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HomeMy WebLinkAboutCT 01-02; CALAVREA HILLS VILLAGE K; INTERIM REPORT OF GEOTECH INV VILL K;HfTERIM REPORT OF CTOIECHNICAL INVESTIGmCN PREPARED FOR: The William Lyon Ccnpany 4330 La Jolla Village Drive, Suite 130 San Diego, Califomia 92122 PREPARED BY: Southem Califomia Soil & Testing, Inc. Post Office Box 20627 6280 Riverdale Street San Diego, Califomia 92120 SOUTHERN CALIFORNIA SOIL 62B0 RIVERDALE ST. SAN DIEGO. CALIF. 92120 • TELE 280-4321 67S ENTERPRISE ST. ESCONDIOO. CALI AND TESTING, INC. P.O. BOX 20627 SAN OIEGO. CALIF. 92120 gZOZS • TELE 746-4544 March 20, 1990 The William Lyon Conpany 4330 La Jolla Village Drive Suite 130 San Diego, Califomia 92122 SCS&T 9021022 Report No. 1 ATTENTION: Mr. George Haviar SUBJECT: Interim Geotechnical Investigation, Calavera Heights, Village K, Carlsbaci, Califomia. Gentlemen: In accordance with your request, have conpleted an interim geotechnical investigation for the subject project. We are presenting herewith our findings and recomrendations. In general, we foiond the site suitable for the proposed development provided the recommendations presented in the attached report are followed. If you have any questions after reviewing the contents contained in the attached report, please do not hesitate to contact this office. This opportunity to be of professional service is sincerely appreciated. DBA: JRH:KAR:mw cc: (2) Submitted (4) Hunsaker and Associates (1) SCS&T, Escondido SOUTHERN INC. TAHIJE OF CONTEWrS Introduction and Project Description 1 Project Scope 2 Findings ^ Site Description ^ General Geology and Subsurface Conditions 3 Geologic Setting and Soil Description 3 Tectonic Setting 6 Geologic Hazards --^ Groundshaking 7 Seismic Survey and Rippability Characteristics 8 General 8 Rippability Characteristic of Granodioritic Rock 10 Rippable Condition (0-4,500 Ft./Sec.) 10 Marginally Rippable Condition (4,500 Ft./Sec.-5,500 Ft./Sec) 10 Nonrippable Condition (5,500 Ft./Sec. & Greater) 11 Rippability Cliaracteristics of Metavolcanics and Associated Hypabyssal Rocks and Tonalitic Rocks 11 Rippable Condition (0-4,500 Ft./Sec.) 11 Marginally Rippable Condition (4,500-5,500 Ft./Sec.) 12 Nonrippable Condition (5,500 Ft.Sec. & Greater) 12 Seismic Traverse Limitations 12 Groundwater 13 Conclusions and Recommendations 13 General 13 Grading 14 Site Preparation 14 Select Grading 15 Cut/Fill Transition 15 Inported Fill 15 Rippability 16 Oversized Rock 16 slope Construction 16 Surface Drainage 16 Subdrains 16 Earthwork 16 Slope Stability 17 Foundations 17 General 17 Reinforcement 18 Interior Concrete Slabs-on-Grade 18 Exterior Concrete Slabs-on-Grade 18 Special Lots 19 General 19 Expansive Characteristics 19 Settlement Characteristics 19 TAHLE OF CCNTENTS (continued) PACs: Earth Retaining Walls 20 Passive Pressure 20 Active Pressure 20 Backfill 20 Factor of Safety 20 Limitations 21 Review, Observation and Testing 21 Uniformity of Conditions 21 Change in Scope 21 Tine Limitations 22 Professional Standard 22 Client's Responsibility 22 Field Explorations 23 Laboratory Testing 23 ATTACHMENrS TABLES Table I Generalized Engineering ClTeiracteristics of Geologic Units, Page 6 Table II Tlie Maximum Bedrock Accelerations, Page 7 Table III Seismic Traverse Sunmary, Pages 8 and 9 FIGURE Figure 1 Site Vicinity Map, Follows Page 1 PLKIES Plates 1-lB Plot Plans Plate 2 Unified Soil Classification Chart Plates 3-5 Trench Logs Plates 6-12 Plates From Referenced Report Plates 13-15 Seismic Line Traverses Plates 16-17 Grain Size Distribution Plate 18 Conpaction Test Results Expansion Test Results Plate 19 Direct Shear Sunmary Plate 20 Oversize Rock Disposal Plate 21 Canyon Subdrain Detail Plate 22 Wea]<Kned Plane Joint Detail Plate 23 Retaining Wall Sutxlraln Detail Plates 24-26 Catepillar Rippability Charts APPODICES A - Logs from Pipevious Investigation B - Reconmended Grading Specification and Special Provisions SOUTHERN CALIFORNIA SOIL AND TESTING, INC. 62B0 RIVERDALE ST. SAN OIEGO. CALIF. 92120 • TELE 2BD-4321 • P.O. BOX 20627 SAN OIEGO, CALIF. 92120 678 ENTERPRISE ST. ESCONDIOO. CALir. 92025 • TELE 746-4544 INIERIM REPCKT OF (2XIIBCHNICAL INVESTIGATICN CALAVERA HEICTTS VILLAGE K CARLSBAD, CALIFORNIA IWERDDUCTION AND PRDOBCT DESCRIPTICN This report presents the results of our interim ireport of geotechnical investigation for Calavera Heights Subdivision, village K, located in the City of Carlsbad, California. The site location is illustrated on the following Figure Number 1. It is our understanding that the site will be developed to receive a residential subdivision with associated paved streets. It is anticipated that the structures will be one and/or two stories high and of vKxxi frame construction. Shallow foundations and conventional slab-on-grade floor systems are proposed. Grading will consist of cuts and fills up to approximately 30 feet and 60 feet deep, respectively. Fill slopes up to approximately 60 feet and cut slopes up to approximately 20 feet high eire also anticipated. To assist with the preparation of this report, we were provided with a grading plan prepared by Hunsaker and Associates dated January 30, 1990. In addition we reviewed our "Report of Preliminary Geotechnical Investigation, Calavera Hills Subdivision," dated August 6, 1984. The site configuration, topography and approximate locations of the subsurface explorations are shown on Plates Nunter 1, lA and IB of this report. SOUTHERN CALIFORNIA SOIL AND TESTING, INC. -^ir35« :« i^/^^^Ua.;?. iP^^ -r- f-i^'^V-- i-^i s ir"?'^ ^'ia^'"" .—. =':ARLG8AD I y\ SOUTHBRN CALIFORNIA AMM/ SOIL A TISTING,INC. •r: CALAVERA HEIGHTS-VILLAGE 'K' KAR/EM JOl MUWtW: 9021022 DATI: 2-2S-90 FIGURE #1 SCS&T 9021022 March 20, 1990 Page 2 PRQJBCr SCOPE This interim report is based on review of the aforementioned preliminary report for the Calavera Hills Subdivision. A site specific report will be prepared at a later date when further field investigation and analysis of laboratory data has been completed. For the purpose of this report, appropriate field investigation and laboratory test data was extracted from the previous report. More specifically, the intent of this interim study was to: a) Describe the subsurface conditions to the depths influenced by the proposed construction. b) The laboratory testing performed in the referenced report was used to evaluate the pertinent engineering properties, including bearing capacities, expansive characteristics and settlement potential, of similar materials which will influence the development of the proposed subject site. Further laboratoiry testing will be performed on actual on-site materials, once additional field investigation is performed. c) Define the general geology at the site including possible geologic hazards which could have an effect on the site development. d) Develop soil engineering criteria for site grading and provide reconmendations regarding the stability of proposed cut and fill slopes. e) Address potential construction difficulties and provide reconmendations conceming these problems. f) Recomnend an appropriate foundation system for the type of structures anticipated and develop soil engineering design criteria for the recomtended foundation design. SCS&T 9021022 March 20, 1990 Page 3 FINDINGS SHE laESCRIPTICN The subject site, designated as Village K in the Calavera Heights developnent, is an irregular shaped portion of land located in Ccirlsbad, Califomia. The site covers approximately 40 acres and is bounded on the north and east by undeveloped land, on the south by undeveloped land and a community park, and on the west by portions of Harwick Drive and Tamarack Avenue. It is also noted that portions of Harwick Drive and Glasgow Drive traverse the western portion of Village K in a north/south direction. Ttopographically, the site is conprised of hilly terrain with v^ll developed drainage swales. Elevation differentials range to approximately 180 feet from the westem portion to the central portion of the site. Drainage is accomplished via sheetflow and the aforementioned drainage swales. The major drainage swales on site drain in easterly and vresterly directions from the higher central portion of the subject site. Vegetation is conprised of a moderate to heavy growth of chaparral, shrubs and grasses. No structures were noted on the site, however subsurface utility nains appecu: to exist on the southerly portion of the site and along the easements for the existing paved streets. (3UERAL (3X3LDGY AND SUBSURFACE CONDITIONS OBOUOGLC SEmNG AND SOU. EESCRIPTION: The subject site is located near the boundary between the Foothills Physiographic Province and the Coastal Plains Physiographic Province of San Diego County and is underlain by materials of igneous origin and surficial residuum. The site is underlain by the basenent complex rocks consisting of Jurassic-age metavolcanic rocks and Cretaceous-age granitic rocks, Quatemary-age alluvium and artificial fill. A brief description of the niaterials on-site, in general decreasing order of age, is presented below. SCS&T 9021022 f^Iarch 20, 1990 Page 4 1) BASEMENT CCMPLEX - JURASSIC METAVOLCANICS AND CRETACBCWS O^ITICS (Jiw/Kqr): The oldest rocks exposed at the site are the Jurassic metavolcanic and associated hypabyssal rocks. The metavolcanic rocks are generally andesite or dacite in composition and the associated hypabyssal rocks are their porphyritic equivalents (ie: diorite porphyry to granodiorite porphyry). The fine grained hypabyssal rocks are considered to be about the same age as the netavolcanics and are consequently older than the other intrusive rocks found at the site. Both the metavolcanics and the associated hypabyssal rocks weather to dark, smooth hills or jagged, angular outcrops with a clayey, rocky topsoil. The metavolcanic and hypabyssal rocks are generally rippable with conventional earth-moving equipment to depths of only a few feet. The other rocks in the basenent conplex are the granitic rocks of the Cretaceous Southem Califomia Batholith which have intruded the older rocks and are, to a large degree, mixed with them. The granitic rocks at the project site appear to he both tonalitic and granodioritic in conposition. The tonalitic rocks are usually dark gray, fine to nedium grained rocks whereas the granodioritic rocks are usually yellowish brown to grayish brown, nedium to coarse grained rocks. The weathering and rippability characteristics of the tonalitic rocks appear to be somewhat similar to those of the netavolcanic/hypabyssal rocks. The tonalitic rocks may be rippable to greater depths than the metavolcanic rocks but ripping may be difficult and time consuming. In addition, it should be noted that the material generated from the tonalitic rocks will have the appearance of the metavolcanic rocks rather than that of good quality "decomposed granite". In contrast to the weathering characteristics of the metavolcanic/hypabyssal rock and the tonalitic rocks, the granodioritic rocks commonly weather to rounded outcrops or boulders in a matrix of grus ("decomposed granite"). The granodioritic rocks are variable in their excavation characteristics but conmonly contain areas which are rippable to SCS&T 9021022 t^rch 20, 1990 Page 5 depths of several feet or several tens of feet, yet include localized areas of boulders or unweathered rock which are not rippable with conventional heavy equipnent. The areas underlain by the respective rock types in the basement complex are intermixed and are not differentiated on the accompanying geologic map. It should be noted that since the different rock types are mixed the areas on the map where given a dual classification. The boundaries between the rock types are very- irregular, therefore they were not differentiated on Plate Number 1. 2) QUATERNARY (HOIiDCENE) AEHJVIUM (Qyal): Younger alluvial deposits consisting of unconsolidated, loose to medium dense deposits of clay, silt, sand, and gravel are present in the modem drainage swales. These deposits range in thickness from less than a foot to several feet. Due to their ubiguitous occurrence, the younger alluvial deposits are not delineated on the geologic map except in the larger drainage swales. 3) A relatively thin layer of loose topsoils and sv±isoils should be anticipated overlying the entire site. These deposits consist of varying mixtures of silts, sands and clays. It is estimated that these deposits do not exceed five feet in combined thickness. 4) ARTIFICIAL FUJL (Qaf): Two areas appear to be underlain by fill soils v\*iich were placed in conjunction with the construction of Elm Avenue and the partially inproved Edgeware Way. The approximate limits of the fills are indicated on Plate Number 1. The fill associated with Elm Avenue is a canyon fill and appears to range up to approximately sixty feet in depth. Artificial fill also underlies the area of Edgeware Way and was placed during the grading for the street inprovements. It was noted that both areas of fill have loose surface soils and it is anticipated that minor remedial grading will be necessary during the developnent of these areas. SCS&T 9021022 l^ch 20, 1990 Page 6 Table I presents some of the pertinent engineering characteristics of the materials at the site. TABEiE I (3MBRALIZED ENGINEERING CHARflCTERISnCS OF MAIN (2X3L0GIC UNITS Amount of Slope Unit Name Oversize Stability/ Expansive and Symbol Rippability Material Erosion Compressibility Potential Grcinitic Rocks-Generally Low to Good Nominal Nominal Kgr Rippable to Moderate (Granodiorite) + 15 Feet Granitic Rocks-Marginally Moderate to Good Nominal Nominal Kgr (Tonalite) Rippable to Nonrippable High Metavolcanic Marginally Moderate to Good Nominal Nominal and Hypabyssal Rippable to High Rocks-Jmv Nonrippable TBCTCWIC SEmUGz A few small, apparently inactive faults have been napped previously within the vicinity of the site. Nb evidence of faulting was noted in ovu: exploratory trenches for the referenced reports but it is possible that future grading operations at the site may reveal some of these faults. Due to their status of activity and geometry, these small faults should be only of minor consequence to the project. It should also be noted that several prominent fractures and joints v^ch are probably related, at least in part, to the strong tectonic forces that dominate the Southem Califomia region are present within the vicinity of the site. These features are usually near-vertical and strike in both a general northviesterly direction (subparallel to the regional structural trend) and in a general northeasterly direction (stibperpendicular to the regional structural trend). All cut slopes should be inspected by a qualified geologist to assess the presence of adverse jointing conditions in the final slopes. SCS&T 9021022 March 20, 1990 Page 7 In addition, it should be recognized that much of .Southem Califomia, is ageracterized by ira jor, active fault zones that could possibly affect the subject site. The nearest of these is the Elsinore Fault Zone, located approximately 20 miles to the northeast. It should also be noted that the possible off-shore extension of the Rose Canyon Fault Zone is located approximately eight miles west of the site. The Rose Canyon Fault Zone conprises a series of northwest trending faults that could possibly be classified as active based on recent geologic studies. Recent seismic events along a small portion of the Rose Canyon Fault Zone have generated earthquakes of 4.0 or less magnitude. Other active fault zones in the region that could possibly affect the site include the Coronado Banks and San Clemente Fault Zones to the west, the Agua Bianca and San Miguel Fault Zones to the south, and the Elsinore and San Jacinto Fault Zones to the northeast. (SCnXiGIC HAZARDS: The site is located in an area which is relatively free of potential geologic hazards. Hazards such as tsunamis, seiches, liquefaction, and landsliding should be considered negligible or nonexistent. OSXINDSHAKING: One of the nost likely geologic hazards to affect the site is groundshaking as a result of movement along one of the major, active fault zones nentioned above. The maximum bedrock accelerations that vvould be attribfuted to a maximum probable earthquake occurring along the nearest portion of selected fault zones that could affect the site are sunmarized in the following Table II. TABLE II Fault Zone Maximum Probable Distance Bedrock Design Acceleration Acceleration Rose Canyon 8 miles 6 .5 nagnitude 0. 36 g 0. 23 g Elsinore 20 miles 7 .3 nagnitude 0. 25 g 0. 17 g Coronado Banks 24 miles 7 .0 nagnitude 0. 18 g 0. 12 g San Jacinto 43 miles 7 .8 nagnitude 0. 14 g 0. 10 g SCS&T 9021022 March 20, 1990 Page 8 Earthquakes on the Rose Canyon Fault Zone are expected to be relatively minor. Major seismic events are likely to be the result of movement along the Coronado Banks, San Jacinto, or Elsinore Fault Zones. Experience has shown that structures that are constructed in accordance with the Uniform Building Code 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 most recent edition of the Uniform Building Code. SEISMIC SURVEY AND RIPPABILITY CHARACTERISTICS GENERAL: The results of our seismic survey and exploratory trenches perforned for the referenced reports indicate that blasting maybe required to obtain proposed cuts. In addition, isolated boulders are anticipated within cut areas that may require special handling during grading operations. A sunmary of each seismic traverse is presented in Table III below, and Plates Number 13 through 15. Our interpretation is based on the rippability characteristics of granitic and metavolcanic rock as described in Pages 10 through 12. TABLE III Seisinic Traverse No. Sk-3 Proposed Cut: 10 Feet Geologic Unit: Granitic Rock (Tonalite) Interpretation: 0'-16' Rippable -t-16' Nonrippable Seismic Traverse No. Sk-4 *' Proposed Cut: 5 Feet Geologic Unit: Ifetavolcanic and Associated Hypabyssal Rock Interpretation: 0'- 5' Rippable with isolated boulders 5'- 9' Marginally Rippable + 9' Nonrippable SCS&T 9021022 March 20, 1990 Page 9 TABLE III (continued) Seismic Traverse No. Sk-5 Proposed Cut: 8 Feet Geologic Unit: Granitic Rock (Tonalite) Interpretation: 0'- 8' Rippable + 8' Marginally to Nonrippable V Seisinic Traverse No. Sk-32 Proposed Cut: 13 Feet Geologic Unit: Metavolcanic and Associated Hypabyssal Rock Interpretation: 0' - 4 ' Rippable + 4' Nonrippable Seismic Traverse No. Sk-33 " Proposed Cut: 7 Feet Geologic Unit: Granitic Rock Interpretation: 0'- 5' Rippable 5'-11' Marginally Rippable +11' Nonrippable Seisinic Traverse No. Sp-30 Proposed Cut: 17 Feet Geologic Unit: Metavolcanic and Associated Hypabyssal Rock Interpretation: 0'- 5' Rippable + 5' Nonrippable Seismic Traverse No. Sp-31 Cr Proposed Cut: 20 Feet Geologic Unit: Metavolcanic and Associated Hypabyssal Rock Interpretation: 0'- 3' Marginally Rippable + 9' Nonrippable In general, our seismic survey indicated that areas underlain by granitic rock present rippable material to depths ranging from approxinately five SCS&T 9021022 March 20, 1990 Page 10 feet to 16 feet, with nonrippable material below this depth. In areas underlain by metavolcanic and associated hypabyssal rock, nonrippable naterials appear to be encountered at depths of approximately four feet to nine feet. In addition, a variable zone of marginally rippable rock usually exists between the rippable and nonrippable rock. Village K appears to be roughly evenly divided betv^n granitic and netavolcanic rock. The generation of fine material during blasting and mining operations is essential due to the characteristics of the on-site rock material. Therefore, "pre-shooting" of nonrippable material before removing the overlying soils and rippable rock is suggested. This procedure often helps to generate more fine naterial and to facilitate the mixing of soil and rock to be used as fill. RIPPABILITY CHARACTERISTIC OF aiANODIORITIC ROCK RipPARTf! CXUDITION (0-4,500 FT./SBC.): This velocity range indicates rippable materials which may consist of decomposed granitic rock possessing random hardrock floaters. These materials will break down into slightly silty, veil graded sand, whereas the floaters will require disposal in an area of nonstructural fill. Some areas containing numerous hcuxirock floaters nay present utility trench problems. Further, large floaters exposed at or near finish grade may present additional problems of removal and disposal. Materials within the velocity range of from 3,500 to 4,000 fps are rippable with difficulty by backhoes and other light trenching equipnent. MARGINALLY RIFPABLE COMDITION (4,500 FT./SBC.-5,500 FT./SBC.): This range is rippable with effort by a D-9 in only slightly weathered granitics. This velocity range nay also include nunerous floaters with the possibility of extensive areas of fractured granitics. Excavations may produce naterial that will partially break down into a coarse. SCS&T 9021022 March 20, 1990 Page 11 slightly silty to clean sand, but containing a high percentage of + 1/4" material. Less fractured or weathered materials may be found in this velocity range that wuld require blasting to facilitate r^raval. Materials within this velocity range are beyond the capability of backhoes and lighter trenching equipnent. Difficulty of excavation would also be realized by gradalls and other heavy trenching equipment. NONRIPPABLE CONDITION (5,500 FT./SEC. & O^EKTER): This velocity range includes nonrippable material consisting primarily of fractured granitics at lower velocities with increasing hardness at higher velocities. In its natural state, it is not desirable for hxiilding pad subgrade. Blasting will produce oversize material requiring disposal in areas of nonstructural fill. This upper limit has been based on the Rippability Chart shown on Plates Number 13 through 15 utilized for this report. Hovrever, as noted in the Caterpillar Chart on Plates Number 25 through 27, this upper limit of rippability may sometimes be increased to 7,000 to 8,000 fps naterial using the D-9 mounted #9 Series D Ripper. RIPPABILrry CHARACTERISTICS OF METAVOLCANICS AND ASSOCIOTED HYPABYSSAL ROCKS AND TONALITIC ROCKS RtPPABEB COMJmON (0-4,500 FT./SEC.): This velocity range indicates rippable naterials which may vary from deconposed netavolcanics at lower velocities to only slightly deconposed, fractured rock at the higher velocities. Although rippable, naterials may be produced by excavation that will not be useable in structural fills due to a lack of fines. Ejqjerience has shown that naterial within the range of 4,000 to 4,500 fps most often consists of severely to moderately fractured angular rock with little or no fines and sizeable quantities of + 1/4" material. SCS&T 9021022 riarch 20, 1990 Page 12 For velocities between 3,500 to 4,500 fps, rippability will be difficult for backhoes and light trenching equipnent. MARGINALLY RIPPABLE CCNDITIGN (4,500-5,500 FT./SBC.): Excavations in this velocity range would be extrenely tine consuming and v>ould produce fractured rock with little or no fines. The higher velocities could require blasting. Trenching equipnent vrould not function. NDNRIPPABEE OONDITION (5,500 FT./SBC. & GREKTER): This velocity range may include moderately to slightly fractured rock which would require blasting for removal. Material produced would consist of a high percentage of oversize and angular rock. Rippability of metavolcanics may be acconplished for higher velocities using the Caterpillar D-9 with the #9 D Series Ripper. Due to the fractured nature of some netavolcanics, ripping might be acconplished in as high as 8,000 fps naterial. SEISMIC TRAVERSE LIMITAnCNS The results of the seismic survey for this investigation reflect rippability conditions only for the areas of the traverses. Hov^er, the conditions of the various soil-rock units appear to be similar for the remainder of the site and nay be assimed to possess similar characteristics. Our reporting is presently limited in that refraction seismic surveys do not allow for prediction of a percentage of expectable oversize or hardrock floaters. Subsurface variations in the degree of weathered rock to fractured rock are not accurately predictable. The seismic refraction nethod requires that naterials becone increasingly dense with depth. In areas vtiere denser, higher velocity materials are underlain by lower velocity materials, the lover velocity naterials would not be indicated by our survey. SCS&T 9021022 March 20, 1990 Page 13 All of the velocities used as upper limits for rippability are subject to fluctuation depending upon such local variations in rock conditions as: a) Fractures, Faults and Planes of Weakness of Any Kind b) Weathering and Degree of IDeconposition c) Brittleness and Crystalline Nature d) Grain Size Further, the range of rippability using Caterpillar equipment may be increased using different equipment. However, it should be noted that ripping of higher velocity naterials nay becone totally dependent on the tine available and the economics of the project. Ripping of higher velocity materials can be achieved but it may become economically infeasible. GROUNDWATER: No groundwater was encountered during our subsurface explorations for the referenced reports. Even though no major groundwater problems are anticipated either during or after construction of the proposed development, seasonal groundwater from precipitation runoff may be encountered within the larger drainage swales during grading for the development. It is suggested that canyon subdrains be installed within drainage swales which are to receive fill. It should be realized that groundwater problems may occur after development of a site even v^ere none vere 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 pattems and an increase in irrigation water. Based on the permeability characteristics of the soil and the anticipjated usage of the development, it is our opinion that any seepage problems v^iich nay occur will be minor in extent. It is firrther our opinion that these problems can be nost effectively corrected on an individual basis if and when they develop. SCS&T 9021022 March 20, 1990 Page 14 CONCLUSIONS AND RECOWENDATIONS GENERAL In general, no geotechnical conditions vere encountered which vould preclude the development of the site as tentatively planned provided the recommendations presented herein are followed. Geotechnical conditions that will affect the proposed site development include expansive soils and hard granitic, metavolcanic and hypabyssal rock. Where possible, select grading is reconmended to keep nondetrinentally expansive soils within four feet from finish pad grade. In areas v^ere this is not feasible, special foundation consideration will be necessary. In order to make the proposed excavations, v^ anticipate that heavy ripping and blasting will be required. It is anticipated that the material generated fram the cuts of the granitic, netavolcanic and hypabyssal rock will contain relatively low amounts of fine soils and large amounts of oversized naterial. Since rock fills require a percentage of fine soil, mining of the site, inporting of fine naterials or exporting excess rock nay be necessary. The purpose of this interim report is to provide preliminary reconmendations based on infomation available from the referenced report. An additional investigation based on the present development scheme will be perforned at a later date. GRADING SITE PREPftRBtnON: Site preparation should begin with the removal of any existing vegetation and deleterious matter from proposed inprovenent areas. Removal of trees should include their root system. Any existing loose surficial deposits such as topsoils, unconpacted fills, and younger alluvium in areas to be graded or to receive fill should be removed to firm ground. The extent of topsoil will be approximately one or two feet. Existing unconpacted fills and younger alluvium are present only in minor scattered SCS&T 9021022 March 20, 1990 Page 15 areas of the site. Firm natural ground is defined as soil having an in-place density of at least 90 percent in proposed fill areas. Soils exposed in the excavations should be scarified to a depth of 12 inches, moisture conditioned and recompacted to at least 90 percent as determined in accordance with ASTM D1557-78, Method A or C. The minimum horizontal limits of removal should include at least five feet beyond the perimeter of the stmctures, and all areas to receive fill and/or settlement-sensitive inprovenents. SELECT GRADING: Exfjansive soils should not be alloved within four feet from finish pad grade. In addition, expansive soils should not be placed within a distance from the face of fill slopes equal to ten feet or half the slope height, whichever is more. Select material should consist of granular soil with an expansion index of less than 50. It is reconmended that select soils have relatively low pemeability characteristics. In areas undercut for select grading purposes, the bottom of the excavation should be slop>ed at a minimum of three percent away from the center of the structiure. Minimum lateral extent of select grading should be five feet away from the perineter of settlement-sensitive inprovenents. CUT/FITiT. TRANSITION: It is anticipated that a transition line between cut and fill soils nay run through sone of the proposed building pads. Due to the different settlement characteristics of cut and fill soils, construction of a structure partially on cut and partially on fill is not reconmended. Based on tJiis, v^ reconmend that the cut portion of the building pads be undercut to a depth of at least three feet below finish grade, and the materials so excavated replaced as uniformly conpacted fill. The mininium horizontal limits of these reconmendations should extend at least five feet outside of the proposed inprovenents. IMPDRSED FILL: All fill soil inported to the site should be granular and should have an ej^jansion index of less that 50. Further, inport fill should be free of rock and lunps of soil larger than six inches in dianeter and should be at least 40 percent finer than 1/4-inch. Any soil to be ijipoirted should be approved by a representative of this office prior to inporting. SCS&T 9021022 March 20, 1990 Page 16 RIPPABILITY: It is anticipated that the proposed cuts will require heavy ripping and blasting. This condition will be further evaluated during the preparation of the preliminary geotechnical investigation report. Additional seismic traverse lines will be performed in areas were deep cuts are proposed. OVERSIZED ROCK: Oversized rock is defined as material exceeding six inches in naximum dinension. It is anticipated that oversized naterial will be generated from proposed cuts. Oversized naterial may be placed in structural fills as described in Plate Nunter 20. SLOPE CONSTRUCTION: The face of all fill slopes should he conpacted by backrolling with a sheepsfoot conpactor at vertical intervals no greater than four feet and should be track walked when conpleted. Select grading should be perfomed to limit expansive soils within ten feet from face of fill slope or one half the slope height, whichever is greater. Recommendations contained within this report reflect a select grading condition. All cut slopes should be observed by our engineering geologist to verify stable geologic conditions. Should any unstable conditions he found, mitigating neasures could be required. SURFACE CKAINAGE: It is recomtended that all surface drainage be directed away from the stmctures and the top of slopes. Ponding of water should not be allowed adjacent to the foundations. SUBDRAINS: A subdrain should be installed in canyon areas to receive fill in excess of ten feet. A subdrain detail is provided in Plate Number 21. EARIIIHORK: All earthwork and grading contenplated for site preparation should he acconplished in accordance with the attached Reconmended 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, stmctural fill and fill should he conpacted to at least 90% relative conpaction at or SCS&T 9021022 March 20, 1990 Page 17 slightly over optimum moisture content. Utility trench backfill within five feet of the proposed stmctures and beneath asphalt pavenents should be conpacted to mininium of 90% of its maximum dry density. The upper twelve inches of subgrade beneath paved areas should be conpacted 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 he part of the mass grading requirenents. The maximum dry density of each soil type should be determined in accordance with ASTM Test Method D-1557-78, Method A or C. sujPE STABmry Proposed cut and fill slopes should be constmcted at a 2:1 (horizontal to vertical) or flatter inclination. It is estinated that cut and fill slopjes will extend to a naximum height of about 60 feet and 20 feet, respectively. It is our opinion that said slopes will possess an adequate factor of safety with respect to deep seated rotational failure and surficial failure (see Plate Nunter 22). The engineering geologist should observe all cut slopes during grading to ascertain that no adverse conditions are encountered. POUNDATIOre QSNERAL: If the lots are capped with nondetrimentally expansive soils, conventional shallow foundations may be utilized for the support of the proposed stmctures. The footings should have a minimum depth of 12 inches and 18 inches below lowest adjacent finish pad grade for one-and-tvo-story constmction, respectively. A minimum width of 12 inches and 18 inches is reconmended for continuous and isolated footings, respectively. A tearing capacity of 2000 psf may be assumed for said footings. This tearing capacity nay te increased by one-third vten considering wind and/or seismic forces. Footings located adjacent to or within slopes should te extended to a depth such that a ndnimum distance of six feet and seven feet exist tetween tte footing and the face of cut slopes or fill slopes, respectively. Retaining walls in similar conditions should te individually revievi by SCS&T 9021022 March 20, 1990 Page 18 this office. If it is found to be unfeasible to cap the lots with nondetrinentally expansive soils as reconmended, special foundation and slab design will te necessary. This generally consists of deepened and more heavily reinforced footings and thicker and more heavily reinforced slate. Recotmendations for expansive soil conditions will te provided after site grading when the expansion index and depth of the prevailing foundation soil is known. REINPORCEMENr: Both exterior and interior continuous footings should te reinforced with at least one No. 4 bar positioned near the tettom of the footing and one No. 4 bar positioned near the top of the footing. This reinforcenent is based on soil characteristics and is not intended to te in lieu of reinforcement necessary to satisfy stmctural considerations. If expansive soils exist within four feet of finish grade, additional reinforcing will te necessary. INTERIOR CONCRETE ON-GRADE SLABS: If the pads are capped with nondetrinentally expansive soils, concrete on-grade slabs should have a thickness of foirc inches and te reinforced with at least No. 3 reinforcing bars placed at 36 inches on center each way. Slab reinforcement should te placed near the middle of the slab. As an altemative, the slab reinforcing may consist of 6"x6"-W1.4xW1.4 (6"x6"-10/10) welded wire mesh. However, it should te realized that it is difficult to maintain the proper position of wire mesh during placement of the concrete. A four-inch-thick layer of clean, coarse sand or cmshed rock should te placed under the slab. This layer should consist of material having 100 percent passing the one-half-inch screen; no more than ten percent passing sieve #100 and no more than five percent passing sieve #200. Where moisture-sensitive floor coverings are planned, the sand or rock should te overlain hy a visqueen noisture barrier and a two-inch-thick layer of sand or silty sand should te provided above the visqueen to allow proper concrete curing. EXTERIOR SLflBS-CN-<3»DE: For nonexpansive soil conditions, exterior slabs should have a minimum thickness of fotir inches. Walks or slabs five feet in SCS&T 9021022 March 20, 1990 Page 19 width should te reinforced with 6"x6"-W1.4xW1.4 (6"x6"-10/10) welded wire nesh and provided with weakened plane joints. Any slabs tetveen five and ten feet should te provided with longitudinal '/^eakened plane joints at the center lines. Slabs exceeding ten feet in width should te provided with a weakened plane joint located three feet inside the exterior perineter as indicated on attached Plate Number 23. Both traverse and longitudinal weakened plane joints should te constmcted as detailed in Plate Nunter 23. Exterior slate adjacent to doors and geurage openings should te connected to the footings by dowels consisting of No. 3 reinforcing bars placed at 24-inch intervals extending 18 inches into the footing and the slab. SPECIAL LOTS GENERAL: Special lots are defined as lots underlain by fill with differential thickness in excess of ten feet. The following increased foundation reconmendations should te utilized for said lots. Footings should te reinforced with tvo No. 4 bars positioned near the tottom of tte footing and two Nb. 4 bars positioned near the top of the footing. Concrete on grade slabs should te reinforced with at least No. 3 reinforcing bars placed at 18 inches on center each way. Lots with fill differentials in excess of thirty feet should te evaluated on an individual basis. EXPANSIVE CHARACTERISTICS: Metavolcanic rock generally weathers to a clayey subsoil, and its presence within four feet of finish pad grade will require special site preparation and/or foundation consideration. SETTLEMENT CHARACTERISTICS: The anticipated total and/or differential settlements for the proposed stmctures may te considered to te within tolerable limits provided the recoitmendations presented in this report are folloved. It should te recognized that minor hairline cracks on concrete due to shrin3cage of constmction materials or redistribution of stresses are normal and nay te anticipated. SCS&T 9021022 March 20, 1990 Page 20 EAKffl REIAINING WALLS PASSIVE PRESSURE: The passive pressure for the prevailing soil conditions may te considered to te 450 pounds per square foot per foot of depth up to a maximum of 2000 psf. This pressure may te increased one-third for seismic loading. The coefficient of friction for concrete to soil may te assuned to te 0.35 for the resistance to lateral movement. Wten combining frictional and passive resistance, the fomer should te reduced by one-third. The upper 12 inches of exterior retaining wall footings should not te included in passive pressure calculations v*ten landscaping abuts the tottom of the wall. ACTIVE PRESSURE: The active soil pressvure for the design of unrestrained earth retaining stmctures with level backfills may be assumed to be equivalent to the pressirre of a fluid veighing 35 pounds per cubic foot. For 2:1 (horizontal to vertical) sloping backfills, 14 pcf should te added to the preceding values. These pressures do not consider any surcharge. If any are anticipated, this office should te contacted for the necessary increase in soil pressure. This value assumes a drained backfill condition. Waterproofing details should be provided by the project architect. A subdrain detail is provided on the attached Plate Nunter 24. BftCKFUL: All teckfill soils should te conpacted to at least 90% relative conpaction. Expansive or clayey soils should not te used for backfill material. The wall should not te teckfilled until the itasorury has reached an adequate strength. FPCTCSl OF SAFETY: The above values, with the exception of the allowable soil tearing pressure, do not include a factor of safety. ./^ropriate factors of safety should te incorporated into the design to prevent the walls from overtuming and sliding. SCS&T 9021022 March 20, 1990 Page 21 LIMITATICNS REVIEW, (SSERVAnCN AND TESTING The recomnendations presented in this report are contingent upon our review of final plans and specifications. Such plans and specifications should te made available to the geotechnical engineer and engineering geologist so that they nay review and verify their conpliance with this report and with Chapter 70 of the Uniform Building Code. It is recomtended that Southem Califomia Soil & Testing, Inc. te retained to provide continuous soil engineering services during the earthwork operations. This is to verify 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 constmction. UNXFORMZTY OF CCNDITIONS The reconnendations and opinions expressed in this report reflect our test estimate of the project requirements based on an evaluation of the subsurface soil conditions encountered at the subsurface exploration locations and on the assunption 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 nay te influenced by undisclosed or unforeseen variations in the soil conditions that may occur in the intemediate and unexplored areas. Any unusual conditions not covered in this report that nay te encountered during site development should te brought to the attention of the geotechnical engineer so that he nay nake modifications if necessary. CHANGE IN SCOPE This office should be advised of any changes in the project scope or proposed site grading so that we may determine if the recommendations contained terein are appropriate. This should te verified in writing or modified by a written addendum. SCS&T 9021022 March 20, 1990 Page 22 TIME LIMITATiaNS 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 te due to natural processes or the work of nan on this or adjacent properties. In addition, changes in the Standards-of-Practice and/or Govemnent Codes may occur. Due to such changes, the findings of this report may te invalidated wholly or in part by changes beyond our control. Tterefore, this report should not te relied upon after a period of two years without a review by us verifying the suitability of the conclusions and reconmendations. PRDFESSICNAL STANDARD In the perfomance of our professional services, we conply 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 nay vary from those encountered at the locations where our trenches, surveys, and explorations are nade, and that our data, interpretations, and reconmendations are tesed solely on the information obtained by us. We will be responsible for those data, interpretations, and recommendations, but shall not te 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 perfomed or to te performed by us, or by our proposal for consulting or other services, or tjy our fumishing of oral or written reports or findings. CLIENT'S RESPONSIBILITY It is the responsibility of The William Lyon Company, or their representatives to ensure that the infomation and recomrendations contained herein are brought to the attention of the stmctural engineer and architect SCS&T 9021022 March 20, 1990 Page 23 for the project and incorporated into the project's plans and specifications. It is further their responsibility to take the necessary measures to insure that the contractor and his suteontractors carry out such recomtendations during construction. FIELD EXPLORATIONS Three subsurface trench explorations vere nade at the locations indicated on the attached Plate Nunter 1 on Decenter 21, 1982 within the subject site (see Plates Numter 3 through 5). In addition, Plates Nunter 6 through 12 from the referenced report contain additional trench excavations of similar soils within the subject subdivision. These explorations consisted of trenches dug by the means of a iDackhoe. Four seismic traverses vere also perfomed July 29, 1983, and three on January 11, 1983. The field work was conducted under the observation of our engineering geology personnel. Tte results are shown on Plates Numter 13 through 15. In addition. Appendix A contains two additional si±>surface e^qjlorations vd.thin the subject site (ERr-6 and ERT-7), perfomed by Earth Research Associates, Inc., dated Febmary 18, 1981. 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, medium dense, dense or very dense. Tte consistency of silts or clays is given as either very soft, soft, nedium stiff, stiff, very stiff, or hard. LABORATORY TESTING Latoratory tests were perfomed in accordance with the generally accepted Anerican Society for Tfesting and Materials (ASTM) test methods or suggested procedures. A brief description of the tests perfomed is presented telow: SCS&T 9021022 March 20, 1990 Page 24 a) CLASSIFICATICN; Field classifications vjere verified in the latoratory by visual examination. The final soil classifications are in accordance with the Unified Soil Classification System. b) MDISTORE-ESIdTY: In-place noisture contents and dry densities were determined for representative soil sanples. This information was an aid to classification and permitted recognition of variations in naterial consistency vrith depth. Tte dry unit weight is determined in pounds per ci±)ic foot, arvd tte in-place moisture content is determined as a percentage of the soil's dry weight. The results are sunmarized in the trench logs. c) GRAIN SIZE DISTRIBUTION: The grain size distribution was determined for representative sanples of the native soils in accordance with ASTM D422. The results of these tests are presented on Plates Numter 16 and 17. d) COMPACTION TEST: The maximum dry density and optimum moisture content of typical soils vere determined in the latoratory in accordance with ASTM Standard Test D-1557-78, Method A. The results of these tests are presented on the attached Plate Nunter 18. e) EXPANSION TEST: The expansive potential of clayey soils was determined in accordance with the following test procedure and the results of these tests appear on Plate Nunter 18. Allow the trinmed, undisturbed or remolded sanple to air dry to a constant noisture content, at a temperature of 100 degrees F. Place the dried sanple in the consolidometer and allow to conpress under a load of 150 psf. Allow moisture to contact the sanple and neasure its expansion from an air dried to saturated condition. SCS&T 9021022 March 20, 1990 Page 25 f) DIRECT SHEAR TESTS: Direct shear tests were perforned to determine the failure envelope tesed on yield shear strength. The shear box was designed to accommodate a sample having a dianeter of 2.375 inches or 2.50 inches and a height of 1.0 inch. Sanples were tested at different vertical loads and a saturated noisture content. The shear stress was applied at a constant rate of strain of approximately 0.05 inches per ndnute. Tte average shear strength values for granitic and netavolcanic rock are presented on attached Plate Numter 19. SUBSURFACE EXPLORATION LEGEND UNIFIED SOIL CLASSIFICATION CHART SOIL DESCRIPTION GROUP SYMBOL ^YP;:AL NAMES I. COARSE GRAINED, more than half of material is larger than No. 200 sieve size. GRAVELS CLEAN GRAVELS GW Well gradec gravels, gravel- More tnan half of sand mixtu-es, little or no coarse fraction is fines. larger than No. 4 GP Poorly graaed gravels, gravel sieve size but sand mixtures, little or no smaller than 3". fines. GRAVELS WITH FINES GM Silty gravels, poorly graded (Appreciable amount gravel-sand-siit mixtures. of fines) GC Clayey gravels, poorly graded gravel-sand, clay mixtures. SANOS CLEAN SANDS SW Well gradei sand, gravelly More than half of sands, ittle or no fines. coarse fraction is SP Poorly 9-3ce; sands, gravelly smaller than No. 4 sands, litiie or no fines. sieve size. SANDS WITH FINES SM Silty sands, poorly graded (Appreciaole amount sand and siity mixtures. of fines) SC Clayey sanas, poorly graaed sand jnd clay mixtures. II. FINE GRAINED, more than half of material is smaller than No. 200 sieve size. SILTS AND CLAYS ML Inorganic siits ond very fine sands, 'ock flour, sandy silt or cl J., ey-sil t-sand mixtures with slight plas- ticity. Liquid Limit CL Inorganic clays of low to less than 50 medium plasticity, gravelly clays, sandy clays, silty clays, lean clays. OL Organic silts and organic silty clays or low plasticity. SILTS AND CLAYS MH Inorganic sills, micaceous or diatomaceous fine sandy or silty soils, elastic silts. Liquid Limit CH Inorganic clays of high greater than 50 plasticiTy, fat clays. OH Organic clays of medium to high plasticity. HIGHLY ORGANIC SOILS PT Peat and other highly organic soils. US - Water level at time of excavation or as indicated Undisturbed, driven ring sample or tube sample CK — Undisturbed cliuni< sample BG — Bulk sample SP — Standard penetration sample yv SOUTHERN CALIFORNIA SOIL A TESTINQ, INC. CALAVERA HEIGHTS-VILLAGE "K" yv SOUTHERN CALIFORNIA SOIL A TESTINQ, INC. BY: KAR/EM DATE 2-28-90 yv SOUTHERN CALIFORNIA SOIL A TESTINQ, INC. JOB NUMBER: 9021022 Plate No. 2 p "RENCH MO. TK-11 C lass DescrlDtion 4 SM SM Red-yellow Brown, Moist, Medium Dense. Silty Sand (Topsoil/Slopewash) Dark Grey, Moist, Dense to Very Dense, Sandy Gravel (Metavolcanic Rock) Refusal at 3 Feet aaUTHSRN CALIFOnNIA CALAVERAS HEIGHTS-VILLAGE "K" BY CRB ^"^^ 12-21-82 JOB NO. 9021022 Plate No. 4 I [RENCH NO. TK-12 .()• Class Description ! SM I Red-brown, Moist, Mediuin Dense, :own. Moist, I Silty Sand (Topsoil) SM Gray-brown, Moist, Dense to Very Dense, Sandy Gravel (Granittc Rock) Refusal at 4 Feet • y\ BOUTHBRN CALIFORNIA 1 * TESTIIMQ, IIMC. CALAVERAS HEIGHTS-VILLAGE "K" BY CRB 12-21-82 JOB NO. 9021022 Plate No. 5 t i Class TRENCH NO. IP-13 Description Red-brown, Moist to Wet, Medium Dense, Clayey Silty Sand (Topsoil) Red/Brown/Gray, Wet, Medium Stiff, Sandy Clay (Weathered Decomposed Granite) Yellow-brown, Moist, Dense to Very Dense, Silty Gravely Sand (Decomposed Granite) Refusal ac 3 Feet yv SOUTHERN CALIFORNIA /15LJS BOIL & TEBTINQ , INC. ^^^^y^ •••a niVMOAi.B •TMIT MAN OiaaO, CALIiiOnNIA ••^•o - CALAVERAS HEIGHTS-VILLAGE "K" BY CRB QATE 12-15-82 JOB NO. 9021022 Plate No. 6 r Class TRENCH NO. TP-14 Description M Brown, Moist, Medium Dense, Clavev Silty Sand (Topsoil) Green-brown, Moist, Stiff, Silty Clav Yellow/Red/Brown, .Moist, Medium Dense, Silty Sand (Weathered Decomposed Granite) Yellov7-brown, Moist, Medium Dense to Dense, Silty Sand (Decomposed Granite) 121.9 12.1 Very Dense Trench Ended at 8 Feet yv SOUTHERN CALIFORNIA yg^ SOIL & TESTINO. INC. ^^^r aAN oiano, cAi.iranNiA ••IBO CALAVERAS HEIGHTS-VILLAGE "K" BY CRB 12-15-82 JOB NO. ~~ 9021022 Plate No. 7 Class 'i TRENCH NO. TP-15 Description SM/ SC SC/ CL SM Brown, Moist, Medium Dense, Clayev Siltv Sand(Topsoil) Red-brown, Moist, Medium Stiff, Sandy Clay (Weathered Decomposed Granite) Yellow-brown, Moist, Dense to Very Dense, Silty Sand (Decomposed Granite) Refusal at 4.5 Feet 129.1 7.3 yv SOUTHERN CALIFORNIA y^^X SOIL & TESTING, INC. ^^^r BAN oiaao, CALIPORNIA ••IBO CALAVERAS HEIGHTS-VILLAGE "K" BY CRB 12-15-82 JOB NO. 9021022 Plate No. 8 Class TRENCH XO. TP-16 Descrip tion y _yy1cL/ I SM/ SC SM Yellow-brown, Moist, Medium Dense, Clayey Siltv Sand (Topsoil) Green-brown, Mioist, Stiff, Silty Clay (Weathered Decomposed Granite) Yellow-brown, Moist, Dense to Very Dense, Silty Sand (Decomposed Granite) Refusal at 6 Feet 99.6 22.8 130. 7 7.9 yv SOUTHERN CALIFORNIA ySCjiS BOIL & TESTINQ , INC. ^^^y BAN OIBBO, CALIFaRNIA ••IBO CALAVERAS HEIGHTS-VILLAGE "K" ^ CRB 12-15-82 JOB NO. 9021022 Plati No. 9 lENCH NO. TP-20 Class Description 1 y 1^ SM/ I Red-broOT, Moist, Medium Dense, Clavev SC , Silty Sand (Topsoil) SM , Gray, Moist, Dense to Very dense, Sandy j Gravel (Metavolcanic Rock) Trench Ended at 5 Feet SOUTHBRN CALIFORNIA BOIL A TESTINQ, INC. CALAVERAS HEIGHTS-VILLAGE "K" BY CRB JOB NO. 9021022 12-21-82 Plate No. 10 TRENCH NO. TO-23 1? / I I 10 Class Descrip ti SM CL SM on Brown, Moisc, Medium Dense, Silty Sand (Topsoil) Gray-brown, .Moist, Stiff, Silty Clay (Weathered Decomposed Granite) Yellow-brown, Moist, Dense to Verv Dense, Silty Sand 'Sandy Silt (Decomposed Granite) Trench Ended at 10 Feet M 123.6 8.0 SOUTHERN CALIFORNIA SOIL & TESTINQ , INC. BAN OIBBO, CALIFORNIA BBIBO CALAVERAS HEIGHTS-VILLAGE "K" Plate No. 11 :RENCH NO. TT-4: Class Description ! SM ' nrown, Moisc, Medium Dense, Silty Sand ITopsoil) SM , Yellow-brown, Moist, Dense to Very Dense, . Silty Sand (Decomposed Granite) J I Trench Ended at 4 Feet BOUTHBRN CALIFORNIA BOH. A TESTINQ , INC. •MO mvanoALB BTRBBT •AM OiaaO, CALIIiONNIA BBIBO CALAVERAS HEIGHTS-VILLAGE "K" BY CRB JOB NO. 9021022 DATE 12-21-82 Plate No. 12 RIPPABILITY NDEX NO RIPPING SOFT MEDIUM HARD -r-T 1 1—. [—. 1 --r— r 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 VELOCITY, FT/SEC RESULTS TRAVERSE NO. 5EDPH. NOTE: THE ABOVE RESULTS ATTEMPT TO SHOW DEPTHS TO HORIZONS OF VARYING DENSITY IN DIFFERENT LOCATIONS OVER THE STUDf AREA. SEISMIC TRAVERSE NUMBERS REFER TO LOCATIONS PiDTED ON ATTACHED PLANS. THE*RIPPABIUTY INDEX'lS A MODIFICATION OF CHARTS BY THE CATERRLLAR CO. AND ARTICLE IN *ROADS AND STREETS; SEPT^ 1967. 1 SOUTHERN CAUFORNIA TESTING LABORATORY. INC. SMgttty 62aO RIVCROALE STREET 1 V SAN OICQO, CALIFORNIA 92120 1 714-2U-6134 CALAVERAS HEIGHTS-VILLAGE "K" 1 SEISMIC RESULTS DBA DATE 7.29-83 1 SEISMIC RESULTS JOB NO. qo21022 Plate No. 13 r RIPPABILITY NDEX NO RIPPING SOFT MEDIUM HARD TT / // BLASTING V / / PT / 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 VELOCITY, FT/SEC. RESULTS TRAVERSE NO. GEDPH* IT NOTE: THE ABOVE RESULTS ATTEMPT TO SHOW DEPTHS TO HORIZONS OF VARYING DENSITY INDIFFERENT LOCATIONS OVER THE STUDf AREA. SEISMIC TRAVERSE NUMBERS REFER TO LOCATIONS PIDTED ON ATTACHED PLANS. THE*RIPPABIUTY INDEX'lS A MODIFICATION OF CHARTS BY THE CATERPILLAR CO. AND ARTICLE IN *ROADS AND STREETS; SEPT, 1967. SOUTHERN CAUFORNIA TESTING ^^l^k UkBORATORY. INC. ^SSl^ 6280 RIVERDALE STREET MN OiEOa CAUFORNIA 92120 714-aU^134 CALAVERAS HEIGHTS_VILLAGE "K" SEISMIC RESULTS DBA 7-29-83 SEISMIC RESULTS JOB NO. 9021022 Plate No. 14 RIPPABILITY INDEX NO RIPPING SOFT MEDIUM HARD BLASTING T—'—I'j'—I—'l'l 0 IOOO 2000 3000 4000 5000 6000 7000 80C» 9000 10000 VELOCITY, FT/SEC. RESULTS TRAVERSE NO. GB3PH* NOTE: THE ABOVE RESULTS ATTEMPT TO SHOW DEPTHS TO HORIZONS OF VARYING DENSITY INDIFFERENT LOCATIONS OVER THE STUCV AREA. SEISMIC TRAVERSE NUMBERS REFER TO LOCATIONS PIDTED ON ATTACHED PLANS. THE*RIPRABIUTY INDEX'lS A MODIFICATION OF CHARTS BY THE CATERPILLAR CO. AND ARTICLE IN 'ROADS AND STREETS; SEPT, 1987. SOUTHERN CALIFORNIA SOIL & TESTINQ LAB, INC. *" BBBO (*IVBnDAI.B BTRBBT BAN OIBaO, CAI.iraRNIA BBIBO CALAVERAS HEIGHTS-VILLAGE "K" SEISMIC RESULTS DBA Ha 9021022 MTC 1-11-83 Plate No. 15 > (/) F5 m o in H CD C H O Z o (D 5 KO o ro I—» o ro ro a ro 3> i Q) ro I I KD O o Pi m s z .55 nz PO 00 cn I 3> Siandard Sieves Yi Vf "IO •20 "Mo t*60 Hydrometer (Minutes) 12 5 JO iao »« r « s 4 J 2 9« ; « S 4 ) 2 '80 UO eo (SO am ) 70 bO 1*. •»0t: S 20 — 10 OOl PARTICLE SIZE LIMITS 1 BOULDER!COBBLES 1 GRAVEL SANO SILT OR CLAY 1 BOULDER!COBBLES 1 Coorat Fint Coarsa Mtdlum Fint SILT OR CLAY (12 in.) 3jn. 3/4in. No.4 No.lO No.40 No.200 U.S. STANDARD SIEVE SIZE TK-10 @ 2' TP-14 (a 2'-3' > Z F5 m g (A H CO c H O z o o 5 o ro I—" o ro ro o ro 3> "O cu ri-tB OJ I H-• Ol i o 0 ft* m 9 Z i z a o 3> PD OO CD OO I Standard Sieves 2' )• KJ' *'0 "SO "MO t^o Hydromet er (Minutes) 2 » JO ISO 9« r « S 4 J 2 Grain Size (mmj i8o 60 70 i4|^,Mx,a.y 50*^ m 305 •«» 20 — '0 — OOl PARTICLE SIZE LIMITS 1 BOULDER!COBBLES 1 GRAVEL SANO SILT OR CLAY 1 BOULDER!COBBLES 1 Coorit 1 Fint Coorit Mtdlum Fint SILT OR CLAY (12 in.) 3 in. 3/4 in. No.4 No.K) No.40 li. S. STANDARD SIEVE SIZE •TP14 0 4'-5' •TP20 0 3'-4' MAXiyUM DENSITY & OPTIMUM MOISTURE CONTENT ASTM D1557-78 METHOD A SAMPLE DESCRIPTiON Maximum Density (pet) Optimum Moisture Cont (•/.) TP-13 0 2'-3' Yellow-Brown, Silty Gravelly Sand 114.8 13.8 TP-14 @ 2'-3' Green-Brown, Sandy Silty Clay 114.0 15.0 TP-14 @ 4'-5' Yellow/Red-Brown, Silty Sand 112.6 14.8 TP-20 g 3'-4' Grey, Silty Sandy Gravel 128.4 11.7 TQ-23 @ 8'-9' Yellow-Brown, Silty Sand/Sandy Silt 120.6 13.3 TT-47 ? 2'-3' Yellow-Brown, Silty Sand 122.7 12.0 EXPANSION INDEX TEST RESULTS SAMPLE TP-14@2'-5' TP-14@ 4'-5' TP-16@ 3' CONDITION Remolded Undisturbed Undisturbed 1 1 INITIAL M.C.C/.) 1 15^1 i 14^8 22.8 1 INITIAL DENSITY (PCFI 101.3 101.8 00.6 FINAL M.C. (•/.) 30.5 26.0 30.3 NORMAL STRESS (PSFJ 150 150 150 EXPANSION INDEX 15.0 8.3 14.0 SOUTHERN CALIFORNIA SOIL A TESTINQ, INC. CALAVERA HEIGHTS-VILLAGE "K" BY: DBA JOB NUMBER : 9021022 DATE: 3-16-90 Plate No. 18 SLOPE STABILITY CALCULATIONS Janbu's Simplified Slope Stability Method C WH Assume strength parameters throughout the slope 0 (°) C (psf) W, (pcf) Incl H (ft) FS Metavolanic & 35 Granitic Rock* Cut & Fill Slopes 200 125 2:1 50 1.8 Average shear strength values Where: 0- = Angle of Internal Friction C = Cohesion (psf) WJ = Unit weight of Soil (pcf) H = Height of Slope (ft) FS = Factor of Safety SOUTHERN CALIFORNIA SOIL A TESTING,INC. CALAVERA HILIS V sr: DBA JOB NUUBER 9021022 IIAfiF "K" DATE 1-10-84 Plate No. 19 u O a z c S a m KO o ro I—' o ro ro -o cu r+ ro ro o o ro oo Ol I KO o c-> PO 3a m I—I CTJ UJ I I CD m OvrR«;i2E RQCK_D1SP.QSAL (Slruclurul Soil" RocK Fill) P/L ^dj^ ZONE B 5' min ZONE A ZONE C '"^f • • f J 3 min-1 ZONE D 1 J 3 min-1 ZONE D 1 min. 1 NOTES 1. Coap4Ct*4 10(1 fill IMII CMttlR It liiit 40 ptrctnt toll tint plttlni 3/4>liiCli tllM, (by •tlghl). tnd b« coNp«ct«t U •ccertfMca ultJi tptclfUttleni for ttructurti rill. 2. lock! o««r 4 fitt In Milaia dltMilon not ptraltttd In nil. Inches In gretleii UGtNO IONC A: CoapMled toll fill. No rock frtgiiicntt over t diHWiiilon. lUNt I: florkt 7 to 4 feet In ajiilmua (ttMflilon placed In cumptcled toll rill conroralng to IONC A. IONC C: Ro'kt ( ln(ti*i lo 2 reel In luilaun diaendon unlforaly dlttrlbu- • ed jnd M*II iptccd In coKptctcd toll nil cenforalnf lo IONC «. IONC 0: Nequired ror tll caltling slopes i:l tnd tteeper, 90X nlnlmn (oaptctlon. ZOMC A. B. or C attcrltl Mty b« uted ror ZONC 0. NATURAL QROUND CANYON SUBDRAIN DETAIL BENCHING REMOVE UNSUITABLE MATERIAL SUBDRAIN TRENCH: SEE DETAIL A ft B DETAIL A FILTER MATERIAL '6 CUBIC FEET/FOOT FILTER MATERIAL SHALL BE CLASS 2 PERMEABLE MATERIAL PER STATE OF CALIFORNIA STANDARD SPECIFICATIONS, AND APPROVED ALTERNATE. CLASS 2 FILTER MATERIAL SHOULO COMPLY WITH THE FOLLOWINQ LIMITS DETAIL A-1 PERFORATED PIPE 4 0 MINIMUM PERFORATED PIPE SURROUNDED WITH FILTER MATERIAL SIEVE SIZE 1 3/4 3/8 No. 4 No. 8 No. 30 No. 50 No. 200 % PASSING 100 90-100 40-100 2 S-40 18-33 5-1S 0-7 0-3 DETAIL B DETAIL B-1 «'MIN OVERLAP FILTER FABRIC (MIRAFI 140 OR APPROVED EQUIVALENT) 1 1/2"MAX QRAVEL OR APPROVED EQUIVALENT 6 CUBIC FEET/FOOT DETAIL B-2 1 1/2"QRAVEL WRAPPED IN FILTER FABRIC DETAIL OF CANYON SUBDRAIN TERMINAL DESIQN FINISH QRADE NON PERFORATED 4'MIN PERFORATED 4'MIN PIPE SUBDRAIN INSTALLATION'-SUBDRAIN PIPE SHALL BE INSTALLED WITH PERFORATIONS DOWN SUBDRAIN PIPE'-SUBDRAIN PIPE SHALL BE PVC OR ABS. TYPE SDR 35 FOR FILLS UP TO 35 FEET DEEP, OR, TYPE SDR 21 FOR FILLS UP TO 100 FEET DEEP SOUTHERN CALIFORNIA SOIL A TESTING.INC. CALAVERAS HEIGHTS-VILLAGE "K" SOUTHERN CALIFORNIA SOIL A TESTING.INC. BY: DBA DATE: 3-16-90 SOUTHERN CALIFORNIA SOIL A TESTING.INC. JOB NUMBER: 9021022 Plate No. 21 I i i i ! WCAKENeO PLANE JQNTS TRANSVERSE WEAKENED PLANE JOINTS 0' ON CENTER (MAXIMUM) W/2 W/2 3* 10* \ 1 5'--0' SLABS IN EXCESS OF 10 FEET IN WIDTH SLABS' 6 TO 10 FEET IN WIDTH PLAN NO SCALE n TOOLED JOINT r/2 (S'xS'-IO/IO) WELDED WIRE MESH \ ^ \ WEAKENED PLANE JOINT DETAIL NO SCALE SOUTHERN CALIFORNIA son. 1 TESTINQ, INC. CALAVERAS HEIGHTS-VILLAGE "K" BYt -DBA DATli-.3-16-90 JOB NUMBOIt 9021022 Plate No. 22 WATERPROOF BACK OF WALL PER ARCHITECTS SPECIFICATIONS /4 INCH CRUSHED ROCK OR MARIDRAIN 9000 OR EQUIVALENT QEOFABRIC BETWEEN ROCK AND SOIL 4" DIAMETER PERFORATED PIPE HOUSE ON QRADE SLAB NOUSE RETAINING WALL SUBDRAIN DETAIL NO SCALE yv SOUTHERN CALIFORNiA ^^f^ SOIL A TESTINQ, INC. CALAVERA HEIGHTS-VILLAGE "K" yv SOUTHERN CALIFORNiA ^^f^ SOIL A TESTINQ, INC. BY: DBA DATE: 3-16-90 yv SOUTHERN CALIFORNiA ^^f^ SOIL A TESTINQ, INC. JOB NUMBER: 9021022 Plate No. 23 DSL CATERPILLAR PERFORMANCE HANDBOOK Edition 17 October 1986 Seismic Velocity Pool Par f oond i MOO 10 11 12 13 14. 15 TOPSOIL CLAY IQNEOUS ROCKS CSRANITE BASALT SEDIMENTARY ROCKS 3HALE SANDSTONE SILTSTONE CLAYSTONE CONOLOMERATE METAMORPHIC ROCKS SCHIST SLATE A / f ./ r ' V , \/ I A / •< V YL rz A -r-r P r- RIPPABLE MAROINAL L NON-HIPPABLE L DBL Ripper Performance • Multi or Single Shanit No. 8 Ripper • Estimated by Seismic Wave Velocities SOUTHERN CALIFORNIA SOIL & TESTING, INC. CALAVERA HEIGHTS-VILLAGE "K" BY: DBA DATE: 3-16-90 JOB NUMBER: 9021022 Plate No. 24, DSL CATERPILLAR PERFORMANCE HANDBOOK Edition 17 October 1986 Seismic Velocity Poat Par SaooiM i lOOO D9L Ripper Performance • Multi or Single Shank No. 9 Ripper • Estimated by Seismic Wave Velocities /^>v^SOUTHERN CALIFORNIA SOIL & TESTING, INC. CALAVERAS HEIGHTS-VILLAfiF "K" BY: DBA JOB NUMBER: 9021022 DATE: 3-16-90 Plate No. 25 Dl 1N CATERPILLAR PERFORMANCE HANDBOOK Edition 17 October 1986 Seismic Velocity Foal Par aaaaaa i IOOO 2 3 4 5 6 7 3 9 10 11 12 13 14 15 i I i TOPSOIL CLAY IGNEOUS ROCKS GRANITE BASALT SEDIMENTARY ROCKS 3HALE SANDSTONE SLTSTONE CLAYSTONE CONOLOMERATE METAMORPHIC ROCKS SCHIST SLATE X///A//A//y/7Y77 yV/A//A//X/77Y7 U/X//X//. \xxxxxx,xx IZZ. zzzzz. VAXXAXX T2zzizzzzzzzz ZZZA \//kxxxxx)(// RIPPABLE MAROMAL NON-RIPPABLE Dl 1 N Ripper Performance • Multi or Single Shanl< No. 9 Ripper • Estimated by Seismic Wave Velocities SOUTHERN CALIFORNIA SOIL Sw TESTING, INC. CALAVERAS HEIGHTS-VILLAGE "K' BY: DBA JOB NUMBER: 9021022 DATE: 3-16-90 Plate No. 26 APPENDIX A SOUTHERN CALIFORNIA SOIL & TESTING, INC. TABLE : J-N- 115-81 2/18/81 LOG OF TEST TRENCHES Test Trench Mu.Tber Depth (ft.) Description TT-1 0.0 - 4.0+ SANDSTONE: Light-brown to white; fine-grained; massive; damp and dense; easily ripped and excavated. TT-2 0.0 - 1.0 CLAYEY SANO: Red-brown; sand fine to coarse; damp and loose; (SC) Soil. 1.0 - 5.0+ GRANITIC ROCK: Light-brown; medium to coarse- grained; moderately to highly fractured; rips with little difficulty; breaks up into cobble size rocks and smaller; sufficient fines. TT-3 0.0 - 7.0+ GRANITIC ROCK: Light-brown; medium to coarse- grained; moderately to highly fractured; rips with little to moderate difficulty; breaks up v/ell except for 5-10% boulders to 48" diameter. TT-4 0.0 - 6.0+ GRANITIC ROCK: Light-brown; medium to-coarse- grained; moderately to highly fractured; rips with little to moderate difficulty; becomes difficult to rip and excavate below 6.0 feet owing to large resistant boulders. TT-S 0.0 - 2.0 CLAYEY SAND: Red-brown; sand fine; damp and loose to medium dense; (SC) Soil. 2.0 - 7.0+ GRANITIC ROCK: Brown to gray; medium to coarse- grained; highly fractured; rips and excavates easily, breaks up into cobble size and smaller; becomes more difficult to rip and excavate . below 5.0 feet. TT-5 0.0 - 1.0 CLAYEY SAND: Red-brown; sand fine to medium with cobbles and boulders; damp and loose; (SC) Soil. 1.0 - 6.0+ GRANITIC BEDROCK: Light-brown; fine to medium- grained; moderately to highly fractured; rips with little to moderate difficulty; breaks up well except for 5-10% boulders to 36" diameter. TT-7 0.0 - 2.0 CLAYEY SAND: Brown; sand fine to medium with cobbles and occasional boulders; numerous roots; damp and loose; (SC) Soil. TABLE V - LOG OF TEST TREflCHES (Continued) Test Trench flu-be r TT-7- cont'd TT-8 TT-g TT-10 TT-n TT-12 2/19/81 TT-13 Depth (ft.) 2.0 - 10.0+ 0.0 - 2.0 0.0 - 1.0 1.0 - 2.0 0.0 - 1.0 1.0 - 2.5 0.0 - 1.5 1.5 - 3.0 0.0 - 2.0 2.0 - 6.0+ 0.0 - 1.0 1.0 - 5.0+ Descriotion GRANITIC ROCKi Brown to gray; fine to coarse- grained; highly fractured; rips and excavates with little to moderate difficulty; breaks up into cobble size or smaller; sufficient fines. GRANITIC BEDROCK: Light-brown to gray; fine to coarse-grained; moderately fractured; very hard, very difficult to rip; large boulders. CLAYEY SANO: Red-brown; sand fine to medium with cobbles and boulders; (SC) Soil. GRANITIC ROCK: Light-brown to gray; fine to medium-grained; moderately fractured; very hard; difficult to rip and excavate. CLAYEY SAND: Brown; sand fine- to medium with cobbles and boulders; (SC) Soil. GRANITIC ROCK: Light-gray to light-brown; moderately fractured; very difficult to rip and excavate; considerable rock generated. CLAYEY SAND: Brown; sand fine to medium with cobbles and boulders; (SC) Soil. GRANITIC ROCK: Light-gray to light-brown; moderately fractured; very difficult to rip and excavate; considerable rock generated. CLAYEY SAND: Red-brown; sand fine to medium; damp and loose; (SC) Soil. GRANITIC ROCK: Light-brown to gray; medium to coarse-grained; moderately fractured and weathered; rips with little to moderate difficulty. CLAYEY SAND: Red-brown; sand fine to medium; deep and loose; (SC) Soil. GRANITIC BEDROCK: Light-browh; moderately weathered and fractured; rips and excavates with moderate difficulty owing to unweathered. areas. APPENDIX B SOUTHERN CALIFORNIA SOIL SL TESTING, INC. CALAVERA HEIOirS, VILLfiGE K, CARLSBAD RBOQMMENCED O^ING SPBCIFICKTICNS - (2NERAL PROVISICWS GQ4E3UVL INIENT The intent of these specifications is to establish procedures for clearing, conpacting natural ground, preparing areas to be filled, and placing and conpacting fill soils to the lines and grades shown on the accepted plans. The recomtEndations contained in the preliminary geotechnical 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 geotechnical report for which they are a part. No deviation from these specifications will be allowed, except where specified in the geotechnical report or in other written communication signed by the Geotechnical Engineer. OBSERVKTICN AMD TESTING Southern California Soil and Testing, Inc., shall be retained as the Geotechnical Engineer to observe and test the earthwork in accordance with these specifications. It will be necessary that the Geotechnical Engineer or his representative provide adequate observation so that he may provide his opinion as to vAiether or not the vork was acconplished as specified. It shall be the responsibility of the contractor to assist the Geotechnical Engineer and to keep him appraised of work schedules, changes and new information and data so that he may provide these opinions. In the event that any unusual conditions not covered by the special provisions or preliminary geotechnical report are encountered during the grading operations, the Geotechnical Engineer shall be contacted for further recCTtnendations. (R-9/89) SCS&T 9021022 March 19, 1990 Appendix, Page 2 If, in the opinion of the Geotechnical Engineer, substandard conditions are encountered, such as questionable or unsuitable soil, unacceptable noisture content, inadequate compaction, adverse weather, etc.; construction should be stopped until the conditions are remedied or corrected or he shall reconmend rejection of this work. Tests used to determine the degree of compaction should be performed in accordance with the following American Society for Testing and Materials test nethods: MaxijiTum Density & Optimum Moisture Content - ASTM D-1557-78. Density of Soil In-Place - ASTM D-1556-64 or ASTM D-2922. All densities ^all be expressed in terms of Relative Compaction as determined by the foregoing ASTM testing procedures. PREPARATICN OF AREAS TO RECEIVE FILL All vegetation, brush and debris derived from clearing operations shall be renoved, 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, the areas to be filled shall be scarified to a depth of 6 inches, brought to the proper moisture content, conpacted and tested for the specified minimum degree of conpaction. All loose soils in excess of 6 inches thick should be removed to firm natural ground v«*iich is defined as natural soils v^iich possesses an in-situ density of at least 90% of its maximum dry density. (R-9/89; SCS&T 9021022 T^ch 19, 1990 Appendix, Page 3 When the slope of the natural ground 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 formational soils. The lower bench shall be at least 10 feet wide or 1-1/2 times the the equipnent width vvMchever 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 conpacted prior to receiving fill as specified herein for conpacted natural ground. Ground slopes flatter than 20% shall be benched when considered necessary by the Geotechnical Engineer. Any abandoned buried structures encountered during grading operations nust be totally renoved. All underground utilities to be abandoned beneath any proposed structure should be renoved 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 conpacted to the requirenents of the Geotechnical Engineer. This includes, but is not limited to, septic tanks, fuel tanks, sewer lines or leach lines, storm drains and water lines. Any buried structures or utilities not to be abandoned should be brought to the attention of the Geotechnical Engineer so that he may determine if any special reconmendation will be necessary. All water wells v^ch will be abandoned should be backfilled and capped in accordance to the requirements set forth by the Geotechnical Engineer. The top of the cap should be at least 4 feet below finish grade or 3 feet below the bottom of footing v^chever is greater. The type of cap will depend on the diameter of the well and should be determined by the Geotechnical Engineer and/or a qualified Structural Engineer. (R-9/89) SCS&T 9021022 March 19, 1990 Appendix, Page 4 FILL MATERIAL Materials to be placed in the fill shall be approved by the Geotechnical Engineer and shall be free of vegetable matter and other deleterious substances. Granular soil shall contain sufficient fine material to fill the voids. The definition and disposition of oversized rocks and expansive or detrinental 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 Geotechnical Engineer. Any import material shall be approved by the Geotechnical Engineer before being brought to the site. PLBCING AND OCWPACTICN OF FILL Approved fill material shall be placed in areas prepared to receive fill in layers not to exceed 6 inches in conpacted thickness. Each layer shall have a uniform noisture content in the range that will allow the conpaction effort to be efficiently applied to achieve the specified degree of compaction. Each layer shall be uniformly compacted to the specified minimum degree of compaction with equipment of adequate size to economically conpact the layer. Conpaction equipment should either be specifically designed for soil conpaction or of proven reliability. The minimum degree of conpaction to be achieved is specified in either the Special Provisions or the reconmendations contained in the preliminary geotechnical investigation report. When the structural fill material includes rocks, no rocks will be allov^ to nest and all voids must be carefully filled with soil such that the minimum degree of compaction recommended in the Special Provisions is achieved. The maximum size and spacing of rock permitted in structural fills and in non-structural fills is discussed in the geotechnical report, v^en ajplicable. (R-9/89) ;^ndix, page 5 March 19, 1990 SCS&T 9021022 ^ compaction laver shall be ^^t.on has b«n the aes^ - ^^^^ ^ by neans of sneep vertical v,=n be conpactea uy ^ners shall be au 3,,^le tour teet. n ^ „^^lled. intervals of ^ „^ vertical or i^^^"-^^. ^„ j^nish contours ratio o£ t« , over-milt and cut-bacK t ^^^^ Steeper UU slo^^ Slo^ =^-- ,^3h^ face - trrr^rrial Si. or »re ihch^ .n^J^^^ dry result in all £rll co^ctron of at 1 pr^isxons °' * '""Ili " co^^^™ l^he slo^s s>.ll Z s^icaticn. t - opinio that the the Geotec^cai Bn,i.eer .s ,,o^s will be stabx technical Engineer durin, contractor '^^ Qeoteot^cal Wmeer or h.s ,,^cation from ^'^ for. of a daily t-^<^ ^ ^^^^ ^ , achieving the ^"f contractor shall contractor fails t v ^ required deqr=- ^rK or remild such s^o^^ ^^^^ ,„,^eer. obtair^d, at no cost to the (R-9/89) SCS&T 9021022 March 19, 1990 ^^pendix, Page 6 COT SLOPES 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 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 are necessary. Unless otherwise specified in the geotechnical report, no cut slopes shall be excavated higher or steeper than that alloved by the ordinances of the controlling govemnental agency. ENGINEERIMG GBSERVKnON Field observation by the Geotechnical Engineer or his representative shall be made during the filling and conpacting operations so that he can express his opinion regarding the conformance of the grading with acceptable standards of practice. Neither the presence of the Geotechnical 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 conpaction. SEASON Lmns 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. Damged site conditions resulting from veather or acts of God shall be repaired before acceptance of work. (R-9/89] SCS&T 9021022 March 19, 1990 Appendix, Page 7 RBOCMMENDED GRADING SPBCIFIOOTiONS - SPECIAL PROVISICWS RELfiTTVE GCMPACTION: The minimum degree of conpaction to be obtained in conpacted natural ground, conpacted fill, and compacted backfill shall be at least 90 percent. For street and parking lot subgrade, the upper six inches should be conpacted to at least 95% relative conpaction. EXEAieiVE SOILS: Detrinentally e.^nsive soil is defined as clayey soil which has an expansion index of 50 or greater v*ien tested in accordance with the Uniform Building Code Standard 29-C. OVERSIZED MKEERIAL: Oversized fill material is generally defined herein as rocks or lumps of soil over 6 inches in diameter. Oversize materials should not be placed in fill unless reconmendations of placement of such material is provided by the geotechnical engineer. At least 40 percent of the fill soils shall pass through a No. 4 U.S. Standard Sieve. TRANBrnCW LOTS: 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 reconpacted as structural backfill. In certain cases that would be addressed in the geotechnical report, special footing reinforcenent or a combination of special footing reinforcenent and undercutting may be required. (R-9/89]