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HomeMy WebLinkAbout; Palomar Airport Business Park Lot 9; Soils Report; 1985-06-20REPORT OF GEOTECHNICAL INVESTIGATION PROPOSED COMMERCIAL BUILDING LOT 9, PALOMAR AIRPORT BUSINESS PARK CARLSBAD, CALIFORNIA PREPARED FOR: Mitsui-Fuddsan U.S.A., Inc. 6354 Corte De1 Abeto, Suite A Carlsbad, California 92008 PREPARED BY: Southern California Soil & Testing, Inc. Post Office Box 20627 6280 Riverdale Street San Diego, California 92120 June 20, 1985 Mitsui-Fuddsan U.S.A., Inc. 6354 Corte De1 Abeto, Suite A SCSET 8521133 Carlsbad, California 92008 Report No. 1 SUBJECT: Report of Geotechnical Investigation, Proposed Commercial Buildings, Lot 9, Palomar Airport Business Park, Carlsbad, California. Gentlemen: In accordance with your request, we have completed a geotechnical investigation for the proposed project. We are presenting herewith our findings and recommendations. The findings of this study indicate that the site is suitable for the proposed development provided the recommendations presented in the attached report are complied with. If you have any questions after reviewing the findings and recommendations contained in the attached report, please do not hesitate to contact this office. This opportunity to be of professional service is sincerely appreciated. Respectfully submitted, SOUTHERN CALIFORNIA SOIL & TESTING, INC. &d-d& Robert‘R.%ssell, R.C.E. #32142 RRR:CRB:mw cc: (2) Submitted (2) Krommenhoek-McKeown (2) Burkett and Wong (1) SCS&T, Escondido SOUTHERN CALIFORNIA SOIL AND TESTING, I N 0. TABLE OF CONTENTS PAGE Introduction and Project Description .................................... ..l Project Scope ............................................................. Findings .................................................................. : Site Description ................................................... ...2 General Geology and Subsurface Conditions .......................... ...3 Geologic Setting and Soil Description ......................... ...3 Tectonic Setting .............................................. ...3 Geologic Hazards ................................................... ...4 Groundwater ..................................................... 5 Recommendations and Conclusions ........................................ ...6 Site Preparation ................................................... ...6 Building Pads ................................................. ...6 Parking Areas ................................................. ...7 Surface Drainage ................................................. Earthwork ........................................................ : Foundations ........................................................... General .......................................................... : Settlement Characteristics ....................................... Retaining Walls ....................................................... i General .......................................................... Backfill ......................................................... ; Bearing Pressure ................................................. 9 Passive Pressure ................................................. 9 Active Pressure ................................................. Factor of Safety ................................................ :i Slope Stability......................................................l 0 Limitation ............................................................... Review, Observation and Testing ...................................... :i Uniformity of Conditions.............................................ll Change in Scope ...................................................... Time Limitations......, ............................................... :: Professional Standard................................................l2 Client's Responsibility..............................................l2 Field Explorations.......................................................l 3 Laboratory Testing.......................................................l3 ATTACHMENTS PLATES Plate 1 Plot Plan Plate 2 Subsurface Exploration Legend Plate 3-6 Trench Logs Plate 7 Direct Shear Test Results Maximum Density and Optimum Moisture Content Expansion Index Test Results APPENDIX Recommended Grading Specification and Special Provisions SOUTHERN CALIFDRNIA SOIL AND TESTINO, INC. bZB0 RIVERDALE 97. SAN DIECiO. CALIF. 9212m . TELE 280.432, . P.O. BOX ZOb27 SAN DIETO, CALIF. 92120 74-821 “ELlE WAY PALM DESERT, CALIF. 91160 - TELE 346-1078 678 ENTERPROSE BT. EBCDNDIDO, EALIF. 9zc115 - TELE 746.4544 GEOTECHNICAL INVESTIGATION PROPOSED COMMERCIAL BUILDINGS LOT 9, PALOMAR AIRPORT BUSINESS PARK CARLSBAD, CALIFORNIA INTRODUCTION AND PROJECT DESCRIPTION This report presents the results of our geotechnical investigation for two proposed commercial/industrial buildings which are to be located at Lot No. 9 in the Palomar Airport Business Park in Carlsbad, California. It is our understanding that two concrete tilt-up structures with 22 foot high walls are planned for this site. It is further understood that only a minimal amount of additional grading will be necessary to develop the site. This information was obtained from conversations with the architect. The site configuration and exploration locations are shown on Plate Number 1 of this report. PROJECT SCOPE This investigation consisted of: surface reconnaissance; subsurface explorations; obtaining representative disturbed and undisturbed samples; laboratory testing; analysis of the field and laboratory data; research of available geological literature pertaining to the site; and preparation of this report, Specifically, the intent of this analysis was to: a) Explore the subsurface conditions to the depths influenced by the proposed construction. SOUTHERN CALIFORNIA -3 0 I L AND TESTINO. I N c. SCS&T 8521133 June 20, 1985 Page 2 b) cl d) e) f) Evaluate, by laboratory tests, the pertinent engineering properties of the various strata which will influence the development, including their bearing capacities, expansive characteristics and settlement potential. Define the general geology at the site including possible geologic hazards which could have an effect on the site development. Develop soil engineering criteria for site grading and provide design information regarding the stability of cut and fill slopes. Determine potential construction difficulties and provide recommendations concerning these problems. Recommend an appropriate foundation system for the type of structures anticipated and develop soil engineering design criteria for the recommended foundation design. FINDINGS SITE DESCRIPTION The project site is a roughly trapezoidal shaped lot of 3.8 acres, located at the northeast end of Corte De1 Nogal, in the Palomar Airport Business Park in Carlsbad, California. The topography consists of a relatively level area bounded by slopes with slope ratios on the order of 1.6:1 (horizontal to vertical) and the following approximate heights: on the northwest side a cut slope ranging from 10 to 28 feet, on the east side a combination cut and fill slope of 20 feet, on the southeast a combination cut and fill slope of up to 39 feet and on the northeast side a combination cut and fill slope of 3 to 4 feet. The site is bounded on all sides by commercial developments. Currently the site is vacant except for a SCE&T 8521133 June 20, 1985 Page 3 rectangular fenced-in storage area approximately 100 by 50 feet on the southeastern portion of the site. On-site vegetation consists of a light growth of weeds and grasses on the flat area and a light to moderate growth of weeds, grasses, landscaping shrubs and several trees on the slopes. GENERAL GEOLOGY AND SUBSURFACE CONDITIONS GEOLOGIC SETTING AND SOIL DESCRIPTION: The subject site is located in the Coastal Plains Physiographic Province of San Diego County and is underlain by Tertiary and Quaternary sediments and artificial fill. The northern portion of the site is cut into Tertiary sediments with the cut and fill line trending approximately southwest to northeast through the southeastern third of the site. The fill in this southern portion of the site consists of light tan-brown to gray-green, humid to moist, medium dense to dense, slightly plastic to plastic, clayey silt to silty clay in excess of 13 feet thick. In the northeastern portion of the fill area the fill was found to be underlain by 3 feet of tanbrown to brown, humid and medium dense, clayey silts. These were underlain by Tertiary sediments which are gray green, humid, medium dense to dense , slightly fissile claystones which are fractured and slightly weathered in the upper 2 l/2 feet. The cut portion of the site was underlain by the same Tertiary claystone. However, on the northwestern portion it is overlain by 2 feet of orange brown to white, humid and medium dense to dense, sandy siltstones. TECTONIC SETTING: No evidence of faulting was noted during our surface reconnaissance or in our exploratory trenches. However, it should be noted that much of Southern California, including the San Diego area, is characterized by a series of Quaternary-age fault zones which typically 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 the zone) are classified as active while others are classified as only potentially active according to the criteria of the California Division of Mines and Geology. Active fault zones are those which have shown conclusive evidence of faulting during the Holocene Epoch SCS&T 8521133 June 20, 1985 Page 4 (the most recent 11,000 years) while potentially active fault zones have demonstrated movement during the Pleistocene Epoch (11,000 to 2,000,OOO years before the present) but no movement, during Holocene time. A review of available geologic literature reveals the presence of numerous minor northeast trending faults in the vicinity of the site that are presently considered not capable of ground rupture, and the Rose Canyon Fault Zone approximately 8 miles to the southwest. The major active fault zones that could possibly affect the subject site include the Elsinore to the northeast and the San Clemente to the southwest. GEOLOGIC HAZARDS The subject site can be considered to be relatively free of geologic hazards. Potential hazards such as tsunamis, seiches, liquefaction, or landsliding should be considered to be negligible or nonexistent. The most likely geologic hazard to affect the site is groundshaking as a result of movement along one of the major, active fault zones mentioned previously. The maximum bedrock accelerations that would be attributed to a maximum probable earthquake occurring along the nearest portion of selected fault zones that could affect the site are summarized in the following table. TABLE I Maximum Probable Maximum Bedrock Fault Zone Distance Ea,rthquake Acceleration Rose Canyon 8 miles 6.0 magnitude 0.28 g Elsinore 23 miles 7.3 magnitude 0.20 g Coronado Banks 24 miles 6.0 magnitude 0.09 g San Clemente 54 miles 7.3 magnitude 0.08 g SCS&T 8521133 June 20, 1985 Page 5 Earthquakes on the Rose Canyon or Coronado Banks Fault Zone are expected to be relatively minor. Major seismic events are likely to be the result of movement along the Elsinore or San Clemente Fault Zones. In addition, we have analyzed the fault zones which could affect the San Diego area in order to determine the probability of groundshaking of any given level. The individual faults and the different fault zones have slip rates which have been calculated to range from very low to very high rates of activity. The following chart summarizes our opinion of the probability of events which would result in the associated maximum and "design" bedrock accelerations. Peak Acceleration 0.50 g 0.40 g 0.30 g 0.25 g 0.20 g 0.15 g 0.10 g Design Acceleration 0.34 g 0.27 g 0.20 g 0.17 g 0.13 g 0.10 g 0.07 g Probability of Occurrence 5 x 10 -4 1 x 10 -3 1 x 10 -2 5 x 10 -2 1 x 10 -1 5 x 10 -1 1 x 10 -0 Probability of occurrence is defined as the 90% probability of any given event occurring during the assumed life of the proposed structure (50 years) which would occur in accelerations of that level. Construction in accordance with the minimum standards of the most recent edition of the Uniform Building Code and the governing agencies should minimize potential damage due to groundshaking. GRDUNDWATER: No groundwater was encountered during our subsurface exploration and we do not anticipate any major groundwater related SCS&T 8521133 June 20, 1985 Page 6 problems, either during or after the construction of the proposed project. However, it should be recognized that minor groundwater seepage problems may occur after development of a site even where none were present before develoment. These are usually minor phenomena and are often the result of an alteration of the permeability characteristics of the soil, an alteration in drainage patterns and an increase in irrigation water. Based on the permeability characteristics of the soil and the anticipated usage of the development, it is our opinion that any seepage problems which may occur will be minor in extent. It is further our opinion that these problems can be most effectively corrected on an individual basis if and when they develop. RECOMMENDATIONS AND CONCLUSIONS SITE PREPARATION BUILDING PADS: A review of the previous grading plan for this site, by Henry Worley Associates, indicated that Building A will be founded entirely on cut soils while Building B will be on both cut and fill soils. In view of this condition and the competent nature of the native soils, it is our opinion that no special site preparation will be required by Building A. We recommend, however, that the upper 12 inches of subgrade be scarified, moisture conditioned to at least 2% over optimum and densified to 90% relative compaction. Since Building B will be founded on both cut and fill soils, which could result in differential settlements, we recommend that the subgrade soils be excavated to a depth of one foot below the bottom of the proposed footings and be stockpiled for future use. The soils exposed at the base of this excavation should then be scarified 12 inches, moisture conditioned and compacted to a minimum of 90% of maximum dry density. The stockpiled soils may then be replaced in eight lifts, moisture conditioned to at least 2% over optimum and densified as indicated above. The horizontal limits of these recommendations should include the area within a perimeter of 3 feet outside of the proposed structure. A sufficient number of in-place density tests should also be performed during grading to document that the above criteria has been complied with. SCS&T 8521133 June 20, 1985 Page 7 PARKING AREAS: We recommend that the subgrade soils beneath all areas to be paved should be scarified 12 inches. The soils within this depth should be moisture treated to 2% over optimum and densified to at least 90%. SURFACE DRAINAGE: We recommend that all surface drainage be directed away from the proposed structures and that ponding of water not be allowed adjacent to their foundations. EARTHWORK: All earthwork and grading contemplated for site preparation should be accomplished in accordance with the attached Recommended Grading Specifications and Special Provisions. All special site preparation recommendations presented in the sections above will supersede those in the standard Recommended Grading Specifications. All embankments, structural fill and fill should be compacted to at least 90% relative compaction at or slightly over optimum moisture content. Utility trench backfill within 5 feet of the proposed structures and beneath asphalt pavements should be compacted to minimum of 90% of its maximum dry density. The maximum dry density of each soil type should be determined in accordance with A.S.T.M. Test Method D-1557-78, Method A or C. FOUNDATIONS GENERAL: Due to the expansive characteristics of the prevailing foundation soils, the following recommendations are made so that structural damage is not likely to occur due to expansion. a) All footings should be founded a minimum of 24 inches below adjacent finish grade and may be designed for an allowable soil bearing pressure of 2000 psf for footings in fill soils and 3000 psf for footings in natural ground. Footings should have a minimum width or diameter of 12 inches. b) Both exterior and interior continuous footings should be reinforced with at least 2 No. 4 bars positioned 3 inches above the bottom of the footings and 2 No. 4 bars positioned 3 inches clear below finish floor. Pier footings need not be reinforced. cl Interior slabs should be a minimum of 4 inches in thickness and underlain by a 6 inch blanket of clean coarse sand or crushed rock. Further, slabs should be reinforced with 6"~ 6"-W1.4xW1.4 welded wire mesh and completely surrounded with a continuous footing. d) Exterior slabs should be a minimum of 4 inches in thickness and underlain by a 4 inch blanket of clean sand or crushed rock. Further, exterior slabs should be reinforced with 6"x6"-W1.4xW1.4 welded wire mesh and provided with weakened plane joints as recommended hereinafter. e) Weakened plane joints for exterior slabs should be provided for any slab greater than five feet in width. Any slab between five and ten feet should be provided with longitudinal weakened plane joint at its center line. Slabs exceeding ten feet in width should be provided with a weakened plane joint located three feet inside the exterior perimeter. f) Clayey soils should not be allowed to dry before placing concrete. They should be sprinkled if necessary to insure that the soils are kept in a very moist condition or at a moisture content exceeding two percent above optimum moisture content. 9) Surface drainage should be directed away from the proposed foundation. Planters should be constructed so that water is not allowed to seep into soils beneath foundations or slabs. SCS&T 8521133 June 20, 1985 Page 8 SCS&T 852 1133 June 20, 1985 Page 9 h) Prior to placing concrete, the foundation excavations should be inspected by a representative of this office to verify compliance with the above recommendations. SETTLEMENT CHARACTERISTICS: The anticipated total and/or differential settlements for the proposed structure may be considered to be within tolerable limits provided the recommendations presented in this report are followed. RETAINING WALLS GENERAL: It is our understanding that the retaining walls planned for the site will be of masonry construction and that they will have a maximum height on the order of 10 feet or less. According to the plans, walls are proposed along the northern limits of the proposed parking area. All walls should have adequate weep holes or a subdrain system to prevent a building of hydrostatic pressure behind the wall. BACKFILL: All backfill soils should be compacted to at least 90% relative compaction. Expansive or clayey soils should not be used for backfill material. The wall should not be backfilled until the masonry has reached an adequate strength. BEARING PRESSURE: The foundation for the proposed walls may consist of spread footings founded in the native soils or compacted fill. Footings should extend through any topsoils or the topsoils should be removed and be replaced as a compacted fill. Footings may be designed for an allowable bearing pressure as previously recommended. PASSIVE PRESSURE: The passive pressure for the prevailing soil conditions may be considered to be 275 pounds per square foot per foot of depth. This pressure may be increased one-third for seismic loading. The coefficient of friction for concrete to soil may be assumed to be 0.40 for the resistance to lateral movement. When combining frictional and passive resistance, the latter should be reduced by one-third. SCSAT 8521133 June 20, 1985 Page 10 ACTIVE PRESSURE: The active soil pressure for the design of earth retaining structures with backfills sloping at a ratio of 2 to 1 may be assumed to be equivalent to the pressure of a fluid weighing 55 pounds per cubic foot for walls free to move at the top (unrestrained walls). This pressure does not consider any surcharge (other than the sloping backfill). If any are anticipated, this office should be contacted for the necessary increase in soil pressure. FACTOR OF SAFETY: The above values, with the exception of the allowable soil bearing pressure, do not include a factor of safety. Appropriate factors of safety should be incorporated into the design to prevent the walls from overturning and sliding. SLOPE STABILITY Based on the findings of this study, it is our opinion that the existing slopes are stable with relation to deep-seated failures. An examination of these slopes, however, revealed that they were constructed at a ratio of approximately 1.6:1 (horizontal to vertical) in lieu of the 2:l ratio shown on the grading plan. Should any changes be proposed to these slopes, this office should review these plans and present our opinion regarding any potential impact on the slope stability. LIMITATIONS REVIEW, OBSERVATION AND TESTING The recommendations presented in this report are contingent upon our review of, final plans and specifications. The soil engineer and engineering geolgist should review and verify the compliance of the final grading plan with this report and with Chapter 70 of the Uniform Building Code. SCS&T 8521133 June 20, 1985 Page 11 It is recommended that Southern California Soil & Testing, Inc. be retained to provide continuous soil engineering services during the earthwork operations. This is to observe compliance with the design concepts, specifications or recommendations and to allow design changes in the event that subsurface conditions differ from those anticipated prior to start of construction. UNIFORMITY OF CONDITIONS The recommendations and opinions expressed in this report reflect our best estimate of the project requirements based on an evaluation of the subsurface soil conditions encountered at the subsurface exploration locations and the assumption that the soil conditions do not deviate appreciably from those encountered. It should be recognized that the performance of the foundations and/or cut and fill slopes may be influenced by undisclosed or unforseen variations in the soil conditions that may occur in the intermediate and unexplored areas. Any unusual conditions not covered in this report that may be encountered during site development should be brought to the attention of the soils engineer so that he may make modifications if necessary. CHANGE IN SCOPE This office should be advised of any changes in the project scope or proposed site grading so that it may be determined if the recommendations contained herein are appropriate. This should be verified in writing or modified by a written addendum. TIME LIMITATIONS The findings of this report are valid as of this date. Changes in the condition of a property can, however, occur with the passage of time, whether they be due to natural processes or the work of man on this or adjacent properties. In addition, changes in the State-of-the-Art and/or SCS&T 8521133 June 20, 1985 Page 12 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 that level of care and skill ordinarily exercised by members of our profession currently practicing under similar conditions and in the same locality. The client recognizes that subsurface conditions may vary from those encountered at the locations where our borings, surveys, and explorations are made, and that our data, interpretations, and recommendations are based solely on the information obtained by us. We will be responsible for those data, interpretations, and recommendations, but shall not be responsible for the interpretations by others of the information developed. Our services consist of professional consultation and observation only, and no warranty of any kind whatsoever, express or implied, is made or intended in connection with the work performed or to be performed by us, or by our proposal for consulting or other services, or by our furnishing of oral or written reports or findings. CLIENT’S RESPONSIBILITY It is the responsibility of Mitsui-Fuddsan U.S.A., Inc., or their representatives to ensure that the information and recommendations contained herein are brought to the attention of the engineer and architect for the project and incorporated into the projects plans and specifications. It is further their responsibility to take the necessary measures to insure that the contractor and his subcontractors carry out such recommendations during construction. SCS&T 8521133 June 20, 1985 Page 13 FIELD EXPLORATIONS Four subsurface explorations were made at the locations indicated on the attached Plate Number 1 on June 11, 1985. These explorations consisted of trenches dug by means of a backhoe. The field work was conducted under the observation of our engineering geology personnel. The explorations were carefully logged when made. These logs are presented on the following Plate Numbers 3 through 6. The soils are described in accordance with the Unified Soils Classification System as illustrated on the attached simplified chart on Plate 2. In addition, a verbal textural description, the wet color, the apparent moisture and the density or consistency are presented. The density of granular materials is given as either very loose, loose, medium dense, dense or very dense. The consistency of silts or clays are given as either very soft, soft, medium stiff, stiff, very stiff, or hard. Disturbed and "undisturbed" samples of typical and representative soils were obtained and returned to the laboratory for testing. LABORATORY TESTING Laboratory tests were performed in accordance with the generally accepted American Society for Testing and Materials (A.S.T.M.) test methods or suggested procedures. A brief description of the tests performed is presented below: a) MOISTURE-DENSITY: Field moisture content and dry density were determined for representative undisturbed samples obtained. This information was an aid to classification and permitted recognition of variations in material consistency with depth. The dry unit weight is determined in pounds per cubic foot, and the field moisture content is determined as a percentage of the soil's dry weight. The results are summarized in the trench logs. SCS&T 8521133 June 20, 1985 Page 14 b) CLASSIFICATION: Field classifications were verified in the laboratory by visual examination. The final soil classifications are in accordance with the Unified Soil Classification System. cl DIRECT SHEAR TESTS: Direct shear tests were performed to determine the failure envelope based on yield shear strength. The shear box was designed to accomodate a sample having diameters of 2.375 inches or 2.50 inches and a height of 1.0 inch. Samples were tested at different vertical loads and a saturated moisture content. The shear stress was applied at a constant rate of strain of approximately 0.05 inches per minute. The results of these tests are presented on attached Plate Number 7. d) COMPACTION TEST: The maximum dry density and optimum moisture content of typical soils were determined in the laboratory in accordance with A.S.T.M. Standard Test D-1557-78, Method A. The results of these tests are presented on the attached Plate Number 7. e) EXPANSION INDEX TEST: An expansion index test on remolded samples was performed on representative samples of soils likely to be used as compacted fill. The test was performed on the portion of the sample passing the 84 standard sieve. The sample was brought to optimum moisture content then dried back to a constant moisture content for about 12 hours at about 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%. The specimen was placed in a consolidometer with porous stones at the top and bottom, a total normal load of 12.63 pounds was placed (144.7 psf), and the sample was allowed to consolidate for a period of 10 minutes. SCS&T 8521133 June 20, 1985 Page 15 The sample was allowed to become saturated, and the change in vertical movement was recorded until the rate of expansion became nominal. The expansion index is reported on the attached Plate Number 7 as the total vertical displacement times the fraction of the sample passing the 84 sieve times 1000. CLASSIFICATION OF EXPANSIVE SOIL EXPANSION INDEX POTENTIAL EXPANSION l-20 very low 21-50 low 51-90 medium 91-130 high Above 130 very high 1-d. /L[ BLD’G; A y &--Ll lJ---.u l+-.Li Lb4J.L . . * : A-.~ % / I . ?====j . (. IL A’ __ . .I / _. ,~ ‘I . - :‘. ‘A- ii -.- i ,, 11; 4 "(. ---L .t.. " // TA -cm p+LyLO? t ,311 ( ( [ I( Il’fl[ ( ( ffl [:I 11 l.i&Lpq I d (--yap $ .’ + 2 0 9 2 LEGEND: m TRENCH LOCATION 0 60 120 1 SOUTHERN CALIFORNIA SOIL & TESTING, INC. q “: S.M.S. DATE: 6-25-85 JOE NUMBER: 8521133 Plate No. 1 SUBSURFACE EXPLORATION LEGEND “NIPIEO 501t CUSSTFICXION CxA!a SOIL DESCXIPTIOW GilO”P S,?,BOL NPICX. NrV,ES 1. CDAx5E GLUSED, Elore than hAIf 0: material is w than NO. 200 sieve *i:e. s CLEAJ ‘RAVELS nor.? thn” half Of coarse fraction is l.lrcJer than ?io. 4 sieve sire but smaller than 3”. GRAVELS WITH FINES Lxppreciable amo”ne of fines, SANDS nDeeth.” half DE-E- SRxD= coarse fraction is saaller than NO. 4 sieve size. sxms WITH FINES (Appreciable amount ot Lines, 11. FT!IE G?aI::ED, nore than half of material is smaller thn 8.3. 200 rieve si--e. sxI.rs AND CUYS Liquid Limit less than 50 5IlTB Am CLAYS SW .sP S” SC CL OL PM well graded gravek. gravel- sand mixeures. little or no fines. Poorly qra3e.d gravels, gravel ;q;psyixcure5. little ai- no Silty gravels, poorly graded gravel-sand-silt mixtures. Clayey gravels, poorly graded gravel-sand. day mixture,s. well graded rand;~qra"elly sands, little or no fines. Poorly qra.de-3 sa"gs,gra"elly sands, little or no fines. silty sands, poorly graded sand and silt mixtures. Clayey sands, porly graded *and and clay mixtures. Inorganic lilts and verf fine sands., rock flour. sandy silt or clayey-silt-sand mixtures with slight plast- icity Inorganic clays of k-4 to medium plasticity.gravelly clays. sandy clays,ailcy clays. lean clays. Organic silts and organic silty clays of La plasticity Inorganic silts. aicaceour or diaeomaceous fine sandy or silts soils, elastic silts. - Lipid Limit CH Inorgdrd clays 01 high greater than 50 plasticity. tat clays. OH Organic clay* of medium co hiq:: plasticity. HIGii‘Y ORGXIIC XrIis FT Peat and other hiq!tly orqanic *oils. + - Water level at time of exzaiation or as indicated US - Undisturbed, dri& ring sample or tube sample CK - Undisturbed chunk sample BS - Bulk sample SOUTHERN CALIFORNIA SOIL 8 TESTING, INC. I aYRRR JoB No. 8521133 DATE - - Plate No. 2 ; bp IY ; TRENCH NUMBER 1 A; k: : 2 ; 7 w- = Au’ EE,- - WO I := -- ,;z z- Ei+ ?iF Y OY ELEVATION ;; z E “: ;g 2 ;j : zw 5; FG -P $zu iT& ,” ; 4s Z” 5 O0 0 z 2 0 0 0 0 DESCRIPTION 0 0 ML Greenish Gray, SILTSTONE Humid Very Stiff Highly Fractured to 4 feet _ BG CK SOUTHERN CALIFORNIA SUBSURFACE EXPLORATION LOG SOIL & TESTING,INC. LOGGED BY: G. s. DATE LOGGED: ,j-11-85 JOB NUMBER: 8521133 Plate No. 3 z ap ,” ; TRENCH NUMBER 2 +w A; z a9 ; 7 = ,: E= $E;; w- z 0 Gi z- ;p -- l- z 55 Y 0% ELEVATION fzk 2zu 2; 2: F mu), E”” !YJy b 2 P 0 -0 2 4 I 6; g; 0 *;g o z s 0 : 0 cd DESCRIPTION 0 u ML Greenish Gray, SANDY SILT Humid to Stiff Moist (Fill) CK 102.8 19.5 90 - _ BG ML Tanish Brown to Brown, Humid Very Stiff 110.7 4.2 97 _ CK SILTSTONE (Native) CK Weathered and Slightly BG Fractured SOUTHERN CALIFORNIA SUBSURFACE EXPLORATION LOG SOIL & TESTING,INC. LOGGEDBV: G.s. DATE LOGGED: 6-11- JOB NUMBER: 8521133 Plate No. 4 zl -z ,” c TRENCH NUMBER 3 I- fJ * > : 2 2 -: = ,z ii: Y- ;i y 0 = re+z z- ;+ ? F ,” Fig ELEVATION 2,’ mL!l ;z Lti : 2,-o z!rj P ; : ;$ _D 5; ii” :za E 2 I5 S” 0 z = 0 z =0 u DESCRIPTION 0 0 -I ML Light Brown, SANDY SILT Moist Medium t- (Fill) Stiff 3- - CK 94.3 14.5 i- BG 1 CK ML/ Greenish Gray, CLAYEY SILT Moist to Stiff 100.1 CL 19.7 (Fill) Wet j- i- CK 96.3 23.1 I- I_ I CK I- BG - CK -f I SOUTHERN CALIFORNIA SUBSURFACE EXPLORATION LOG SOIL & TESTING,INC. LOGGEDBV: G.s. DATE LOGGED: 6-11-85 JOB NUMBER: 8521133 Plate No. 5 z s ,” ; TRENCH NUMBER 4 *> E I- 0 z ; 7 z 4 zzk w- z ii - -‘u- YWU) z- ;; I CCL2 tzb ELEVATION Y OY 2: yd’; gz 2;;: 2: k g “z 5: 0 i” 255 n: : ‘, z & z u 0 0 8 =0 DESCRIPTION 0 S"i4L Orange -Brown, SAND AND SILT Humid Medium Dense CK 106.2 9.3 1 CK ML/ CL Greenish Gray, CLAYEY Humid Very SILTSTONE Stiff - BG _ CK - - -! SOUTHERN CALIFORNIA SUBSURFACE EXPLORATION LOG SOIL & TESTING,INC. LOGGED BV: Gas. DATE LOGGED: 641-85 JOB NUMBER: 85~~13~ Plate No. 6 DIRECT SHEAR TEST RESULTS I DESCRIPTION MAXIMUM DENSITY 8 OPTIMUM MOISTURE CONTENT ASTM 1557-78 METHOD A DESCRIPTION EXPANSION TEST RESULTS I FINAL M.C. (O/o) SOUTHERN CALIFORNIA TESTING I LABORATORY, INC. BY RRR DATE 6-25-85 6280 RIVERDALE STREET SAN DIEGO. CALIFORNIA 92120 ‘OB No. 8521133 Plate No. 7 714-283-6134 \ PROPOSED COMMERCIAL BUILDINGS, LOT 9, PALOMAR AIRPORT BUSINESS PARK RECOMMENDED GRADING SPECIFICATIONS - GENERAL PROVISIONS GENERAL INTENT The intent of these specifications is to establish procedures for clearing, compacting natural ground, preparing areas to be filled, and placing and compacting fill soils to the lines and grades shown on the accepted plans. The recommendations contained in the preliminary soil investigation report and/or the attached Special Provisions are a part of the Recommended Grading Specifications and shall supersede the provisions contained hereinafter in the case of conflict. These specifications shall only be used in conjunction with the soil report for which they are a part. No deviation from these specifications will be allowed, except where specified in the soil report or in other written communication signed by the Soil Engineer. OBSERVATION AND TESTING Southern California Soil and Testing, Inc., shall be retained as the Soil Engineer to observe and test the earthwork in accordance with these specifications. It will be necessary that the Soil Engineer or his representative provide adequate observation so that he may provide an opinion that the work was or was not accomplished as specified. It shall be the responsibility of the contractor to assist the soil engineer and to keep him apprised of work schedules, changes and new information and data so that he may provide these opinions. In the event that any unusual conditions not covered by the special provisions or preliminary soil report are encountered during the grading operations, the Soil Engineer shall be contacted for further recommendations. SCS&T 8521133 June 20, 1985 Appendix, Page 2 If, in the opinion of the Soil Engineer, substandard conditions are encountered, such as; questionable or unsuitable soil, unacceptable moisture content, inadequate compaction, adverse weather, etc., he will be empowered to either to either stop construction until the conditions are remedied or corrected or recommend rejection of this work. Test methods used to determine the degree of compaction should be performed in accordance with the following American Society for Testing and Materials test methods: Maximum Density & Optimum Moisture Content - A.S.T.M. D-1557-78. Density of Soil In-Place - A.S.T.M. D-1556-64 or A.S.T.M. D-2922. All densities shall be expressed in terms of Relative Compaction as determined by the foregoing A.S.T.M. 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 unsightly debris. Any abandoned buried structures encountered during grading operations must be 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 from the above described procedures should be backfilled with acceptable soil that is compacted to the requirements of the Soil Engineer. This includes, but is not limited to, septic tanks, fuel tanks, sewer lines or leach lines, storm SCS&T 8521133 June 20, 1985 Appendix, Page 3 drains and water lines. Any buried structures or utilities not to be abandoned should be investigation by the Soil Engineer to determine if any special recommendation will be necessary. All water wells which will be abandoned should be backfilled and capped in accordance to the requirements set forth in the Geotechnical Report. The top of the cap should be at least 4 feet below finish 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 Soil Engineer and/or a qualified Structural Engineer. When the slope of the natural qround receiving fill exceeds 20% (5 horizontal units to 1 vertical unit), the original ground shall be stepped or benched. Benches shall be cut to a firm competent soil condition. The lower bench shall be at least 10 feet wide or 1 l/2 times the the equipment width which ever is greater and shall be sloped back into the hillside at a gradient of not less than two (2) percent. All other benches should be at least 6 feet wide. The horizontal portion of each bench shall be compacted prior to receiving fill as specified hereinbefore for compacted natural ground. Ground slopes flatter than 20% shall be benched when considered necessary by the Soil Engineer. After clearing or benching, the natural ground in areas to be filled shall be scarified to a depth of 6 inches, brought to the proper moisture content, compacted and tested for the minimum degree of compaction in the Special Provisions or the recommendation contained in the preliminary soil investigation report. All loose soils in excess of 6 inches thick should be removed to firm natural ground which is defined as natural soils which possesses an in-situ density of at least 85% of its maximum dry density. SCS&T 8521133 June 20, 1985 Appendix, Page 4 FILL MATERIAL Materials placed in the fill shall be approved by the soil 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, expansive and/or detrimental soils are covered in the soils report or Special Provisions. Expansive soils, soils of poor gradation, or soils with low strength characteristics may be thoroughly mixed with other soils to provide satisfactory fill material, but only with the explicit consent of the soil engineer. Any import material shall be approved by the Soil 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 inches 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 shall be uniformly compacted to a minimum specified degree of compaction with equipment of adequate size to economically compact the layer. Compaction equipment should either be specifically designed for soil 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 soil investigation report. When the structural fill material includes rocks, no rocks will be allowed to nest and all voids must be carefully filled with soil such that the minimum degree of compaction recommended in the Special Provisions is SCS&T 8521133 June 20, 1985 Appendix, Page 5 achieved. The maximum size and spacing of rock permitted in structural fills and in non-structural fills is discussed in the soil report, when applicable. Field observation and compaction tests to estimate the degree of compaction of the fill will be taken by the Soil Engineer or his representative. The location and frequency of the tests shall be at the Soil Engineer's discretion. When the compaction test indicates that a particular layer is less than the required degree of compaction, the layer shall be reworked to the satisfaction of the Soil Engineer and until the desired relative compaction has been obtained. Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compaction by sheepsfoot rollers shall be at vertical intervals of not greater than four feet. In addition, fill slopes at ratios of two horizontal to one vertical or flatter, should be trackrolled. Steeper fill slopes shall be over-built and cut-back to finish contours. 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% of maximum dry density or that specified in the Special Provisions section of this specification. The compaction operation on the slopes shall be continued until the Soil Engineer is satisfied that the slopes will be stable in regards to surficial stability. Slope tests will be made by the Soils Engineer during construction of the slopes to determine if the required compaction is being achieved. Where failing tests occur or other field problems arise, the Contractor will be notified that day of such conditions by written communication from the Soil Engineer in the form of a daily field report. SCS&T 8521133 June 20, 1985 Appendix, Page 6 If the method of achieving the required slope compaction selected by the Contractor fails to produce the necessary results, the Contractor shall rework or rebuild such slopes until the required degree of compaction is obtained, at no additional cost to the Owner or Soils Engineer. CUT SLOPES The Engineering Geologist shall inspect all cut slopes excavated in rock or lithified formational material during the grading operations at intervals determined at his discretion. If any conditions not anticipated in the preliminary report such as perched water, seepage, lenticular or confined strata of a potentially adverse nature, unfavorably inclined bedding, joints or fault planes are encountered during grading, these conditions shall be analyzed by the Engineering Geologist and Soil Engineer to determine if mitigating measures and necessary. Unless otherwise specified in the soil and geological report, no cut slopes shall be excavated higher or steeper than that allowed by the ordinances of the controlling governmental agency. ENGINEERING OBSERVATION Field observation by the soil Engineer or his representative shall be made during the filling and compacting operations so that he can express his opinion regarding the conformance of the grading with acceptable standards of practice. The presence of the Soil Engineer or his representative or the observation and testing shall not release the Grading Contractor from his duty to compact all fill material to the specified degree of compaction. SCS&T 8521133 June 20, 1985 Appendix, Page 7 SEASON LIMITS Fill shall not be placed during unfavorable weather conditions. When work is interrupted by heavy rain, filling operations shall not be resumed until the proper moisture content and density of the fill materials can be achieved. Damage site conditions resulting from weather or acts of God shall be repaired before acceptance of work. RECOMMENDED GRADING SPECIFICATIONS - SPECIAL PROVISIONS The minimum degree of compaction to be obtained in compacting natural ground, in the compacted fill, and in the compacted backfill shall be at least 90 percent. Detrimentally expansive soil is defined as soil which will swell more than 3 percent against a pressure of 150 pounds per square foot from a condition of 90 percent of maximum dry density and air dried moisture content to saturation. Oversized fill material is defined as rocks or lumps over 6 inches in diameter. At least 40 percent of the fill soils shall pass through a No. 4 U.S. Standard Sieve. TRANSITION LDTS: Where transitions between cut and fill occur within the proposed building pad, the cut portion should be undercut a minimum of one foot below the base of the proposed footings and recompacted as structural backfill.