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HomeMy WebLinkAbout; Seaview Way Lot Split; Soils Report; 1989-02-08- - - - - - RmR.l!(P czccmQmcAL~GL4rIrn -Lul!spLzT sEAvIEw~ -,- ,- - PREPARED FOR: - - - - - - Mr. Fdprartice 8479 Verrada De Padre Goleta, California 93117 PREPARED BY: soUtbrnCalifomiaSoil&lksting,Inc. Post Office Box 20627 6280 Riverdale Street San Dieyo, California 92120 - - - - .- - - ,- - - 4% T February 8, 1989 Mr. Ed Prentice 8479 Verrada me Padre Goleta, California 93117 SCS&T 8921004 RepxtNo.1 SUBJECT: Report of Geotechnical Investigation, Prqosed Lot Split, Seaview Way, Carl&ad, California. Gentkmn: In accordance with your request, we have performed a geotechnical investigation for the proposed project. W are presenting herewith our findings and reccmmmdations. In general, we found the site suitable for the proposed developrr?nt provided the recmndations presented in the attached report are followed. The sits is underlain by coqressible fill, slopewash and topsoil deposits extending to a m%imm c&ined depth of six feet. This material will require -al and replacemxt as ccmpacted fill. If you have any questions after reviewing the findings and reccmnendations contained in the attached report, please do not hesitate to contact this office. This opportunity to be of professional service is sincerely appreciated. Daniel B. Mler, R.C.E. #36037 Curtis R. Burdett, C.E.G. #lo90 DBA:CF&nw cc: (6) Sulmitted (1) SCS&T, Escondido SOUTHERN CALIFORN,* SOIL AND TESTINO. I N c. - - l!ABu3oF- PAc;E Intrcduction and Project Description ....................................... 1 Project Scope ............................................................ ..l Findings ................................................................ ...2 Site Description ....................................................... 2 General Geology and Subsurface Conditions ........................... ...3 Geologic Setting and Soil Descriptions ......................... ...3 crectonic setting ............................................... ...3 Geologic Hazards ....................................................... 4 General ........................................................ ...4 Groundshaking .................................................. ...4 Groundwa.ter ............................................................ 6 Conclusions and captions ......................................... ...6 General ............................................................. ...6 Grading ............................................................. ...7 Site Preparation ............................................... ...7 Surface Drainage ............................................... ...7 Iqorted Fill .................................................. ...7 Earthwxk ......................................................... 7 Foundations .......................................................... ..E General ......................................................... ..E Reinforc~nt ................................................... ..E Concrete Slake-onGrade ........................................... 8 Expansive Characteristics ....................................... ..g Settlemnt Characteristics ..................................... ...9 Earth P&aini.ng Walls ................................................ ..g Passive Pressure ................................................ ..g r42t1ve PlreSSure ................................................... 9 Backfill.........................................................l 0 Factor of Safety.................................................lO Limitations ............................................................. ..lO Review, Observation and Testing.......................................1 0 Uniformity of Conditions..............................................lO Change in sCope.......................................................ll Tim Limitations......................................................l 1 - - - - - - .- - _- - - - TABLEOF- (continud) Pm3 Professional Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..ll Client's Responsibility...............................................12 Field E~lorations........................................................12 Laboratory Testing........................................................13 Table I Figure 1 Plate 1 Plate 2 Plates 3-5 Plates 6 Plate 7 Plate 8 Plate 9 Plate 10 Maximm Eedrcck Accelerations, Page 5 Site Vicinity Map, Follohs Page 1 Plot Plan Subsurface Exploration Legend TrenchLogs Grain Size Distribution Maximum Dry Density and Gptinnna Misture Content Expansion Index Test Results Direct Shear Sumwy Single Point Consolidation Test Results Retaining Wall Subdraintkatail Recommended Grading Specification and Special Provisions - - - - - - - - - - - - SC T PW3POSEDLOTSPLIT SEAVIEW WAY CARLSBAD,cALIFoRNIA This report presents the results of our geotechnical investigation for the subject project located adjacent to and east of Seaview Way, City of Car&bad, California. The site location is illustrated on the following Figure 1. It is our understandingthatthe site will be developedtoreceivetwoone- and/or-two-story residential structures. The structures will be of kood- frams construction. Shallow foundations and conventional slab-on-grade floor systenm are anticipated. Grading will consist of fills less than ten feet deep. To assist in the preparation of this report, we were provided with a preliminary site plan prepared by Warren W. Scott Architecture, dated October 19, 1988 and an undated grading plan prepared by Conway and Associates, Inc. The site configuration and approximate locations of our subsurface explorations are shown on Plate Nmker 1 of this report. This investigation consisted of: surface reconnaissance, subsurface explorations, obtaining representative disturbed and undisturbed sanples, SOUTHERN CALIFORNIA SOIL AND TESTINO. I l-4 c. -. - - .~ - .-~ .~- .- .- -- __ - - - SOUTHERN CALIFORNIA PROPOSED LOT SPLIT SOIL & TNSTINQ,INC. BV: D8A oATC: Z-08-89 ~0s NUYBE~: 8921004 Figure No. 1 - - - - - - - - -- - - - - SCS&T 8921004 February 8, 1989 Page 2 laboratory testing, analysis of the field and laboratory data, research of available geological literature pertaining to the site, and preparation of this report. More specifically, the intent of this analysis was to: a) b) Cl d) e) Explore the subsurface conditions to the depths influenced by the proposed construction. Evaluate, by laboratory tests, the pertinent engineering properties of the various strata which will influence the development, including their bearing capacities, expansive characteristics and settl-t potential. Describe the general geology at the site including possible geologic hazards which could have an effect on the site devel-nt. Lkvelop soil engineering criteria for site grading and provide design information regarding the stability of fill slopes. Fddress potential construction difficulties and provide recomnandations concerning these pmblene. Ret-nd an appropriate foundation systm for the type of structures anticipated and develop soil engineering design criteria for the ret-ndsd foundation &sign. SITE mm The subject property consists of two adjacent and rectangular parcels of land, totalling approximately 1.2 acres in area. The property is located on the west side of Maria Lane in the City of Carlsbad, California. The property is bordered on the north by an existing nursery and residential property and on the wast and south by residential property. A drimy easenent enters the southwast comer of the property Via Seaview Way. - - - .- - - .- - - -~ - - - SCS&T 8921004 February 8, 1989 Page 3 A single family residence in the process of being demolished is located on the west end of the property and is situated over both parcels. An asphalt paved parking area is located at the southwest comer of the site. A matal storage shed exists at the northeast comer of the property. Vegetation on the site consists of scattered grasses and weeds and several landscape shrubs and trees. A dense covering of reeds and shrub trees exists at the northwast comer of the property. A tw-foot-high concrete block retaining ml1 has been constructed along a portion of the eastern property line. The property slopes gently to moderately to the w?zst. A 2:l (horizontal to vertical) ccqosite cut and fill slope, a maximrm of ten feet in height, exists along the western property line. -C! SJTITIX AND SOIL DEXRPlT(3hG: The subject lot is located in the Coastal Plains Physiographic Province of San Diego County and is underlain by Quaternary marine terrace deposits, slopewash, topsoil and artificial fill. The mine terrace deposits are collprised of orange-brown, humid, msdium dense to dense sands. Over the northern half of the site, the terrace materials are overlain by approxinately 1 to 1 l/2 feet of topsoils, which are in turn overlain by 1.5 to four feet of slopewash deposits. The topsoils consist of dark brown, humid, medium dense, slightly silty sands. The slopewash consists of loose materials similar to the topsoils and are rrpst probably derived from eroded topsoil. On the southern end of the site, the terrace deposits are overlain by a "wedge of fill soils ranging to a rmxinum thickness of approxinWely six feet. The fills are poorly to moderately compacted and comprised of a mixture of the above described soils. TECIUWZ SEITIIG No faults, are known to traverse the subject site but it should be noted that nuch of Southern California, including the San Diq .- .- SCS&T 8921004 February 8, 1989 page 4 county area, is characterized by a series of -ternary-age fault zones which typically consist of several individual, en echelon faults that generally strike in a northerly to northwsterly direction. Scans 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 Epuch (the mst recent 11,000 years) while potentially active fault zones nave demonstrated mnvemsnt during the Pleistocene Epoch (11,000 to 2 million years before the present) but no m3vemantduringRolccenetine. - A review of available geologic maps indicates that the site is 0.25 mile southeast of a srmll unnaned fault. In addition, the Rose Canyon Fault Zone is located six miles to the wast. Recent earthquake activity along faults in the southern extension of the Rose Canyon Fault Zone indicates that this zone could be classified as active. The recent seismic events along a smll portion of the Rose Canyon Fault Zone generated earthguakes of magnitude 4.0 or less. Other active fault zones in the region that could possibly affect the site include the Coronado Banks and San Clestente Fault Zones to the wast, the Elsinore and San Jacinto Fault Zones to the northeast, and the Agua Blanca and San Miguel Fault Zones to the south. - -- GENERAL: The site is located in an area which is relatively free of potential geologic hazards. Hazards such as tsunamis, seiches, liquefaction, or deep-seated landsliding should be considered negligible or nonexistent. m: One of the m3st likely geologic hazards to affect the site is groundshaking as a result of movement along one of the fault zones mentioned atove. The maximrm bsdtvck accelerations that wuld be attributed to a nm&wa probable earthguake occurring along the nearest portion of selected fault zones that could affect the site are summarized in the following table. - .- - - - - - - SE&T 8921004 Februaq' 8, 1989 TAPUI Page 5 MaximmProlmble Bedrock Design Fault Zone Distance EarthquAe Wceleration Axeleration Rose Canyon 6 miles 6.0 magnitude 0.37 g 0.25 g Elsinore 23 miles 7.3 magnitude 0.23 g 0.15 g Coronado Ranks 20 miles 6.0 mgnitude 0.13 g 0.09 g San Jacinto 43 miles 7.8 magnitude 0.14 g 0.09 g San Cl-te 55 miles 7. 3magnitude 0.08 g 0.05 g Earthquakes on the Rose Canyon or Coronado Ranks Fault Zones are expected to be relatively minor. Major seismic events are likely to be the result of reverent along the Elsinore, San Jacinto or San Clearante Fault Zones. In addition, we have analysed the fault zones which could affect the project site in order to detemune the probability of groundshaking of any given level. The individual faults and different fault zones have slip rates which have keen calculated to range from very low to very high rates of activity. The following chart smmr izes our opinion of the prcbsbility of events which muld result in associated maximie and "design" bedrock accelerations. Peak Acceleration Design Wceleration Probability of Cmurrence 0.39 g 0.24 g 1 x 10 -4 0.30 g 0.20 g 1 x 10 -3 0.25 g 0.17 g 1 x 10 -2 0.20 g 0.13 g 1 x 10 -1 0.15 g 0.10 g 5 x 10 -1 0.10 g 0.07 g 1 x 10 -0 Probability of cccurre nce is defined as the probability of any given event occurring during the assumd life of the proposed structures (50 years) which wuld occur in accelerations of that level. - SCS&T 8921004 February 8, 1989 Page 6 - .- .- - -~.. - - - Experience has shown that structures that are constructed in accordance with Uniform Building Code Standards are fairly resistant to seismic related hazards. It is, therefore, our opinion that structural damage is unlikely if such buildings are designed and constructed in accordance with the minimum standards of the nest recent edition of the Uniform Building Code. c No groundwater was encountered in our exploratory trenches. No major groundwater problems are anticipated either during or after construction. However, it should be recognizedthatminor groundwater seepageproblens may occur after development of a site even where none were present before development. 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. Sasedonthe permeability characteristics of the soil and the anticipated usage of the developsent, it is our opinion that any seepage problems which may occur will be minor in extent. It is further our opinion that these problenm can be most effectively corrected on an individual basis if and when they develop. - In general, no geotechnical conditions wxe encountered which weld preclude the development of the site as presently proposed provided the reccmsrsndations presented herein are followed. - .- The site was found to be underlain by up to six feet of ccrqxessible surface deposits (fill, topsoil and terrace deposits). Due to their settlement potential, these deposits are considered unsuitable, in their present condition for the support of settlevent-sensitive inprovems nts and will require removal and replacement as compacted fill. An additional - - ~- - - - -~ .~.. - - -. .- - SE&T 8921004 FeJxuary 8, 1989 consideration is the amunt of fill to be placed to achieve proposed finish grade. Increased foundation and slab-on-grade reinforcement will be remmended due to this condition. SITIT PREPAR?fFICN: Site preparation should begin with the demlition of existing *rovema nts and the remval frum the site of all resulting debris as wall as existing vegetation and deleterious mtter detrimsntal to the proposed development. Existing collpressible topsoil, slopewash and fill underlying the proposed settlemsnt-sensitive inproveae nts (exterior slabs included) should be remved to firm natural ground. Based on our findings, rlaxinnun remval depth will be six feet. The bottom of the excavation should be scarified to a depth of 12 inches, watered heavily and reccqacted to at least 90 percent as determined in accordance with AST?l D1557-78, Method A or C. SURFXE lXWN?W: It is ret-nded that all surface drainage be directed away fmmthe structures and the top of slopes. Pondingof mter should not be allowed adjacent to the foundations. IMKRBTI FlLT.6 Iqorted fill should consist of nondetrimntally expansive soil with an expansion index not exceeding 50. Inported fill should be approved by this office prior to site delivery. EAKR1K)RR: All earthwxk and grading contemplated for site preparation should be accomplished in accordance with the attached Pet-aded Grading Specifications and Special Provisions. All special site preparation ret-ndations presented in the sections above will supersede those in the standard RecWed Grading Specifications. All esbnknents, structural fill and fill should be compacted to at least 90% relative compaction at or slightly over optimna misture content. Utility trench backfill within five feet of the proposed structures aad beneath asphalt paveman ts should be compacted to minimm of 90% of its maximsa dry density. The upper twalve - SCS&T 8921004 February 8, 1989 .- - - - .- - - inches of sutqrade beneath paved areas should be coqacted to 95% of its maximum dry density. This compaction should be obtained by the paving contractor just prior to placing the aggregate base material and should not be part of the mass grading rquiremsnts. The mximna 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. fXNEBAL: Shallow foundations my be utilized for the support of the proposed structures. The footings should have a lninimm depth of 12 inches and 18 inches below lowest adjacent finish grade for single and two-story structures, respectively. A minimm width of 12 inches and 24 inches is reccm-ended for continuous and isolated footings, respectively. A bearing capacity of 1500 psf may be assumed for said footings. This bearing capacity nkay be increased by one-third when considering wind and/or seismic forces. Footings located adjacent to or within fill slopes should be extended to a depth such that a mininum distance of eight feet exist betwaen the footing and the face of the slope. Ftetaining wall footings in similar conditions should be individually reviewed by this office. RJZB: Both exterior and interior continuous footings should be reinforced with t+.u #4 bars (or one #5) positioned near the bottom of the footing and two #4 bars (or one #5) positioned near the top of the footing. This reinforcemnt is based on soil characteristics and is not intended to be in lieu of reinforcesent necessary to satisfy structural considerations. cXX!fWE SLABS-: Concrete slabs-on-grade should have a thickness of four inches andbe underlain by a four-imhblanketof clean, poorly graded, coarse sand or crushed rock. This blanket should consist of 100 percent material passing the two-inch screen and no aore than ten percent and five percent passing sieves #lOO and #200, respectively. The slab should be reinforced with #3 reinforcing bars placed at 24 inches on center each way. A 6"x6"-W2.9xW2.9 xelded wire mash my b-a used in lieu of the rebars. Slab - .- -. - - - -. - .- _- .- SCSfiT 8921004 February 8, 1989 Page 9 reiuforcemnt should be placed within the middle third of the slab. where moisture sensitive flax coverings are planned, a visgueen barrier should be placed on top of the sand layer. A one-inch-thick layer of clean sand should be placed over the visqueen to allow proper concrete curing. EXPANSIVE -SIWS: The prevailing foundation soils xere found to be nondetrinentally expansive. Imported fill soils will also be nondetri- nrantally expansive. This recomsmdations contained in this report reflect this condition. - -cs: The anticipated total and/or differential settlements for the proposed structure may be considered to be within tolerable limits provided the reconneudations presented in this report are followed. It should be recognised that minor hairline cracks on concrete due to shrinkage of construction materials or redistribution of stresses are normalandnmybe anticipated. PAssIvEpRpssuRE: The passive pressure for the prevailing soil conditions ~~ybeconsideredto be 400 pounds per square foot per foot of depthup to a rnurhnn of 2500 psf. This pressure may be increased one-third for seismic loading. The coefficient of friction for concrete to soil may be assumsd to be 0.35 for the resistance to lateral movement. When combining frictional and passive resistance, the fomer should be reduced by one-third. The upper 12 inches of exterior retaining wall footings should not be included in passive pressure calculations. ELLTIVE PRESSURE: The active soil pressure for the design of unrestrained earth retaining structures with level backfills may be assumed to be equivalent to the pressure of a fluid weighing 33 pounds per cubic foot. These pressures do not consider any surcharge. If any are anticipated, this office should be contacted for the necessary increase in soil pressure. This value ass-s a drained backfill condition. Waterproofing details should be provided by the project architect. A subdrain detail is provided on the attached Plate Number 10. SCS&T 8921004 February 8, 1989 Page 10 - - - - .~ - - - - BIIMFILL: All backfill soils should be c-cted 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 reac'hed an adequate strength. FXIDROFSAFETY: The above values, with the exception of the allowable soil bearing pressure, do not include a factor of safety. *ropriate factors of safety should be incorporated into the design to prevent the walls from overturning and sliding. The ret-ndations presented in this report are contingent upon our review of final plans and specifications. Such plans and specifications should be made available to the soil engineer and engineering geologist so that they may reviewandverify their compliance with this report andwithChapter 70 of the Uniform Building Code. It is ret-nded that Southern California Soil & Testing, Inc. bs retained to provide continuous soil engineering services during the earthwork operations. This is to observe compliance with the design concepts, specifications or ret-ndations and to allow design changes in the event that subsurface conditions differ frmn those anticipated prior to start of construction. The ret onnmndations 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 - - - - - SCS&T 8921004 February 8, 1989 Page 11 perfo rmnce of the foundations and/or cut and fill slopes may bs influenced by undisclosed or unforeseen variations in the soil conditions that my occur in the intermediate and unexplored areas. Any unusual conditions not covered in this report that my be encountered during site developrent should be brought to the attention of the soils engiueer so that he may neke mxiifications if necessq. This office should be advised of any changes in the project scope or proposed site grading so that it my be determined if the reccmrandations contained herein are appropriate. This should be verified in writing or modified by a written addendum. The findings of this report axe valid as of this date. ChXKpillti condition of a property can, however, occur with the passage of time, whether they be due to natural processes or the mrk of man on this or adjacent properties. In addition, chsnges in the State-of-the-Practice and/or Gove rnmsnt Codes my cccur. Due to such changes, the findings of this report my 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 ret-hdations. In the perfomance of our professional service, w comply with that level of care and skill ordinarily exercised by nenbers of our profession currently practicing under similar conditions and in the sane locality. The client recognizes that subsurface conditions nay vary fm those encountered at the locations where our borings, surveys, and explorations are made, and that our data, interpretations, and reconsendations are based solely on the - -. - - - - .- - -~ - - - - - SCS&T 8921004 February 8, 1989 Page 12 information obtained by us. We will be responsible for those data, interpretations, and ret-ndations, 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 -IBILITy It is the responsibility of Mr. IM ITeMice, or his representatives to ensure that the infornmtion and ret-ndations contained herein are brought to the attention of the engineer and architect for the project and incorporated into the project's plans and specifications. It is further his responsibility to take the necessary maasures to insure that the contractor and his subcontractors carry out such ret-ndations during construction. Four subsurface explorations ware nmde at the locations indicated on the attached Plate Wunber 1 on January 13, 1989. 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 Plates Wun&zer 3 through 5. The soils are described in accordance with the Unified Soils Classification System as illustrated on the attached sinplified chart on Plate 2. In addition, a verbal textural description, the wet color, the apparent moisture, and the density or consistency are provided. The density of granular soils is given as either very loose, loose, madium dense, dense, or very dense. The consistency of silts or clays is given as either very soft, soft, nedium stiff, stiff, very stiff, or hard. - SE&T 8921004 February 8, 1989 Page 13 - - .- Disturbed and undisturbed samples of typical and representative soils here obtained and returned to the laboratory for testing. Laboratory tests wsre performad 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) CLAssIFImm: Field classifications wxe verified in the laboratory by a visual examination. The final soil classifica- tions are in accordance with the Unified Soil Classification system. b) MxsluRE-DEzsIlY: Field moisture content and dry density xere determined for representative samples obtained. This infornmtion was an aid to classification and permitted recognition of variations in material consistency with depth. The dry unit. waight is determined in pounds per cubic foot, and the field moisture content is determined as a percentage of the soil's dry waight. The results are sunnmrised inthetrenchlogs. Cl GRAIN SIZE D-m: The grain size distribution was determined for representative samples of the native soils in accordance with A.S.T.M. Standard Test D-422. The results of these tests are presented on Plate knker 6. d) ocswmm Tlsr: The nmximrn dry density and optinum moisture content of typical soils ware determined in the laboratory in accordance with A.S.T.M. Standard Test D-1557-78, Mathod A. The results of these tests are presented on Plate Kunker 7. - - - - SCS&T 8921004 February 8, 1989 Page 14 - .- - - - e) MpILNsI(3N m TEST: Expansion index tests on remolded samples were performed on representative sanples of soils likely to be used as compacted fill. The test was performed on the portion of the sanple passing the #4 standard sieve. The sample was brought to optimum moisture content then dried back to a constant moisture content for 12 h- at 230 +/- 9 degrees Fahrenheit. The spchmwas then conpacted in a 4-inch-dianetermold intm equal layers bymsans of a tanper, then trimsad to a final height of 1 inch, and brought to a saturation of approximately 50%. The specimen was placed in a consolidoneter with porous stones at the top and bottom, a total normal load of 12.63 pounds was placed (144.7 psf), and the saaple was allowed to consolidate for a period of 10 minutes. The sample was allowad to become saturated, and the change in vertical nuvemantms recordeduntil the rate of expansion became nominal. The expansion index is reported on Plate W 7 as the total vertical displacesent tines the fraction of the sample passing ths #4 sieve times 1000. f) cLA5sIFI~moFmANsmsoIT.l ExP~IcNINmx KJmmIAL~~IoN l-20 very low 21-50 low 51-90 Insdium 91-130 high Atxwe 130 very high DIRECT SHEAR !ESE: Direct shear tests wsre perforned to determine the failure envelope based on yield shear strength. The shear box was designed to accommodate a sample having dianeters of 2.375 inches or 2.50 inches and a height of 1.0 inch. Sanples ware tested at different vertical loads snd a saturated moisture content. The shear stress was applied at a constant rate of strain of approximately 0.05 inch per minute. The results of these tests are presented on attached Plate Ku&er 8. - - SCS&T 8921004 Februsq 8, 1989 Page 15 9) -al Tsr: Single point consolidation tests ware performed on selected "undisturbed" sanples. The consolidation apparatus MS designed to acccmnrdate a l-inch high by 2.375-inch or 2.500-inch d&mater soil sanple laterally confined by a brass ring. Porous stones were placed in contact with the top and bottom of the sample to permit the addition or release of pore fluid during testing. Selected loads wsre applied to the sanples and the resulting deformations were recorded. The percent consolidation for each load cycle is reposed as the ratio of the amunt of vertical compression to the original one-inch sample height. The test samples were inundated to determine their behavior under the anticipated footing load as soil misture increases. The results of these tests are presented on Plate Nurber 9. - - - - - - - - - - ..- - .-. SUBSURF ACE EXPLORATION LEGEND UNlFIED SOIL CLASSIFICATIDN CHART SOIL DESCRIPTION GROUP SYMBOL TYP:ZAL NAMES . COARSE GRAINED. more than half of material is'- than No. 200 sieve s?ze. RAVELS CLEAN GRAVELS ore tnan half of oarse fraction is arger than No. 4 ieve size but GW GP Well graded travels, gravel- sand mixtures. little or no fines. Poorly graded gravels, gravel sand mixtures. little or "a mailer than 3". fines. GRAVELS WITH FINES GM Silty gravels, poorly graded (Appreciable amount gravel-sand-silt mixtures. of fines) GC Clayey gravels, poorly graded gravel-sand, clays mixtures. ANOS CLEAN SANDS SW Ftha" half of Well graded sand, gravelly sands. little or no fines. oat-se fraction is SP Poorly graded sands, gravelly mailer than No. 4 sands. little or no fines. ,ievc size. SANDS WITH FINES SM Silty sands. poorly graded (Appreciable amount sand and silty mixtures. of fines) SC Clayey sands, poorly graded sand and clay mixtures. I. FINE GRAINED, more than half of material is smaller than No. '200 sieve size. SILTS AND CLAYS ML Liquid Limit less than 50 CL OL SILTS AND CLAYS MH inorganic silts and very fine sands, rock flour. sandy silt or clayey-silt-sand mixtures with slight plas- ticity. Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays. lean clays. Organic silts and organic silty clays or low plasticity Inorganic silts, micaceous or diatomaceous fine sandy or silty soils. elastic Liquid Limit greater than 50 CH OH silts. Inorganic clays of high plasticity, fat clays. Organic clays of medium to high plasticity. HIGHLY ORGANIC SOILS PT Peat and other highly organic soils. - Water level at time of excavation CK - Undisturbed chunk sample or as indicated BG - Bulk sample - Undisturbed, driven ring sample or tube sample SP - St.andard penetration sample SOUTHERN CALIFORNIA PROPOSED LOT SPLIT’ SOIL & TESTINO, INC. py: DBA DATE: Z-08-89 Joe WuYaER: 8921004 Plate No. 2 .- - - ,~ - - .- - - .~. - E z kJ : c TRENCH NUMBER 1 = ,s :: *> co+ : I z: zz- 2. u, w- wyu) 5b WO z z- 1 F: - I !Y sii ELEVATION em “k: k ; an;i : :s 2,o ;; -P :E $2 z < <I :o’g z 0’; 30 ii m : 0 0 0 =0 0 1 DESCRIPTION SP/ Dark Brown, SLIGHTLY SILTY Moist Loose to SM SAND (SLOPEWASH) Medium i - Dense , _ i- i - CK Medium 113.9 3.0 Dense i- SM/ Orange Brown, SLIGHTLY SILTY Humid Dense SP SAND (TERRACE DEPOSITS) I -CK 108.1 9.1 - 1- I- Trench Ended at 9' S&THERM CALIFORNIA .SUBSURFACE EXPLORATION LOG SOIL & TESTINQ,INC. LOGGED EY: J BR DATE LOGGED: 1-13-8g JOG NUYIlER:8g21004 Plate No. 3 - - - - - ,- .- .,- - _- .~~ - - ,~. ;: F 4 iu- 2” z : 0 sp/ SM $7 sp/ SM - rRENCH NUMBER 2 ELEVATION DESCRIPTION lark Red Brown, SLIGHTLY jILTY SAND (FILL) lark Red Br wn SLI HTLY ;ILTY SAND TObSOIL 9 F Jrange Brown, SLIGHTLY SILT\ ;AND (TERRACE DEPOSITS) rrench Ended at 7' loist ry to umid umid ,oose edium ense ense 94.9 23.3 4.1 4.9 SCiUTHERN CALIFORNIA .SUBSURFACE EXPLORATION LOG SOIL A TESTING,INC. .- - .~. - -~ .- - - -- - -- -. - - -~ E ; TRENCH NUMBER 3 ;;* t ic : ii Y- ; : 2 z < :: “0: gz!: YUU) ii -‘I! E&Z t- 5+ YO ,g E 2 ou ELEVATION NY) WY)- ilz 2,; g; l-2 -P “E f,” 5 r: 0 8. z 5 ‘d *og i; : d DESCRIPTION 0 0 a: ‘0 0 0 I Sp/ Dark Brown, SLIGHTLY SILTY Moist Loose SM sAND (SLOPEWASH) - BAG SP/ Dark Red Brown, SLIGHTLY Moist SM SILTY SAND (TOPSOIL) SP/ Orange Brown, SLIGHTLY SILTY Humid 9.7 SAND (TERRACE DEPOSITS) Loose to Medium Dense BAG - CK Very Dense 113.8 6.9 Trench Ended at 6' - SP/ Dark Brown, SLIGHTLY SILTY Humid Loose to SM SAND (FILL) Medium Dense SP/ Orange Brown, SLIGHTLY SILTY~Humid SM SAND (TERRACE DEPOSITS) Dense Trench Ended at 5' S&THERM CALIFORNIA ,SUBSURFACE EXPLORATION LOG SOIL & TESTING,INC. LOGGED BY: ,,B,j DATE LOGGED: 1-13-89 JOB NGhtG,?tt:8g21004 Plate No. 5 2” 1” w ” ” : ;: : : : :: : : i : : :: : : : : : _ : : : j : :: : :: 43 2 i ii T3 @ 0.5’-1.5’ us Standard sieves ti *lo xzo w “60 PARTICLE SIZE , ..- LliL Hydrometer fMimted 125 30 LIMITS I I GRAVEL BOULDER ;COGBLES I SAND SILT OR CLAY , COOnO Fine caorlr Mrdiun Fine (12 in.) 3 in. 3/4 in. No.4 No.10 No.40 No. 200 u. s. STANDARD SIEVE SIZE MAXIYUY DENSITY I O?tlMUY MOISTURE CONTENT EXPANSION INDEX TEST RESULTS SAMPLE CONDITION T3 @ 0.5'-1.5 REMOLDED INITIAL M.C. C-1.) 8.2 INITIAL DENSITY WCFI116.0 FINAL M.C. C/d 15.7 I NORMAL STRE.SS(PSF) 144.7 EXPANSION INDEX 0 I / ~.-.;wuI~Y mm. .emmu.r 1 PRflPOSFn I OT SPI TT 3"" I "r"" ~mLlr"m",LL .._. __-- -_. _. __. SOIL & TESTINQ, INC. BY: DBA DATE: 2-08-89 8921004 Plate No. 7 - - DIRECT SHEAR SUMMARY IIiIIIIIIIIIIII o~~~~~““““~~~~~~~~~~~~~~~~~~~t+tl 1 2 3 4 5 2M L NORM: STRESS, KSF ANOLE OF INTERNAL COHESION IN FRICTION (‘1 bSf) 31 100 SAMPLE DESCRIPTION r3 @ 0.5'-1.5' REMOLOED TO 90% TERCEPT SOUTHERN CALIFORNIA PROPOSED LOT SPLIT SOIL & TtsTIWQ,IWC. IV: DBA DATE: 7-Ogq9 JoB WUYIER:8921004 Plate No. 8 SINQLE POINT CONSOLIDATION TEST RESULT SAMPLE NO. T2 @ 4' T2 @ 6' I I I I - INITIAL MOISTURE, % 4.1 4.9 - INITIAL DENSITY, PCF 94.9 123.3 - % CONSOLIDATION BEFORE WATER ADDED 1.6 1.4 - "< CONSOLIDATION AFTER WATER ADDED 8.2 2.1 - FINAL MOISTURE, % 17.2 10.2 - AXIAL LOAD, KSF 2.58 2.58 SOUTHERN CALIFORNIA PROPOSED LOT SPLIT 801~ & TCSTIWQ, INC. I)“: WI DATE: 2-08-89 JoI) IIUYI)LII: a921004 Plate No. 9 \ WATERPROOF BACK OF WALL PER ARCHITECT’8 SPECIFICATIORS S/4 INCN CRUINED ROCK OR MIRADRAIN SDDD OR EQUlVALENT QEOFASRIC l ETWEEN ROCK AND SOIL 4” DIAYETER PERFORATED PIPE -8iAB-ON-QRADE RETAININO WALL SUBDRAIN DETAIL NO 8CALE SOUTHRRN CALIFORNIA PROPOSED LOT SPLIT SOIL & TE8TlNo,lNC. w: DBA DATE: 2-09-89 - - -IorsPLIT,~vrEw~,cARLsBAD - (Lzu!Dm sPE!I.FI~~ - caNERAL PfmJISIcRs The intent of these specifications is to establish procedure s for clearing, c-cting natural ground, preparing areas to be filled, and placing and compacting fill soils to the lines and grades shown on the accepted plans. The ret-ndations contained in the preliminary geotechnical investigation report and/or the attached Special Provisions are a part of the F&ccmuend& Grading Specifications and shall supersede the provisions contained hereinafter in the case of conflict. These specifications shall only be used in conjunction with the geotechnical report for which they are a part. No deviation from these specifications will bs allowed, except where specified in the geotechnical soil report or in other written ccnmmnication signed by the Soil Engineer. 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 hark was or was not acconplished as specified. It shall be the responsibility of the contractor to assist the soil engineer airI to keep him appraised 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 Sngineer shall bs contacted for further ret-ndations. ..- If, in the opinion of the Soil Engineer, substandard conditions are encountered, such as; questionable or unsuitable soil, unacceptable moisture (R-am) - - - - - - - SE&T 8921004 February 8, 1989 pppendix, Page 2 content, inadequate compaction, adverse weather, etc., construction should be stopped until the conditions are remedied or corrected or he shall recoanend rejection of this wrk. Test methods used to determine the degree of coqoaction should bs performed in accordance with the following Amsrican Society for Testing and Materials test methods: Maximnn Density & Gptinnnn IWisture 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. 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. 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, ccqacted and tested for the minimrn degree of coqaction in the Special Provisions or the recomnendation contained in the preliminary geotechnical 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 90% of its nw2dmm dry density. When the slope of the natural ground receiving fill exceeds 20% (5 horizontal units to 1 vertical unit), the original ground shall be stepped (R-8/87) - - - - - ,. .- - ,- .~ - SCSLT 8921004 February 8, 1989 -,PF3 or benched. Benches shall bs cut to a fina c-tent soil condition. The lowar bench shall be at least10 feet wide or 11/2 tines the the equivt width which ever is greater and shall be sloped back into the hillside at a gradient of not less than tm (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 herein for ccqected natural ground. Ground slopes flatter than 20% shall bs benched when considered necessary by the Soil Engineer. Anyabandonedburied structures encountereddusLnggradingoperationsnust be totally removed. All underground utilities to be abandoned beneath any proposed structure should be ?zemmed fromwithin feetofthesixucture and properly capped off. The resulting depressions frcm 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, sewar lines or leach lines, stem drains and water lines. Any buried structures or utilities not to be abandoned should be brought to the attention of the Soil Engineer so that he my determine if any special remmmxWion will be necessary. All water walls which will be abandomd should be backfilled and capped in accordance to the reguixemsnts set forth by the Soil Engineer. The top of the cap should be at least 4 feet below finish grade or 3 feet below the bottomof footingwhicheveris greater. The type of cap will depend on the diamater of the wall and should be determined by the Soil Engineer and/or a qualified Structural Engineer. Materials to be placed in the fill shall be approved by the Soil Engineer and shall be free of vegetable mtter and other deleterious substances. (R-8/87) - .~. - -, .~ ,~ - - - SCSLT 8921004 February 8, 1989 %F=f3hpage4 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 geotechnical 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 iqmrt material shall be approved by the Soil Engineer before being brought to the site. *proved fill material shall bs placed in areas prepared to receive fill in layers not to exceed 6 inches in coqacted thickness. Each layer shall have a uniform moisture content in the range that will allow the coqmction effort to be efficiently applied to achieve the specified degree of compaction. Each layer shall be uniformly coqacted to a minimrm specified degree of ccqaction with equipment of adeguate size to econmically compact the layer. Coqaction equipment should either be specifically designed for soil coqaction or of proven reliability. The mininun degree of compaction to be achieved is specified in either the Special Provisions or the ret-udations contained in the preliminary geotechnical investigation report. when the structural fill material includes rocks, no rocks will be allawed to nest and all voids mst be carefully filled with soil such that the minimum degree of compaction recommended in the Special Provisions is achieved. The mxi.mm~ size and spacing of rock permitted in structural fills and in non-structural fills is discussed in the geotechnical report, when applicable. Field observation and compaction tests to estimte the degree of ccnpaction of the fill will be taken by the Soil Engineer or his representative. The (R-8/87) SCS&T 8921004 February 8, 1989 ILppendix,page5 .- - - - - - - - - - - location and frequency of the tests shall be at the Soil Engineer's discretion. When the coqaction test indicates that a particular layer is less than the required degree of colrpaction, the layer shall be mrkedto the satisfaction of the Soil Engineer and until the desired relative compaction has bsen obtained. Fill slopes shall be compacted by mans of sheepsfcot rollers or other suitable equipment. Coqaction 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 bs trackrolled. Steeper fill slopes shall be over-built and cut-back to finish contours after the slope has been constructed. Slope coaqction operations shall result in all fill mterial six or nme inches inward fmn the finished face of the slope having a relative coqaction of at least 90% of maximsa dry density or that specified in the Special Provisions section of this specification. The coqaction operation on the slopes shall be continued until the Soil Engineer is of the opinion 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 detemine if the required ccqaction is being achieved. Where failing tests occur or other field problem arise, the Contractor will be notified that day of such conditions by written commm 'cation fm the Soil Engineer or his representative in the form of a daily field report. If the nrathcd of achieving the required slops conpaction selected by the Contractor fails to produce the necessary results, the Contractor shall remrk or rebuild such slopes until the required degree of coqaction is obtained, at no cost to the Owner or Soils Engineer. (R-8/87) SCS&T 8921004 February 8, 1989 - - - - .- ,.- -. - - -~ - - The Engineering Geologist shall inspect 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 relzort such as perched xater, 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 maasures are necessary. Unless otherwise specified in the geotechnical report, no cut slopes shall be excavated higher or steeper than that allowad by the ordinances of the controlling qve-ntal agency. Field observation by the Soil Engineer or his representative shall be n&e during the filling and ccnpacting operations so that he can express his opinion regarding the confonmnce of the grading with acceptable standards of practice. The presence of the Soil Engineerorhis representativeorthe observation and testing shall not release the Grading Contractor from his duty to compact all fill material to the specified degree of coqaction. Fill shall not be placed during unfavorable weather conditions. When work is interrupted by heavy rain, filling operations shall not be resumad until the proper moisture content and density of the fill materials can be achieved. Eamqed site conditions resulting from waather or acts of Cod shall be repaired before acceptance of work. (R-8/87) - - .- .- SCS&T 8921004 February 8, 1989 ILppendixrpage7 REL?WYE~~~:Themininaun degree of compaction to be obtained in c-cting natural ground, in the c-cted fill, and in the c-cted backfill shall be at least 90 percent. For street and parking lot s&grade, the upper six inches should be compacted to at least 95% relative compaction. EXPAEIVE SOILS: Detrinentally expansive soil is defined as clayey soil which has an e-ion index of 50 or greater when tested in accordance with the Uniform Euilding Code Standard 29-C. wEEIzH)I@ERI&z Oversized fill material is generally defined herein as rocks or lqs of soil over 6 inches in dianeter. Oversize nmterials should not be placed in fill unless recomnenda tions of plac-t of such material is provided by the soils engineer. At least 40 percent of the fill soils shall pass through a NJ. 4 U.S. Standard Sieve. TfwtwTIoN Ilns: where transitions between cut and fill occur within the prcI~~edbuilding pad, the cut portion should be undercut a mininmm of one foot below the base of the propped footings and rec-cted as structural backfill. In certain cases that wuld be addressed in the geetechnical repoa I special footing reinforcenent or a conbination of special footing reinforcemantandundercuttingmayte required. (R-8/87)