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HomeMy WebLinkAboutCT 00-02; CALAVERA HILLS VILLAGE U; INTERIM REPORT OF GEOTECHNICAL INVESTIGATION;Oey> nWERIM RERKT OF GBOTEXMUCAL INVESnGRTION CALAVERA HEIQflS VILUVCS: U TAMARACK AVQ]UE AND GOLLEXX BOULEVARD CARLSBAD, CALIFCWNIA PREPARED FDR: Lyon Ccnnunities, Incorporated 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 JO SOUTHERN CALIFORN 6280 RIVERDALE ST. SAN DIEGO, CALIF. 92120 678 ENTERPRISE ST. ESCON I A SOIL TELE 2B0-432I O I D a. CALIF. AND TESTING, INC. P.O. BOX 20627 SAN DIEGO, CALIF. 92120 92025 • TELE May 22, 1990 Lyon Ccdtnunities, Incorporated 4330 La Jolla Village Drive Suite 130 San Diego, Califomia 92122 SCS&T 9021053 Report No, 1 ATTENTION: Mr. George Haviar SUBJECT: Interim Report of Geotechnical Investigation, Calavera Heights Village U, Teunarack Avenue and College Boulevard, Carlsbad, Califomia, Gentlemen: In accordance with your request, have conpleted an interim geotechnical investigation for the subject project. Vie are presenting herewith our findings and recommendations. In general, we found the site suitable for the proposed developnent 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 opportiinity to be of professional service is sincerely appreciated. Respectfully svifendtted, SOyilfe?N CmLIFQRN^J^^p^ & TESTING, INC, Daniel B.^Adleft, R.C.E, '#36037 DBA:JRH:KAR:mw cc: (2) Submitted (4) Hunsaker and Associates (1) SCS&T, Escondido SOUTHERN CALIFDRNIA hn R. High, C.E.G. #123 N D N C , TABU: OF coNiTSNiy PAGE Introduction and Project Description 1 Project Scope 2 Findings 3 Site Description 3 (General Geology and Subsurface Conditions 3 Geologic Setting and Soil Description 3 1) Basement Conplex-Jurassic Metavolcanics and Cretaceous Granitics (Jmv/Kgr) 4 2) Lusardi Formation (Kl) 5 3) Itertiary Volcanic Rock (Tv) 5 4) Younger Quatemary (Holocene) Alluvium (Qyal) 6 5) Topsoil/Subsoil 6 6) Artificial Fill (Qaf) 6 Tectonic Setting 8 (Geologic Hazards 9 Groundshaking 9 Seismic Survey and Rippability Characteristics 9 General 9 Rippability Characteristic of Granodioritic Rock 11 Rippable Condition (0-4,500 Ft./Sec.) 11 Marginally Rippable Condition (4,500 Ft./Sec.-5,500 Ft./Sec) 11 Nonrippable Condition (5,500 Ft./Sec. & Greater) 12 Rippability Characteristics of Metavolcanics and Associated Hypabyssal Rocks and Tonalitic Rocks 12 Rippable Condition (0-4,500 Ft./Sec.) 12 Marginally Rippable Condition (4,500-5,500 Ft./Sec.) 13 Nonrippable Condition (5,500 Ft.Sec. & Greater) 13 Seismic Traverse Limitations 13 Groundwater 14 Conclusions and Recomnendations 14 General 14 (fading 15 Site Preparation 15 Select Cirading 16 Cut/Fill Transition 16 Inported Fill 16 Rippability 16 Oversized Rock 17 Slope Construction 17 Surface Drainage 17 Subdrains 1*7 Earthwork 17 Slope Stability 18 Foundations 18 General 18 Reinforcement 19 Interior Concrete Slabs-on-Grade 19 Exterior Concrete Slabs-on-Grade 19 Special Lots 20 TABUE OF CCNTEINTS (continued) PAGE Expansive Characteristics 20 Settlement Characteristics 20 Earth Retaining Walls 20 Passive Pressure 20 Active Pressure 20 Backfill 21 Factor of Safety 21 Limitations 21 Review, Observation and Testing 21 Uniformity of Conditions 22 Change in Scope 22 Time Limitations 22 Professional Standard 23 Client' s Respons ibility 23 Field Explorations 23 Laboratory Testing 24 ATTflCHMEOTS TABOLES Table I Table II Table III (Generalized Engineering Characteristics of Geologic Units, Page 7 The Maximum Bedrock Accelerations, Page 9 Seismic Traverse Sunmary, Pages 10 and 11 FIGURE Figure 1 Site Vicinity Map, Follows Page 1 PLKTES Plates lA-lB--IC Plot Plans Plate 2 Unified Soil Classification Chart Plates 3-10 Trench Logs from December 1982 Plate 11 Grain Size Distribution Plate 12 Conpaction Test Results E^^jansion Test Results Plate 13 Direct Shear Sunmary Plate 14 Oversize Rock Disposal Plate 15 Canyon Subdrain Detail Plate 16 Slope Stability Calculations Plate 17 Vfeakened Plane Joint Detail Plate 18 Retaining Wall Subdrain Detail Plates 19-21 Caterpillar Charts Plates 22-24 Seismic Results APPENDIX Reconmended Grading Specification and Special Provisions SOUTHERN CALIFORNIA SOIL AND TESTING, INC. 6280 RIVERDALE ST. SAN OIEGO, CAUr. 92120 • TELE 280-4321 • P.O. BOX 20627 SAN OIEGO, CALIF. 921 20 67B ENTERPRISE ST. ESCONDIDO. CALIF. 9202S • TELE TAfi-^S** INIERIM REPOTT OF CTXjrBCHNICAL mVESTIGftTION CALAVERA HEIGHTS VILLflGE U TAMARACK AVENUE AND COLLEGE BOULEVARD CARLSBAD, CALIFORNIA INIRODOCTICN AND PROJECT DESCRIPTICN This report presents the results of our interim report of geotechnical investigation for Calavera Heights Subdivision, Village U, Tamarack Avenue and College Boulevard located in the City of Carlsbad, Califomia. 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 stmctures will be one and/or two stories high and of vrood frame construction. Shallow foundations and conventional slab-on-grade floor systems are proposed. Grading will consist of cuts and fills up to approximately 25 feet and 30 feet deep, respectively. Fill slopes up to approximately 30 feet and cut slopes up to approximately 25 feet high at a 2:1 (horizontal to vertical) are also anticipated. To assist with the preparation of this report, we v^re provided with a grading plan prepared by Hunsaker and Associates dated December 6, 1989. In addition we reviewed our "Supplenental Soil Investigation, Calavera Hills Subdivision," dated October 6, 1988, our "Report of Geotechnical Investigation, Village Q and T, Calavera Hills Subdivision," dated January SOUTHERN CALIFORNIA SOIL AND TESTING. INC. SOUTHIRN CALIFORNIA ^ SOiL A TUTINQ.INC. CALAVERA HEIGHTS-VILLAGE U SOUTHIRN CALIFORNIA ^ SOiL A TUTINQ.INC. gy. KAR/EM DATI: 5-21-90 SOUTHIRN CALIFORNIA ^ SOiL A TUTINQ.INC. JOINUMBCR: 9021053 FIGURir#1 SCS&T 9021053 May 22, 1990 Page 2 10, 1984 and our "Sunmary of Geotechnical Investigation for Lake Calavera Hills," dated August 6, 1984. The site configuration, topography and approximate locations of the subsurface explorations are shown on Plates Number lA, IB and IC. PROJECT SCOPE This interim report is based on the review of the aforementioned reports for the subject 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 previously nentioned reports. More specifically, the intent of this study was to: a) Describe the si±»surface conditions to the depths influenced by the proposed constmction. 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 the anticipated materials which will influence the development of the proposed stibject site. c) Describe the rippability characteristics of the existing rock. d) Define the general geology at the site including possible geologic hazards v^ich could have an effect on the site development. e) Develop soil engineering criteria for site grading and provide reconmendations regarding the stability of proposed cut and fill slopes. f) Address potential constmction difficulties and provide recomnendations conceming these problems. SCS&T 9021053 May 22, 1990 Page 3 g) Reconmend an appropriate foundation system for the type of stmctures anticipated and develop soil engineering design criteria for the reconmended foundation design. FINDINGS SITE DESCRTPnON The subject site is an irregular shaped parcel of land located within the Calavera Heights cemmunity in Carlsbad, Califomia. The site, designated as Village "U", covers approximately 65 acres and is bounded by residential and undeveloped land on the west and undeveloped land on the north, east and south property boundaries. Topographically, the site consists of hilly terrain with veil developed drainage courses. Elevations on site range from approximately 380 feet (MSL) at the western property boundary to approximately 90 feet (MSL) near the southeastem comer. Inclinations of the natural hillside slopes are on the order of 2 to 1 (horizontal to vertical) or flatter. Drainage is acconplished via sheetflow and several well developed drainage courses drain in an overall easterly and southerly direction. Vegetation is conprised of moderate to dense chaparral on the hillsides and relative dense shrubs and small trees within the larger drainage swales. The site is vaccint with the exception of overhead utility lines which traverse the site in a southwest to northeast direction. C3WEFJAL AM) SUBSURFACE COtfOmOtS GSOLOGIC SEmNG AND SOIL DESCRIPTION: 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 both igneous and sedimentary origin. Most of the site is underlain by the basement complex rocks consisting of Jurassic-age metavolcanic rocks, Cretaceous-age granitic rocks, and Tertiary-age volcanic rocks. The renaining areas of the site are underlain by the conglomerate sediments of SCS&T 9021053 May 22, 1990 Page 4 the Lusardi Fomation, Holocene alluvium, and manmade fill. A brief brief description of the materials observed, in general decreasing order of age, is presented below. 1) BASEMENT OWPLEX - JURASSIC METAVQLONICS AND CRETflCBOUS (3RANITICS (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 metavolcanics and are consequently older than the other intmsive roclcs found at the site. Both the metavolcanics and the associated hypabyssal rocks veather 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 basement conplex are the granitic rocks of the Cretaceous Southem Califomia Batholith which have intmded 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 composition. 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 rocks appear to be somewhat similar to those of the metavolcanic/hypabyssal rocks. The tonalitic rocks may be rippable to greater depths than the metavolcanic rocks but ripping may be difficult and time consimiing. 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 SCS&T 9021053 May 22, 1990 Page 5 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 commonly contain areas which are rippable to 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 equipment. The areas underlain by the respective rock types in the basement complex are undifferentiated on the acconpanying geologic map. It should be noted that the different rock types are mixed and the areas on the map only indicate v^ch rock type is dominant. Where the symbol for the metavolcanic rock is listed first (ie: Jmv,/Kgr), the area is characterized largely by metavolcanic and hypabyssal rocks with lesser amounts of granitic rock. Conversely, where the symbol for the granitic rock is listed first (ie: Kgr/Jmv), the ara appears to be underlain piredominantly by granitic rock with lesser amounts of metavolcanic and hypabyssal rocks. 2) USARDI FORMKnON (Kl): The Lusardi Formation is a Cretaceous conglomerate that rests nonconformably on the basement conplex and was deposited on a high-relief surface called the "Sub-Lusardi" unconformity. This formation consists largely of granitic and metavolcanic boulders in a matrix of coarse grained sandstone and siltstone. The conglomerate is usually poorly sorted and the clasts are commonly angular to subrounded. The only area of Lusardi Fomation on the subject sit proper v^ich is large enough to map as part of this investigation is on the extrene eastem portion of the site. Other areas of Lusardi Formation may be encountered at other portions of the site in subsequent, more-detailed investigations. 3) TERTIAPy VOLCANIC ROCK (Tv): Cerro de la Calavera is part of a volcanic neck that has intmded the older rocks in the Carlsbad area. The volcanic rock is usually brown to brownish gray and SCS&T 9021053 May 22, 1990 Page 6 appears to include both dacite and andesite. The weathering characteristics and excavation characteristics of the Tertiary volcanic rock are similar to those of the Jurassic metavolcanic rocks. The only area of Tertiary volcanic rock of sufficient dinension to map for this project was found on the extreme eastem portion of the site, just west of Cero de la Calavera. It is possible that future grading operations or more detailed geologic mapping may reveal more of the Tertiary volcanic rock. 4) TOONGER QUKTERNARY (HOLOCENE) ALLUVIUM (Qyal): Younger alluvial deposits consisting of unconsolidated, loose to medium dense deposits of clay, silt, sand, and gravel are present in the larger drainage covurses. These deposits range in thickness from iess than a foot to over ten feet. Due to their ubiquitous occurrence, the younger alluvial deposits are not delineated on the geologic map except in the larger channels. 5) TOPSOIL/SUBSOIL: A relatively thin layer of loose topsoils and subsoils should be anticipated overlying the entire site. These deposits consist of varying mixtures of silts, sands and clays. It is estinated that these deposits do not exceed 3.5 feet in combined thickness. 6) ARTIFICIAL FILL (Qaf): Several areas of manmade fill, which have been obtained from the on-site native materials or other nearby sources, were observed. These areas are generally limited to a small earthen dam and/or minor roads associated with previous agricultural operations. Table I presents some of the pertinent engineering characteristics of the bedrock materials at the site. SCS&T 9021053 May 22, 1990 Page 7 TABU: I GENERALIZED ENGINEERING CHARACTERISTICS OF MAIN (3X3L0GIC UNITS Unit Name and Synfcol Topsoils Amount of Oversize Rippability Material Rippable Nominal Slope Stability/ Expansive Erosion Compressibility Potential Moderately to Highly Erodible Moderate to Low to High High Younger .M luvium-Qyal Rippable Nominal Moderately to Highly Erodible Moderate to High Moderate to High Tertiary Volcanic Rock-Tv Marginally Rippable to Nonrippable Moderate to High Generally Good Ncmiinal Nominal Lusardi Formation-Kl Rippable Low to Moderate Moderately Erodible Low Low Granitic Rocks- Kgr (Granodiorite) Generally Rippable to + 15 Feet Low to Moderate Good Nominal Nominal Granitic Rocks- Kgr (Tonalite) Marginally Rippable to Nonrippable Moderate to High Good Nominal Nominal Metavolcanic and Hypabyssal Rocks-Jmv Marginally Rippable to Nonrippable Moderate to High Good Nominal Nominal SCS&T 9021053 May 22, 1990 Page 8 TECTONIC SETTING: A few small, apparently inactive faults have been mapped previously within the vicinity of the site. No evidence of faulting was noted in oior 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 are present within the vicinity of the site. These are probably related, at least in part, to the strong tectonic forces that dominate the Southem Califomia region. These features are usually near-vertical and strike in both a general northwesterly direction (subparallel to the regional stmctural trend) and in a general northeasterly direction (subperpendicular to the regional stmctural trend). All cut slopes should be inspected by a qualified geologist to assess the presence of adverse jointing conditions in the final slopes. In addition, it should be recognized that much of Southem Califomia, is characterized by major, active fault zones that could possibly affect the subject site. The nearest of these is the Elsinore Fault Zone, located approxinately 20 miles to the northeast. It should also be noted that the possible off-shore extension of the Rose Canyon Fault Zone is located approxinately 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. It is anticipated that the Rose Canyon Fault Zone will be classified as active in the near future. 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 vest, the Agua Bianca and San Miguel Fault Zones to the south, and the Elsinore and San Jacinto Fault Zones to the northeast. SCS&T 9021053 May 22, 1990 Page 9 OEXDUOGIC 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. GROUNDSHAKING: One of the most likely geologic hazards to affect the site is groundsha]cing as a result of movement along one of the major, active fault zones mentioned above. The maximum bedrock accelerations that would be attributed to a naximum 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 magnitude 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 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 BanJcs, San Jacinto, or Elsinore Fault Zones. Experience has shown that stmctures that are constmcted in accordance with the Uniform Building Code are fairly resistant to seismic related hazards. It is, therefore, our opinion that stmctural damage is unlikely if such buildings are designed and constmcted in accordance with the minimum standards of the most recent edition of the Uniform Building Code. SEISMIC SURVEY AND RIPPABILITy CHARACTERISTICS GQiERAL: Four seismic refraction traverses have been performed within or adjacent to the subject site. The results of that traverses are presented SCS&T 9021053 May 22, 1990 Page 10 below and on Plates Number 22 through 24. However, it is anticipated that the rippability characteristics of the materials within Village "U" will be similar to those of the surrounding areas. It is expected that the metavolcanic and hypabyssal rocks will be rippable to depths of approxinately 5 to 10 feet while the granitic rocks will be rippable to greater depths, on the order of 10 to 20 feet. TAHLE III Seismic Traverse No. SU-10 Area: U Geologic Unit: Ciranite Rock (Granodiorite) Interpretation: 0' - 17' Rippable 17' + 30' Nonrippable Seismic Ttavetse No. SU-IO-R Area: U Geologic Unit: Granite Rock (Granodiorite) Interpretation: 0' - 17' Rippable 17' + 30' Nonrippable Seismic Traverse No. SW-13 Area: W Geologic Unit: Granite Rock (Tonalite) Interpretation: 0' - 15' Rippable 15' - 30' Nonrippable Seismic Traverse No. SW-14 Area: W Geologic Unit: (Sranitic Rock (Tonalite) Interpretation: 0' - 21' Rippable 21' - 30' Nonrippable SCS&T 9021053 May 22, 1990 Page 11 TABLE II (continued) Seismic Traverse No. SW-14-R Area: W Geologic Unit: Granitic Rock (Tonalite) Interpretation: 0' - 14' Rippable 14' - 30' Marginally Rippable Seismic Traverse No. S-73-14 Area: W Geologic Unit: Metavolcanic Interpretation: 0' - 16' Nonrippable RIPPABIIilTY CHARACTERISTIC OF aWNODIORITIC ROCK RIPPABLE CONDITION (0-4,500 FT./SEC.): 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, well graded sand, whereas the floaters will require disposal in an area of nonstmctural fill. Some areas containing numerous hardrock floaters may 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 fron 3,500 to 4,000 fps are rippable with difficulty by backhoes and other light trenching equipnent. MARGINAEIiY RIPPABLE CONDITION (4,500 FT./SBC.-5,500 FT./SEC.): 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 extensive areas of fractured granitics. Excavations may produce material that will partially break down into a coarse, 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. SCS&T 9021053 May 22, 1990 Page 12 Materials within this velocity range are beyond the capability of backhoes and lighter trenching equipment. Difficulty of excavation would also be realized by gradalls and other heavy trenching equipment. NONRIPPAHLE aMDrnON (5,500 FT./SEC. & (SWEATER): 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 material requiring disposal in areas of nonstmctural fill. This upper limit has been based on the Rippability Chart shown on Plates Number 22 through 24 utilized for this report. However, as noted in the Caterpillar Chart on Plates Nunter 19 through 21, this upper limit of rippability may sometimes be increased to 7,000 to 8,000 fps material using the D-9 mounted #9 Series D Ripper. RIPPABILITy CHARACTERISTICS OF MEIMWICANICS AND ASSOCIATED HyPABySSAL ROCKS AMD TONALITIC ROCKS PTPPARTJ: CONDITION (0-4,500 FT./SEC.): This velocity range indicates rippable materials v^ich may vary from deconposed metavolcanics at lower velocities to only slightly decomposed, fractured rock at the higher velocities. Although rippable, materials may be produced by excavation that will not be useable in stmctural fills due to a lack of fines. E:qperience 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" naterial. For velocities between 3,500 to 4,500 fps, rippability will be difficult for backhoes and light trenching equipment. SCS&T 9021053 May 22, 1990 Page 13 MARGINALLY RIPPABLE CONDITION (4,500-5,500 FT./SEC.): Excavations in this velocity range would be extremely time consuming and would produce fractured rock with little or no fines. The higher velocities could require blasting. Trenching equipment would not function. NONRIPPABEE CONDITION (5,500 FT./SEC- & GREATER): 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 sone metavolcanics, ripping might be accomplished in as high as 8,000 fps naterial. SEISMIC TRAVERSE LIMITKnONS The results of the seismic survey for this investigation reflect rippability conditions only for the areas of the traverses. Hovever, the conditions of the various soil-rock units appear to be similar for the remainder of the site and may be assumed 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 acciirately predictable. The seismic refraction method requires that materials become increasingly dense with depth. In areas where denser, higher velocity materials are underlain by lower velocity materials, the lower velocity materials would not be indicated by our survey. All of the velocities used as upper limits for rippability are subject to fluctuation depending upon such local variations in rock conditions as: SCS&T 9021053 May 22, 1990 Page 14 a) Fractures, Faults and Planes of Weakness of Any Kind b) weathering and Degree of Deconposition 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 materials may become totally dependent on the tijTB available and the economics of the project. Ripping of higher velocity materials can be achieved but it may become economically infeasible. OROUNDWATER: No groundwater was encountered during our subsurface explorations for the referenced reports. Even though no major groundwater problems are anticipated either during or after constmction 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 which are to receive fill. It should be realized that groundwater problems may occur after development of a site even where none were present before development. These are usually minor phenomena and are often the result of an alteration of the permeability characteristics of the soil, an alteration in drainage pattems and an increase in irrigation water. Based on the permeability characteristics of the soil and the anticipated usage of the development, it is our opinion that any seepage problems which may occur will be minor in extent. It is further our opinion that these problems can be most effectively corrected on an individual basis if and v^en they develop. CONCLUSIONS AND RECOMMENDATIONS tiKKKAL In general, no geotechnical conditions were encountered which would preclude the development of the site as tentatively planned, provided the recomtendations presented herein are followed. SCS&T 9021053 I^Y 22, 1990 Page 15 The main geotechnical condition that will affect the proposed site developnent include hard granitic, netavolcanic, volcanic and hypabyssal rock, which will require heavy ripping and blasting in order to make the proposed excavations. It is anticipated that the material generated from the cuts of the granitic, metavolcanic, volcanic and hypabyssal rock will contain relatively low amounts of fine soils and large amounts of oversized material. Since rock fills require a percentage of fine soil, mining of the site, inporting of fine materials or exporting excess rock may be necessary. Existing loose surficial deposits such as topsoils, subsoils, younger alluvium, and any weathered formational materials encountered are considered unsuitable for the support of settlement sensitive inprovements, and will require rentjval and/or replacement as conpacted fill. Expansive soils were also present within the subject area. Where possible, select grading is recomtended to keep nondetrimentally expansive soils within four feet from finish pad grade. In areas viiere this is not feasible, special foundation consideration will be necessary. However, it is anticipated that only minor amounts of expansive soils will be encountered. GRADING SITE PREPARflnCNi Site preparation should begin with the removal of any existing vegetation and deleterious natter from proposed improvement areas. Removal of trees should include their root system. Any existing loose surficial deposits such as topsoils, subsoils, uncompacted fills, and younger alluvium in areas to be graded should be removed to firm natural ground. The extent of the topsoils and subsoils will be up to approximately one to two feet. Firm natural ground is defined as soil having an in-place density of at least 90 percent. Soils exposed in the bottom of 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 D 1557-78, Ifethod 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 inprovements. SCS&T 9021053 May 22, 1990 Page 16 SEUSCT GRADING: Expansive soils should not be allowed 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, v*iichever is more. Select material should consist of granular soil with an expansion index of less than 50. It is recommended that select soils have relatively low permeability characteristics. 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 stmcture. Minimum lateral extent of select grading should be five feet away from the perimeter of settlement-sensitive improvements. COT/FILL TRANSmON: It is anticipated that a transition line betveen cut and fill soils nay run through some of the proposed building pads. Due to the different settlement characteristics of cut and fill soils, constmction of a stmcture partially on cut and partially on fill is not reconmended. Based on this, we 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 minimum horizontal limits of these recamendations should extend at least five feet outside of the proposed inprovements. IMPORTED FILL: All fill soil inported to the site shouid be granular and should have an ejqansion index of less that 50. Further, import 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 representative of this office prior to inporting. RIPPABILITy: It is anticipated that the proposed cuts will require heavy ripping and blasting. Plates Nunter 22 through 24 contain the results of our seismic traverses. The results are sunmarized within this report. This condition will be further evaluated during the preparation of the geotechnical investigation report. A±iitional seismic traverses will be performed in areas where deep cuts are proposed. SCS&T 9021053 May 22, 1990 Page 17 OVERSIZED ROCK: Oversized rock is defined as material exceeding six inches in maximum dinension. It is anticipated that oversized material will be generated from proposed cuts. Oversized material may bp placed in stmctural fills as described in Plate Number 14, SLOPE CONSTRUCTION: The face of all fill slopes should be conpacted by backrolling with a sheepsfoot conpactor 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 required. SURFACE nxUVINfiGE: It is reconmended 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 15. EARIHHORK: All earthwork and grading contenplated for site preparation should be accomplished in accordance with the attached Reconmended Grading Specifications and Special Provisions. All special site preparation recomnendations presented in the sections above will supersede those in the Standard Reconmended Cirading Specifications. All entanJatents, stmctural fill and fill should be conpacted to at least 90% relative conpaction at or slightly over optimum moisture content. Utility trench backfill within five feet of the proposed stmctures and beneath asphalt pavements should be conpacted to minimum of 90% of its naximum dry density. The upper tvelve 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 naterial and should not SCS&T 9021053 May 22, 1990 Page 18 be part of the nass grading requirements. The maximum dry density of each soil type should be determined in accordance with ASTM Method D 1557-78, Method A or C. SLOPE STABnjTy Proposed cut and fill slopes should be constmcted at a 2:1 (horizontal to vertical) or flatter inclination. It is estimated that cut and fill slopes will extend to a maximum height of about 20 feet and 30 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 Number 16). The engineering geologist should observe all cut slopes during grading to ascertain that no adverse conditions are encountered. FOUNDATIGNS GENERAL: If the lots are capped with nondetrimentally expansive soils, conventional shallow foundations nay 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-two-story constmction, respectively. A minimum width of 12 inches and 18 inches is recomtended for continuous and isolated footings, respectively. A bearing capacity of 2000 psf may be assumed for said footings. This bearing capacity nay be increased by one-third v^en considering wind and/or seismic forces. Footings located adjacent to or within slopes should be extended to a depth such that a minimum distance of six feet and seven feet exist between the footing and the face of cut slopes or fill slopes, respectively. Retaining walls in similar conditions should be individually revieved by 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 be necessary. This generally consists of deepened and more heavily reinforced footings, thicker, more heavily reinforced slabs. Reconnendations for expansive soil conditions will be provided after site grading when the expansion index and depth of the prevailing foundation soils are known. SCS&T 9021053 May 22, 1990 Page 19 REINPOTCEMENT: Both exterior and interior continuous footings should be reinforced with at least one No. 4 bar positioned near the bottom of the footing and one No. 4 bar positioned near the top of the footing. This reinforcement is based on soil characteristics and is not intended to be in lieu of reinforcenent necessary to satisfy stmctural considerations. If expansive soils exist within four feet of finish grade, additional reinforcing will be necessary. INTERIOR CONCRETE ON-GRADE SLABS: If the pads are capped with nondetrinentally expansive soils, concrete on-grade slabs should have a thickness of four inches and be reinforced with at least No. 3 reinforcing bars placed at 36 inches on center each way. Slab reinforcement should be placed near the middle of the slab. As an altemative, the slab reinforcing nay consist of 6"x6"-W1.4xW1.4 (6'x6"-10/10) welded wire mesh. However, it should be 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 be placed under the slab. This layer should consist of material having 100 percent passing the one-half-inch screen; no nore 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 be overlain by a visqueen moisture barrier and a two-inch-thick layer of sand or silty sand should be provided above the visqueen to allow proper concrete curing. EEEERIOR SLflBS-aN-a»LE: For nonexpansive soil conditions, exterior slabs should have a minimum thickness of four inches. Walks or slabs five feet in width should be reinforced with 6"x6"-W1.4xW1.4 (6"x6 "-10/10) velded wire mesh and provided with weakened plane joints. Any slabs between five and ten feet should be provided with longitudinal weakened plane joints at the center lines. Slabs exceeding ten feet in width should be provided with a weakened plane joint located three feet inside the exterior perimeter as indicated on attached Plate Number 17. Both traverse and longitudinal weakened plane joints should be constmcted as detailed in Plate Nunter 17. Exterior slabs adjacent to doors and garage openings should be 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. SCS&T 9021053 May 22, 1990 Page 20 SPECIAL LOTS: Special lots are defined as lots underlain by fill with differential thickness in excess of ten feet. The following increased foundation reconmendations should be utilized for said lots. Footings should be reinforced with two Nb. 4 bars positioned near the bottom of the footing and two No. 4 bars positioned near the top of the footing. Concrete on grade slabs should be 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 be evaluated on an individual basis. EXPANSIVE CHARMnERISTICS: 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 CHZVP/CIERISTICS: The anticipated total and/or differential settlements for the proposed stmctures may be considered to be within tolerable limits provided the reconmendations presented in this report are followed. It should be recognized that minor hairline cracks on concrete due to shrinkage of constmction materials or redistribution of stresses are normal and may be anticipated. EAREH RETAINING WALLS PASSIVE PRESSURE: The passive pressure for the prevailing soil conditions may be considered to be 450 pounds per square foot per foot of depth up to a maximum of 2000 psf. This pressure may be increased one-third for seisndc loading. The coefficient of friction for concrete to soil may be assuned to be 0.35 for the resistance to lateral movement. When combining frictional and passive resistance, the former should be reduced by one-third. The upper 12 inches of exterior retaining wall footings should not be included in passive pressure calculations v^en landscaping abuts the bottom of the wall. ACTIVE PRESSURE: The active soil pressure for the design of unrestrained earth retaining stmctures with level backfills may be assumed to be equivalent to the pressure of a fluid veighing 35 pounds per cubic foot. For SCS&T 9021053 May 22, 1990 Page 21 2:1 (horizontal to vertical) sloping backfills, 14 pcf should be added to the preceding values. These pressures do not consider any surcharge. If any are anticipated, this office should be contacted for the necessary increase in soil pressure. This value assumes a drained backfill condition. Waterproofing details should be provided by the project architect. A subdrain detail is provided on the attached Plate Number 18. BACKFILL: All backfill soils should be conpacted to at least 90% relative conpaction. Expansive or clayey soils should not be used for backfill material. The wall should not be backfilled until the masonry has reached an adequate strength. FICIOR OF SAFETY: The above values, with the exception of the allowable soil bearing pressure, do not include a factor of safety. .?^ropriate factors of safety should be incorporated into the design to prevent the walls from overtximing and sliding. LIMITKTIONS REVIEW, OBSERVKTICK AND "USSl'JJWS The reconnendations presented in this report are contingent upon our review of final plans and specifications. Such plans and specifications shouid be made available to the geotechnical engineer and engineering geologist so that they may review and verify their conpliance with this report and with Chapter 70 of the Uniform Building Code. It is recomiended that Southem Califomia Soil & Testing, Inc. be retained to provide continuous soil engineering seirvices during the earthwork operations. This is to verify compliance with the design concepts, specifications or reconmendations and to allow design changes in the event that sx±)surface conditions differ from those anticipated prior to start of constmction. SCS&T 9021053 May 22, 1990 Page 22 UNiPORMrry OF OONDITIONS The reconnendations and opinions expressed in this report reflect our best estimate of the project requirements based on an evaluation of the subsurface soil conditions encountered at the subsurface exploration locations and on the assumption that the soil conditions do not deviate appreciably from those encountered. It should be recognized that the perfomance of the foundations and/or cut and fill slopes may be influenced by undisclosed or unforeseen variations in the soil conditions that may occur in the intermediate and unexplored areas. Any unusual conditions not covered in this report that may be encountered during site development should be brought to the attention of the geotechnical engineer so that he may make modifications if necessary. CHSNGE 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 herein are appropriate. This should be verified in writing or modified by a written addendum. TIME LIMETflTICNS 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^ther they be due to natural processes or the work of man 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 may be invalidated wholly or in peurt by changes beyond our contml. Therefore, this report should not be relied upon after a period of two years without a review by us verifying the suitability of the conclusions and reconnendations. SCS&T 9021053 May 22, 1990 Page 23 PROFESSIONAL STANDARD In the performance of our professional services, we comply with that level of care and skill ordinarily exercised by members of our profession currently practicing under similar conditions and in the sane locality. The client recognizes that subsurface conditions may vary from those encountered at the locations where our trenches, surveys, and explorations are made, and that our data, interpretations, and reconmendations are based solely on the information obtained by us. We will be responsible for those data, interpretations, and reconnendations, but shall not be responsible for the interpretations by others of the information developed. Our seirvices consist of professional consultation and observation only, and no warranty of any kind whatsoever, express or implied, is made or intended in connection with the work performed or to be performed by us, or by our proposal for consulting or other services, or by our fumishing of oral or written reports or findings. CLIENT'S RESPONSIBILITy It is the responsibility of Lyon Communities Incorporated, or their representatives to ensure that the information and reconmendations contained herein are brought to the attention of the stmctural engineer and architect 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 subcontractors carry out such reconnendations during constmction. FIELD EXPLDRKTIONS Six subsurface trench explorations vere made at the locations indicated on the attached Plate Nunter IA and IB and IC on Decenter 16 and 21, 1982, adjacent to or within the subject site (see Plates Number 3 through 7). In addition. Plates Nunter 8 through 10 from the referenced reports contain additional trench excavations made December 15, 1982, of similar soils SCS&T 9021053 May 22, 1990 Page 24 within the subject subdivision. These explorations consisted of trenches dug by the neans of a backhoe. Three seismic traverses were also performed January 11, 1983, and one April 14, 1973. The field work was conducted under the observation of our engineering geology personnel. The results are shown on Plates Nunter 22 through 24. The soils are descrited in accordance with the Unified Soils Classification System as illustrated on the attached siitplified 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. The consistency of silts or clays is given as either very soft, soft, medium stiff, stiff, very stiff, or hard. LABORATORy TESTING Laboratory tests were perfomed in accordance with the generally accepted American Society for Testing and Materials (ASTM) test methods or suggested procedures. A brief description of the tests perfomed is presented below: a) CLASSIFICKTION: Field classifications were verified in the laboratory by visual examination. The final soil classifications are in accordance with the Unified Soil Classification System. b) lOISIURE-COISITy: In-place moisture contents and dry densities were determined for representative soil samples. This information was an aid to classification and permitted recognition of variations in material consistency with depth. The dry unit weight is determined in pounds per cubic foot, and the 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 vras determined for representative sanples of the native soils in accordance with ASTM D422. The results of these tests are presented on Plate Number 11. SCS&T 9021053 May 22, 1990 Page 25 d) COMPACTION TEST: The maximum dry density and optimum moisture content of typical soils vere determined in the laboratory in accordance with ASIM Standard Test D-1557-78, Method A. The results of these tests are presented on the attached Plate Number 12. 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 12. Allow the triimed, undisturbed or remolded sanple to air dry to a constant moisture content, at a temperature of 100 degrees F. Place the dried sanple in the consolidometer and allow to compress under a load of 150 psf. Allow moisture to contact the sanple and measure its expansion from an air dried to saturated condition. f) DIRECT SHEAR TESTS: Direct shear tests vere perfomed to determine the failure envelope based 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 heiqht of 1.0 inch. Samples 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. The average shear strength values for granitic and metavolcanic rock are presented on attached Plate Number 13. INSERT DRAWINGS HERE SUBSURFACE EXPLORATION LEGEND UNIFIED SOIL CLASSIFICATION CHART SOIL DESCRIPTION GROUP SYMBOL Sieve size. CLEAN GRAVELS I. COARSE GRAINED, more than naif of material is 1arger tnan No. 200 GRAVELS More tnan naif of coarse fraction is larger than No. 4 sieve size but smaller tnan 3". GRAVELS WITH FINES (Appreciable amount of fines) SANDS More tnan naif of coarse fraction is smaller tnan No. 4 sieve size. :LEAN SANOS GW GP GM GC SW SP SANDS WITH FINES SM (Appreciable amount of fines) SC II. FINE GRAINED, more than naif of material is sma Her than No. 200 sieve size. SILTS AND CLAYS Liquid Limit less than 50 SILTS AND CLAYS Liquid Limit greater than 50 ML CL OL MH CH OH HIGHLY ORGANIC SOILS PT -Y?::AL NAMES Well gradefi gravels, gravel- sand mixtures, little or no fines. Poorly graoed gravels, gravel sand mixtures, little or no fines. Silty gravels, poorly graded gravel-sano-silt mixtures. Clayey gravels, poorly graded gravel-sand, clay mixtures. Well graded sand, gravelly sands, little or no fines. Poorly graced sands, gravelly sands, little or no fines. Silty sands, poorly graded sand and silty mixtures. Clayey sands, poorly graded sand and clay mixtures. Inorganic silts and very fine sands, rocic flour, sandy silt or clayey-silt-sand mixtures witn slight plas- ticity. Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays. Organic silts and organic silty clays or low plasticity. Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, elastic silts. Inorganic clays of high plasticity, fat clays. Organic clays of medium to high plasticity. 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 y\ SOUTHERN CALIFORNIA SOIL A TESTINQ, INC. CALAVERA HEIGHTS-VILLAGE U BY: KAR JOB NUMBER: 9021053 DATE: 5-15-90 Plate No. 2 Class TRENCH .\'0. TT-A<i Description 7, SM/ SC SO/ CL Brown, Moist, Mediuin Dense, Clayey Silty Sand (Topsoil) Yellow-brown, Moist, Stiff, Sandy Clay SM Yellow-brown and Gray-brown, Moist, Dense to Very Dense, Gravely Silty Sand (Granite Rock) Trench Ended at 4 Feet .--^ BOUTHERN CALIFORNIA ^^SL^ SOIL & TESTINQ , INC. IAN OiraO, CALiranNIA CALVERA HEIGHTS-VILLAGE U BY JOB NO. CRB 9021053 DATE 12-If;-.q 2 Plate No. 3 TRENCH NO. TT-48 Class Description Z / I SM :L Brown, Moist, Mediuin Dense, Silty Sand (Topsoil) Gray-brown, Moist, Stiff, Sandy Clay (Weathered Rock) Yellow-brown and Gray-brown, Moist, Dense to Very Dense, Silty Sand (Granitic and Metavolcanic Rock) Trench Ended at 5 Feet SOUTHERN CALIFORNIA SOIL & TESTING , INC. •••o nivanoALB BTRMT •AN oiaao, CAkiFonNiA ••iao CALAVERA HEIGHTS-VILLAGE U BY CRB JOB NO. 9021053 OATE 12-21-82 Plate No. I Class SM TRENCH NO. TT-50 Description Gray-brown, Moist, Dense to Very Dense, Silty Sand (Decomposed Granite) Trench Ended at 4 Feet . SOUTHERN CALIFORNIA X SOIL & TESTING , INC. •AN oiaoa. CALiKHNiA ••^•a CALAVERA HEIGHTS-VILLAGE U BY CRB OATE 12-21-82 JOB NO. ~ 9021053 Plate Mo. 6 TRENCH NO. Class Description / SM CL SM Brown, Moist, Medium Dense, Silty Sand (Topsoil) ray-brown, r-ioist, btitt, tlandy Ciay (Weathered Rock) Yellow-brown and Gray-brown, Moist, Dense to Very Dense, Silty Sand (Granitic and Metavolcanic Rock) Trench Ended at 3 Feet I I SOUTHBRN CALIFORNIA •OIL & TESTING, INC. CALAVERA HEIGHTS-VILLAGE U BY JOB NO. CRB 9021053 OATE 12-21-82 Plate No "5 Class •i) •61 7 SM/ ^C SM TRENCH NO. TV-51 Description Red-brown, Moist, Medium Dense, Clayey Silty Sand (Topsoil) Dark Gray, Moist, Dense to Very Dense, Sandy Gravel (Granitic Rock) Refusal at 1.5 Feet SOUTHERN CALIFORNIA SOIL & TESTING , INC. •••o RivanoACB •TnaaT • AN OIBOa, CAi.ll>aRNIA ••IBO CALAVERA HEIGHTS-VILLAGE U BY CRB JOB NO. 9021053 OATE 12-21-82 Plate iNu. r I TRENCH NUMBER < u —1 15 u. 1 1 s 1 in < 1 1 —. U 1 • EECi=;if="riCN SM/Sq RED BROWN, CLAYEY SILTY SAND (TOPSOIL) •11 iii = < tn a. — X O < 2 Z Ul oc < a. Q. CO z o o z c o z Ui a >-c Q IT 3 t- W Z CO Ui 1 z 2 o (J Ui oc < a. S o u SOUTHERN CALIFORNIA SOIL A TESTING,INC. SUBSURFACE EXPLORATION LOG LOGGED BY: CRB JOB NUMBER '• 9021053 DATE LOGGED: 12-15-82 Plate No. 8 z t TRENCH NUMBER -o 15 I u. 1 5i_EVATlC: "sl •ESC=i : N - X ... X ^ < tn a. — a. O < Z = z C JJ oJ CO ac a. a. < V) tii 2 O o O tfl z _ Ui — > X a Oi il X 3 I- Z 1 ^ 2 O Ui Q > — < < -< a. •= o BAG^M/SC c:-: I RED BROWN. CLAYEY SILTY SAND (TOPSOIL) MOIST MEDIUM DENSE SM CK CK YELLOW BROWN, SILTY SAND (DECOMPOSED GRANITE) MOIST DENSE TO VERY DENSE 118.2 10.8 TRENCH ENDED AT 8' TRENCH NUMBER TO-7 CK RED BROWN. SILTY SAND (TOPSOIL) MOIST MEDIUM DENSE — ML SM N DARK GRAY, GRAVELY SILTY SAND (DECOMPOSED GRANITE) MOIST DENSE TO VERY DENSE — \ i 1 TRENCH ENDED AT 2' — J ^ SOUTHERN CALIFORNIA SUBSURFACE EXPLORATION LOG rr SOIL A TESTING,INC. LOGGED BY: „„„ CRB DATE LOGGED: 12-15-82 rr SOIL A TESTING,INC. JOB NUMBER: go2i053 Plate No. 9 r 1 f 'TRENCH NUMBER ~ : - : < I I ^ I 5 ^ ; E_5VAT;-NJ - I - I 71 L Q. I 5 I ,^ f— < I < t -I G I < cn Q. — i o • EEC=ilPTlCN E < a a. < — I— X O CO z _ Ui — > X a Ui CO O s z o a Ui > Ui E Z o o < a 2 o u - SM/ I RED BROWN, CLAYEY SILTY SC I SAND (TOPSOIL) MOIST MEDIUM DENSE GM \-BAGI GRAY, SANDY GRAVEL (METAVOLCANIC ROCK) MOIST DENSE TO VERY DENSE — TRENCH ENDED AT 5' — 1 TRENCH NUMBER TQ-9 - SM/ SC RED BROWN, CLAYEY SILTY SAND (TOPSOIL) MOIST MEDIUM DENSE — CL GRAY BROWN, SANDY CLAY (WEATHERED DECOMPOSED GRANITE) MOIST STIFF — GRAY BROWN, SANDY CLAY (WEATHERED DECOMPOSED GRANITE) CK SM YELLOW BROWN, SILTY SAND (DECOMPOSED GRANITE) MOIST DENSE TO VERY DENSE 128.1 10.1 — -si BAG — 6 TRENCH ENDED AT 5' 1 ~ — SOUTHERN CALIFORNIA SUBSURFACE EXPLORATION LOG SOIL A TESTING,INC. LOGGED BY: DATE LOGGED: 12-15-82 SOIL A TESTING,INC. JOB NUMBER: 9021053 Plate No-. 10 Q 33 > Z N m 2 CD c H o z sf 9 o ro I—" o tn CO 5a o mO pa •a z > n > |— m 36 100 90 ao 70 I 60 so S 40 t 30 20 10 IOOO US Standard Sieves ,- Kz" '4" •'<) •20 •40 iHiO 21 Hydrometer (Minutes) I 2 S JO IOO »e 74 S « 1 i 180 DO eo 70 10' tu 99 I i I « i 2 ^ tt •I. 20 — U 1 rt n> o I 00 cn CO I PARTICLE SIZE LIMITS 1 BOULDER! COBBLES 1 GRAVEL Coorit Fint (12 in ) 3 in. 3/4 in. U. S. Tq-2 @ 3' TQ-2 @ 4'-5' TQ-8 0 4'-5' SANO Coorit Mfdium Fina SILT OR CLAY No.4 No.lO STANDARD No.40 SIEVE No.200 SIZE }4AXiyUli DENSITY & OPTIMUM MOISTURE CONTENT ,STM 01557-73 METHOD A .AMP c DESCRiP'lON Maximum Densit y (pet) Optimum Moisture Cont (•/.) -3' 1 Yellow Brown, Silty Gravelly Sand 114.8 13.8 iU-2 a 2 j Green Brown, Sandy Silty Clay 114.0 15.0 -2 0 4 -5' j Yellow/Reddish Brown, Silty Sand 112.6 14.8 |TQ-8 @ 3 ' -4' j Grey, Silty Sandy Gravel 128.4 11.7 EXPANSION TEST RESULTS 1 SAMPLE TQ-Z LJ 2'-3' TQ-2 (3 3'-4' CONDITION Remolded 'i Remolded 1 NllTIAL M.C. (•/.) 1 1(3.1 ' 14.8 ! 1 ' INITIAL lEMSITY tPCFl 101.3 101.8 | j • INAL M.C. (•/.) 30.5 26.0 1 ^'ORMAL STRESS CPSF) 150 150 1" -XPANSION % 15.0 0 SOUTHERN CALIFORNIA SOIL A TESTING, INC. CALAVERA HEIGHTS-VILLAGE BY: KAR JOB NUMBER 9021053 DATE: 1-10-84 Plate No, 12 I 0) UJ £ )- c < UJ X (A DIRECT SHEAR SUMMARY 1 2 2M L 2L NORMAL STRESS, KSF SAMPLE DESCRIPTION ANQLE OP INTERNAL FRICTION (•) COHESION INTERCEPT (psf) TQ-8(33'-4' Remolded to 90% 38 200 CALAVERA HEIGHl "S-VILLAGE •T: KAR DATE: 5-01-90 JOB NUMBCR: 9021053 Plate No. 13 SOUTHBRN CALIFORNiA SOiL A TESTING,INC. o n 01 H O z o (A o c H Z PI o > r o m a CO o ro I—• o cn CO Ol rf ID > H m cn I ' cn I CO o 3> m TO m t—I tn 3: -I c/1 I cn jm:fiSIZ£_BQClL_DISPQSAL_ ( Slruclurul Soil" Rock Fill ) P/L _ ^ min. ZONE D I Q . 12' 'min. • mm COi^tCttd toll rill tMII CMlKlR tt l«<lt 40 ptrctnt tall itiM M*tlM 3/4.Uck «ltt«, (b| •tliht), tnd k« coa^tct«4 U ccctrdMU xlU MMirictiloni for itr«ct«r«l rill. Itckt avar 4 rati U MIIMI 4laMflon not ptralttld IN rill. {OK «: lUNC I: IONC C: IONC 0: HUM hu rock frtgncnti over i Incnci In qrtHtM pitred In Comfnam toll nil. dUMAtloA. RiKks 2 lo 4 feet In aiiiliiiui* diMefltlon •:iMP4ClCd toll rill confurMlnf to IONC A. toKki i Inchet lo ? <cel In KialiKM diaenilon unWomly dlvlrlbu- led tn4 Mtll iptceii In coadicled toll nil tonforaU) le IOU «. Nequired for tll ealvlln) tlopet (:| «nd tieeptr, 901 alnlmm co^iMtlon. IONC A. I, or C Mtlcrltl aiy bc uted for lONt 0. NATURAL 3ROUND BENCHING REMOVE UNSUITABLE MATERIAL SUBDRAIN TRENCH: SEE DETAIL AAB ETAIL A FILTER MATERIAL e CUBIC FEET/FOOT I i I I FILTER MATERIAL SHALL BE CLASS 2 PERMEABLE MATERIAL PER STATE OF CALIFORNIA STANDARD SPECIFICATIONS, AND APPROVED ALTERNATE. CLASS 2 FILTER MATERIAL SHOULD COMPLY WITH THE FOLLOWINQ LIMITS OETAIL A-1 PERFORATED PIPE 4' « MINIMUM DETAIL A-2 PERFORATED PIPE SURROUNDED WITH FILTER MATERIAL SIEVE SIZE 1 3/4 3/8 No. 4 Ho. a No. 30 No. 60 No. 200 % PASSINQ 100 90-100 40-100 28-40 18-33 5-16 0-7 O-S ETAIL B DETAIL OF CANVON SUBDRAIN TERMINAL « MIN OVERLAP DESIQN FINISH QRADE FILTER FABRIC MIRAFI 140 OR APPROVED EOUIVALENT) "TTTT —r-— .MP •.io 1 < ETAIL \ 1 1/2 MAX QRAVEL OR / DETAIL B-1 ^ APPROVED EOUIVALENT V-2 6 CUBIC FEET/FOOT 1/2"QRAVEL WRAPPED IN FILTER FABRIC '^'JBDRAIN INSTALLATION:SUBDRAiN PIPE SHALLBE INSTALLED WITH PERFORATIONS DOWN ISUBDRAIN 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 /X SOUTHERN CALIFORNIA CALAVERA HEIGHTS-VILLAGE SOIL A TESTING, INC. BY: KAR DATE: 5-15-90 SOIL A TESTING, INC. JOB NUMBER: 9021053 Plate No. 15 I I i I I SLOPE STABILITY CALCULATIONS Janbu's Simolified Slooe Stabilitv Method Assume Homogeneous Strength Parameters througnout the slooe ^ C(psf) W.(pcf) Incl. H (ft) 38 200 130 2:1 30 2.3 Metavolcanic & Granitic Rock * :ut & Fill Slopes * Average Shear Strength Values VJhere: ,3' C w s H FS Angle of Internal Friction Cohesion (psf) Unit weight of Soil (pcf) Height of Slope (ft) Factor of Safety yv SOUTHBRN CALIFORNIA CALAVERA HEIGHTS - VILLAGE {nr^ SOIL A TESTING,INC. BV: KAR DATE: 5-15-90 {nr^ SOIL A TESTING,INC. JOB NUMBER: 9021053 Plate No. 16 TRANSVERSE WEAKENED PLANE JOINTS Q' ON CENTER (MAXIMUM) SLABS IN EXCESS OF 10 FEET IN WIDTH PLAN NO SCALE w/2 w/2 i » » SLABS' 5 TO 10 FEET IN WIDTH 1 n TOOLED JOINT r/2 (6'X6-.10/10) WELDED WIRE MESH \ \ WEAKENED PLANE JOINT DETAIL NO SCALE SOUTHERN CALIFORNIA SOIL 1 TESTING, INC. CALAVERA HEIGHTS-VILLAGE BYI KAR- 9021053 DATE... 5-15-90 Plate No. 1 7 WATERPROOF BACK OF WALL PER ARCHITECTS SPECIFICATIONS 3/4 INCH CRUSHED ROCK OR MARIDRAIN MOO OR EQUIVALENT QEOFABRIC BETWEEN ROCK AND SOIL 4" DIAMETER PERFORATED PIPE HOUSE ON QRADE SLAB i I HOUSE RETAINING WALL SUBDRAIN DETAIL NO SCALE SOUTHBRN CALIFORNIA CALAVERA HEIGHTS-VILLAGE U ^^t^ SOIL A TESTING, INC. BV: KAR DATE: 5-15-90 ^^t^ SOIL A TESTING, INC. JOB NUMBER: 9021053 Plate No. 18 Salamic Velocity •••t POT •• • 1000 OSL CATERPILLAR PERFORMANCE HANDBOOK Edition 17 October 1986 ^0 11 12 13 14 15 TOPSOIL CLAY IGNEOUS ROCKS QRANITE 3ABALT SEDIMENTARY ROCKS SHALE SANDSTONE SILTSTONE CLAYSTONE CONOLOMERATE METAMORPHIC ROCKS SCHIST SLATE yy 1/ y \y i y z TTT 1.'" I RIPPABLE MARaiNAL L NON-RIPPABLE L DSL Ripper Performance • Multl or Single Shank No. 8 Ripper • Estimated by Seismic Wave Velocities SOUTHERN CALIFORNIA SOIL & TESTING, INC. CALAVERA HEIGHTS-VILLAGE BY: KAR JOB NUMBER: 9021053 DATE: 5-15-90 Plate No. 19 DSL CATERPILLAR PERFORMANCE HANDBOOK Edition 17 October 1986 Salamic Velocity '••I Pmr »maamm u lOOO 10 n 12 13 14 15 TOPSOIL CLAY IGNEOUS ROCKS aHANITE 3ASALT SEDIMENTARY ROCKS 3HALE SANDSTONE SILTSTONE CLAYSTONE CONOLOMERATE METAMORPHIC ROCKS SCHIST SLATE il i K \y I RIPPABLE MARQINAL L NON-RIPPABLE L D9L Ripper Performance • Multi or Single Shank No. 9 Ripper • Estimated by Seismic Wave Velocities SOUTHERN CALIFORNIA SOIL 3. TESTING, INC. CALAVERA HEIGHTS-VILLAGE BY: KAR JOB NUMBER; 9021053 DATE: 5-15-90 Plate No. 20 f I I I CATERPILLAR PERFORMANCE HANDBOOK Edition 17 October 1986 jolamic Velocity "at Pm nmmmmm • iooo I I I I D1 1 N Ripper Performance o Multl or Single Shank No. 9 Ripper • Estimated by Seismic Wave Velocities SOUTHERN CALIFORNIA ^ ^ SOIL 1-TESTING, INC. CALAVERA HEIGHTS-VILLAGE JOB NUMBER; 9021053 f RIPPABILITY NDEX NO RIPPING SOFT MEDIUM HARD BLASTING T |"l"|"r'|" r . p-j 1 ' I ' I' 1000 2000 3000 4000 5000 6000 700O 8000 9000 10000 VELOCITY, FT/SEC. RESULTS TRAVERSE NO. secPHi NOTE.* THE ABOVE RESULTS ATTEMPT TO SHOW DEPTHS TO HORIZONS OF VARYING DENSITY INDIFFERENT LOCATIONS OVER THE STUCYAREA, 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. SOUTHEniM CALIFOniMIA SOIL & TESTIMB LAB, INC. • ••O RIVEPOAl.* BTnEET •AN OIBOO, CALIFOPNIA aaiso CALAVERA HEIGHTS-VILLAGE U SEISMIC RESULTS BY DBA JOB NO. 9021053 DATE 1-11-83 Plate No. 22 RIPPABILITY INDEX NO RIPPING SOFT MEDIUM HARD BLASTING 6000 7000 8000 9000 10000 VELOCITY, FT/SEC RESULTS T:^ AVERSE NO. 33PHi a I b —r~ X ai Q NOTE: THE ABOVE RESULTS ATTEMPT TO SHOW DEPTHS TO HORIZONS OF VARYING DENSITY INDIFFERENT LOCATlC.*;S C. THE STUCY AREA. SEISMIC TRAVERSE NUMBERS ^ REFER TO LOCATIO^.S r iO: ZD ON ATTACHED PLANS. T«'RIPPABIUTY INDEX'lS A MCDIFICATION OF CHARTS BY THE CATERPILLAR CO. ANO ARTICLE IN 'ROADS A:;D STrZETS' SEPT. 1967. i I SOUTHEHN CALIFO-rjrA SOIL & TESTIMG LAE . .. ^ •••a RivanoALE smEEv BAN OIBOO, CAt-IPOniMIA BS. ..z: CALAVERA HEIGHTS-VILLAGE U SEISMIC RESULTS DBA JOB Na 9Q21Q53 DATE 1-11-83 Plate No. 23 RIPPABILITY NDEX NO RIPPING SOFT MEDIUM HARD BLASTING . •'^-i—'—r"^—r , 1000 2000 3000 400O 5000 6000 7000 8000 9000 10000 VELOCITY, FT/ SEC. RESULTS TRAVERSE NO. S73-5 S73-6 S73-8 S73-9 S73-lCS73-l;S73-l^S73-l; S73-l( GEDPH, IE a |& 0. IU Q ft MJ I I 1 NOTE: THE ABOVE RESULTS ATTEMPT TO SHOW DEPTHS TO HORIZONS OF VARYING DENSITY IN DIFFERENT LOCATIONS OVER THE STUW AREA. SEISMIC TRAVERSE NUMBERS REFER TO LOCATIONS PIOTED ON ATTACHED PtANS. THE'RIPRABIUTY INDEX'lS A MODIFICATION OF CHARTS BY THE CATERRLLAR CO. AND ARTICLE IN 'ROADS AND STREETS; SEPT 1967. SOUTHERN CAUFORNIA USTINQ LABORATORY. INC eaao RIVERDALE intccr CAUFORNIA 92120 134 CALAVERA HEIGHTS-VILLAGE U SEISMIC RESULTS DBA JOB Na 9021053 BATE 4-14-73 Plate No. 24 CALAVERA HEICSfTS VTLLflS: U, TAMARACK AVEHUE AND COLLEGE BOULEVARD, CARTSBAD RBCXHMENDED GRADING SPECIFICKTIONS - (3NERAL PROVISICNS GENERAL INHNr The intent of these specifications is to establish procedures for clearing, conpacting natural ground, preparing areas to be filled, and placing and compacting fill soils to the lines and grades shown on the accepted plans. The reconitEndations contained in the preliminary geotechnical investigation report and/or the attached Special Provisions are a part of the Recaimended 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. OBSERVAnCN AIO lESTING 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 VN^iether or not the vrork was accomplished 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 inforniation 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 reconnendations. (R-9/89) SCS&T 9021053 May 22, 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 compaction, adverse weather, etc.; construction should be stopped until the conditions are remedied or corrected or he shall reconmend rejection of this vork. Tests used to determine the degree of conpaction should be performed in accordance with the following American Society for Testing and Materials test methods: Maximum Density & Optimum Maisture Content - ASTM D-1557-78. Density of Soil In-Place - ASTM D-1556-64 or ASTM D-2922. All densities shall be expressed in terms of Relative Compaction as determined by the foregoing ASTM testing procedures. PREPARATION OF AREAS TO RECEIVE FILL All vegetation, brush and debris derived from clearing operations shall be removed, and legally disposed of. All areas disturbed by site grading should be left in a neat and finished appearance, free from unsightly debris. 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 vMch is defined as natural soils v^ich possesses an in-situ density of at least 90% of its maximum dry density. (R-9/89) SCS&T 9021053 May 22, 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 equipment width whichever 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 must be totally removed. All underground utilities to be abandoned beneath any proposed structure should be removed from within 10 feet of the structure and properly capped off. The resulting depressions from the above described procedures should be backfilled with acceptable soil that is compacted to the requirements of the 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 reccnTtendation will be necessary. All water wells v^ich will be abandoned should be backfilled and capped in accordance to the requirenents 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 whichever 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 Structvural Engineer. (R-9/89) SCS&T 9021053 May 22, 1990 Appendix, Page 4 FILL MKIERIAL 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 detriitental 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. PLACING AND COMPitTION OF FILL i^roved 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 moisture 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 compact 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 reconnendations 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 naximum size and spacing of rock permitted in structural fills and in non-structural fills is discussed in the geotechnical report, v^en applicable. (R-9/89) SCS&T 9021053 May 22, 1990 Appendix, Page 5 Field observation and conpaction tests to estimate the degree of compaction 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 conpaction, 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 other suitable equipnent. Compaction 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 compaction is being achieved. Where failing tests occur or other field problems arise, the Contractor will be notified that day of such conditions by written conmunication from the Geotechnical Engineer or his representative in the form of a daily field report. If the method of achieving the required slope conpaction selected by the Contractor fails to produce the necessary results, the Contractor shall rework or rebuild such slopes until the required degree of conpaction is obtained, at no cost to the Owner or Geotechnical Engineer. (R-9/89) SCS&T 9021053 I^y 22, 1990 Appendix, 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 allowed by the ordinances of the controlling governmental agency. ENGINEERENG OBSERTKEIGN 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 UMTTS 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. Daitaged site conditions resulting from weather or acts of God shall be repaired before acceptance of work. (R-9/89) SCS&T 9021053 May 22, 1990 Appendix, Page 7 RBCXWMENLED GRADING SPECIFICATICNS - SPECIAL PROVISIONS RELATIVE CCMEflC!nON: The minimum degree of compaction to be obtained in conpacted natural ground, conpacted fill, and conpacted hackfill 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: Detrimentally expansive soil is defined as clayey soil which has an expansion index of 50 or greater when tested in accordance with the Uniform Building Code Standard 29-C. OVERSIZED MKIERIAL: 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 Nb. 4 U.S. Standard Sieve. TRANSmON DDIS: Where transitions betveen cut and fill occur within the proposed building pad, the cut portion should be undercut a minimum of one foot below the base of the proposed footings and recompacted as structural backfill. In certain cases that would be addressed in the geotechnical report, special footing reinforcenent or a confcination of special footing reinforcement and undercutting may be required. (R-9/89)