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HomeMy WebLinkAboutCT 00-02; CALAVERA HEIGHTS VILLAGE K; INTERIM REPORT OF GEOTECHNICAL INV; 1990-03-20I • p ^ I I I I lOTERIM REPCKP OF GEOTECHNICAL INVESnGRTIGN CACAVER^ HEICSirS PREPARED FOR: 1)16 William Lyon Gcnpanjr 4330 La Jolla Village Drive, Suite 130 San Diego, Califomia 92122 PREPARED BY: Southern CcLLifornia Soil & Ttesting, Inc. Post Office Box 20627 6280 Riverdale Street San Diego, Califomia 92120 SOUTHERN CALIFORNIA SO.L AND TESTING, .NC S2B0mV«0ALEST.SAN0,EGa.CAL.r.92,2n . TEL. 280-432, • P.O. BOX 20627 SAN OlEGO. CAUr. 92,20 r/ " x. e .SCO. o.OO. c..,. ..o.s - X... , March 20, 1990 The William Lyon Cortpany 4330 La Jolla Village Drive Suite 130 San Diego, Califomia 92122 ATTENriON: Mr, George Haviar SCS&T 9021022 Report No. 1 SUBJECT: Interim Geotechnical Investigation, Calavera Heights. Village K, Carlsbad, Califomia. li Gentlemen: in accordance with your request, we have conpleted an interim geotechnical investigation for the subject project. We are presenting herewith our findings and reconmendations. In general, we found the site suitable for the proposed development provided the recomrendations 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. sutmitted. DBA:JRH:KAR:itw cc: (2) Submitted //i^ (4) Hunsalcer and Associates (1) SCS&T, Escondido SOUTHERN CALIFORNIA INC I I I I I I r I I p i I I I I I I TPJ3LE OF COMilSMiS Pi^ Introduction and Project Description ^ . 2 Project Scope Findings Site Description General Geology and Subsurface Conditions 3 Geologic Setting and Soil Description 3 Tectonic Setting ^ Geologic Hazards ^ GroundshaJcing ^ Seismic Survey and Rippability Characteristics 8 General ^ Rippability Characteristic of Granodioritic RocJc 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 Characteristics of Metavolcanics and Associated Hypabyssal Rocks and Tonalitic Rocks H 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 Groundwater Conclusions and ReccDnmendations General 14 Grading 14 Site Preparation Select Grading Cut/Fill Transition •^-^ Inported Fill Rij^>ability Oversized Roclc Slope Construction Surface Drainage Subdrains EarthworJc Slope Stability Foundations 17 General 18 Reinforcement Interior Concrete Slabs-on-Grade ^8 Exterior Concrete Slabs-on-<i:ade 19 Special Lots General IQ Expansive Cliaracteristics -^^ Settlement caiaracteristics TABLE OF COMTEtnS (continued) PPGE i I Earth Retaining Walls Passive Pressure Active Pressure Backfill Factor of Safety Limitations Review, Observation and Testing Uniformity of Conditions Change in Scope Time Limitations Professional Standard Client's Responsibility Field Explorations Laboratory Testing TflTBCHMrafPS TAHLJES Table I Generalized Engineering Characteristics of Geologic Units, Page 6 Table II The Maximum Bedrock Accelerations, Page 7 Table III Seismic Traverse Sunmary, Pages 8 and 9 FIGURE Figure 1 Site Vicinity Map, Follows Page 1 PLflaCES 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 E:q>ansion Test Results Plate 19 Direct Shear Sunmary Plate 20 Oversize Rock Disposal Plate 21 Clanyon Subdrain Detail Plate 22 Weakened Plane Joint Detail Plate 23 Retaining Wall Subdrain Detail Plates 24-26 Catepillar Rippability Charts AFPEIDICES A - Logs from Previous Investigation B - Reconrnended Grading Specification and Special Provisions .20 .20 .20 .20 .20 .21 .21 .21 .21 .22 .22 .22 .23 .23 I I I I I I I I f I I I I I I I SOUTHERN CALIFORNIA SOIL AND TESTING, INC. 6280 RIVERDALE ST. SAN DIEQO. CALIF. 92,20 • TELE 280-432, • P.O. BOX 20627 SAN OIEGO. CALIF. 92120 6-78 ENTERPRISE ST. ESCDNDIOQ. CALIF. 92DZ5 • TELE -J A. 6 • A S A * INTERIM REPORT OF OTOTBCHNICAL IMVESTIGKnCN CALAVERA HEICTTS CARLSBAD, CALIFORNIA nWRDDUCTION AND PROJECT DESCRIPTICN This report presents the results of our interim report 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 Nuntoer 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 v^ood 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 are also anticipated. It) 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 CALIFDRNIA SOIL AND TESTING, INC I ' -..4^ • , •^'•»''*0*ti; SITE ''•ARLSBAD f CMt*MM 't «M MMM » VM TUt#*k tl M* PtkCAOO •'.;^5»">'i- yv SOUTNBRN CALIPORNIA SOIL A TUTINajNC. •T: CALAVERA HEIGHTS-VILLAGE "K" KAR/EM 40B WUMim: 9021022 DATI: 2-2S-00 FIGURE #1 I I SCS&T 9021022 I^ch 20, 1990 Page 2 PROJECT 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 fiirther 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 v^ich will influence the development of the proposed subject site. Further laboratory 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 vAiich could have an effect on the site development. d) Develop soil engineering criteria for site grading and provicie reconmendations regarding the stability of proposed cut and fill slopes. e) Address potential construction difficulties and provide reconmendations conceming these problems. f) Reconmend an appropriate foundation system for the type of structures anticipated and develop soil engineering design criteria for the recommended foundation design. SCS&T 9021022 March 20, 1990 Page 3 P FINDINGS SITE DESCRIPnCH The subject site, designated as Village K in the Calavera Heights developnent, is an irregular shaped portion of land located in Carlsbad, Califomia. The site covers afproximately 40 acres and is bounded on the north and east by undeveloped land, on the south by undeveloped land and a conmunity 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. Topographically, the site is conprised of hilly terrain with well develcsped drainage swales. Elevation differentials range to approximately 180 feet frx3m the westem portion to the central portion of the site. Drainage is acconplished via sheetflow and the aforenentioned drainage swales. The major drainage swales on site drain in easterly and westerly (directions from the higher central portion of the subject site. Vegetation is conprised of a moderate to heavy growth of chaparral, shrubs and grasses. Nd structures were noted on the site, however siibsurface utility mains appear to exist on the southerly portion of the site and along the easements for the existing paved streets. (3HERAL GEOUXSI AND SUBSURFACE COMDITIONS (XauOGIC SEETINS AND SOIL CESCRIPnCN: 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 londerlain by materials of igneous origin and surficial residuum. The site is underlain by the basement complex rocks consisting of Jurassic-age metavolcanic rocks and Cretaceous-age granitic rocks, Quatemary-age alluvium and artificial fill. A brief description of the materials on-site, in general decreasing order of age, is presented below. I I I I I I f I I p SCS&T 9021022 Ilarch 20, 1990 Page 4 1) BASEMENT CCMPLEX - JURASSIC METAVOLCANICS AT© CRETTACBCIUS O^ITICS {Jmr/Kgr): 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 sane 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-ntjving equipment to depths of only a few feet. The other rocl<s in the basement conplex are the granitic rocks of the Cretaceous Southem Califomia Batholith v^iich have intruded the older rocks and are, to a large degree, mixed with them. The granitic rocks at the project site appear to be both tonalitic and granodioritic in ccmposition. The tonalitic rocks are usually (dark ^ gray, fine to medium grained rocks whereas the granodioritic rocks are usually yellowish brown to grayish brown, medium to coarse grained rocks. The weathering and rippability characteristics of the tonalitic nxrlcs appear to be somewhat similar to those of the metavolcanic/hypabyssal rocks. The tonalitic roc)<s may be rippable to greater depths than the metavolcanic roc3cs 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 cjuality "decomposed granite". In contrast to the weathering cheoracteristics 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 granixlioritic rocks are variable in their excavation characteristics but conmonly contain areas v^iich are rippable to I I I I I I r I I p SCS&T 9021022 I^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 acconpanying geologic map. It should be noted that since the different mck types are mixed the areas on the map v^re given a dual classification. The boundaries between the rock types are very irregular, therefore they vere not differentiated on Plate Nunter 1. 2) YOUNGER QUMERNARy (HOLDCENE) ALLUVIUM (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 subsoils should be anticipated overlying the entire site. These deposits consist of varying mixtures of silts, semds and clays. It is estimated that these deposits do not exceed five feet in combined thickness. 4) ARnFICIM. FTUJ (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 asscxriated 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 development of these areas. I I I I I I r I I p SCS&T 9021022 March 20, 1990 Page 6 Table I presents some of the pertinent engineering characteristics of the materials at the site. TABLE I (3NERALIZED ENGINEERING CHARACTERISTICS OF MAIN GEOLOGIC UNITS Unit Name and Symbol Rippability Anount of Oversize Material Slope Stability/ Erosion Conpressibility Expansive Potential Granitic Rocks- Kgr (Granodiorite) Generally Rippable to + 15 Feet Low to Moderate Good Ntaninal Nominal Granitic Rocks- Kgr (Tonalite) Marginally Rippable to Nonrippable Moderate to High Good Ncminal Nominal Metavolccinic and Hypabyssal Rocks-Jmv Marginally Rippable to Nonrippable Moderate to High Good Nominal Nominal TOBCKWIC SEmSGi A few snell, apparently inactive faults have been mapped previously within the vicinity of the site. No evidence of faulting was noted in our 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 gecmetry, these small faults should be only of minor consecjuence to the project. It should also be noted that several prominent fractures and joints which are probably related, at least in piart, 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 northwesterly (direction (subparallel to the regional structural trend) and in a general northeasterly (direction (subperpendicular 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. I I I I I I r I I p SCS&T 9021022 March 20, 1990 Page 7 In addition, it should be recotjnized that much of .Southern Califomia, is ageracterized by major, 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 viest of the site. The Rose Canyon Fault Zone comprises 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. GEOLOGIC HAZARDS: The site is lcx:ated in an area v*iich is relatively free of potential geologic hazards. Hazards such as tsunamis, seiches, liquefaction, and lancdsliding should be considered negligible or nonexistent. (3C0NDSHAKING: One of the most 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 would be attributed to a maximum probable earthquake occnirring along the nearest portion of selected fault zones that could affect the site are sunmarized in the following Table II. TABL£ II Fault Zone Distance Maxinum Probable Eeuithquake Bedrock Design Acceleration Acceleration Rose Canyon Elsinore Coronacdo Banks San Jacinto 8 miles 20 miles 24 miles 43 miles 6.5 nagnitude 7.3 nagnitude 7.0 nagnitude 7.8 nagnitude 0.36 g 0.25 g 0.18 g 0.14 g 0.23 g 0.17 g 0.12 g 0.10 g I I I I I I r I I B i I 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 heis shown that structures that are constructed in accordance with the Uniform Building Ccxde are fairly resistant to seismic related hazards. It is, therefore, our opinion that structiural 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 GEINERAL: The results of our seismic survey and e.xploratory trenches perfomied for the referenced repxorts indicate that blasting ma^te re(5uired to obtain proposed cuts. In addition, isolated boulders are anticipated within cut areas that may recjuire sp)ecial handling during grading operations. A summary of each seismic tra-verse is presented in Table III bel(3w, and Plates Number 13 through 15. Our interpretation is based on the rippability cheuracteristics of granitic and netavolcanic rock as described in Pages 10 through 12. TAB[£ III Seismic Tcaverse No. Sk-3 Proposed Cut: 10 Feet Geologic Unit: Granitic Rock (Tonalite) Interpretation: 0'-16' Rippable +16' Nonrippable Seismic Traverse No. Sk-4 *- Proposed Cut: 5 Feet Geologic Unit: Metavolcanic and Associated Hypabyssal Rock Interpretation: 0'- 5' Rippable with isolated boulders 5'- 9' Marginally Rippable + 9' Nonrippable I I I I I I f I I p SCS&T 9021022 March 20, 1990 TABLE III (continued) Seismic Ttaverse No. Sk-5 Proposed Cut: 8 Feet Geologic Unit: Granitic Rock (Tonalite) Interpretation: 0'- 8' Rippable + 8' Marginally to Nonrippable V Seismic Traverse No. Sk-32 Proposed Cut: 13 Feet Geologic Unit: Metavolcanic and Asscxriated Hyp)abyssal Rock Interpretation: 0'- 4' Rippable + 4' Nonrippable Seismic Traverse No. SJc-33 " Page 9 Proposed Cut: Geologic Unit: Interpretation: 7 Feet Granitic Rock 0'- 5' Rippable 5'-11' Mcurginally Rippable +11' Nonrippable Seiamic TtHvecse No. Sp-30 Proposed Cut: Geologic Unit: Interpretation: 17 Feet Metavolcanic and Associated Hypabyssal Rock 0'- 5' Rippable + 5' Nonrippable Seismic Traverse No. Sp-31 C Proposed Cut: 20 Feet Geologic Unit: Metavolcanic and Asscx:iated Hypabyssal Rock Interpretation: 0'- 3' Marginally Rippable + 9' Nonrippable In general, our seismic survey indicated that areas underlain by granitic rock present rippable naterial to depths ranging from approxinately five I I I I I I I I p 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 materials 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 between granitic and metavolcanic 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 I overlying soils and rippable rock is suggested. This procedure often helps to generate more fine material and to facilitate the mixing of soil and rock to be used as fill. i RIPPABILITY CHARACTERISTIC QF OWNODIORITIC ROCK RIFPABS^ aWDmON (0-4,500 FT./SEC.): This velocity range indicates rippable materials which may consist of decomposed granitic rock possessing randcm hardrock floaters. These materials will break down into slightly silty, well graded sand, whereas the floaters will recjuire disposal in an area of nonstructural fill. Some areas containing nuneixnis hardrock floaters may present utility trench problons. 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 equipment. MARGINKU:.Y RIFPAHLE COHDITION (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 numerous floaters with the possibility of extensi-ve areas of fractvured granitics. Excavations nay produce naterial that will partially break down into a coarse. I i I SCS&T 9021022 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 would require blasting to facilitate removal. 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. NDNRIPPABE£ GDWrnCK (5,500 FT./SEC. & O^EATER): 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 building pad subgrade. Blasting will produce oversize naterial requiring disposal in areas of nonstructural fill. This upper limit has been based on the Rippability Chart shown on Plates Nunter 13 through 15 utilized for this report. However, 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 IP using the D-9 mounted #9 Series D Ripper. RIPPABIUTY CHARACTERISTICS OF METAVOLCANICS AND ASSOCIAEEED HYPABYSSAL ROCKS AND TONALITIC ROCKS RTPPAHTK caornON (0-4,500 FT./SBC.): This velocity range indicates rippable materials v*iich may vary from deconposed metavolcanics at lower velcxrities to only slightly deconposed, fractured rock at the higher velocities. Although rippable, materials may be produced by excavation that will not be useable in structural fills due to a lack of fines. E:^rience 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. p SCS&T 9021022 March 20. 1990 Page 12 For velocities between 3,500 to 4,500 fps, rippability will be difficult for backhoes and light trenching equipment. MARGINALLY RIPPABEJE CONDITION (4,500-5,500 FT./SBC.): Excavations in this velocity range would be extremely tine consimiing and vrould procduce fractured rock with little or no fines. The higher velocities could require blasting. Trenching equipment would not function. NONRIFPAB[£ OlDITION (5,500 FT./SBC. & OffiKEER); This vel(OCity range may include moderately to slightly fractured rock which would re<quire blasting for removal. Material produced would consist of a high percentage of oversize and angular rock. Rippability of neta-volcanics may be acconplished for higher velocities using the Caterpillar D-9 with the #9 D Series Ripper. Due to the fractured nature of some metavolcanics, ripping might be acconplished in as high as 8,000 fps naterial. SEISMIC TRAVERSE LIMITBTICNS The results of the seismic survey for this investigation reflect rippability conditions only for the areas of the traverses. Ffovrever, the conditions of the various soil-rock units appear to be similar for the remainder of the site cind nay be assuned to possess similar characteristics. Our repx5rting is presently limited in that refraction seismic surveys do not allow for prediction of a percentage of e;qDectable oversize or heurdrock floaters. Subsurface variations in the degree of weathered rock to fractured rock are not accurately predictable. The seismic refraction nethcxi recquires that materials becone increasingly dense with depth. In areas where denser, higher velocity materials are underlain by lower velocity naterials, the lower velocity materials would not be indicated by <our survey. p 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 Itocal variations in rock conditions as: a) Fractures, Faults and Planes of Weakness of Any Kind b) Weathering and Degree of Decomposition 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 naterials can be achieved but it may becone econcmically 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 developnent. It is suggested that canyon subdrains be installed within drainage swales \diich are to receive fill. It should be realized that grouncdwater problems may cxrcnir after development of a site even where none were present before developnent. These are usually minor phenomena and are often the result of an alteration of the permeability characteristics of the soil, an alteration in (drainage E)attems and an increase in irrigation water. Based on the permeability characteristics of the soil and the anticipated usage of the development, it is our opinion that any seepage problems vrfiich nay occur will be ndnor in extent. It is further our opinion that these problems can be most effectively corrected on an in(±Lvidual basis if and v*jen they develop. p f SCS&T 9021022 -March 20, 1990 Page 14 CONCLUSIONS AND RECOMMENDATIONS (XNERAL In general, no geotechnical conditions vere encountered which would preclude the development of the site as tentatively planned provided the reconmencdations presented herein are follioved. Geotechnical conditions that will affect the proposed site development include ejqansive soils and hard granitic, metavolcanic and hypabyssal rock. Where possible, select grading is reconmended to keep nondetrimentally expansive soils within four feet from finish pad grade. In areas where this is not feasible, special foundation consideration will be necessary. In order to make the proposed excavations, ve anticipate that heavy ripping and blasting will be required. It is anticipated that the naterial generated from the cnits of the granitic, meta-volcanic and hypabyssal rock will contain relatively low amounts of fine soils and large amounts of oversized material. Since rock fills re(3uire a percentage of fine soil, mining of the site, inporting of fine naterials or exporting excess rock may be necessary. The purpose of this interim report is to provide preliminary rectonmendations based on infomation available from the referenced report. An additional investigation based on the present development scheme will be perfomed at a later date. GRADING SITE PREPARBCnCll: Site preparation should begin with the removal of any existing -vegetation and deleterious natter from propxDsed inprovenent areas. Removal of trees should include their root system. Any existing loose surficial d^xosits such as topsoils, unconpacted fills, and younger alluvium in areas to be graded or to recei-ve 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 p I 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 structures, and all areas to receive fill and/or settlement-sensitive improvenents. SELECT GRADING: Expansi-ve soils should not be allowed within four feet frcm finish pad grade. In addition, expansi-ve soils shcould not be placed within a distance from the face of fill slopes ecqual 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 recommended that select soils have relati-vely low permeability cliaracteristics. In areas undercut for select grading purposes, the bottom of the excavation should be sloped at a minimum of three percent away from the center of the structure. Minimum lateral extent of select grading should be fi-ve feet away from the perineter of settlement-sensitive inprovements. CUT/FHIJ TRfllBinON: It is anticipated that a transition line betveen cut and fill soils nay nm through scare of the proposed building pads. Due to the (different settlement characteristics of cut and fill soils, construction of a structure partially on cut ard partially on fill is not reconmended. Based on this, we recommend that the cut portion of the building pacds be undercut to a depth of at least three feet below finish grade, and the naterials so excavated replaced as uniformly ctonpacted fill. The minimum horizontal limits of these recconmendations shcould extend at least fi-ve feet outside of the proposed inprovements. IMPORTED FIUJ: All fill soil inported to the site should be granular and should have an expansion 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 inported should be approved by a representati-ve of this office prior to inporting. I I I I I I I I p SCS&T 9021022 March 20, 1990 Page 16 RIPPABILITY: It is anticipated that the proposed cuts will re(5uire heavy ripping and blasting. This condition will be further evaluated during the preparation of the preliminary geotechnical in-vestigation report. Additional seismic traverse lines will be performed in areas were deep cuts are proposed. OVERSIZED ROCK: Oversized rtock is defined as naterial exceeding six inches in naximum dinension. It is anticipated that oversized material will be generated from proposed cuts. Oversized naterial may be placed in structural fills as described in Plate Nunter 20. SLOPE 0CX6TRUCTI0N: The face of all fill slopes should be conpacted by backrolling with a sheepsfoot compactor at vertical intervals no greater than four feet and should be track walked v^en 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 be found, mitigating measures could be re(5uired. SURFACE DRAINAQB; It is reconmended that all surface drainage be directed away from the stmctures and the top of slopes. Ponding of water should not be alltoved adjacent to the foundations. SUBDRAIN5: A subdrain should be installed in canyon areas to receive fill in excess of ten feet. A subdrain detail is provided in Plate Nunter 21. EARSBHORR: All earthwork and grading contenplated for site preparation shcould te acconplished in accordance with the attached Reccommended Grading Specifications and Special Provisions. All special site preparation reconmendations presented in the sections above will supersede those in the Standard Reconmended Grading Specifications. All entenknents, structural fill and fill should he conpacted to at least 90% relati-ve conpaction at or p SCS&T 9021022 March 20, 1990 Page 17 slightly over optimum moisture content. Utility trench backfill within five feet of the prcposed structures and loeneath asphalt pavenents should te ctonpacted to minimum of 90% of its naximum dry density. The upper tvel-ve inches of subgrade teneath paved areas should te conpacted to 95% of its maximum dry density. This compaction should be obtained by the paving contractor just prior to placing the aggregate base naterial and should not te part of the nass grading requirements. The naximum dry density of each soil type should be determined in accordance with ASTM Test Method D-1557-78, Method A or C. SLOPE STABILITY Proposed cut and fill slopes should te constructed at a 2:1 (horizontal to vertical) or flatter inclination. It is estinated that cut and fill slopes will extend to a naximum height of about 60 feet and 20 feet, respecti-vely. It is our opinion that said slopes will possess an acdecjuate factor of safety with respect to deep seated rotational failure and surficial failure (see Plate Nunter 22). The engineering geologist should observe all cmt slopes during grading to ascertain that no acdverse conditions aire encountered. FCKSOfSnOtG GENERAL: If the lots are capped with nondetrimentally expansive soils, conventional shall(OW foundations may be utilized for the support of tte proposed structures. The footings should have a minimum depth of 12 inctes and 18 inctes telow lowest adjacent finish pad grade for one-and-two-story constmction, respectively. A mininium width of 12 inches and 18 inches is recoimended for continu<ous and isolated footings, respectively, A bearing 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 Icocated adjacent to or within slopes should te extended to a depth such that a niinimum distance of six feet and seven feet exist tetween tte fcxjting and the face of cmt slcjpes or fill slopes, respectively. Retaining walls in similar conditions should te individually revieved by SCS&T 9021022 March 20, 1990 Page 18 this office. If it is found to be unfeasible to cap the lots with nondetrimentally expansive soils as reconmended, special foun(dation and slab design will te necessary. This generally consists of deepened and more heavily reinforced footings and thicker and more heavily reinforced slate. Reconmendations for expansive soil conditions will te provided after site grading wten the expansion index and depth of the prevailing founcdation soil is laiown. REINFORCEMENT: Both exterior and interior continuous fcxjtings should te reinforced with at least one No. 4 bar positioned near tte tottom of tte l| footing and one No. 4 bar positioned near the tcp of the fexiting. This reinforcement is based on soil characteristics and is not intended to te in lieu of reinforcenent 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 nondetrimentally expansi-ve soils, concrete on-grade slabs should have a thickness of four 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 altemati-ve, the slab reinforcing may consist of 6"x6"-W1.4xW1.4 (6"x6"-10/10) velded wire mesh. However, it should te realized that it is difficnilt to maintain the proper position of wire mesh during placement of tte concrete. A four-inch-thick layer of clean, coarse sand or crushed rock should te placed uncier tte slab. TMs 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 fi-ve percent passing sieve #200. Wtere moisture-sensiti-ve flcor coverings are planned, the sand or rock should te overlain by a viscjueen moisture barrier and a tvo-inch-thick layer of sand or silty sand should te provided above the visqueen to allow proper concrete curing. EXTERIOR SUVBS-CN-GRADB: For nonexpansive soil conditions, exterior slate should have a minimum thickness of four inctes. Walks or slate five feet in P p 1^ SCS&T 9021022 March 20, 1990 Page 19 width should te reinforced with 6"x6"-Wl,4xWl,4 (6'x6'-10/10) velded wire mesh and provided vdth weakened plane joints. Any slabs tetveen fi-ve and ten feet should te provided with longitudinal weakened plane joints at the center lines. Slabs exceeding ten feet in width should te provided with a weakened plane joint Icxrated three feet inside the exterior perimeter 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 footisxg 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 reconnendations should te utilized for said lots. Footings should te reinforced with tvro No. 4 bars positioned near the tottom of tte footing and two No. 4 bars positioned near the top of the footing. Concrete on grade slate should te reinforced wi-th at least No. 3 reinforcing bars placed at 18 inctes on center each way. Lots with fill differentials in excess of thirty feet should te evaluated on an indiviciual tosis. EXPANSIVE CHARACTERISTICS: Meta-volcanic rock generally veathers to a clayey subsoil, and its presence within four feet of finish pad grade will require special site preparation and/or foundation consideration. SETTLEMENT CEBttUCIERISTICS: Tte anticipated total and/or differential settlements for tte proposed stmctures nay te considered to te within tolerable limits provided the reconmencdations presented in this report are followed. It should te reccjgnized that minor hairline cracks on concrete due to shrinkage of constmction naterials or redistribution of stresses are nomal and may te anticipated. I I I I I I I I I p SCS&T 9021022 March 20, 1990 Page 20 EAKffl RETAINING WALLS PASSIVE PRESSURE: The passive pressure for the prevailing soil conditions may te considered to te 450 pounds per scjuare fcx3t per foot of depth up to a naximum of 2000 psf. This pressure nay te increased one-third for seismic loading. Tte coefficient of friction for concrete to soil may te assuned to te 0.35 for tte resistance to lateral novenent. Wten contoining 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 viien landscaping abuts the tottom of the wall. PCnVE PRESSURE: The acti-ve soil pressure for the design of unrestrained earth retaining structures with level backfills may be assumed to be ecjuivalent to the pressure of a fluid veighing 35 pounds per cubic toot. For 2:1 (horizontal to -vertical) sloping teckfills, 14 pcf should te added to the preceding values. Ttese 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 te provided by the project architect. A subdrain detail is provided on the attached Plate Nunter 24. BACKFILL: All teckfill soils should te conpacted to at least 90% relative conpaction. Expansi-ve or clayey soils should not te used for teckfill material. Tte wall should not te backfilled until the masonry has reached an adetguate strength. FACTCSl OF SAFETY: Tte above values, with the exception of the allowable soil tearing pressure, do not include a factor of safety. Appropriate factors of safety stould te incorporated into the design to prevent tte vails frc3m overtuming and sliding. f p SCS&T 9021022 March 20, 1990 Page 21 LIMITKTIONS REVIEW, OBSERVMTCN AM5 TESTCW; The reconmendations presented in this report are contingent upon our review of final plans and specifications. Such plans and specifications stould te made available to the geotechnical engineer and engineering geologist so that they nay review and -verify their conpliance with this repxort and with Chapjter 70 of the Uniform Building Ccxde. It is reconmended 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 recomnencdations and to allow design changes in the event that suteurface conditions differ from those anticipated prior to start of constmction. IWUrUHMITY OF CXlDITiare The recciramendations and opinions expressed in this report reflect our test estimate of the project recjuirements 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 tte foundations and/or cut and fill slopes nay te influenced by unciisclosed or unforeseen variations in the soil conditions that nay occur in tte intermediate 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 te nay make modifications if necesseury. CHSNGE IN SGOFE This office should be advised of any changes in the project scop>e or proposed site grading so that we may determine if the recommendations contained herein are appropriate. This should te verified in writing or modified by a written addendum. f p SCS&T 9021022 March 20, 1990 Page 22 TIME IiIMITAnONS 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, v^ether 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 Government Codes nay occur. Due to such changes, the findings of this report nay te invalidated v^olly or in part by changes beyond our control. Therefore, 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. PROFESSICNAL SEAtDARD In the perfomance of our professional services, we conply with that level of care and skill ordinarily exercised by memters of our profession currently practicing under similar conditions and in the sane locality. Tte client recognizes that subsurface conditions may vary from those encountered at tte locations vtere our trenches, surveys, and explorations are made, and that our data, interpretations, and reconmendations are tesed solely on tte information obtained by us. We will be responsible for those data, interpretations, and reconmencdations, but shall not te responsible for tte interpretations by others of the information developed. Our services consist of professional consultation and oteervation only, and no warranty of any kind whatsoever, express or implied, is made or intended in connection with tte work performed or to te perfomed by us, or by our proposal for ccjnsulting or other services, or by 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 reconmendations contained herein are brou^t 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 reconmendations during constmction. FIELD EXPIRATIONS Three suteurface trench explorations vere made at the locations indicated on tte attached Plate Nunter 1 on Decenter 21, 1982 within the subject site (see Plates Nunter 3 through 5). In addition. Plates Nunter 6 through 12 p 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 bacldioe. Four seismic tra-verses 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 Number 13 through 15. In addition, Appendix A contains two additional suteurface ejqjlorations within tte subject site (ERT-6 and ERT-7), perfomed by Earth Research Associates, Inc., dated February 18, 1981. P The soils cu:?e 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 gi-ven as either very loose, loose, meciium dense, dense or very dense. Tte consistency of silts or clays is given as either -very soft, soft, meciium stiff, stiff, very stiff, or hard. LABORATORY TESTINS Latoratory tests were perfomed in accordance with the generally accep)ted American Society for Testing and Materials (ASTM) test methods or suggested procedures. A brief description of the tests perfomed is presented telcjw: p SCS&T 9021022 tiarch 20, 1990 Page 24 a) CLASSIFICKTION: Field classifications were verified in the latoratory by visual examination. The final soil classifications are in accordance with the Unified Soil Classification System. b) MDISTORE-OEIdTY: In-place moisture contents and dry densities were detemiined for representative soil sanples. This infomation was an aid to classification and permitted recognition of variations in naterial consistency with depth, Tte dry unit weight is determined in pounds per cubic foot, and the in-place raoisture content is determined as a percentage of tte soil's dry weight, Tte results are sunmarized in the trench logs. c) GRAIN SIZE DISTRIBUTION: The grain size distribution was cietermined for representative sanples of the nati-ve soils in accordance with ASTM D422. The results of these tests are presented on Plates Nunter 16 and 17. d) GCMPACTION TEST: The maximum dry density and optimum moisture content of typical soils vere determined in tte latoratory in accordance with ASIM Standard Test D-1557-78, Method A. Tte results of these tests are presented on the attached Plate Nunter 18. e) EXPANSION TEST: Tte expansive potential of clayey soils was cietermined in accondance with tte following test procedure and tte results of these tests appear on Plate Nunter 18. Allow the trinned, undisturbed or remolded sanple to air dry to a constant moisture content, at a tenperature of 100 degrees F. Place the dried sanple in tte consolidometer and allow to conpress under a load of 150 psf. Allow moisture to contact tte sanple and neasure its expansion from an air ciried to saturated condition. I I I I I I I I p SCS&T 9021022 March 20, 1990 Page 25 f) DIRECT SHEAR TESTS: Direct shear tests vere perfomed 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 vere tested at different vertical loads and a saturated moisture content. The shear stress was applied at a constant > rate of strain of approximately 0.05 inches per minute. Tte average stear strength values for granitic and meta-volcanic rock are presented on attached Plate Nunter 19. INSERT DRAWINGS HERE I I I I I I ff I I i SUBSURFACE EXPLORATION LEGEND UNIFIED SOIL CLASSIFICATION CHART SOIL DESCRIPTION GROUP SYMBOL "YPICAu 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 mixtj-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. SANDS CLEAN SANOS SW Well gradei sand, gravelly More than naif of sands, ittle or no fines. coarse fraction is SP Poorly gra-ed sands, gravelly smaller than No. 4 sands, littie or no fines. sieve size. SANDS WITH FINES SM Silty sands, poorly graaed lAppreciaole amount sand ana siUy mixtures. of fines) SC Clayey sanas, poorly graaed sand and clay mixtures. II. FINE GRAINED, more than half of material is smaller than No. 200 sieve size. SILTS AND CLAYS ML Inorganic silts -md very fine sands, -ock flour, sandy Silt or cl3..ey-siIt-sand mixtures with slight plas- tic! ty. Liquid Limit CL Inorganic clays of low to less than 50 medium plasticity, gravelly clays, sandy clays, silty clays, i»an clays. OL Organic silts and organic silty clays or low plasticity. SILTS ANO CLAYS MH Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, elastic silts. Liquid Limit CH Inorganic clays of high greater than 50 plastici ty, fat cl ays. 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 chunk sample BG — Bulk sample SP — Standard penetration sample SOUTHIRN CALIFORNIA SOIL A TISTING,INC. CALAVERA HEIGHTS-VILLAGE "K" SOUTHIRN CALIFORNIA SOIL A TISTING,INC. BY: KAR/EM DATE 2-28-90 SOUTHIRN CALIFORNIA SOIL A TISTING,INC. JOB NUMBER: 9021022 Plate No. 2 I -I 1 ' TRENCH NO. TK-li Class DescrlDtion SM SM Red-yellow Brown, Moist, Medium Dense, Silt->' Sand (Topsoil/Slopewash) Dark Grey, Moist, Dense to Very Dense, Sandy Gravel (Metavolcanic Rock) Refusal at 3 Feet i 4 il i i i I I I I aCSUTHBRN CALIFORNIA A TBSTING, INC. mmmm mvanoAi.a sTmaT CALAVERAS HEIGHTS-VILLAGE "K" BY CRB JOB NO. 9021022 DATE 12-21-82 Plate No. 4 I I I I I i i i i i I I I I I I I I I I f I I I I l.- IO \ p - « Class [RENCH NO. TK-12 Descriotion .0 \ SM I Red-brown, Moist, Medium Dense, i Silty Sand (Topsoil) SM Gray-brown, Moist, Dense to V^ery Dense, Sandy Gravel (Granitfc Rock) Refusal at 4 Feet yv aOUTHBRN CALIFORNIA XgrX aCML A TEBTlNa. INC. ^^^^ BAM airaO, CAkiPOKMIA ••^•b CALAVERAS HEIGHTS-VILLAGE "K" BY CRB 0*TE 12-21-82 JOB NO. 9021022 Plate No. 5 p Class TRENCH NO. TP-I3 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 SOUTHERN CALIFORNIA son. ll TEBTINQ, INC. •AM Oirao, CALiraNNIA ••lao CALAVERAS HEIGHTS-VILLAGE "K" BY I I I I I I I i i I I i i Class : Y TRENCH XO. TP-14 Description SM/ SL CL/ CH SM/ ML SM Brown, Moist, Medium Dense, Clayev Silty Sand (Topsoil) Green-brown, Moist, Stiff, Siltv Clav Yellow/Red/Brown, Moist, Medium Dense, Silty Sand (Weathered Decomposed Granite) Yellow-brown, Moist, Medium Dense to Dense, Silty Sand (Decomposed Granite) 121.9 12.1 Very Dense Trench Ended at 8 Feet SOUTHERN CALIFORNIA son. k TESTINQ, INC. •••o mvanBAkB aTmBT •AN oirao, BAkifianNiA ••iao CALAVERAS HEIGHTS-VILLAGE "K" BY CRB 12-15-82 JOB NO. 9021022 Plate No. 7 Class 1^ 1 SM/ SC SC/ CL SM ~RENCH XO. TP-15 Description Brown, Moist, Medium Dense, Clayey 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 M 129.1 7.3 y/V SOUTHERN CALIFORNIA XSrX son. & TESTINQ, INC. ^^^r BAN oiaao, CALIPOMMIA ••^•a CALAVERAS HEIGHTS-VILLAGE "K" BY CRB OATE 12-15-82 JOB NO. 9021022 Plate No. 8 I i i I I i i i I I i i m 1. Class TRENCH NO. TP-16 Descrio tion d 7- SM/ sc _X/CL/ 1 SM Yellow-brown, Moist, Medium Dense, Clayey Silty Sand (Topsoil) Green-brown, Moist, Stiff, Silty Clay (Weathered Decomposed Granite) 99.6 22.8 Yellow-brown, Moist, Dense to Very Dense, Silty Sand (Decomposed Granite) 130. 7 7.9 Refusal at 6 Feet y\ SOUTHERN CALIFORNIA XgrX son. & TESTHMQ , INC. ^^^^ BAN oiraa, cAuraRNiA ••iao CALAVERAS HEIGHTS-VILLAGE "K" y\ SOUTHERN CALIFORNIA XgrX son. & TESTHMQ , INC. ^^^^ BAN oiraa, cAuraRNiA ••iao «^ CRB 12-15-82 9021022 Plata No. 9 p TRENCH NO. TP-20 •Q ft .0. KY Class Descriotion SM/ 1 Red-brown, Moist, Medium Dense, C SC , Silty Sand (Topsoil) lavev SM Gray, Moist, Dense to Very dense, Sandy Gravel (Metavolcanic Rock) Trench Ended at 5 Feet y/V SOUTHERN CAUFORNIA /j^LS son. A TESTHMQ, INC. X 1 y^ mvanoAka aTMaaT "AM eiaso, OAkiranNiA aa^ao CALAVERAS HEIGHTS-VILLAGE "K" BY • CRB 12-21-82 1 JOB NO. 9021022 Plate No. 10 1 I I I I I I ff; I I I p If.: I I I 1 I I I I I I I I? I 10 / TRENCH NO. TO-23 Class Description SM CL SM Brown, Moist, 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) 123.6 8.0 Trench Ended at 10 Feet yv SOUTHERN CALIFORNIA XSrX son. A TESTINQ, INC. ^^^^ BAM oiaae, CAuranNiA aa^ao CALAVERAS HEIGHTS-VILLAGE "K" BY CRB OATE 12-16-82 9021022 Plate No. 11 ff i J TRENCH NO. TT-47 Class Description '^ro;m. Moist, Medium Dense, Silty Sand ITopsoil) SM . Yellow-brown, Moist, Dense to Very Dense, Silty Sand (Decomposed Granite) Trench Ended at 4 Feet SOUTHBRN CALIFORNIA soft. A TESTHMQ, INC. aaaa mvaRaAt.a BTRBBT BAM oiaao, CAkiraaNiA aaiao CALAVERAS HEIGHTS-VILLAGE "K" Plate No. 12 RIPPABILITY INDEX NO RIPPING SOFT MEDIUM HARD BLASTING 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 VELOCITY, FT./SEC. RESULTS TRAVERSE NO. SEDPH^ NOTE: THE ABOVE RESULTS ATTEMPT TO SHOW DEPTHS TO HORIZONS OF VARYING DENSITY INDIFFERENT LOCATIONS OVER THE STUDY AREA. SEISMIC TRAVERSE NUMBERS ^ REFER TO LOCATIONS PiDTED ON ATTACHED PLANS. THE •RIPPABIUTY INDEX* IS A MODIFICATION OF CHARTS BY THE CATERPILLAR CO. AND ARTICLE IN 'ROADS AND STREETS; SEPT 1967. SOUTHERN CAUFORNIA TESTING ^^1^ LABORATORY. INC. VBMT <2W RIVEIIOALE STREET VT^r SAM OtEOa CALIFORNU 92120 714-aBS-6134 CALAVERAS HEIGHTS-VILLAGE "K" SEISMIC RESULTS DBA OATE 7-29-83 SEISMIC RESULTS JOB NO. q021022 Plate No. 13 RIPPABILITY INDEX NO RIPPING SOFT MEDIUM HARD TT: BLASTING 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 VELOCITY, FT/SEC. RESULTS TRAVERSE NO. fl & I 9 lb a Ib I 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*RIPPABIUTY INDEX'lS A MODIFICATION OF CHARTS BY THE CATERPILLAR CO. AND ARTICLE IN 'ROADS AND STREETS/ SPT 1967. ^^\^ SOUTHERN CAUFORNIA TESTING /Sf^ LABORATORY. INC. ^Bpl^ 62S0 RIVEROALE STREET ^^Ejr SAN Mcaa CAUPORNU 92120 7U4BS4134 CALAVERAS HEIGHTS VILLAGE "K" ^^\^ SOUTHERN CAUFORNIA TESTING /Sf^ LABORATORY. INC. ^Bpl^ 62S0 RIVEROALE STREET ^^Ejr SAN Mcaa CAUPORNU 92120 7U4BS4134 SEISMIC RESULTS •V DBA '>*TE 7-29-83 SEISMIC RESULTS JOB NO. 9021022 Plate No. 1« I RIPPABILITY INDEX NO RIPPING SOFT MEDIUM HARD BLASTING 1000 2000 3000 4000 5 VELOCITY, 1—'——I ' r 6000 7000 8000 9000 10000 FT/SEC. RESULTS TRAVERSE NO. NOTE: THE AflOVE RESULTS ATTEMPT TO SHOW DEPTHS TO HORIZONS OF VARYING DENSITY INDIFFERENT LOCATIONS OVER THE STUDY AREA. SEISMIC TRAVERSE NUMBERS REFER TO LOCATIONS Pli3TED ON ATTACHED PLANS. THE'RIPRABIUTY INDEX'lS A MODIFICATION OF CHARTS BY THE CATERPILLAR CO. AND ARTICLE IN 'ROADS AND STREETS/ SEPT, 1967. SOUTHERN CALIFORNIA SOIL A TESTINQ LAB, INC. BAN OiaaO, CAklFORNIA BBiaO CALAVERAS HEIGHTS-VILLAGE "K" SEISMIC RESULTS DBA Ra 9021022 OATE 1-11-83 Platp No. 15 o 70 > z (A R m o m c H O Z i 9 o ro (—' o ro ro ca CTI CO I I o I o 0 c b za Pi o 3» m CO I 3» CD lOOr 36' IS" 24' I2' 90 80 70 § 60 50 ^ 40 20 10 0 IOOO 6' 4 ) 2' l/.S. Standard Sieves Vc *\0 •so "Mo ••60 .»a J 6 60 4 ^ Hydrometer (Minutas) s 30 lao 9« r • I Grain Sue (mm) 9a ;s s « 3 U4Q liOOm) 100 90 80 70 i 40t; » Ss QJ S 20 — OOl PARTICLE SIZE LIMITS 1 BOULOERI COBBLES 1 GRAVEL SANO SILT OR CLAY 1 BOULOERI COBBLES 1 Coorst Fin* Cooraa Mtdiuffl Pint SILT OR CLAY (12 in.) 3in. 3/4in. No.4 No.10 No.40 No.200 U.S. STANOARD SIEVE SIZE TK-10 @ 2' TP-14 @ 2'-3' > z (A F5 m o 70 S c H O o ro I-" o ro ro o ro 3> TJ a> 11) CTl I VO O 5 o 1— <; m ya oo cn CO I CJ 6<5 Standard Sieves Z' {• Vc •xo "zo •40 *6Q Hydrometer (Minutes) I 2 s 30 lao 1440 ISO 0ml 100 90 BO 70 »•r • s 4 3 Groin Size (mm) lib, iiooem) 50 40^ w§ soi^b 20 — o 10 —^ 001 PARTICLE SIZE LIMITS 1 BOULDER! COBBLES 1 GRAVEL SANO SILT OR CLAY 1 BOULDER! COBBLES 1 CoorM Fin* Coora* 1 Modium 1 FIno SILT OR CLAY (12 in.) Sin. 3/4 in. No.4 No.lO No.40 No.200 U. S. STANDARD SIEVE SIZE 'TP14 0 4'-5' •TP20 0 3'-4' I I I I I I MAXIMUM DENSITY A OPTIMUM MOISTURE CONTENT ASTM D1557-78 METHOD A SAMPLE DESCRIPTION Maximum Density Optimum Moisture TP-13 @ 2'-3' Yellow-Brown, Silty Gravelly Sand j 114.8 | 13.8 | TP-14 @ 2'-3' Green-Brown, Sandy Silty Clay 114.0 15.0 1 TP-14 @ 4'-5' Yellow/Red-Brown, Silty Sand 112.6 14.8 1 TP-20 @ 3*-4' Grey, Silty Sandy Gravel 128.4 11.7 1 TQ-23 g 8'-9' Yellow-Brown, Silty Sand/Sandy Silt 120.6 13.3 1 TT-47 g 2'-3' Yellow-Brown, Silty Sand 122.7 12.0 ff I I i EXPANSION INDEX TEST RESULTS SAMPLE TP-14@2'-5' TP-14@ 4'-5' TP-16@ 3' CONDITION Remolded Undisturbed Undisturbed 1 1 1 1 INITIAL M.C.C/.) [ j^g ^ 14.8 1 22.8 1 1 INITIAL DENSITY (PCR 101.3 101.8 00.6 1 FINAL M.C. (•/.) 30.5 26.0 30.3 .MOR MAL STRESS (PSF> 150 150 150 EXPANSION INDEX 15.0 8.3 14.0 yv SOUTHBRN CALIFORNIA SOIL A TESTINQ, INC. CALAVERA HEIGHTS-VILLAGE "K" BY: DBA JOBNuyBER: 9021022 OATE: 3-16-90 Plate No. 18 SLOPE STABILITY CALCULATIONS Janbu's Simplified Slope Stability Method Assume strength parameters throughout the slope 0 (°) C (psf) (pcf) Incl. H (ft) *1etavolanic & 35 Granitic Rock* Cut & Fill Slopes i u 200 125 2:1 50 * Average shear strength values Where: = Angle of Internal Friction C = Cohesion (psf) WJ = Unit weight of Soil (pcf) H = Height of Slope (ft) FS = Factor of Safety FS 1.8 yv SOUTHERN CALIFORNIA SOIL A TESTING,INC. CALAVERA HILLS Vl 1 1 A'^-f "K" ' yv SOUTHERN CALIFORNIA SOIL A TESTING,INC. BY: DBA DATE 1-10-84 yv SOUTHERN CALIFORNIA SOIL A TESTING,INC. JOB NUMBER 9021022 Plate No. 19 (0 o r B> H ill (R H Z O S o O c H X m o > r O c m O •< • z c s DB • 3> o m > I— 3» -c vo m o TO ro > I—* o IE ro m ro l—l ED ZC -o O CO lat 'Mil 1 <= n> m l—l r-z r-o > . CO 1 m ro t—l o CTl = 1 VO s o 0Vpp<J7F RQCK^_CaSP-QSAL— (Struclural Soil-Rock Fill) P/L Ft * ^ i P , imin- ^ 1 , imin- ^ 1 'min. » a. MRS Coapact«4 (all fill Ibtll CMt«t« tt Ititt 40 ptrcint tell <1iM M(**M )/4-<Mk tlt«t, (by •ilfht). Md b« coaMCM U •ccsrtfMU «tU M*<<flC4tlM« tor ttrMCtaral fill. laclii Mfr 4 fMt ta walaMi ataaiilM Mt paralttad In Mil. lECCNO IONC *: Coiiip«cl«l toll fill. No rocli frtginenti over 6 Inchei In grc4teil dliwittlon. ZONC i: Ro<ks 2 lo 4 reel In •MIMM dlaeiitlon pitted In cu«p«cic<l ioll nil conforaln, lo ZONE A. IONC C: aockt i Inchet to 2 feet In Milaua diaentlon unlforaly dUlrlbu- •ed 4nd well (ptccd In coaptclcd toll fill (onforalng le lOK A. IONC 0: Nequired (or ell eiitllni tlopct (:l «nd tteeper. 90S KlnlMjui coiNi«ctlon. IONC A. I. or C aatcrUI any be uted for IONC D. NATURAL QROUND BENCHINQ CANYON SUBDRAIN DETAIL 77777777777Z COMPACTED FILL ^w/'//M REMOVE UNSUITABLE MATERIAL SUBDRAIN TRENCH: SEC DETAIL ABB DETAIL A FILTER MATERIAL '6 CUBIC FEET/FOOT FILTER MATERIAL SHALL BE CLASS 2 PERMEABLE MATERIAL PER STATE OF CALIFORNIA STANDARD SPCCIPICATIONS, ANO APPROVCD ALTERNATE. CLASS 2 FILTER MATERIAL SHOULO COMPLY WITH THC FOLLOWINQ LIMITS OETAIL A-1 PCRFORATCD PIPE 4 • MINIMUM PCRFORATCD PIPC SURROUNDCD WITH FILTCR MATCRIAL SIEVE SIZE 1 3/4 3/B No. 4 No. 8 No. 30 No. 80 Ne. 200 % PASSING 100 90-100 40-100 28-40 18-33 8-18 0-7 0-3 DETAIL B DCTAIL B-1 8' MIN OVCRLAP FILTCR FABRIC (MIRAFI 140 OR APPROVCD EQUIVALCNT) 1 1/2"MAX QRAVCL OR APPROVCD CQUIVALCNT 8 CUBIC FCCT/FOOT DCTAIL B-2 1 1/2"QRAVCL WRAPPED IN FILTCR FABRIC DCTAIL OF CANYON SUBDRAIN TCRMINAL DCSIQN FINISH QRAOe NON PCRFORATCD 4 MIN PCRFORATCD 4'MIN PIPC SUBDRAIN INSTALLATlON-SUBDRAiN PIPE SHALL BE INSTALLED WITH PERFORATIONS DOWN SUBDRAIN PIPE:SUBDRAIN PIPE SHALL BE PVC OR ABS, TYPE SDR 3S FOR FILLS UP TO 35 FEET DEEP. OR, TYPE SDR 21 FOR FILLS UP TO 100 FEET DEEP yv SOUTHERN CALIFORNIA SOIL A TESTING, INC. CALAVERAS HEIGHTS-VILLAGE "K" yv SOUTHERN CALIFORNIA SOIL A TESTING, INC. BY: DBA DATE: 3-16-90 yv SOUTHERN CALIFORNIA SOIL A TESTING, INC. JOB NUMBER: 9021022 Plate No. 21 I i i i i i i; •i >i i I I I I I I THANSVERSE WEAKENED PLANE JOINTS e' ON CENTER (MAXIMUM) w W/2 . w/2 1 5'--"'0' SLABS IN EXCESS OF 10 FEET IN WIDTH SLABS' 6 TO 10 FEET IN WIDTH PLAN NO SCALE TOOLED JOINT r— ' ^ WEAKENED PLANE JOINT DETAIL NO SCALE SOUTHERN CAUFORNIA son. 1 TESTINQ, INC. CALAVERAS HEIGHTS-VILLAGE "K" •Vl DBA DATSi ..3-16-90 JM NUMMt 9021022 Plate No. 22 i 1^ WATERPROOF BACK OF WALL PER ARCHITECTS SPECIFICATIONS 3/4 INCH CRUSHED ROCK OR MARIDRAIN SOOO OR EQUIVALENT QEOFABRIC BETWEEN ROCK AND SOIL 4" DIAMETER PERFORATED PIPE HOUSE ON QRADE SLAB i HOUSE RETAININQ WALL SUBDRAIN DETAIL NO SCALE yv SOUTHIRN CALIFORNIA SOIL A TESTINQ,INC. CALAVERA HEIGHTS-VILLAGE "K" yv SOUTHIRN CALIFORNIA SOIL A TESTINQ,INC. BY: DBA DATE: 3-16-90 yv SOUTHIRN CALIFORNIA SOIL A TESTINQ,INC. JOB NUMBCR: 9021022 Plate No. 23 DSL CATERPILLAR PERFORMANCE HANDBOOK Edition 17 October 1986 Salamic Velocity PMt Por aeoona i MOO a 9 10 11 12 13 14 15 TOPSOIL CLAY IQNEOUS ROCKS GRANITE BASALT SEDIMENTARY ROCKS SHALE 3AN08T0NE 3ILTSTONE CLAYSTONE CONOLOMERATE METAMORPHIC ROCKS SCHIST SLATE I A / •< V z: ——I i' I— \/y A/- • r / / i! RIPPABLE MAROMAL NON-RIPPABLE L DSL Ripper Performance • Multi or Single Shank No. 8 Ripper • Estimated by Seismic Wave Velocities \ y/s. SOUTHERN CALIFORNIA i/gilN CALAVERA HEIGHTS-VILLAGE "K" \ y/s. SOUTHERN CALIFORNIA i/gilN BY: DBA DATE: 3-16-90 SOIL & TESTING. INC. BY: DBA DATE: 3-16-90 SOIL & TESTING. INC. i JOB NUMBER: 9021022 Plate No. 24, I i I I 1 I I i I D9L CATERPILLAR PERFORIVIANCE HANDBOOK Edition 17 October 1986 Saismic Velocity FOM Por aoooM i iooo TOPSOIL CLAY IGNEOUS ROCKS QRAMTE BASALT SEDIMENTARY ROCKS SHALE SANDSTONE SLTSTONE CLAYSTONE CONOLOMERATE METAMORPHIC ROCKS SCHIST SLATE RIPPABLE I I 'III I I I I J I MAROMAL L 3 9 10 11 12 13 ! I 14 15 -f IT- NON-RIPPABLE D9L Ripper Performance • IVIultl or Single Shank No. 9 Ripper • Estimated by Seismic Wave Velocities SOUTHERN CALIFORNIA SOIL & TESTING. INC. CALAVERAS HEIGHTS-VILLAGE "K" BY: DBA JOB NUMBER: 9021022 DATE: 3-16-90 Plate No. 25 I D11N CATERPILLAR PERFORMANCE HANDBOOK Edition 17 October 1986 Seismic Velocity POM Por aooim I 1000 a 9 10 11 12 13 14 15 i i TOPSOIL CLAY IQNEOUS ROCKS QRAMTE BASALT SEDIMENTARY ROCKS SHALE SANDSTONE SLTSTONE CLAYSTONE CONOLOMERATE METAMORPHIC ROCKS SCHST SLATE WZZZZZZZ2ZZZZL VZ2ZZZZ21 V/){//){//){//\ RVPABLE MARGINAL NON-RIPPABLE D1 1 N Ripper Performance • Multl or Singie Shank No. 9 Ripper • Estimated by Seismic Wave Velocities >/Vw SOUTHERN CAUFORNIA ^^jy SOIL & TESTING. INC. CALAVERAS HEIGHTS-VILLAGE "K" >/Vw SOUTHERN CAUFORNIA ^^jy SOIL & TESTING. INC. BY: DBA DATE: 3-16-90 >/Vw SOUTHERN CAUFORNIA ^^jy SOIL & TESTING. INC. JOB NUMBER: 9021022 Plate No. 26 APPENDIX A SOUTHERN CALIFORNIA SOIL SL TESTING, INC. TABLE I J-N. 115-81 2/18/81 LOG OF TEST TRENCHES Test Trench Mu.Tber Depth (ft.) Description TT-l 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 well 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-5 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-6 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-lOX boulders to 36" diameter. TT-7 0.0 - 2.0 CLAYEY SAND: Brown; sand fine to mediun with cobbles and occasional boulders; numerous roots; damp and loose; (SC) Soil. TA5LE V - LOG OF TEST TRENCHES (Continued) Tsit Trench ilu-.bsr TT-7- cont'd i TT-8 TT-9 TT-IG TT-11 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+ Description 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 SAND: 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 & TESTING, INC. I CALAVERA. HEIGHTS, VTLLfiffi K, CARLSBAD RECXHMOflOED (3«DINS SPBCIFICATIGNS - GENERAL PROVISIONS GENERAL ZNHNT The intent of these specifications is to establish procedures for clearing, conpacting natiiral ground, preparing areas to be filled, and placing and compacting fill soils to the lines and grades shown on the accepted plans. The recommendations contained in the preliminary geotechnical investigation report and/or the attached Special Provisions are a part of the Reconmended 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 conrrunication signed by the Geotechnical Engineer. OBSERVKTIGN AND TESTING Southern California Soil and Testing, Inc., shall be retained as the Geotechnical Engineer to observe and test the earthwDrk 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 work 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 reconmBndations. (R-9/89) I I I I I I i r I I i I 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 moisture content, inadequate conpaction, adverse weather, etc.; constiruction should be stopped until the conditions are remedied or corrected or he shall recommend rejection of this vrork. Ttests used to detennine the degree of conpaction should be performed in accordance with the following American Society for Testing and Materials test methods: Maxinum Density & Optimum Moisture Content - ASIM 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 Conpaction as detennined by the foregoing ASTM testing procedures. PREPARflnCN OF AREAS TO RECEIVE FILL All vegetation, brush and debris derived from clearing operations shall be removed, and legally disposed of. All areas disturbed by site grading should be left in a neat and finished appearance, free from unsightly debris. After clearing or benching the natural ground, the areas to be filled shall be sccurified 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 renoved to firm natural ground vAiich is defined as natural soils v^ich possesses an in-situ density of at least 90% of its maximum dry density. (R-9/89) i SCS&T 9021022 March 19, 1990 i^pendix. 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 caipetent formational soils. The lower bench shall be at least 10 feet wide or 1-1/2 times the the equipment width vMchever 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 v*.en considered necessary by the Geotechnical Engineer. Any abandoned buried structures encountered during grading operations must be totally removed. All underground utilities to be abandoned beneath any proposed structure should be removed from witJiin 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 requirements 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 brou^t to the attention of the Geotechnical Engineer so that he may determine if any special reconmendation will be necessary. All water wells which will be abandoned should be backfilled and capped in accordance to the requirements set forth by the Geotechnical Engineer. Hie top of the cap should be at least 4 feet below finish grade or 3 feet below the bottom of footing wiiichever 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) f 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 e}^)ansive or detximental soils are covered in the geotechnical report or Special Provisions. E^qjansive 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. PLACING AND CCMPACTICN QF 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 nioisture 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 conpaction with equipment of adequate size to economically conpact the layer. Conpaction equipnent 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 structioral fill naterial includes rocks, no rocks will be allowed to nest and all voids must be carefully filled with soil such that the minimum degree of compaction recommended in the Special Provisions is achieved. Uie naximum size and spacing of rock pennitted in structured fills and in non-structural fills is discussed in the geotechnical report, v«^n applicable. (R-9/89) SCS&T 9021022 f^arch 19, 1990 Appendix, Page 5 Field observation and conpaction tests to estimate the degree of conpaction of the fill will be taken by the Geotechnical Engineer or his representative. The location and frequency of the tests shall be at the Geotechnical Engineer's discretion. When the conpaction test indicates that a particular layer is at less than the required degree of compaction, the layer shall be reworked to the satisfaction of the Geotechnical Engineer and until the desired relative conpaction has been obtained. Fill slopes shall be conpacted by means of sheepsfoot rollers or ot±er suitable equipment. Conpaction by sheepsfoot rollers shall be at vertical intervals of not greater than four feet. In addition, fill slopes at a ratio of two horizontal to one vertical or flatter, should be trackroUed. Steeper fill slopes shall be over-built and cut-back to finish contours after the slope has been constructed. Slope conpaction operations shall result in all fill material six or more inches inward from the finished face of the slope having a relative conpaction of at least 90% of maximum dry density or the degree of conpaction specified in the Special Provisions section of this specification. The conpaction operation on the slopes shall be continued until the Geotechnical Engineer is of the opinion that the slopes will be stable surficially stable. Density tests in the slopes will be made by the Geotechnical Engineer during construction of the slopes to determine if the required conpaction is being achieved. Where failing tests occtu: or other field problems arise, the Contractor will be notified that day of such conditions by written communication from the Geotechnical Engineer or his representative in the form of a daily field ireport. If the met±od of achieving the required slope conpaction selected by the Contractor fails to produce the necessary results, the Contractor shall rework or r^3uild such slopes until the required degree of conpaction is obtained, at no cost to the Owner or Geotechnical Engineer. (R-9/89) I I I I I I I I f SCS&T 9021022 March 19, 1990 A^jendix, 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 allovred by the ordinances of the controlling governmental agency. QIGINEERING GBSERVKnON Field observation by the Geotechnical Engineer or his representative shall be nade during the filling and conpacting operations so that he can e3q)ress his opinion regarding the conformance of the grading with acceptable stiandards 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 v^eather conditions. When vrork 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. Damaged site conditions resulting from v«^ther or acts of God shall be repaired before acceptance of vrork. (R-9/89) I I I I I I I I # SCS&T 9021022 March 19, 1990 Appendix, Page 7 RBCXHMENEED O^ING SPECIFICATICNS - SFBCmj PROVISICNS RELfiTTVE CXMPAinCiN: The minimum degree of conpaction to be obtained in conpacted natural ground, conpacted fill, and conpacted 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. EXPANSIVE SOILS: Detrinentally expansive soil is defined as clayey soil which has an expansion index of 50 or greater when tested in accordance witih the Uniform Building Code Standard 29-C. OVERSIZED MKIERIAL; Oversized fill naterial is generally defined herein as rocks or lunps 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. 'QUVNSrnGN LCTES: 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 reinforcement or a combination of special footing reinforcement and underxmtting may be required. (R-9/89)