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HomeMy WebLinkAboutCT 73-18; Ponderosa Homes Development Olivenhain; Soils Report; 1972-11-17- - - - - SOIL INVESTIGATION FOR THE PROPOSED PONDEROSA HOMES DEVELOPMENT OLIVENHAIN AREA; CALIFORNIA for Ponderosa Homes 2082 Business Center Drive Irvine, Cdlifornia 92064 WOODWARD-GIZIENSKI & ASSOCIATES Consulting Soil and Foundation Engineers and Geologists (An Affiliate of Woodward-Clyde Consultants) - :. .- - - - - TABLE OF CONTENTS LETTER OF TRANSMITTAL SCOPES FIELD INVESTIGATION LABORATORY TESTS SITE, SOIL AND GEOLOGIC CONDITIONS CONCLUSIONS RECOMMENDATIONS LIMITATIONS FIGURE 1 - SITE PLAN FIGURE 2 - LOG OF TEST BORING 1 FIGURE 3 - LOGS OF TEST BORINGS 2 6 3 FFGURE 4 - LOGS OF TEST BORINGS 4 & 5 FIGURE 5 - LOGS OF TEST BORINGS 6 & 7 FIGURE 6 - LOG OF TEST BORING 8 FIGURE 7 - LOG OF TEST BORING 9 FIGURE 8 - LOGS OF TEST BORINGS 10 & 11 FIGURE 9.-.~LOG.OF TEST BORING 12 FIGURE 10 - GRAIN SIZE DISTRIBUTION CURVES FIGURE 11 - RESULTS OF CONFINED COMPRESSION TESTS ATTACHMENT - SPECIFICATIONS FOR CONTROLLED FILL . Page 1 1 2 2 4 5 8 ,. WOODWARD-GIZIENSKI & RSSOCIKTES CO**"Lv"O so011 A"0 Ic.uNDAIIO* I"CDNIC"S ANO *loLoa,ll, _.* .I WOODWARD - GIZIENSKI & ASSOCIATES CONSULTlNG SOIL AND FOUNDATION ENGlNEERS AND GEOLOG,STS - An ajjiliafo of Woodmrd - Clyde Con.wltnnts - - - - - r r~ r 7 3467 KUrtz street San .mieg.a November 17, 1972 California 92110 Project No. 72-253 VI4 224.2911 Ponderosa Homes 2082 Business Center Drive Irvine, California 92064 Attention: Mr. John C. Vann, Jr. fin accordance with our authorized made an investigation of the underlying soil and geologic conditions at the site of the proposed Ponderosa Homes Development located in the Olivenhain area of California. The results of our studies have not revealed any major adverse soil or geologic conditions that would preclude the development ~of plans for the property. Alluvial soils are present on the site, however, and special treatment of these materials during grading will be required. The accompanying report presents our conclusions and recomnendations, as well as the results of the subsurface exploration and laboratory tests upon which the recommendations are based,’ The engineers assigned to this project were,Richard P. While and Walter Crampton of our firm. Louis J. l.#, R.E. 14129 RPW/WC/LJL/mb . Attachments - (4) ,,Project No. 72-253 SCOPE - - - - - - - - - - - This report describes an- investigation of the underlying soii:~and geologic conditions at a proposed Ponderosa Homes Development located north of Olivenhain Road, approximately 2700 ft east of its intersection with El Camino Real in the Olivenhain area of San Diego County, California. The purpose of the investigation is to determine the general physical characteristics of the subsurface soils, including general excavation charac- teristics of the formational materials, and the approximate depths and limits of 'potentially compressible alluvial and potentially expansive clay soils, if any; the general recommendations for site grading and fill compaction; the most suitable~depth and type of foundation for use at the site; allowable soil bearing pressures for soils in & natural undisturbed state and as compacted fill, and allowable heights and inclinations for cut and fill slopes. -. It is our understanding that the proposed construction will be limited to residential, wood-frame structures with relatively light loads. It is further anticipated that conventional shallow footings will be utilized for the support of the structures, and that concrete slabs-on-grade will be used. At this time, there are no grading plans available to indicate hqw and to what extent the site will be graded. ' FIELD INVESTIGATION A field investigation was performed at the site on September 27, 1972, which included a visual reconnaissance and the drilling of 12 test borings. All field work was done under the supervision of a staff engineer from our office. All test borings were made with a 6-in. diameter, continuous-flight, truck-mounted power auger at the approximate locations shown on the Site Plan, Fig. 1. Field boring logs were prepared by the engfneer on the basis of an examination of the samples secured and the excavated material, as well as the action of the drilling equipment. The Logs of WOODWARD. GIZIENSKI b ASSOCIATES Test Borinqs co**"LIwm SmIIL A"0 FO"NOATIO* cHCI*TTI* *no E~O,OD,~,, -,, ,. .Project No. 72-253 Page 2 - presentedion Figs. 2 through 9, are based on an inspection of the samples - - secured, the laboratory test results and the field boring logs. The,borings were approximately located in the field with the aid of two County of San Diego Topographic Survey Sheets (Coordinates 330-1689 and 326-1689). The approximate boundaries of the~site were platted on the topographic maps from an undated and untitled Red\ Estate Plat furnished us, _- and.which indicated the limits'of the site. LABORATORY TESTS - The soils encountered in the test borings were visually classified - - - and evaluated with respect to strength, compressibility characteristics, grain size, moisture content and dry density: The visual classification was substantiated by grain size analyses and determination of plasticity characteristics. The strength and compressability characteristics were - - evaluated by ~direct shear tests and confined compression tests on selected samples. and by a consideration of the dry density, and moisture content of the samples, the penetration resistance of the sampler and the geologic - characteristics of the.formations. - The results of the moisture content, dry density and direct shear tests are shown with the penetration resistance of the sampler at the core - responding sample locations on the Logs of the Test Borings. The results of the grain size analyses and confined compression tests are shown on Figs. - 10 & 11, respectively. - - - SITE. SOIL AND GEOLOGIC CONDITIONS The subject site consists of a 60 acre parcel of land situated on the lower and middle northerly slopes of a westward draining tributary to Green Valley northeast of Encinitas, California. The elevation of the site ranges from 130 to 277 ft (USCAGS datum). Two major subtributaries drain WOODWARD. GIZIENSKI & ASSOCIATES CO”I”L~W~ IIL Arm Ic.“*Dlno* I”01”Ll”, *ND CEOLrnl” - - - - - - - - Project No. 72-253 Page 3 the site from north to south from a knoll area in the northern portion of the site. A smaller tributary drains the knoll in'an, easterly direction. In general, the site is covered by a moderate growth of brush, although some patches support no vegetation, A turkey ranch currently occupies an area near the eastern boundary. Two small breached dams were noted in'the major drainage and minor scattered dumped fill and trash was observed. The sub- surface soils on the site can generally be divided into two grpups: (1). An overburden consisting of a thin mantle of topsoil over most of the site and alluvial - colluvial soils in the major sub- tributary draws. Alluvial and colluvial soils are recent soils deposited under the action of water and wind, in the case of ,alluvial soils, and gravity, in the case of colluvial soils. (2) 'Underlying the overburden soils are found massive poorly to moderately indurated sandstone which appears to be similar to the Torrey Formation of Eocene Age. This material out- crops on the site in draws and eroded areas, extends to sig- nificant depths on the site and should provide significant quantities of select fill material. The topsoil, where present, is generally 12 in. or less in thickness and !s composed of a loose dry porous silty sand. Some patches of sandy clay is commonly present below the topso/il, however, none was noted in the borings nor in exposures. The alluvial - colluvial soils are found on the bottoms of the major tributary draws .and borings indicate that the materials consist of a loose to medium dense silty sand derived from erosion of the Torrey Formation. The thickest portion of these materials encountered was on the order of 20 ft. This soil is somewhat porous and should be considered potentially compressible. The lower portions of alluvial - colluvial soils were wet indicating considerable moisture in the soils; however, no water seeps were noted. No ground water was encountered in the test borings at the time of drilling. ., WDODWARD . GIZIENSKI (1 ASSOCIATES CoNI”L,~W~ SOIL wm ro”UDArlON E”B,WEE”, I”ca C~OLO~,I,I - Y ,Project No. 72-253 Page 4 - - - - - - - - - - - Our reconnaissance of the site revealed no major faults on shear zones. Our examination of recent geol.ogfc maps indicates that no active faults traverse the site. In general other geologic structural features are of minor significance. The massive formational sandstone exhibits little or no bedding, except for minor crossbedding, joints and fractures are tight and spaced relatively far apart. CONCLUSIONS (l)- There are no apparent significant adverse soil or geologic conditions on the subject site which would in our opinion preclude the proposed development.' (2) The subsurface soils on the site can generally be divided into two groups; an overburden consisting of a thin mantle of topsoil plus deeper alluvial - colluvial soils, found on the ridges and the bottoms of the tributary draws, respectively; and an underlying massive poorly to moderately indurated sandstone unit which extends to significant depths on the site. (3) The Eocene sandstone found beneath the overburden soils is a relatively competent unit and should be satisfactory for the support of the proposed new loads. (4) The alluvial and colluvial materials found in both major drainage channels, as general.ly shown on Fig. 1, are loose to medium dense and,,as,indicated by confined compression tests, have a potential for com- pression under new loads when saturated. In their present condition, therefore, they are in our opinion unsuitable for the direct support of compacted fill and/or structures since excessive differential settlement could occur, should these materials become saturated. (5) Soils encountered on the site range from nonexpansive to slightly expansive in nature and should be suitable for use as a select WOODWARD-GIZIENSKI A ASSOCIATES CoNI"LrlYo SDlL AWD Ic."NDAI1O" l"Ol"LrlP A"0 rLO,c.C,lR - - _- - - - - - - - - - Fill. S~lopes Cut Slopes P,age 5 . Project No. 72-253 material at finish grade, both as a compacted fill and in its natural state. (6) The deeper portions of alluvial soils were noted to.be quite wet; however, unless deep cuts are anticipated in this material permanent water seeps are not anticipated to be a problem. Some difficulty may be encountered in this regard during excavation and recompaction of the alluvial - colluvial soils. (7) Based on the results of test borings, and our previous ex- perience in the general area, it is. our opinion that the formational sand- stone on the site can be excavated by medium ripping with heavy duty excavating equipment. (8) It is our opinion that slopes built in accordance with the plans and specifications, the table below, and the following recommendations will have an adequate factor of safety against a deep seated slope failure: I I Unsupported Slope Height (ft) 2:l Slope Inclination 11-l/2:1 Slope Inclination I *FHA 1 NON-FHA 1 *FHA 1 NON-FHA 1 40 55 25 40 70 70 60. 60 I . . *FHA requires a.safety factor of 1.5 for slope conditions including a seismic factor of O.lg. The material that will compose both cut and fill slopes is highly succeptable to erosion and may be difficult to plant. Fill slopes should be carefully compacted by back rolling with sheepsfoot during construction to help, control1 erosion. Benches at 25 ft vertical intervals may also help control1 erosion. RECOMMENDATIONS (1) The ground which will reaeive fill and/or residential struc- WOODWARD. CIZIENSKI & ASSOCIATES co*I”LII*o SOIL’AWD .o”wcuwJ* E*.a,*rm$ AND CcOLn.a,*R _. Project No. 72-253 Page 6 - ..~ - - - ,- - - - - - - - - - - tures, will have an adequate bearing value to safely support the proposed loads when treated as described in the attached "Specifications for Controlled Fill," and the recorenendattons below. Conventional spread or continuous footings for residential one and two-story, wood-frame and stucco structures placed on nonexpansive undisturbed native soils or properly compacted non- expansive fill may be designed for the following allowable soil bearing pressures: AllowabJe soil bearing pressure psf Natural undisturbed' Compacted Fill sandstone ,...... ~~. .,.,...~,., ,~.~. ,,, ,, ** 12 4000 2000 *** 18 5000 2500 * Below lowest adjacent rough or compacted grade. ** Minimum width should be 12 in. &*? San O&ego County minimums require 18" depth and 15" minimum width for two-story, wood-frame and stucco structures. (2) It is recommended that loose and/or porous surface soils and alluvial - colluvial soils not removed by the grading operations be excavated or scarified, as required, replaced, and compacted before fill, footings, or slabs-on-grade are constructed. Over most of the site these materials generally range in depth from 0 to 2 ft; however, in the drainage channels they may reach depths up to approximately 20 ft. Because of the variations in thickness of these loose and/or porous surface materials, the actual excavation and compaction should be controlled in the field by the soil . . - WOODWARD-GIZIENSKI & ASSOCIATES coN*"LII*~ *or1 AWD vcuWmAItOH raril*rmn AND CmLWlbn - ‘_ .. Project No. 72-253 Pqe 7 .’ engineer upon visual examination of the exposed soil. _- (3) As an alternative to removing and properly recompacting,the alluvial~- colluvial materials on the site, it is recommended that a pre- saturation scheme be used that would saturate the colluvial materials at - depth, such that settlements would occur as fill loads are placed. As indicated on the confined compression test results, Pig. 11. A moisture content of approximately 18% should cause settlement upon placing the fill loads. Settle- ment of the fjll at some future time, after construction of houses is thus - - minimized. In this regard, it is our opinion that because of the medium- dense materials on-site, it will be difficult for water placed at the surface to penetrate the entire depths of soil. Therefore, it is recommended that, - if this procedure is used, test pits be dug during grading tom determine the extent of colluwium deeper than approximately l,O ft. At,these locations, the surface material should be excavated to a depth such that the remaining - alluvial - colluvial soils are not deeper than 10 ft. If this alternative is selected, it shall be necessary to obtain several samples of the wetted - - colluvial soils after sbaking in order to determine if saturation has reached acceptable values. Also fills should be placed irenediately after verification to minimize any drying action. , (4) As a second alternative, it is suggested that an attempt be 'made to design the subdivision such that no buildings are placed in the deeper alluvial areas. These areas could be planned as green belt areas. Some minor excavation for open space, or streets and recompaction may be required at the front of l.ots depending on street widths and house set back distances. (5) It is recommended that any potentially expansive soils encountered - along daylight lines or in areas of shallow cut or fill be removed to a . . WOODWARD. GIZIENSKI A ASSOCIATES CONWLII”C SOIL AND ro”*oATIo* r*cmrmr AND .x.aLWIITI -., .., Project No. 72-253 Page 8 - depth of 2 ft within the entire level lot area and replaced with nqnexpansive _.~ soil available on-site. Similarly, it Is recorenended that the upper 2 ft - of fill be composed of nonexpansive soil. The clay soils may be spread in .- - the deeper portions of the fills. (6) A set of "Specifications for Controlled Fill" is attached.. Recommendations made as a part of this report shall become apart of these specifications. All grading should be observed and compacted fill tested by Woodward-Gizienski & Associates. LIMITATI,ONS - - The conclusions and recorunendations made in this report are based on the assumption that the soil conditions do not deviate appreciably from those disclosed by the test borings. If variations are encountered during - construction, we should be notified so that we may make supplemental recotn- mendations, if this should be required. Evaluation and utilization of soil materials and rock formations - fpr support of structures includes investigation of the subsurface conditions, ..- .- - - - analysis, formulation of recommendations, and inspection during grading. The 'soil investigation is not completed until the soil engineer has been able to examine the soil and rock in excavatipns or slopes so that he may make the necessary modifications, if needed. We emphasize the importance of the soil engineer continuing his services through the inspection of grading, including construction of fills and foundation excavations. WOODWAAD . GIZIENSKI & ASSOCIATES ,- - - - - - - - - - - - - - I’? ? 200 ,* I : 2?5 250 Olivenbain . ! Road ' Subdivision boundary taken from undated, xeroxed, Real Estate Plat. LEGEND: .&. indicates approximate location of Test Goring. ._.-...a Indicates approxipate location of ground surface contours~ B indicates approximate limits of overburden (exclusive Of topsoil) ~,' Alluvium and Colluvlum soils. Partially porous silty sand. [I indicates approximate limits of Torrey Formation - Poorly to moderately indurated sandstone of Eocene Aae,. SITE PLAN PONDEROSA HOMES DEVELOPMENT 0liVFNHAiN SITE II .- . . GIZIENSKI & ASSOCIATES II CONWLTING SOIL MD FOUNDATION ENGINEERS AND GEOlMjiSTS SAN DIEGD, CALIFDRIIIA DR. GY:MRR GS 1 APPRDX. SCALE: 1" = 400'1 PRDJ. NO: 72-253 CK'D By: DC I DATE: 10/17/72 IF&&&! : I .- - - - - - - - - - - Boring I 5- % q D3: f IO- 15- IS- 6316 IDE 0 1 Torrey Sandstone .LEGEND: WC = Water Content in percent of dry weight DD = Dry Density in pcf. BC = Number of blws by IUO-lb. hammer falling 30 inches to drive sampler 12 Inches. Sampler Data: IO = 2.0', OD = 2.5' DS f Direct Shear Test Data: # = Anglb of Apparent Friction in degrees. C = Apparent Cohesion in psf. (SM) = Group classification symbol in acc&dance with the Unified Soil Classification Systenb -I 2 = Sample Number I LOG OF TEST BORING I PONDEROSA HOMES DEVELOPMENT t DLIVENHAIN SITE WOODWARD - GIZIENSKI h ASSOCIATES I CDNSIJLTING SOIL MD FDUNDATlOn ENGINEERS AND GEOLOGISTS "I.. ..lF..^ ^.I #Fl-eYIA DR. BY: MRR GS 1 APPROX. SCALE: I" = 5' 1 PRUJ. NO: 72-253 D BY: bG 1 DATE: 10/17/72 1 FIGURE MO: 2 - - - - - - - - - - - - - - - - Boring 2 a Torrey Sandstone Boring 3 ry loose to madim dense, damp, ray silty sand (94) CPorous Alluvium BC= I3 Alluvia BC' I4 Col,luviun BC= 13 For Legend, see Fig. 2 LOGS OF TEST BORINGS 2 & 3 PONDEROSA HOMES DEVELOPMENT OLIVENHAIN SITE WOODWARD - GIZIENSKI b ASSOCIATES CONSULTING SOIL AND FDUMDATIDN ENGINEERS AND GEDLDGISTS .- - - -. - - - - -- - - 0 5 IO Boring 4 Wim dense, dmp, brown silty sand (84) with trace clay Boring 5 8 Torrey~Sandstone - -. - t tar Legend, see Fig. 2 I LOGS OF TEST BORINGS 'I & 5 PONDEROSA HOMES DEVELOPMENT I OLIVENHAIN SITE WOOOWARD - GIZIENSKI h ASSOCIATES CONSULTING SOIL AND FOUNDATIDN ENGINEERS AND GEOLOGISTS ~ ‘. - .- - - - _. - - ..~ - __ -. - - -- - - 0 IO 15 18 Boring 6 (34) with trace clay Colluviun Boring 7 Loose, damp, gray silty sand (94) ~rous topsoil 2 ; la61 ' BC= 1 iun ysee:,dmp, light gray silty , -.,, Colluviun Dens, dmmp, gray & brm silty Sati (s) with trace clay I. I Colluvium , damp, yello!+brcwn silty Torrey Sandstone For Legend, see Fig. 2; - - - - - - - - - Boring 8 For Legend, see Fig. 2 I LOG OF TEST BORING 8 PONDEROSA HOMES DEVELOPMENT OLIVENHAIN SITE I WOODWARD - GIZIENSKI h ASSOCIATES CONSULTING SOIL AND FOUNDATIDN ENGINEERS AND GEOLOGISTS SAN DIEGO, CALIFORNIA DR. BYiMRR GS 1 APPROX. SCALE: I" = 5' 1 PROJ. ND: 72-253 - ,,’ .- - - - - - - - - - - O- % 2 I 5- a : t s m 5 IO- ,o " zi 5 5 l5- 0. $ 201 23- Boring 9 1 Colluviun very dense, mist, yellow brcwn Silty sand (SM) with trace Clay Torrey Sanstone For Legend, see Fig. 2 I LOG OF TEST BORING 9 I PONDEROSA HOMES DEVELOPMENT OLIVENHAIN SITE WOODWARD - GIZIENSKI & ASSOCIATES CONSULTING SOIL AND FOUNDATION ENGINEERS AND GEOLOGISTS SAN DIEGO, CALIFORNIA DR. SY:MRR GSi APPROX. SCALE: I" = 5' 1 F'ROJ. NO: 72-253 I I _.,, ._ .’ ~- - - - - - - - - - - - - DR. By: MR sSI APPROX. SCALE: In = 5' 1 PROJ. NO: 72-2s 0 5 IO I5 20 23 Boring IO wim dense, danp, brzl;yit; sand Q (g,j) rise, damp, red-brown silty sand '(W Torrey Standstone Very dense, damp, yellow-brown silty sand (3.41 Torrey Standstone Boring II Dense, wet, brown clayey sand (SC) For Legend, see Fig. 2 LOGS OF TEST BORINGS 10 h II I PONDEROSA HOMES DEVELOPMENT OLIVENHAIN SITE WJDWARD - GIZIENSKI h ASSOCIATES CONSULTING SOIL AN0 FOUNDATION ENGINEERS AND GEOLOGISTS S&l DIEGO, CALlFChWiIA - ‘. ‘- - - - - - - - - - - Goring I2 I For Legend, see Fig. 2 LOG OF TEST BORING I2 PONDEROSA HOMES DEVELOPMENT OLIVENHAIN SITE WOODWARD - GIZIENSKI & ASSOCIATES CONSULTING SOIL AND FOUNDATION ENGINEERS AND GEOLMilSTS SAN DIEGO, CALIFCRNIA DR. BY:MRR GS 1 APPROX. SCALE: I" = 5' i PRDJ. NO: 72-253 CK'D EY:flc 1 DATE: 10/17/72 1 FICiE NO: S - - - - - - - - - - - - GRAVEL COBBLES I SAND coarse SILT and CLAY Fine llbarsd Medium 1 Fine Mesh Opening - ins. Sieve Size* r Hydra&w Amlrsis I I 0 Go IO Bo m 70 30 9 60 "$ z! 50 5okj % w 60 30 70 m Bo IO 90 0 loo ID0 50 10.0 5.0 1.0 0.1 405 0.01 0.005 QOOI GRAIN SIZE IN HILLMTERS r SAMPLE CLASSIFICATION AND SYFBOL; *LL *PI l-2 Siltv fine sand (SHl 3-3 Silty fine sand (94) NP NP 3-9 Silty fine sand (SH) *LL q Liquid Limit *PI = Plasticity Index GRAIN SIZE DISTRIBUTION CURVES PONDEROSA HOE.4ES DEVELOPMENT OLIVENHAIN SITE WOOBJARD - GIZIENSKI & ASSOCIATES CWISULTING SOIL AND FOUNDATION ENGINEERS AND GEOLOGISTS SAJI DIEGO. CALIFORNIA DR. BY:MRR GS ~APPROX. SCALE: - - - - IPROJ. NO: 72-253 CK'D BY:+C IDATE: lD/l7/77 IFIGURE NO: IO I - .- - - .- - - - - - - - - - - - RESULTS OF CONFINED COMPRESSION TESTS z 2 ii ‘Z .- E % be I 3-3-3 SW.7 9.6 30 97.3 20 75 Pressure Psf PRESSURE - psf 0 1000 2000 3000 woo 6000 1 I 2 3 Y 5 6 RESULTS OF CONFINED COMPRESSION TESTS PONDEROSA HOMES DEVELOPMENT OLIVENHAIN SlTE WOOCWARD - GIZIENSKI & ASSOCIATES CONSULTING SOIL AND FOUNDATION ENGINEERS AND GEOLOGISTS SAN DIEGO. CALIFORNIA OR. BY:MRR GS I APPROX. SCALE: w - - - I PROJ. ND: 72-25s CK'O BY: 1°C l DATE: lO/l7/72 l FIGURE NO: II -A 'Project No. 72-253 Attachment Page 1 of 4 SPECIFICATIONS FOR CONTROLLED FILL GENERAL These specifications cover preparation of existing surfaces to receive fills; the type of soil suitable for use in fills; the control of com- pactionand the methods of testing compacted fills. It shall be the Contractor's responsibility to place, spread, water and compact the fill in strict accordance with these specifications. A Soil Engineer shall be the Owner's representative to inspect the construction of fills. Exca- vation and the placing of fill shall be under the direct inspection of the Soil Engineer and he shall give written notice of conformance with the specifications upon completion .of grading. Deviations from these specifications will be permitted only upon written authorization from the Soil Engineer. A soil investigation has been made for this project; any recommendations made in the report of the soil investigation or subsequent reports shall become an addendum to these specifications. SCOPE The placement of controlled fill by the Contractor shall include all clearing and gruboing,.removal of existing unsatisfactory material, preparation of the areas to be filled, spreading and compaction of fill in the areas to be filled, and all other work necessary to complete the grading of the filled areas. MATERIALS :' 1. ~Materials for compacted fill~shall consist of any~material imported or excavated from the cut areas that, in the opinion of the Soil Engineer, is suitable for use in constructing fills. The material shall contain no ~-rocks nor hard lumps greater than 6 inches in size and shall contain at ,. least 40% of material smaller than l/4 inch in size. No material of a perishable, spongy, or otherwise improper nature shall be used in filling. .- - I. - - - - .II. -, III. 2. Material placed within 24 inches of rough lot grade shall be select material that contains no rocks'or hard lumps greater than 6 inches in size~and that swells less than 3% when compacted as hereinafter specified - for compacted fill and when subjected to an axial pressure of 160 psf. 3. Representative samples of material to be used for fill shall be tested in the laboratory by the Soils Engineer in order to determine the maximum density, optimum moisture content and classification of the soil. In addition, the Soil Engineer shall determine the approximate bearing value of a recom- .- pacted, saturated sample by direct shear tests or other tests applicable to the particular soil. 4. During grading operations, soil types other than those analyzed in the - report of the soil investigation may be encountered by the Contractor. The Soil Engineer shall be consulted to determine the suitability of these soils. - - WOODIVkRD-GIZIENSKI & ASSOCIATES cow*"LrI*o son AND ,0""oA.,0" w40,"~l"l A"0 0I0,001," -- Project No. 72-253 Attachment P,age 2 of 4 .- IV. - -. - - - .- .' - ..~ i - - -. - COMPACTED FILLS I. General (a) Unless otherwise specified, fill material shall be compacted by the Contractor while at a moisture content near the optimum .moisture content and to a density that is not less than 90% of the maximum density determined in accordance with ASTM Test No. D1557-70T, or other density methods that will obtain equivalent results. (b) Potentially expansive soils may be used in fills below a depth of 24 inches and shall be compacted at a moisture content greater than the optimum moisture content for the material. 2. Clearing and Preparing Areas to be Filled (a) All trees,~brush, grass and other objectionable material shall be collected, piled and burned or otherwise disposed of by the Con- tractor so as to leave the areas that have been cleared with a neat finished appearance free from unsightly debris. (b) All vegetable matter and objectionable material shall be removed by the Contractor from the surface upon which the fill is to be placed and any loose and porous soils shall be removed or compacted to the ~depth shown on the plans. The surface shall then be plowed or scarified to a minimum depth of 6 inches until the surface his free from uneven features.that would tend to prevent uniform compaction by the equipment to be used. (c) Where fills are constructed on hillsides or slopes, the slope of the original ground on which the fill is to be pl.aced shall be stepped or keyed by the Contractor as shown on the attached figure. The steps shall extend completely through the soil mantle and into the underlying formation materials. (d) After the foundation for the fill has been cleared, plowed or scarified, it shall be disced or bladed by the Contractor until it is uniform and free from clods, brought to the proper moisture content and compacted as specified for fill. 3. Placinq, Spreadina, and Compaction Fill Material (a) The fill material shall be placed by the Contractor in layers that when compacted shall not exceed 6 inches. Each layer shall be spread evenly and shall be thoroughly mixed during the spreading to obtain uniformity of material in each layer. (b) When the moisture content of the fill material is above that specified by the Soil Engineer, the fill material shall be aerated by by the Contractor by blading, mixing or other satisfactory methods until the moisture content is as specified. WDOD\VRRD. GIZIENSKI & RSSOCIRTES CDIIWLIINC IOll ANO Fo"*oA,1oN CNElNClll AND cLoLousT~ 2 a~~ _-‘. I. Project No. 72-253 .’ I- - -~ - V. - - VI. (c) When the moisture content of the fill material is below that specified by the Soil Engineer, water shall be added by the Con- tractor until the moisture content is as specified. (d) After each layer has been placed, mixed and spread evenly, it shall be thoroughly:, compacted by the Contractor to the specified density. Compaction shall be accomplished by sheepsfoot rollers, vibratory roller, multiple-wheel pneumatic-tired rollers or other types of acceptable compacting equipment. Equipment shall be of such design that it will be able to compact the fill to the specified density. Compaction shall be continuous over the entire area and the equipment shall make sufficient trips to insure that the desired density has been obtained throughout the entire fill. (e) Surface of fiil slopes shall be compacted and there shall be no loose soil on the slopes. INSPECTION 1. Observations and compaction tests shall be made by the Soil Engineer during the filling and compaction operatiions so that he can state his opinion that the fill was constructed in accordance with the specifications. 2: The Soil Engineer shall make field density tests in accordance with ASTM Test No. 0-1556-64T. Density tests shall be made in the compacted materials below the surface where the surface is disturbed. When these tests indicate that the.density of any layer of fill or portion thereof is below the specified density, the particular layer or portions shall be reworked until the specified density has been obtained. .~. . PROTECTION OF WORK Attachment Page 3 of 4 - .I_ 1. i -. 2. During construction the contractor shall properly grade all excavated surfaces to provide positive drainage and prevent ponding of water. He shall control surface water to avoid damage to adjoining properties. or to finished work on the site. The Contractor shall take remedial measures to prevent erosion of freshly graded areas and until such time as permanent drainage and erosion control measures have been installed. After completion of grading and the Soil Engineer has finished his observations of the work, no further excavation or filling shall be done except under the observation of the Soil Engineer. - - WOODWARD. GIZIENSKI & ASSOCIATES r - Original Ground ‘. Slope Ratio = g H Slope to be such that Sloughfng or Sliding does not occ”r Remove all Topsoil . See Note See Note NOTES - The minimum width 9” of key shall be 2 feet wider than the cmpaction equipment, and not less than 10 feet. The outside edge of bottom key shall be below topsoil or loose surface material. Keys are required where the natural slope is E~teeper than 6 horizontal to 1 vertical. or where specified by Soil Engineer.