent. .In pavement areas, that portion of the trench backfiH within the pavement sect'ion should conform to the material and compaction requirements of the a~jacent pavement section. 9. Drainage Positive surface gradients should he provided adjacent to buildings so as to direct s.urface water away from foundations and sl~bs toward suitable discharge facilHies. Ponding of surface ~ater should not be allowed adjacent to structures or on pavements. : . .' . (I Ji 11 • -I • I fI J I I- I I [J I I I 1 -[I ~ 10. Construction Observation 218-3 Page 7 Variations in soil conditions are possible and may be encountered during construction. In order to permit correlation between the preliminary soil data and the actual soil conditions encountered during construction, (md so to assure cOl'lformance with the plans and specifications as or'iginally contemplated, it is essential that the soil engineer be retained to perform on-site review during the course of construction • All earthwork should be performed under the observation of the soi I engineer',s'representa- tive to assure proper site preparatioA, selection of satisfac,tory fill materials, as well as placement and compoction -of the fills. Sufficient notification prior to earthwork operations is essential to make certain that the work will be properly observed. All earthwork should be performed -in accordance with the Guide Earthwork Specifications presented in Appendix C. It should be pointed out, however, that the guide specifications are only general in nature and the actual job specifications should also incorporate all requirements contai-ned in fhe text of this report. B. Foundations The foundation requirements for individual buildings on specific lots will vary depending upon the type of materials actually comprising the Hnish subgrode of the building pad! As individual lots are finish graded, the soil engin~er should determine the foundaHon require- ments based on his evaluation of the actual subsurface conditions within the area of the proposed buildihgconstruction. - 1. Footings The proposed buildings may be supported on conventionol continuous and/or individual spread fObtings. Where non-expansive materials are exposed at the finish subgrade surface to a depth of at least 2 feet, footings should be founded at least 16 inches below the lowest adjacent finished grade or 12 inches below rough pad grade, whichever is deeper. Where expansive materials are present at or within 2 feet of the finish subgrade surface, footings should be founded at least 24 inches below the lowest adjacent finishec:f grade or 20 inches below rough pad grade, whichever is deeper. In cut areas where footings will be founded in undisturbed formational materials, th~y may be' designed for allowable bearing pressures of 4,000 pounds per square foot (psf) for dead loads" 5,000 psf for combined dead and Bve loads, and 6,500 psf for all loads incfuding wind or seismic. In areas where footings will be founded in compacted fill and/or natural soils, they should be designed for allowable bearing pressures of 2,500psf,for dead loads, 3,500 psf for combined dead and live loads, and 4;500 psf for all loads incfuding wind or seismic. All footings should, -however, have a minimum width of 12 inches. Footings located adjacent to the tops of either cut or fi II 'slopes should be founded at sufficient depth so as to provide at least 5 feet of horizontal cover between the footing and the slope face at the footing bearing level. ), D 218-3 Page 8 All continuous footings should be reinforced with top and bottom reinforcement to provide structural continuity and to permit spanning of local irregularities. To assure that footings are founded in material of adequ.ate bearing capacity, it is essential that the soil engineer inspect the footing excavations prior to placing reinforcing steel or, concrete. 2. Reinforced Concrete Box Culvert A reinforced concrete box culvert will be constructed beneath Camino Vida Roble at the approximate location indicat<ed on the Site Plan, Figure 1. Based on our evaluation of the soi Isin the general vicinity of the proposed culvert, we ant'icipate that the foundation soils wUI be suitable for the direct support of the culvert. We estimate that any settlements resulting from the weight of the culvert and overlying fill loads will be negligible. 3. Siabs-on-Grade We recommend that all ,building floor slabs as well as exterior concrete slabs-on-grade be supported on a 24-inch minimum thickness of rion-expansive soil. On those lots where expansive soils are, present within a 24-inch depth of the finish subgrade surface, we' recommend that the subgrade soils within the bui'lding area be removed and replaced wit.h non-expansive fill to b minimum depth of 24 inches. In buildings of relatively large areal extent, the required th ickness of non-expansive fi II within the building area may be reduced to 12 inches at a distance of 25 feet from the perimeter footing of the building. Slab reinforcing should be provided in accordance with the anticipated use' and loading of the slab •. As a minimum, however, we recommend that the slabs be reinforced with 6><.6-10/1-0 wire mesh for control of shrinkage cracks~ In areas where moisture-sensitive floor coverings are to be utilized and in other areas where floor dampness would be undesirable, we recommend that consideration be given to providing an impermeable membrane beneath the slabs. The membrane should be covered with 2 inches of sand to protect it during construction. The sand should be lightly moistened just prior to placing the concrete. ' 4. Lateral Loads Lateral load resistance for building foundations may be developed in friction between the foundation bottoms and the supporting subgrade. Anallowahle friction coefficient of 0.30, is considered applicable. An additional allowable passive resistance equal to an equivalent fluid weighing 300 pounds per cubic foot acting against the foundations maybe used in design provided the footings are poured neat against undisturbed soil. For footings founded in undisturbed formational material, an allowable friction coefficient of 0.35 and a passive resistance of 2,000 pounds per square foot are applicable. a 1- 0 _I t I I (] I - II ~I I 11 I II I 1 11 [) • C. Pavements 218-3 . Page 9 Based on our past experience in connection with the construction of the Phase I portion of the business park, we anticipate that R-va!:ues of about 10 and 40 wi" be typical for' the on-site expansive clayey soils and the better quality sandy soils.; respectively •. For comparison and preliminary planning purposes, we have developed the following typical pavement sections using Procedure 301-F of the State of CaHfornia Department of Public Works, Division of Highways.. Pavement sections are presented for traff·ic indices of 3.5,5.0 and 7.5. The ,3.5 index is considered to be a r~asonable value for automobile parking areas and the 5.0 index reasonable for parking areas and access drivewqys which are subjected to ligbt truck traffic. A traffic ·index of 7.5 was required by the City of Carl sbad for Camino Vi da Robl e in the Phase I portion of t.he busi ness park. Subgrade Material Type SANDY SOILS CLAYEY SOILS TYPICAL PAVEMENT SECTIONS Pavement Components Design Asphalt Traffic Design Concrete Aggrega.te Base Index R-Value (Inches) Class 2' (Inches) 3.5 40 2.0 4.0 5.0 40 2.5 5.0 1'.5 40 4.0 8.5 3.5 10 2.0 6..5 5.0 10 2.5 10.0 7.5 10 4.0 . 16.5 Total Thickness (Inches) 6.0 7.5 12.5 8.5 12.5 20.5 Note: The pavement sections given above for the sandy subgrade soil would be applicable to clayey subgrade areas provided that 12 inches of sandy fill so i I overl i es cI ayey soil. The above pavement sections are for general information only and represent the approximate. extremes in pavement requirements anticipated at the site based on the quality of the sub- grade materials. Pavement designs should be performed for individual lots based on the actual material type(s) c()mprising the subgrade and the anticipated use of and vehicular loadings on the pavements. Aspha It concrete, aggregate base, and preparation of thesubgrade should conform to and be placed in accordance with the California Division of Highwoys, Standard Specifications, January 1971 edition, eX'cept that the test method for compaction should be determined by ASTM D1557-70. II Q Bose: LEGEND TP-4 $- 2 0 14.-$- 60 5 0 : A ,lAO ,. .. --~-.. ~ / / ApprQximate Scale (feet) r*-. '''-tM' ~ _ -CG .. :) _ o 250 500 100 Indicates approximate location of exploratory test pit performed by Robert Prat~r Associates for Phose II investigat,ion. . Indicates approximate location of exploratory test pit performed by Lowney/Kaldveer Associates for PT &T alignment investigation. . . Indicates approximate location of exploratory boring performed by Lowney/Kaldveer Associates for Phose I investigation. Indicates approximate focption of exploratory test pit performed' by Lowney/KaldveerAssociates for Phose I investigati.on. Indicates approximote locaHon of exploratory boring perfofm'ed by Woodward-Gizienski & Associates for preliminary fnvestigation report doted June 18, 1973. Wi !ldan Associates. SITE PLAN ROBERT PRATER ASSOCIATES COr,svll"Q 50.1. Four-dollen & GreloQ.col fnQ,nrr'l PALOMAR AIRPORT BUSINESS PARK -PHASE II Carlsbad, California' PROJECT NO. DATE 218-3 September 1977 Figure • I -I I -[1 1 II 1 II 1) Ex i s,t i ng ground surface Notes: Horizontal benches into firm ground Compacted Fi I I Toe Key -width to be determined by Soil Engi.neer, but not less than 10 feet I Toe Key - 2 ft.. min • . into firm ground Zone of loose surface soil 1) Fills to be keyed and benched as shown in'to existing ground where the existing slopes are steeper than 5 horizontal to 1 vertical. 2) Finished fill slope.jndination to be no steeper than 1.5 horizontal to 1 vertical ROBERT PRATER ASSOCIATES Cor ,v""g 50.(. Foundor.on ! G".olog.co' Eng.n"",. SCHEMATIC ONLY NOT.TO SCALE REC NDATION FOR FILLING ON SlOPI G G OUND PALOMAR AIRPORT BUSINESS PARK -PHASE II Carlsbad, California NO. 218-3 September 1977 Figure 2 • II Ij APPENDIX A FIELD INVESTIGATION A-,l The field investigation consisted of a surface reconnaissance and a subsurface exploration program using a Case 580B backhoe. Fourteen ·exploratory test pits were excavated at the site on August 22, 1977 to a maximum depth of 14 feet at the approximate locati.ons shown on the Site Plan, Figure, 1. The materials encountered in the test pits. were con- tinuously logged in the field by our soil engi·neer and described in accordance with the Unified Soil Classification System (ASTM D2487). The approximate e'Jevations shown on the test pit logs were estimated from an undated preliminary grading plan .provided. by Willdan Associates. The logs of the test ptts as well as a key for soH classIfication are included as part of this appendix. Representative samples were obtained from the exploratory test pits at selected depths appropriate to the investigation. All somples were returned to ou'r laboratory for evalua- tion and appropriate testing. The test pit logs show our interpretation of the subsurface conditions on the date and at the locations indicated, and it is not warranted that they are representative of subsurface conditions at other locations and times • II • • • I • I I I -I ~ (5 (f) o w Z ~ t:J w (f) ex: 8 ~ 6 (f) o w Z .~ t:J w Z u:: PRIMARY DIV4INS GRAVELS MORE THAN HALF OF COARSE FRACTION IS LARGER THAN NO.4 SIEVE SANDS MORE THAN HALF OF COARSE FRACTION IS SMALLER THAN NO.4 SIEVE CLEAN' GRAVELS (lESS THAN 5% FINES) GRAVEL WITH FINES CLEAN SANDS (LESS THAN 5% FINES) SANDS WITH FINES SILTS AND CLAYS LIQUID LIMIT IS lESS THAN 50% SILTS AND CLAYS LIQUID LIMIT IS GREATER THAN 50% GROUP SYMBOl GW G·p GM GC SW SP SM SC ML CL Ot MH CH OH .NDARY DIVISIONS Well graded gravels. gravel-sand mixtures. little or no fines. Poorly 9raded gravels or gravel-sand mixtures. little or no fmes.· l' Silty gravels, gravel-sand~silt mixtures. non-plastic fines. Clayey gravels. gravel-sand-clay mixtures .. plastic fines. Well graded sands. gravelly sands. little or no' fines. . Poorly graded sands or gravelly sands. litt Ie or no fires. Silty sand.s.sand-silt mixtures. non-plastic fines. Clayey. sands. sand-clay mixtures. plastic fines. Inorganic silts and very fine sands rock flour silt.y or clayey fine sands or clayey silts with slight plasticity. Inorganic clays of low to medium plasticity. gra"elly clays. s,!ndy clays. silty t.lays. lean clays .. Organic silts and organic silly clays of low plasticity. Inorganic sillS. mic,!ccous or diatomaceous fine sandy or silty SOils. elastic. s"ilts. Inorganic clays of high plasticity. fat 'clays. Organic clays of mediuri)to high plasticitV. organic silts. HIGHLY ORGANIC SOILS Pt Peat and other highly organic soils. DEFINITION OF -TERMS lJ.S. STANDARD SERIES SIEVE CLEAR SQUARE SIEVE OPENINGS 200 40' 10 4 3/4" 311 1211 SAND SILTS AND CLAYS GRAVEL r-------.,J-----.----~t-----T--'---'---i COBBLE$. BOULDERS FINE MEDIUM I COARSE PINE J 'COARSE , GRAIN SIZES , . SANDS:GRAVELS AND BLOWS/FOOT t CLAYS AND STRENGTH· . BLOWS/FOOT t NON-PLASTIC SILTS PLASTIC SILTS VERY lOOSE 0-4 VERY SOFT 0 -1,/4 o -2 'LOOSE 4 -10 SOFT 1/4 -1/2 2 - 4 FIRM 112 - 1 4 - 8 MfDlUM DENSE 10 -30 STIFF 1 - 2 8 .,. 16 'DENSE 30-50 VERY STIFF 2 -4· 16 -32 VERY DENSE (NER 50 HARD OVER 4 OVER 32 ~ RELATIVE DENSITY CONSISTENCY . tNumber of blows of 14Q pound hammer falling 30 inches to drive a 2 inch d.D. (1-3/8 inch 1.0'> split spoon (ASTM 0-1586)." . + lklcon,fined compressive strength ·in tons/sq. ft. a~ determined by labo(atory testing or approxim'atl!(f by the standard penetration test (ASTM 0-1586). pocket penetromet,er. torvane. or lii~ual observation. ROBERT PRATER ASSOCIATES Con,ul',np So". Foundahan 'Gealap,cal (np.nee" KEY TO EXPLORATORY TEST PIT LOGS Unified Soil Classification: System (ASTM 0-2487) PALOMAR AIRPORT BUSINESS PARK -PHASE" Carlsbad, California PROJECT NO. DATE 218-3 September 1977 Fig\Jre A-1 ---,'<' ,~ II q RIG Case 580B Back SURFACE ELEVATION240 tx.)1 LOGGED BY CRG DEPTH TO GROUNDWATER None Test Pit excavated with 24 inch bucket on 8/22/17 Zw-' .. w DESCRIPTION AND CLASSIFICATION 1* w 120~ . ;rz > ;r a: a:-..... ~ -.... DEPTH w .-z ......... w .... a:-0> --~o-'-~~'" DESCRIPTION AND REMARKS SILTY SAND (SANDSTONE) SANDY and CLAYEY SILT (SlLTSTONE) Bottom of Test Pit = 13.0 Feet Notes: 1) IIX" denotes jar sample. 2) IISII denotes sack sample. Nole: The .,ralincollon line. ,ep, •• enl the opproxlmol. lbe e,oci.:ortw .. n "",'.rlol 'We, and-the I,,,,,,ilion ""''I '~6~· ROBERT PRATER ASSOCIATES COll .... '''''Q So,I, Fcwttdof'O" "G~Iog,co' Eng,~er, -' .... Z ~ z-a:: ~ I.LWZIL Q. .... "':t «'" zcc.w(l) SOIL (FEB) ;:E "'-0 ~~ :r""0'" OCLa::~ COLOR CONSIST. « z"'-, Ill' a: .... -0;:E .... '" wWm 0 ..... TYPE ",>-zo'" Q.1r_ 0 CD =>0 gray medium SM I--dense -I-1 - dense ..... - I-2 -x 10 I-- ..... 3 -very l-.'. dense ML 4 ,- gray -very "-, tan dense 1--5- "-- r 6 -S 17 I-- I-7 -.. ..... - ..... 8 -x 19 "-- grayish .r-9 - ..... -brown -1.0-x -- l-II - ..... - r-12 .;.. -- 13 - I-- I-- e------ 1-' - I-- I-- I-- I-- ~ - I-- I--- EXPLORATORY TEST prf LOG PALON\AR AIRPORT BUSINESS PARK ... PHASE II Carlsbad, California PROJE NO. DATE TEST PIT NO.. 218-3 September 1977 1 11 I • • I I fI I I I I I 1 1 -I 1 J RIG Case 580B Back"hiJ SURFACE ELEVATION254 a;;.)1 LOGGED ~Y CRG DEPTH TO GROUNDWATER None Test Pit excavated with 24 inch bucket on 8/22/77 .. DESCRIPTION AND CLASSIFICATION ~ ____________________________ ~~~----,-------,---~DEPTH . r::;: W z I-UJ <I-~z DESCRIPTION AND REMARKS I~'~~t COLOR CONSIST, ,i?~~: (FEET) o () SILTY SAND -SANDY SILT SILTY SAND .(SANDSTONE) Bottom of Test Pit = 14.0 Feet Notes: 1) "X" denotes jar sample. 2) "S" denotes sack sampre. Nol.: Th. I'notlneatlon 11nc. 'ep, ... ,,1 ,he approxlmal. bo./"dary betw •• " _1.,101 typ •• and the ,,, ... illon -y be vnadual. ' ROBERT PRATER ASSOCIATES Cons"I"nQ So,I. Fo..ndo,)on 'Geolog'co' Eng)n .. " reddish brown medium ISM-f--x dense ML I-1 _ yellow-dense sh tan light gray -very yellow-dense ish tan - SM f-. 2 - I-- I-3 - .- -4 .- f-... 1'-5- f-- i-6 .,- ,... - I-7 - f-- i-a - ----9 - --. f--10- I-- I-11 - ;.. ...., -12 --- -13 - --' 14 -- -.- -- r----,. -- ----, f-.;. -------- s 20 ) ., EXPLORATORY TEST PIT LOG PALOMAR AIRPORT BUSINESS PARK :-PHASE /I Carlsbad, California PROJECT NO. DA' TEST PIT NO. 218-3 September 1977 2 J Case 5808 Back'"'hcllJ SU.RFACE ELEVATION 272 rox .)1 LOGGED BY CRG ~~~ __ ~ ____________ ~~----~r-------~--------~ RIG DEPTH TO GROUNDWATER None Test Pit excavated with 24 inch bucket on 8/22/77 Z",~ 1£1 :-I~ x 00·...; ::rZ a: t=ZLL a:-~ b~ ~ a~(;: w «"" 1£1 .... DE$CRIPTION AND CLASSIFICATION ~ ____ ~ ____________ ~ ________ ,-__ ~ __ ~-r __ -----r--~ DEPTH DESCRIPTION AND REMARKS eLA YEY ~SAND SANDY CLAY SILTY SAND:(SANDSTONE) SANDY GRAVEL "(CONGLOMERATE) Bottom of Test Pit = 5.0 Feet (met refusal) , Note: 1) IIXII denotes jar sample. No,.: n. .'ralificolion 11M, repre,.n' ,he approxl_'. :' "'tw •• n _,.rlol type, and ,he 'ransition -r Ib._.ra~'. ROBERT PRATER ASSOCIATES Conwl,,"g So". Fovfl(/or,on ,G",log,eol Eng,,,,,.,, ! COLOR brown brown tan tar) CONSIST. I i~~~ (FEET! Id:~;~m SC ~ very stiff - hard dense very dense CL SM GP . , f--1 f-- 2 ~ ~ 3 f-- 4 f- 5 ~ ~ f- f- f- I- I- I- I- f-. f- ~ I- I- ~ f-- f- I- I- r- I- ~ I- I- I- ~ ~ r I- I-- - -- - - .. .- - - - ;.... - - - - - - - - - - - - - - - - - .,... - - -- - - - - ..J ::\i;~ I-Z C1. <w ~ ~t3g ~~ < \I) 0 ~a:~ 0 x .19 X X EXPLORATORY TEST PIT lOG .... z a: ." I~ z." x wo " .... " ."a:I--a:_ .... \i;~ 15 \I) PALOMAR AIRPORT BUSINESS PARK-PHASE /I . Carlsbad, California ' .. PROJECT NO. DATE TEST.PIT NO. 218-3 September 1977 3 RIG Case 580B BacldtlJ SURFACE ELEVATION 21b~ :.)1 LOGGED BY CRG DEPTH TO GROUNDWATER None Test Pit excavated with 24 inch bucket on 8/22/77 DESCRIPTION AND CLASSIFICATION cr DEPTH w . . Ii:;: ~.~ :t'~ .., A. :l SOIL CONSIST. TYPE DESCRIPTION AND REMARKS ~~~. COLOR (F~ET) ..: IJi o u SILTY SAND (SANDSTONE) Bottom of Test Pit = 10.0 Feet . Note: "X" denotes jar sample. ROBERT PRATER ASSOCIATES Consvlltng So.I.IOIIndof.on 'G~'~'col Eng,nrrtl light brown grayish tan light gray medium SM f-- dense f-1 .. dense-I-- very "'" 2 - dense .... - f-3 - f--.. -4 .. - 1-5- f-- f-6 ,.. ;.. . - .,.-7 - - - f-8 -x 8 f-- I-9 - I-- 10 -- -- '-- I---- -- -- f-,.. f--,.. -- -- l-'- I-,.. .,.. - -. ,.. -- f-,.. f--,.. .,.. - --- EXPLORA'FORY TEST PIT LOG PALOMAR AIRPORT BUSINESS PARK -PHASE II Carlsbad, California t-_P __ R_OJ_' E_C_T_' N_O __ • ___ f-__ D_A'-T_E_---.;;.~ TEST PIT NO; 218-3 September 1977 4 • n RIG Case 580BBac~ SURFACE ELEVATION225~.)ILOGGED BY CRG DEPTH TO GROUNDWATER None Test Pit excavated with 24 inch bucket on 8/22/77 %",-. '" o~:t Qut • ::z:Z cr ffi;:-HI~ DEPTH '" rz ...... a:t;~-..J c:<(/) .... % ~ztr~ 0.. ~~~ (FEET) ~ <w r Wo ", SOIL w-o ~~ CONSIST. <. Z~...J l/l' a: .... - TYPE II) 0 :;;~ ~a:~ u DESCRIPTION AND CLASSIFICATION D~SCRIPTtON AND REMARKS ISY~. COLOR SILTY SAND -SANDY SILT SILTY SAND (SANDSTONE) ! Bottom of Test Pit = 9.0 Feet Note: "x" denotes jar sample. No,.: The .'ratiflcation II ..... repre.ent the ClppfOxi_'. ~,~Zorh .. cn material type. and, ,he 'ranoltion -y ROBERT PRATER ASSOCIATES CO~Su",~g So:'..!ourtdahOtl 'G~'og,co' fng,"~"" light medium SM-1-0-ML brown dense ---+--~--~~~ gray . dense SM f- f-- ~ - - - - 1 .. - 2 - - 3 - .. 4 .. f-5--- -- -6 - --... 7 - -- ~ 8 - -- 9 f-,- ----- - -- ~ - I-,- f-- f-- -- I-- f-.- f-~ r-- f-- f-- -, - '-.- :-- f---- -- -' - X 9 EXPLORATORY TEST PIT LOG PALOMAR AIRPORT BUSINESS PARK -PHASE II Carlsbad, CalHornia t-_P_R-:OJ~E~CTn-N_O_. -f-=--_..:,..D~A_T_E..."....,; ........ -I TEST PIT NO. 218-3Septeinber 1977 5 : " .. I~ I • • • • -II • • • • • II • • • • 11 -. SURFACE ELEVATION 240 ~ LOGGED BY CRG Case 5808 Bac RIG DEPTH TO GROUNDWATER None Test Pit excavated with 24 inch bucket onS/22/77 DESCRIPTION AND CLASSIFICATION DESCRIPTION ANO REMARKS I~~~.-COLOR SILTY SAND (SANDSTONE) Bottom of Test Pit ;::: 9.0 Feet .. Note: "X" denotes jar sample. ! , , R08ERT PRATER ASSOCIATES Conlul"ng So,I, FoundOloon "G.,olog,col Eng,n,,"'l light gray, CONSIST. SOIL TYPE. medium dense dense very dense SM .... -' -1 - -- - 2 - ~ - ~ 3 - -.- - 4 .-< ~ 1-5- ..-,.. -6 -... ..., ~ 7 - I-- l-S -x 9 -- 9 I-- I-- ~ --- -- -- -- I---- >--: --. -' -'- ---.-- -- -- --' .,; ~ - .---- -- EXPLORATORY TEST PIT lOG PALOMAR AIRPORT BUSINESS PARK -PHASE II- Carlsbad, California PROJECT NO. DATE TEST PIT NO. 21S-3 September 1977 6 '. II RI'G Case 580B BackhoA DEPTH TO GROUNDWATER None SURFACE ELEVATION 255~ LOC3GED BYCRG Test Pit excavated with 24 inch bucket on 8/22/77 zw-. W DESCRIPTION AND CLASSIFICATION Ou": . J:Z a: t=zll. rr; a: 0~ -DEPTH W «« ....... W z DESCRIPTION AND REMARKS SILTY and CLAYEY SAND (SANDSTONE) SILTY SAND (SANDSTONE) Bottom of Test 'Pit = 8 Feet Notes: 1) "XII denotes jar sample. 2) "S" ~enotes sack sample. INole: The .lratiFicalion lines r ....... nl lhe opproxl .... l • . __ :,-!'-tween _I.rlal typel end ,he lron,illon ""'Y ~'I'D_I. ..J ... (FEET) ::!! « en I~;..~· COLOR CONSIST SOIL IOV'-• TYPE reddish idense -ISM- tan Ivery SC f- -x Idense f-1 - light Ivery gray idense - SM f-2 - f-- f-3 - f-.. f-4 '. f- f--5- f-- I-6 - f-- f-7 - f-- 8 b-- I-- r .., I---.... - f-- .... -' I-- I-... I-- I-- .... - f-- f--- .... - I-- .... - .... ' - I-- I-- f-- f-- r-- I--- S a:>-1Il >-", >-en~ ~~ w-o zen..J ~~S 0 u EXPLORATORY TEST PIT LOG «za:1L UJwoCf) ~a: .... ~ >->-enID Ii W > J: iii>-en\!)-zwz::; oll:W", oc.a:-z~:;; ::> 0' ROBERt PRATER ASSOCIATES Con"'''',!Q So". Fourtdor.on ,Geo'og.co' E,.'g,,..e,, PALOfv1AR AIRPORT BUSINESS PARK -PHASE II Carlsbad, California t-_P_R_OJ-::-:-EC-=-T-:N::-O_.~I--"-_...:D:.:..A..:...:T-=E~_-I TEST PIT NO. 218-3, September 1977 7 d ''-- II • • • • 11 • • • -. • I [I I. • • .. =-, --. RIG Case 580B Back. SURFACE ELEVATION 184~ LOGGED BY CRG DEPTH TO GROUNDWATER None Test Pit excavated with 24 inch bucket on 8/22/77 ZUJ-: .. W I~ UJ DESCRIPTION AND CLASSIFICATION a: Ou~ . :z:Z > :z: -z .... .a::;: a: 0 ~ -.. ~ -... DEPTH w ~< ...... .~ ~ C) ~ ... <I) .w z DESCRIPTION AND REMARKS SILTY SAND SIL TY SAND (SANDSTONE) Bottom of Test Pit log = 13.5 Feet Notes: 1) "Xl~ denotes jar sample. 2) "s", denotes sack sample. No •• : The •• ,atlnullon II .... repr •• en. the approxlmal. __ .. ' _~tw .. n "", •• rlal types and .he ' ... n.ltion_y be ervaua •• '~S~ ROBlIn PRATER ASSOCIATES Co,...,I"nQ So.I. F""ndohon 'GlK>/og.col Engl~~" COLOR light brown dark brown light brown / light tan CONSIST. medium dense dense very dense SOIL TYPE SM SM (FEET) ... .,. -1 - -- 2 - ~ - ~ 3- -.- '-'4 .- :- f-5-:- I-- I-6 --- ~ 7 - ~ - '-8 - ~ --9 ,.. ~ - ~10--' ~ - ~ 11 - -- -12 - -- r-13 - f-. 14 --- -. ---- ~ - I-- >---- -- f-. - ~ - r-- ~ - -J 0. ... <I)~. ~w ::Ii < ... < ~ffig ~z <I) 0 ~4"~ 0 S x 9 EXPLORATORY TEST PIT LOG <zo: .... UJZ wwo'" a:w ~a:~~ uo.a: lii~ z::lili; ;::)8 PALOMAR AIRPORT BUSINESS PARK -PHASE II . Carlsbad, California PROJECT NO. DATE TEST PIT NO. r---~~~--~~----------~ 218:"3 September 1977 8 ~ RIG Case 580B Bac SURFACE ELEVATION 218~~1 LOGGED BY CRG . DEPTH TO GROUNDWATER None . Test Pit excavated with 24 inch bucket on 8/22/77 Z",-, w OW DESCRIPTION AND CLASSIFICATION -: 001-:tz w> I: cc ~zl4.. cr-t-<. Zen"- DEPTH W 00:<' w,~ a:~>_ -Ul~-.~ oct-'" t-"'~ .... w <t-~ZLr~ ~wz~ I~b~· COLOR (FEET) ::I< x "'0:1( o cc W.:I( CONSIST. SOIL < "'Via ··~z ",a:I-"" oo..·cc - TYPE '" Zw-' 0 :;;~ z~:;; ~a:!!? 0 ::>0 DESCRIPTION AND REMARKS SILTY SAND Bottom of Test Pit -12.5 Feet Note: "X" denotes jar sample. Note: The ItrotiOcotion line' reprelent the approximate 1::~Zottweitn IIIO'.rlol I)1>e, and 'he 'ron,ition may ROBERT PRATER ASSOCIATES . COI>Iu".ng So.I.lo..<tdo,.on 'G.olog.col ("".nee" tan light tan - gray loose -:- medium dense SM ~ .,. ~ 1 -X 27 I-.,. I-2 - I-- 1-. 3 . .,. ~ .- ~ 4 .- I- ~5- ~ - I-6 --tan -idense gray SM ~ f- 7 - - I-8 -X 9 I-- I-9 - I-.,. f-10- .... - ~ 11 .,. I-~ I-12 .,. .... 13 - I-.,. I-.,. . ~ .,. f-,---, I-- ~ - I-... I-- I-.,. f-- .... --- .-- f-.... EXPLORATORY TEST PIT LOG PALOMAR AIRPORT BUSINESS PARK -PHASE ~Ir Carlsbad, California PROJECT NO. ·DATE TEST PIT NO. 218-3 September 1977 9 [I "- II I • • I rJ _I' I • ••• I •• • [I ! • I ; • I '. • 11 11 ~R~_'G~~_C_a_s_e+5_8_0_B_B_a_c_k~ __ ~~ ____ +-S_U_R_F_AC_E~E-LE_V_A_T_10_N __ 24_5_~(~IJI LOGGED BY CRG T est Pit excavated with 24 inch bucket on 8/22/77 DEPTH TO GROUNDWATER None DESCRIPTION AND CLASSIFICATION DESCRIPTION AND REMARKS I~~tt COLOR SILTY SAND (SANDSTONE) tan gray Bottom of Test Pit = 14.0 Feet Note: "x" denotes jar sample. ROBER.T PRATER. ASSOCIATES COr.lu".ng So.I. FovttdOI.On 'G.olog.col Eng.nn" CONSIST.', ;~~k dense very dense . SM ~ - ~ 1 - -- f-2 - ~ ". I-3 - -.- f-4 - l- I--5- ~ - f-6 - f-- I-7·- '"" - f-a - I-- f-9 - f-- ~10- I-- I-11 - f-- ~ 12 - f-- I-13 - l-. - 14 I-- ~ -- f-- r - I-- I-- f-- I-- ~ - I---- t-- x X -; . a:;: W z !<.~ 3:z o o 17 EXPLORATORY TEST PIT LOG PALOMAR AIRPORT BUSINESS PARK -PHASE II CarlsbQd, Cal·ifornia PROJECT NO. BATE TEST PIT NO. r-~2~178_~3~-4~S~cp,~1~1-19~77 10 RIG Case 580B B~ SURFACE ElEVATION 284 ~.~ LOGGED BY CRG DEPTH TO GRO\JNDWATER None Test Pit excavated with 24 inch bucket on 8/22/77 ZW~ w OW ~ 00": xz w>x cr t=ZLL rr:;: a: .... < ziijl- DEPTH w «< ...... -cnO-crl-I/) W z <Cl>y:-LLUJZI.L. OESCRIPTION AND CLASSIFICATION DESCRIPTION AND REMARKS SILTY SAND SANDY CLAY SILTY SAND Bottom of Test Pit = 14.0 Feet " ' Notes: 1) "x" denotes jar sample. 2) "S" denotes sock sample. Not.: n.. alrotifieotion 11,* rcp,.,.n' the approxlmat. IoouncIaty betw •• n """.,lal typeJ and ,he Iron.lIion may be troMI. SYM- BOL ROBERT PRATER ASSOCIATES Con.."""" So". Fcwrtdot.o ... , G.oIQQ.col £""''' •• '1 COLOR brown light brown orange- ish tan- gray CONSIST. medium d~nse very stiff dense- very dense SOIL T-YPE SM ~ -' 0.. (FEET) ::E « '" - x ·1 -. CL _ - x 2 -SM ~ .,. ~ 3 --.. -4 .. - r--,. 5- "" - -6 -S -- ~ 7 - f-..,. ..,. 8 .... .... - -9 - I-- f-1O- I-- -11 - ~ - ~ 12 - 1-' - ~ 13 - -- 14 ~ - f--...... ---- ~ - '------ i.,. - -- -- -- .... "'~ .... w <0-",-0 ~z z:3-, 0 ~a:S 0 19 I EXPLORATORY TEST PIT LOG - UJ Z'C:: VJ Z a: w·U] x"'o", oo..cr:!. "'a:: .... _ 0::Eo-0-' ",>-,~o I/) CD ' 0 , .. - ' . PALOMAR AIRPORT BUSINESS PARK -PHASE II Carlsbad, Cal ifornia PROJECT NO. DA' , TEST PIT NO. t--=21::-:a:-_3=----f--Sep-'te-m~lb---,e-r -1-977-, -I -11 1I~ 11 • • II • • • •• • II • • • • • I \ \ RIG Case 580B Baca SURFACE ELEVATION200~ LOGGED BY CRG DEPTH TO GROUNDWATER None T est Pit excavated with '24 inch bucket on 8/22/77 Z",_ .. W OW DESCRIPTION AND CLASSIFICATION cr ou~ . xz w > :t -z"-a::-cr t;~ -ziii'" DEPTH w ~<;n-w'" -II)CI-LL.wzw.. ..J .... ~ 0.. .:: ti; ~ <za:'" wwo</) za:wtJ) SOIL (FEET) ::E w iii.a ~~ ~crl-~ 80... a: ~ < CONSIST. </) zw-' '0 ti;~ z::Eti; TYPE ~crS u ::>8 . DESCRIPTION AND REMARKS ~~~. COLOR SANDY and c;.LAYEY SILT SILTY CLAY Bottom of Test Pit = 10.0 Feet Note: 1) "x" :denotes jar sample. iNola; The ,'ratlficolion line, repre .. nl the eppro~'/ftOla __ ~/_~tw .. n _Ierlol type. and lhe lron.ilion_y be .JII'O_'. . ROBERT PRA-TER ASSOCIATES Con,ulllilg So.I. Fouttdor.on I. G~Iog.col ["{I' nu'. light 'Ioose ML -- brown ~ 1 -x ~ --2 - I-- -3 - f-.. 4 .. gray-very CH f-.. tan stiff ~5- f-. - ~ 6 - ~ - ~ 7 -X 19 f-- '-8 - ~ - hard ~ 9 - ~ :- 10 I-- - ~ - ~ - ~ - I-- ~ - I-- f-- -- -- -- I--: ... - --. -- -- I-- r-- f-- EXPLORATORY TEST PIT LOG PALOMAR AIRPORT BUSINESS PARK -PHASE iI· Carlsbad, California PROJECT NO. DATE tEST PIT NO. r-~~~--~~--~------~ 218-3 September 1977 12 "-~ ----~------~-------, I LOGGED BY eRG SURFACE ELEVATION Case 580B Backh RIG DEPTH TO GROUNDWATER None Test Pit excaveted with 24 inch bucket 6n 8/22/77 II: DEPTH w DESCRIPTION AND CLASSIFICATION -" "- SOIL (FEET) ~ < TYPE fJ) DESCRIPTION AND REMARKS 1~6t: COLOR CONSIST. SILTY SAND (SANDSTONE) Bottom of Test Pit = 6.5 Feet Note: "x" denotes jar sample. ItO.ERT PRATER ASSOCIATES Conlu/""Q So". Foundol,on 'G~/OQ,col Enp,~~~r' brown medium reddishr dense orange 'dense' tan-very white dense SM '-- '-1 o. x ,--- -2 - '-- f-3 -x 11 r .- -4 .- f- f--5- '-- r-6 - f-7 - f-- f-- -- f-- I-- I-- f-- r' - -- -- -- -,- -- f-- -- -- -"- I-- -- -- -- -... '-- f-- I-- !-- EXPLORATORY TEST PIT LOG PALOMAR AIRPORT BUSINESS PARK -PHASE II Carlsbad, Col,ifornio PROJECT NO. DATE TEST PIT NO. 218-3 ;eptember 1977 13 I' J • • • • I • • • • • I • • • •• I I :II RIG Case580B~ SURFACE ELEVATION • f LOGG.ED BY CRG DEPTH TO GROUNDWATER None Test Pit excavated with 24 inch bucket on 8/22/77 DESCRIPTION AND CLASSIEICATION DEPTH SOIL (FEET) CONSIST. TYPE DESCRIPTION AND REMARKS I~~~t COLOR SC I--brown cLAyEY SAND ~i~L-1 '- SM ~ _______________ ~ ________ ~ __ ~~~o~ra~n~Qle~~~~-+--~ SILTY SAND (SANDSTONE) white Bottom of Test Pit = 5.5 Feet (met refusal) Notes: 1) "x" denotes jar sample. 2) liS'" denotes sack sample. INote: The IIrallFiCGtion II"., ,epre .. nt the approxImate __ .=.~!>-tw •• n InCII.rlol typ., ."d the tron,ition rrwzy Ibc __ .,.v_ .. brown - orange very dense . I-- I:-2 - I:-- f-3 - f- r 4 .. I:- ~5- I:-6 - I:-- I-- f-- I:-- I:-- I:-- I:-- f-- I-- '"" - -- f-- f-... f-- -- I:-- I:-.;. ~ - I-- I:-- f-- I-- f-- I:-.. I-- I:-- f-- f-- zw-. ou"": . 'II: i=Z"-a:;: w «' .... 1I:f-'" W z A. .... .,,~ !<~ ::E w-O ~z < z~...J ." 0 ~cr~ U S x 6 EXPLORATORY TEST PIT LQG w J:Z '~ 0 ~ u: w z·a: C/.) r"'O'" ."a:f--Iii >-' CD OW W > J: z;;;'"' -.,,0-\.Lwzl.L zcrw~ o",a:1S U;lf-zo'" ::>u ROBERT PRATER ASSOCIATES PALOMAR AIRPORT BUSINESS PARK -PHASE II Carlsbad, California . Con~ulhng So". Foundohon 'G~Iog,col Eng,~e" t-_P_R-:OJ~E~C-;:T~N_O_._I---= _____ D_A-:--T.:..E -:-::=---I TEST PIT 'NO. 218-3 Sept .. lib",. 1977 14 II II' APPENDiX B LABORATORY TESTING B-1 The natural water content was determined on selected samples and is recorded on the t'est pit logs at the appropriate sample depths. Two Atterberg Limits tests p,nd twelv,e No. 200 sieve tests were performed on selected samples of the subsurface materials to determine the range of water content over which- these materials exhibit plasticity and to aid in classifying the soils aq::ording to'the Unified Soil Classification System. The results of these tests are presented on Figures B-1 and B-2. Two laboratory gradat.ion tests were performed on selected samples of the materials en- countered in the t~st pits., The results of these tests are presented on Figure B-3. Two laboratory compaction tests (ASTM D 1557-70) were performed on selected, bulk samples of the on-site materials. The results of these test~ are presented on Figures B-4 and B-5. 'Two .Iaboratory-direct shear tests were performed on remoJded samples of the on-site materials 'compacted to approximately 90 percent of the maximum dry dens-ity as, det'ermined by ASTM Test Designation D 1!557-70. The samples were sheared at a constant rate under _ various surcharge pressure's. Failure was taken at the peak shear stress. Tbe resul'ts of the direct shear tests are presented on Figures B-6 and B-7. .~ ~ ~. • I.· I I • • • ¥. • • --• 1 -< 60 50 ~V .vV ,... CH fI!. Y v 40 V )( , / w Cl 0 z 30 >-V· t: MH u ~ ~ 20 V or ~ ....I A OH 0.. 10 7 ~ , 4 CL-ML V// V/7 ML or OL 0 ML V' I ,,- 0 10 20 30 40 50 60 70 -80 90 100- LIQUID LIMIT (%) y TEST NATURAL PASSING UNIFIED KEY PIT SAMPLE LIQUID PLA$TICITY --LIQUIDITY SOIL' SYMBOL DEPTH WATER LIMIT INDEX NO. 200 INDEX CL.A.SSIFICATION-NO. CONTENT SIEVE ( feet) % % % % SYMBOL --1 2.0 10 ----1B --SM 0 1 6.0 17 38 11 69 --. -ML --1 B.O 19 ----79 --ML --2 0.5 20 ----50 --SM-ML --3 1.0 19 ----6,5 --CL --4 B.O B ---.-17 --SM --B 9.0 9 ----37 ' .... -SM --9 1.0 27 -- --46. --SM --9· B.O 9 -----38 --SM PLASTICITY CHART AND DATA ROBERT PRATER ASSOCIATES PALOMAR AIRPORT BUSINESS PARK -PHASE II ConSIlIr'"Q So". FOllndofton 'G~oIog,co' Eng,"~~fI Carlsbad, California PROJECT NO. DATE 218-3 Sept~mb~r 1977 ' Figure 8-1 60 : 50 ./ ,... ';fl. v 40 >< w 0 Cl ~ 30 >-, ... U ~ en 20 ~ ~ Q. 10 7 4 0 MH . ~y r-~-t-----r----+-~~V--~~----~----~·ot~----~--~~ ~ . OH ..,..-,.---,.--+-___ tr' CL-ML ,/7/V/7 Mlor Ol ML,'/ ., 0 30 40 50 60 70 80 90 100 LIQUID LIMIT C%) TEST NATURAL UNIFIEO KEY SAMPLE LIQUID PASSING , PLASTICITY LIQUIDITY ,SOIL PIT WATER SYMBOL NO. DEPTH LIMIT INDEX NO. 200 INDEX CONTENT SIEVE CLASSIFICATION ( feet) % ---10 11.0 17 ---11 1.5 19 0 12 7.0 19 J ROBERT PRATER ASSOCIATES ConSIII"ng 50./, Follnder,on 'Geo/og.cel Eng,neefS % % % SYMBOL .. ----36 --SM ----55 --CL 59 30 90 --'CH PLASTICITY CHART AND DATA PALOMAR AIRPORT BUSINESS PARK -~P-HASE II Carlsbad, <;:alifornia' PROJECT NO, DATE 218-3 September 1977 Figure B-2' I L .¥ I • 100 to I 10 70 " I' ! .. 60 .. '" L I-% SO .. U -I C .. 40 L t )0 --20 10 --0 I II • • • ' I • -. • • • . e UNIFIED SOIL CLASSIFICATION SYSTEM U. S. STANDARD SIEVE SIZES 7 , .3 2 I 3'14 \/1 114 4 • .10 a 10 30 40 SO 60 '10 100 200 32S .0 10 20 30 40 SO 60 70 .0 to joo 100 50 10.0 5.0 1.0 0.5 0.1 .OS .01 .005 .001 PARTICLE SIZE iN MILLIMETERS GRAVEL. SANO CO.BL£S~-------r--------+---~r---------T---------~ SILT ANO CLAY COA"SE f'IN£ co-."s£ FINE' TEST UNIFIED KEY PIT SAMPLE ELEV. SOIL SYMBOL DEPTH (feet) CLASSIFICATION SAMPLE DESCRIPTION NO • (Ieet) SyMBOL ; -1 6.0 236 ML SANDY and CLAYEY SILT, gray-tan ---2 5.0 249 SM SILTY SAND, yellowish tan GRADATION TEST DATA ROBERT PRATER ASSOCIATES co,~,,/I,nll So". Founc/Oloon ~ Geo/co,eol Eng,neers PALOtMR AIRPORT ,BUSINESS PARK -PHASE II Carlsbad, California PROJECT NO. S FIGURE B-'3 ;~ptember 1977 ' 0 .. ! '!< I-'" a: I-Z '" V :t '" L II II "I SAMPLE DEPTH SPECIFIC LlOUIQ PLASTIC HO. IFT.1 SAMPLE DESCRIPTION GRAVIT Y L.II~kl INOE.X . TP-l 6.0 SANDY and CLAYEY S'IL T (ML), gray-tan ---- . Zero Air Voids Curve Specific Gravity = 2.70 ,;':;;;" .. 125 , \ , t; \ f ! ., !\ . , . --\ 120 . r\ ' j .. ' \ ..... . . 0 a. . .. '->-I-115 ".. -(/) _."\: K \ z ,,/' " liJ ./ \, '0-. !f" ~ . )...:.. \ \ '""' >-/ '8... 0:: \ 0 \ 110 . 1\ ~ .\ \ h \ 'i. r\ " 105 ; \. (j 5 10 15 20 25 , MOISTURE CONTENT 0/0 . OPTIMUM WATER CONTENT % . 13.6 MAXIMUM DRY D~NSITY I pef 114.9 TEST DESIGNATION ASTM D 1557-70 , COMPACTION TESTRESU\,. TS ItOIERT PRATER ASSOCIATES PALOMAR AIRPORT BUSINESS PARK ... PHASE II COtIIU".ng So.I. Fou"(/Ohon ,·Gro'og.col fng.nre.11 Carlsbad, California PROJECT NO. DATE FIGURE 8 .. 4-218-3 September 1977 I~ I • t-" • [I • • • • • 11 • • • • II [I Ji S ..... PLE DEPTH SPECIFIC LIQUID PLASTIC HO. 1FT,) SAMPLE DESCRIPTION GRAVITY L~~.!T INDEX TP-2 5.0 SILTY SAND (SM), yellowish tan. ------ Zero Air Voids Curve Specific Gravity = 2.60 -130 , 1\ , J \ \ ~ 125 ~, \ , -u ~ Q. . \ r t-120 \ -(/) \ z IJ.J h 0 / • r , H \' \ 0:: / ~' _h 0 ~ 1\ . 115 V ) ~I i\\ ;; f\ , "\ - \ 110 \' 0 5 10 15 20 25' MOISTURE CONTENT 0/0 , J : QPTIMUM WATER CONTENT % 12.5 MAXIMUM DRY DENS-ITY. pef 118.4 TEST DESIGNATION ASTM D 1557-70 COMPACTION TEST RESULTS: It08~RT PRATER ASSOCIATES PALOMAR AIRP.ORT BUSINESS PARK -PHASE II Consul,mg So". FoundO',on 'G,olog,col fng,nrr,s Carlsbad, California PROJECTHO. , DATE 218-3 ISeptember 1977 FIGURE 8-5 II • II II -> s.o . -. - 4.0 u::-~ )/ (/) 3.0 ~. ~ ---(/) ~ 00 ~ w a: ----I-00 , ----a: < 2.0 .--w ~ I-"" <: ~ J: (/) ~ V , ~ .. 1.0 .. , .. ., 0 1.0 2.0 3.0 4.0 5.0, 6.0 NORMALPRESSURE(KS~ SAMPLE DATA TEST DATA DESCRIPTION: SANDY and CLAYEY SILT (ML), TEST NUMBER 1 2 3 .. gray-tan NORMALPRESSUREIKS~ 1.00 2.50 5.00 SHEAR STRENGTH (KSF) 1.75 1.93 3.09 Test Pit N~.": 1 INITIAL HJO CONTENT (~.) 13.6 13.6 13.6 DEPTH (II,): 6 ~ 0 .1 ELEVATION (11):234approx. FINAL H,o CONTENT (-to)' 21.9 21.9 21.9 TEST RESUL T~ INITIAL DRY DE'NSITY (PCF) 103.4 103.4 103.4 APPARENT COHESION IC!: 1.2a ksf FINAL DRY DENSITY (PCF) . -------"-- APPARENT ANGLE OF INTERNAL FRICTION I~): 190 STRAIN RATE: 0.02 inches/minute fapprox~) Note:· Test was performed on'sample remolded to approximately 900k of the laboratory maximum density and then allowed to saturate before shearing • j . DIRECT SHEAR TEST D.ATA ROBERT PRATER AS-SOCIATES PALOMAR AIRPORT BUSINESS PARK -PHASE II C<;l","1"ng 50,1, FOundo"on "Geolog,col Eng'~e" Cadsbod~ California PROJECT NO, DATE 218-3 September 1977 Figure 8-6 : • ~ J J -5.0 • • ~ rr- l---v l------4.0 ~ , l---- l.-----• l---l.--( tJ -u.. en 3.0 ~ • -en en UJ a: t- II en a: ct UJ 2.0 ::r: • en , • ! , 1.0 • , . . . -. 0 1.0 2.0 3.0 4.0 5.0 6.0 , '. NORMAL PRESSURE (KSF) -. : ., fI • SAMPLE DATA TEST DATA DESCRIP110N: SILlY SAND (SM), yellowish TEst NUMBER 1 2 3 • tan NORMALPRESSURE(KS~ l.OC 5.00 SHEAR STRENGTH (KSFI 3.42 4.70 Test Pit No.' 2 INITIAL H/O CONTENT'(%) .12.6 12~6 11 DEPTH (11.1: 5 0 .1 ELEVATION (11):249(oppro~. FINAL tlJO CONTE'NT (0,;.1 16. 1 16.1 TEST RESUL T$ INITIAL DRY·DENSITY (PCF) 106.3 106 3 APPARENT CQHESION (e;: 3. 11 ksf FINAL DRY DENSITY (PCF.) ~-----• 'APPARENT ANGLE OF INTERNAL FRICTION lfi): 17° STRAIN RATE: 0.02 incheSlminute (opprox.) , Note: Test wos"'performed on sompleremolded t.o approximately 90% of the laboratory ~'. maximum density and then allowed to' saturate before shearing. DIRECT SHEAR TEST DATA -I ROBERT PRATER ASSOCIATES PALOMAR AIRPORT BUSINESS PARK -PHASE II Con",rltnQ So.r .. FoundOl.on 'G~orOQ,cor EnQ'ne~!1 Carlsbad, CoUfornia 11 PROJECT NO. DATE 218-3 September 1977 Figure ·B-7 .' 1. GENERAL A. Scope of Work • APPENDIX C GUIDE SPECIFICATIONS -SITE EARTHWORK FOR PALOMAR AIRPORT BUSINESS PARK -PHASE II CARLSBAD, CALIFORNIA c:-1 These specifications and applicable plans pertain to and include all sHe earthwork indud.,. ing, but not limited to, the furnishing of all 'labor, tools, and equipment necessary for site' clearing and stripping, disposal of excess materials, excavation, preparation of foundation materials, for receiving fill, and placement and compaction of fiH fo the lines and grades shown on the project grading plans. B. Performance The COfltractor warrants all work to be performed and aU materialsto be furnisheq under this c~nftact against defects in materials or workmanship for (] period ,of . year:{s)' from the .date of written acceptance of-the entire constructi'on wO,rk by .the Owner. Upon written notice of any defect in materials or workmanship during said year period, the Contractor sholl, 'Of the option of the Owner, repair or replace said defect and any damage to other work caused by or resuiting from such defect without cost to the Owner. This sholl not limit any rights of the Owner under the "acceptance and inspectiol')u clouse of this contract. The Contractor shall be responsible for the saJisfactory completion of all site earthwork in accordance with the project plans and specifications. This work shall be observed and ' tested by a representative of Robert Prater Associates, hereinafter known as the Soil Engineer. Both the Soil Engineer and the Architect/Engineer are the Owner'$ representqtives.' If the Contractor should foil to meet the technical or design requirements embodied in this docl:Jment and on the opplicable plqns, he sholl make t.he necessary readj'ustments until all work is deemed satisfactory os determined by the Soil Engineer anq the Architect/Engineer. No, deviation from the specifkations sholl be made except upon written approval of the Soil Engineer or Architect/Engineer. ' . No si te eorthwork shall be performed without the physical presence or opproval of the Soil Engineer. The Controctar sholl notify the Sail Engineer at least 24 hours prior to commencement of any aspect of the site earthwork: The Soil Engineer sholl be the Owner's representative to observe the earthwork operations duri-ng the site prepar:ation work ond placement and compaction of fills. He shall make , ~ •.. ~-~~~ ... ,...,.. fI; · j; II .: ., I. I. ~ •• •• • • • [I, • • • • ~I· I' • C-2 enough visits to the site to familiarize himself generally with the progress and quality of the work. He sholl make a sufficient number of tests and/or observations to enable him to form on opinion regarding the adequacy of the site preparation, the acceptability of the fill material, ond the extent to which the compa.ction of the HlI, as placed, meets the specification requirements. Any fill that does not meet the specification requirements shall be removed and/or recompacted until the requirements are satisfied. In accordance with generally accepted construction practices, the Cont.ractor shall be solely and completely responsible for working conditions at the job site, including safety of all persons dnd pr~perty during performance of the work. Tbis requirement shall apply . continuously and shall not be limited to normal working hours. Any construction review of the Contractor's performance conducted by the Soil Engineer is not intended to inc,' ude review of the adequacy of theContractor's safety measures in, on or n.ear .the construction site • Upon completion of the construction work', the Contractor shall certify that at! compacted fills and foundations are in place at the correct 10cQtions, have the correct dimensions, are plumb, and have been constructed in accordance with sound construction 'practice. In addition, he sholl certify that the materials used are of the types, quantity andqualHy required by the plans and specifications. C. . Site and Foundation Condi tions The Cont.ractor is presumed to have visited tbe site and to have familiarized' himself with existing site, conditions and the soil report tit.led "Geotechnical Investigation, Palomar Airport Business Pork -Phase II, Carlsbad, California, II doted September 19, 1977. The Contractor sholl not be relieved of liability under the contract for any loss sustained as a result of any variance between conditions indicated by or deduced frbm the.soilreport and the actual condit'ions encountered during the course of the work. . The Contractor shall, upon becoming aware of surface and/or subsurfoce condi tions differ~ ing from those disclosed by the original soil investigation, promptly notify the Owner as to the nature' ond extent of the dHfering conditions, first verbally to permit ve'rific~tion of the conditions, and' then in writing. No claim by the Con.tractor for any conditions differing from those anticipated in the plans and specifications and disclosed by the soil investigoHon will be allowed unless the Contractor has so notified the Owner, verbally and in writing, as required above, of such changed conditions. O. Dust Control The Contractor shall assume responsibility for the alleviation or prevention of ony dust nui.sance on or about the site or off-site borrow areas. The Contractor sholl assume all \'iability, including court costs of co-defendants, for all claims retQted to dust or wind- blown materials attributable to his work. • • C-3 II. DEFIN ITION OF TERMS STRUCTURAL FILL -All soil or soil-rock material placed at the sHe in order to raise grades or to backfill excavations, and upon which the Soil Engineer has made sufficient tests and/or observations to enable him to issue a written statemehttbat, in his opinion, the fill has been placed and compac.ted in accordance with the specification reGuirements. ON -SITE MATER IAL -Material obtained from the reguired site excavations. IMPORT MATERIAL .l Material obtained from off-site borrow'areas. ASTM SPECIFICATIONS -The 1970 edition oJ the American Society for Tesfing and Materials Standards. DEGREE OF COMPA<;:TION -The ratio,expressed as a percentage, of the in-place dry density of the compacted fill material to the md~imum dry density oJ the same material as determined by ASTM Test Designation D 1557 -70. III. CLEARING AND STRIPPING All areas,to be graded shall be cleared c;>f debris, brush, chaparral, designated trees, and asso~iated roots. The Cleared materials shall be disposed of off-site. ' , After clearing, any cl,Jltivated areas as ~ell as all other areas supporting a growth of surface grass and weeds shall be stripped too sufficient depth to remove all surface, vegetation and organic laden topsoil. The actual stripping depth shall be determined in the field by the Soil ~ngineer at the time of construction. IV. EXCAVATION All excavation sholl be performed to the lines and grades and within the tolerances specified on the project grading plans. All over-excavation below the grades specified sholl be backfilled at the Contractor's expense and shall be compacted in accordance with the specifications. The Contractor shall assume full responsibility for the stability of all temporary construction slopes at the site. . , V. PREPARATION FOR FILLING Surfaces to receive compacted fill shall be scarified to a minimum'depth of 6 inches, moisture conditioned and compacted. Any pockets of loose, saturated colluvium sholl be removed ond recompacted. The need for removal and recompoction shall be determined by the Soil Engineer In the field at the time of construction. All ruts, hummocks, or other uneven surface features sholl be removed by surface grading prior'toplacement of any fill materials. All areas which are to receive fill material ~hall be approved by the Soil Engineer prior to the J?lacement .of any filt material. • • I • • JI -I • • • • • 1 • • • -I --I • (.' ~ • • . C-4 Fills constructed on naturol slopes having an indination ~teeper than 5 horizontal to 1 vertical shall be keyed and benched into firm natural ground below any loose surface soils at the direction of the Soil Engineer. VI. MATERIALS FOR Fill All existing on-site soils are in general suitable for reuse as fill. Fill material shall not, however, contain rocks or lumps larger than 6 inches in greatest dimension with not more than 15 percent larger than 2 •. 5 inches. The use of potentially expansive soil as fill shall conform to the requirements of Section VII, II EX PANS IVE SOILS. II .AII material for use as fill shall be subject to approval by the Soil Engineer. The existing topsoil stockpile located in the southeast portion of the site may be' reused as fill in the lower portions of the deeper site fills. However, any concentration of organic material shall be selectively removed an"d disposed of off-site. The method of placement and suitability of the materials shall be subject to the SoH Engineer's approval. VII. EXPANSIVE SOilS Potentially expansive soils taken from the required site excavations shall be used as fill only up to within 2 feet of the design finish grades in street pavement areas and on lots; the upper 2 feet of fill shell be comprised of non-expan~ive sandy fill material. The dete'rmination as to which materials are expansive and which are not shall be made in the, fie·ld durin'g construc.tion by the Soil Engineer. ' VIII. PLACING AND COMPACTING FILL MATERIAL All structural fill shall be compacted 'by mechanical means to produce a minimum degree of compaction of 90 percent as determined by ASTM Test Designation -o'1557-7(L Field density tests shall be perform~d in accordance with either ASTM Test Designation D1556-64 (Sand-Cone Method) or ASTM Test Designation D2922-71 and D3017-72 (Nuclear Probe Method)~ The locations and number of field density ·tests sha'lI be determin~d by the Soil Engineer •. The results of these tests and compliance with these'spec.it.c~tioi1s shall be the basis upon which satisfactory completion of work shall be judged by the Soil Engineer • Fill material shall be placed in uniform lifts not exceeding 8 inches in uncompacted thick-' ness. Before compaction begins, the fill shall be brought to a water content that will permit proper compaction by either: 1) .aerating the fj II jf it is too wet, or 2) moistening the fill with water if it is too dry. Each !.ift shall be thoroughly mixed befor.e compaction to insure a uniform distribuHon of moisture. Fill slopes shall be constructed so as to assure that a minimum degree of compaction of 90 percent is attained to within 18 inches of the. finished slope face and that a minimum degree of compaction of 85 percent is attained in the outer 18 inches. This sholl be accomplished by, IIbackrolling ll with a sheepsfoot roller or other suitable equipment in 5 to 8 footverfical increments as the fill is raised. ~Iacement of fill near the tops' of slopes sholl be carried out in such a manner as to assure that loose, uncompacted soils are not sloughed over the tops ,ahd allowed to accumulate on the slope face. •• • C-s It shall be the Contractor's obligation to take all measures deemed nec;essaryduri'ng grading to provide erosion control devices in order .to protect slope areas and adjacent properties from st9rm damage and flood hazard originating on this project.. It shall be the Contractor's responsibility to maintain slopes in their as-graded form untfl all sl9pes, berms, and associated drainage devices are in satisfactory compliance with the prbj.ect plans and specjfi~ations. . IX. TRENCH BACKFILL Pipeline trenches: shall be backfill'ed with compacted fill. Backfill materiqlshaU be placed in lift thicknesses appropriate to the type of compaction equi·pmen,tutilited and, compacted to a minimum degree of compaction ·of 85 percent by mechanical means. ·In all slab-on-grade and pavement areas the upper portion of the backfrll to a depth equal to 1.5 times the trench width, but not less than 3 feet, shall be compacted to a minimum degree of compaction of 90 percent. In pavement areas, that portion of the trench backfill within the pavem'~nt section shall conform to the materi'al and compact:ion requirements of the adjacent pavement section. X. TREATMENT AFTER COMPLETION 'OF EARTHWORK After the earthwork operations have been completed and the Soil Engineer has finished his observation of the work, no further operations shall be performed except with the approval of and under the observation of the Soil Engineer.