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1996-4580 G '. Street Address -'8t~ç Category I L¡ ~~LfLf Serial # 'Is tJO 6¡ Name I Description Year Plan ck. # recdescv PASCO ENGINEERING, INC. 535 NORTH HIGHWAY 101. SUITE A SOLANA BEACH, CA 92fJ75 (619) 259-8212 FAX (619) 259-4812 WAYNE A. PASCO R.C,E. 29577 City of Encinitas 505 So. Vulcan Avenue Encinitas, CA 92024 _.. ... PE 649G [ߌ ~ lS u ~I ~lill JAM 19 1996 ENGINEERING SERVICES CITY OF ENCINITAS January 19, 1996 Attn: Blair KnolllHans Jensen RE: HYDROLOGY FOR FRANSON BIRmING STABLES GRADING PLAN Dear Blair and Hans: The purpose of this letter is to address the impact of storm runoff on the grading as proposed on the above referenced grading plan. First, the proposed pads are to be used as birthing stables for horses. The structures will be of an open frame, pre-fab style with roofs, but no slabs on grade. Second, the location of the pads is approximately 300 feet from the top of the existing ridge. Third, the drainage area intercepted by the proposed grading is only approximately 0.16 acres. Therefore, we feel that the potential impact of storm runoff to the proposed structures is minimal and that the actual drainage area is small enough to be considered insufficient to require full calculations. It is the professional opinion of Pasco Engineering, that in light of the facts mentioned above, the drainage features shown on the above referenced grading plan will adequately intercept, contain and convey QlOO to appropriate points of discharge without significant impact to the proposed pads or structures. If you have any questions or comments regarding the above, please do not hesitate to contact us. Very truly yours, PASCO ENGINEERING, INC. Wayne Pasco, President RCE 29577 AJ r f cØ<-ð WP/js I I I I I I I I I I I I I I I I I I I . J"t ,/ ~ Geotechnics ~ Incorporated January 16, 1996 Principals: Anthony F. Belfast Michael P. Imbriglio W Œ lIQ l5 U ill LSl!!j W.IÆ"V~dorlm~( FEB 06 1996 Project No. 0261-002-00 ENGINEERING SERVICES Doc. #6-0009 Crr;y OF ENCINITAS Mr. Dennis Franson P.O. Box 30 Bonsall, California 92003 SUBJECT: REPORT OF GEOTECHNICAL INVESTIGATION 3453 Bumann Road Encinitas, California 1.0 INTRODUCTION In accordance with your request, we have completed our geotechnical investigation of the property located at 3453 Bumann Road in Encinitas, California. The following report presents our findings, conclusions, and recommendations of our geotechnical investigation for the planned construction of a residence, pool, several barns, and associated improvements at the subject site. 2.0 SCOPE OF WORK The purpose of our investigation was to evaluate existing conditions at the site as they relate to the proposed construction, and to provide recommendations regarding foundation design and earthwork construction. To accomplish this, our scope of work included: Review of published geologic maps and literature, stereographic aerial photographs, and the preliminary project plans prepared by Stephen W. Hall (1995). . Field investigation consisting of a reconnaissance, the excavation of eight test pits utilizing a John Deere 710 backhoe, and the collection of bulk samples for laboratory testing. Laboratory testing of samples collected in the field to classify the soil for determining presumptive engineering properties. Engineering analysis of field and laboratory data to develop our conclusions and recommendations. Preparation of this report. P.O. Box 26500-224 . San Diego Califomia . 92196 Phone (619) 536-1000 . Fax (619) 536-8311 I I I I I I I I I I I I I I I I I I I Mr. Dennis Franson January 16, 1996 Project No. 0261-002-00 Doc. # 6-0009 2 3.0 SITE DESCRIPTION The subject site consists of a rectangular parcel encompassing approximately 3 acres of rural property situated on a north-facing slope. The slope is gently inclined an average of 6:1 (hòrizontal to vertical) from a high elevation of approximately 334 feet above mean sea level (MSL) in the southeast corner of the site, to a low of approximately 266 feet MSL in the northwest corner of the site at Bumann Road. Small terraces, roughly 50 feet wide, exist in the southeast corner and in the west-central portions of the site. A single-family residence and a shed have been constructed on the terrace in the west-central portion of the site. The residence consists of a single story, wood-fram~d building with a paved driveway from Bumann Road. Horse corrals occupy the north-central portion of the site. Much of the site is vegetated with a light growth of grass and scattered eucalyptus trees. 4.0 PROPOSED DEVELOPMENT We understand, based on a review of the Preliminary Site Plan (Hall, 1995) and discussions with the project architect, that a wood-framed, two-story residence will be constructed in the area of the existing terrace located in the southeast corner of the site. The structure will have a split-level floor plan to accommodate the existing topography. A separate garage and parking court will be located next to the residence. The driveway will extend from Bumann Road to the garage along the eastern site boundary. A swimming pool may be located in the area south of the proposed residence. A horse barn, hay barn, birthing stables, and an exercise ring will be constructed over the remaining portions of the site. The barn structures will be founded by individual posts set into the ground and will have earth floors. The existing residential structure will remain. Although grading plans were not available at the time of this investigation, we understand that minor earthwork is anticipated to prepare the building pads and driveways. Excavations are anticipated to be less than 8 feet deep and fill depths are anticipated to be equally shallow. Fill slopes are anticipated to be inclined at 2: 1 or flatter. Gcotcchnics Incorporatcd I I I I I I I I I I I I I I I I I I I Mr. Dennis Franson January 16, 1996 Project No. 0261-002-00 Doc. # 6-0009 3 5.0 GEOLOGY AND SUBSURFACE CONDITIONS Based on published geologic maps and reports, and our observations, the site is underlain by Jurassic-age metavolcanic rock known as the Santiago Peak Volcanics, with a relatively shallow màntle of topsoil. Minor fill deposits also exist at the site along the down-slope side of the terraces. The approximate distribution of these materials are depicted on the Geotechnical Map, Plate 1. Descriptions of the specific units observed are as follows. 5.1 Santiaao Peak Volcanics Metavolcanic rock was observed in each of the test pit excavations, generally 1 to 3 feet below the surface, and was observed in outcrops next to the existing structure. As observed in the test pits, the rock was generally yellow-brown to red-brown in color, moderately to intensely weathered grading to slightly weathered at depth. Fracturing in the rock varied from intensely to moderately spaced. The backhoe encountered virtual excavation refusal in five of the eight test pits. In two of the test pits, TP-2 and TP-5, hard rock was encountered at approximately 3 feet below the surface. In TP-1, the eastern part of the test pit encountered hard rock a depth of approximately 3 feet, but was excavated to a depth 8-1/2 feet tothe west where the rock was more fractured and weathered due to a fault. 5.2 Topsoil/Colluvium Topsoil and/or colluvium appeared to mantle much of the site. As observed in the test pits, the topsoil was generally 1 to 3 feet thick, and consisted of red-brown, soft to firm, sandy clay. The clay was moderately to highly plastic, and ranged from dry to wet. Expansion index testing conducted on a sample of the fat clay (TP-4), indicated a very high potential for expansion. 5.3 Fill Fill soils associated with the existing terraces at the site appeared to be derived from on- site excavations. As observed in the test pits, the fill consisted of red-brown sandy clay and clayey sand with gravel. The fill was generally dry to moist, soft to firm or loose to medium dense, and porous. Deleterious materials were not observed in the fill soils. Gcotcchnlcs Incorporated I I I I I I I I I I I I I I I I I I I Mr. Dennis Franson January 16, 1996 Project No. 0261-002-00 Doc. # 6-0009 4 5.4 Groundwater Groundwater was not observed in the test pits and suñace seepage was not observed at the site. Given the topography of the site, shallow groundwater or seepage, if it were to occur, would more likely be encountered in the lower elevations of th.e property where perched groundwater from seepage through fractures in the metavolcanic rock or overlying topsoil may accumulate. Changes in rainfall, irrigation, site drainage, or an on-site septic system could produce areas of perched groundwater and/or suñace seepage. 6.0 GEOLOGIC HAZARDS AND SEISMICITY The subject site is not located within an area previously known for significant geologic hazards. There are no known active faults underlying the site nor was any evidence of past soil failures or landslides noted during our investigation. A fault was encountered in the test pit excavated in the southeast part of the site (TP-1); however, evidence of offset suñicial soil was not observed, indicating that the fault should not be considered active. The nearest known active fault is the Rose Canyon fault zone which is located approximately 7 miles west of the site. Assuming a maximum probable earthquake magnitude of 6.4 (Treiman, 1984), the estimated peak ground acceleration for the site would be approximately 0.29g based on attenuation curves by Mualchin and Jones (1992). Design of the structures should comply with the requirements of the governing jurisdictions, building codes and standard practices of the Association of Structural Engineers of California. Gcotcchnics Incoq)oratcd I I I I I I I I I I I I I I I I I I I Mr. Dennis Franson January 16, 1996 Project No. 0261-002-00 Doc. # 6-0009 5 7.0 CONCLUSIONS AND RECOMMENDATIONS Based on the our geotechnical investigation, it is our opinion that the proposed development is feasible from a geotechnical standpoint provided sound construction practices and the reèommendations contained in this report are incorporated. Geotechnical conditions which would preclude the proposed residential construction were not encountered. The primary geotechnical aspects of the proposed development include the following: There are no known active faults, ancient landslides, or other geologic hazards underlying the subject site. The nearest known active fault is associated with the Rose Canyon fault zone which is located approximately 7 miles west of the site. The estimated peak ground acceleration for the site is 0.29g. The site is primarily underlain by metavolcanic rock. The rock possesses excellent bearing capabilities and is considered suitable for the direct support of structural loads. Based on the excavations conducted with the backhoe during this investigation, difficult excavation conditions may be encountered at depths less than 8 feet; however, blasting at the site is not expected to be necessary unless excavations deeper excavations are attempted. Excavations in the rock should generally be achievable to depths less than 8 feet provided heavy earthmoving equipment operated by experienced personnel is used. Some areas of less weathered rock may be encountered that would require extra ripping effort or perhaps some rock breaking. The excavations in the rock should produce some generally granular materials suitable for use in structural fills, however oversize materials may be generated will be unsuitable for use in fill. Oversize material should be disposed of in on-site, non-structural areas, or be hauled off-site. Because of the potential for generation of oversize material, the quantity of suitable fill material available from cuts may be limited. Topsoil and/or colluvium mantles much of the site and relatively minor fill deposits also exist near the terraces. These materials are compressible and are not considered suitable in their present condition for the direct support of structural loads. These surficial soils may be suitable for use in structural fills provided any deleterious materials are removed. However, it should be noted that much of the colluvium is critically highly expansive. Wè do not recommend that this material be placed within 5 feet of proposed grade in areas that will receive structures, including buildings, exterior slabs, and hardscape. Gcotcchnics IncoflHlratcd ,I I I I I I I I I I I I I I I I I I I Mr. Dennis Franson January 16, 1996 Project No. 0261-002-00 Doc. tI 6-0009 6 . Based on the Preliminary Site Plan, the main residential structure may be partially underlain by fill and partially underlain by relatively undisturbed rock. Structures that straddle cut-fill transitions may be subject to differential settlement. We recommend special site preparation to decrease this potential. The remainder of this report presents recommendations regarding the geotechnical aspects of the project. These recommendations are based on empirical and analytical methods typical of the standard of practice in southern California. Design values may include presumptive parameters based on professional judgement. If these recommendations appear not to cover any specific feature of the project, please contact our office for additions or revisions to the recommendations. 7.1 Site Preparation Areas of planned construction should not be underlain by deleterious materials. Vegetation, roots, or other deleterious material which may exist should be removed and hauled off-site. Site preparation in proposed graded areas (building pads, flatwork, and driveway areas) should consist of removing the existing loose surficial soil to expose competent metavolcanic rock. This should be confirmed by observation of the project geotechnical consultant. Based on the conditions observed in the test pits, the depth of removals are anticipated to be generally on the order of 3 feet. The clay portion of the on-site surficial soils are expansive. Shallow expansive soils may induce heaving of the ground surface. We recommend that expansive materials be removed from the upper 5 feet, and not be included in fills within 5 feet of finish grade in all areas to receive structures, concrete slabs, or movement-sensitive hardscape. The removal of the expansive material should extend 5 feet beyond the perimeter of the residential and garage structures. To decrease the potential for cracking or distress related to transitions from bedrock to compacted fill, it is recommended that each structure be founded entirely on either relatively undisturbed rock or on a relatively uniform depth of compacted fill. The metavolcanic rock portion(s) of the building pads should be over-excavated so that the difference in fill depth across the structure differs by no more that a factor of two. For example, if 10 feet of fill is anticipated under a portion of the building pad, the rock portion of the pad should be over-excavated 5 or more feet. Site removals and re-compaction for both loose soils and transitions should extend beyond the perimeter of the proposed Gcotcchnics IncorlHlratcd I I I I I I I I I I I I I I I I I I I Mr. Dennis Franson January 16, 1996 Project No. 0261-002-00 Doc. # 6-0009 7 structures and fill areas at a projected 1: 1 plane, or to a minimum horizontal distance of 5 feet. Backfilling of the excavation should be as recommended in Section 7.3. 7.2 Excavation and Grading Observation Foundation excavations and site grading excavations should be observed by Geotechnics Incorporated. During grading, Geotechnics Incorporated should provide observation and testing services continuously. Such observations are considered essential to identify field conditions that differ from those anticipated by the preliminary investigation, to adjust designs to actual field conditions, and to determine that the grading is accomplished in general accordance with the recommendations of this report. The recommendations presented in this report are contingent upon Geotechnics Incorporated performing such services. Our personnel should perform sufficient testing of fill during grading to support our professional opinion as to compliance with compaction recommendations. 7.3 Fill Compaction All fill and backfill to be placed in association with site development should be accom- plished at slightly over optimum moisture conditions and compacted using equipment that is capable of producing a uniform product. The minimum relative compaction recommended for fill is 90 percent of the maximum density based on ASTM 01557 (modified Proctor). Rocks placed in the compacted fill should be no larger than 12 inches in largest dimension, with the rock placed separately to avoid 'nesting' or voids around the rock. Sufficient observation and testing should be performed by Geotechnics Incorporated so that an opinion can be rendered as to the compaction achieved. Imported fill sources should be observed prior to hauling onto the site to determine the suitability for use. Representative samples of imported materials and on site soils should be tested by the geotechnical consultant in order to evaluate their appropriate engineering properties. Imported soil should have an expansion index of 50 or less. During grading operations, soil types other than those analyzed during this investigation may be encountered by the contractor. The geotechnical consultant should be notified to evaluate the suitability of these soils for use as fill and as finish grade soils. Gcotcchnics IncoqJOratcd I I I I I I I I I I I I I I I I I I I Mr. Dennis Franson January 16, 1996 Project No. 0261-002-00 Doc. ## 6-0009 8 7.4 Slope Stability Cut and/or fill slopes should be stable at inclinations of 2: 1 or flatter. Fill slopes should be founded on firm bedrock and, where the natural ground surface slopes steeper than 5: 1 (horizontal:vertical), benches should be excavated to produce a level area to receive the fill. Benches should be wide enough to provide complete coverage by the compaction equipment. The construction of compacted fill slopes should be performed in accordance with section 7.3, Fill Compaction. The slope faces should be compacted to the recommended 90 percent relative compaction, either by rolling with a sheepsfoot roller or other suitable heavy equipment, or by overfilling the slope and cutting back to design grade. 7.5 Bedrock Rippability Excavations in the metavolcanic rock at the site should generally be achievable to depths less than 8 feet provided heavy earthmoving equipment is used and operated appropriately. Zones or boulders of hard rock may be encountered that would require heavy ripping or perhaps some rock breaking. Deeper excavations may be more economically performed by blasting the bedrock. Excavations in hard rock may generate over-sized rocks (fragments larger than 12 inches) that are not suitable for placement in structural fills. Provisions should be made to segregate and dispose of such oversize fragments. It may be possible to dispose of such material on-site if a dedicated non-structural area is available. Otherwise, the material should be hauled off-site. 7.6 Site Drainaç¡e Foundation and slab performance depends greatly on how well the runoff waters drain from the site. This is true both during construction and over the entire life of the structure. The ground surface around structures should be graded so that water flows rapidly away from the struc;tures without ponding. The surface gradient needed to achieve this depends on the prevailing landscape. In general, we recommend that pavement and lawn areas within five feet of buildings slope away at gradients of at least two percent. Densely vegetated areas should have minimum gradients of at least five percent away from buildings in the first five feet. Densely vegetated areas are considered those in which the planting type and spacing is such that the flow of water is impeded. Gcotcchnic!I Incorporatcd I I I I I I I I I I I I I I I I I I I Mr. Dennis Franson January 16, 1996 Project No. 0261-002-00 Doc. # 6-0009 9 Planters should be built so that water from them will not seep into the foundation, slab, or pavement areas, Site irrigation should be limited to the minimum necessary to sustain landscaping plants. Should excessive irrigation, surface water intrusion, water line breaks, or unusually high rainfall occur, saturated zones or "perched" groundwater may develop in the underlying soils. 7.7 Foundation Recommendations These recommendations are considered generally consistent with methods typically used in southern California. Other alternatives may be available. The foundation recommendations herein should not be considered to preclude more restrictive criteria of governing agencies or by the structural engineer. The design of the foundation system should be performed by the project structural engineer, incorporating the geotechnical parameters described in the following sections. The following design parameters assume that the foundations will bear entirely on undisturbed rock, or entirely on compacted fill materials that were prepared as previously described. These recommendations assume that highly expansive soils will not be present within 5 feet of finish grade. The expansion potential of the soils beneath the structure should be evaluated upon completion of the finish pads. Conventional foundations can consist of continuous footings or isolated footings or piers. F or foundations in moderately expansive materials: Allowable Soil Bearing: 2,500 psf (allow a one-third increase for short-term wind or seismic loads) Minimum Footing Width: 12 inches Minimum Footing Depth: 18 inches below lowest adjacent soil grade Minimum Reinforcement: Two No.4 bars at both top and bottom in continuous footings. Lateral loads against structures may be resisted by friction between the bottoms of footings or slabs and the supporting soil. A coefficient of friction of 0.35 is recommended. Alternatively, a passive pressure of 350 pcf is recommended for the portion of vertical foundation members embedded into compacted or formational soil. If friction and passive pressure are combined, the passive pressure value should be reduced by one-third. Gcotcchnics Incorporated I I I I I I I I I I I I I I I I I I I Mr. Dennis Franson January 16, 1996 Project No. 0261-002-00 Doc. ## 6-0009 10 7.8 Settlement Settlement resulting from the bearing loads recommended are not expected to exceed 3/4- inch and 1/2-inch, respectively for total and differential settlements across the length of the proposed structures. 7.9 On-Grade Slabs Building slabs will be supported by either undisturbed rock or compacted fill materials. Slabs should be designed for the anticipated loading. If an elastic design is used, a modulus of subgrade reaction of 250 kips/fe should be suitable. As a minimum, slabs overlying moderately expansive soil should be at least 5 inches in thickness and be reinforced with at least No.3 bars on 24-inch centers, each way. Slabs overlying highly expansive soil should be at least inches in thickness and be reinforced with at least No. bars on 24-inch centers, each way. Concrete slabs constructed on soil ultimately cause the moisture content to rise in the underlying soil. This results from continued capillary rise and the termination of normal evapotranspiration. Because normal concrete is permeable, the moisture will eventually penetrate the slab unless some protection is provided. To decrease the likelihood of problems related to damp slabs, suitable moisture protection measures should be used where moisture sensitive floor coverings or other factors warrant. A commonly used moisture protection consists of about four inches of clean sand covered by 'visqueen' plastic sheeting. In addition, 2 inches of sand are placed over the plastic to decrease concrete curing problems associated with placing concrete directly on an impermeable membrane. However, it has been our experience that such systems will transmit from approximately 6 to 12 pounds of moisture per 1000 square-feet per day. This may be excessive for some applications. If more protection is needed, we recommend that the slab be underlain by at least 6 inches of minus 3/4-inch crushed rock, with no plastic membrane. In addition, it is recommended that a low water-cement ratio concrete (0.5 maximum) be used and that the slab be moist-cured for five to seven days in accordance with guidelines of the American Concrete Institute. On-site quality control should be used to confirm the design conditions. Gcotcchnics Incor Hlratcd I I I I I I I I I I I I I I I I I I I Mr. Dennis Franson January 16, 1996 Project No. 0261-002-00 Doc. # 6-0009 11 7.10 Reactive Soils Because of the likelihood that the sulfate content of the on-site soil or groundwater is sufficient to react adversely with normal cement, we recommend that Type II cement be used in all concrete which will be in contact with soil. 7.11 Earth Retainina Structures Detrimentally expansive soil should not be as retaining wall backfill. The following recommendations assume that the expansive index of backfill soil will not exceed 50. Cantilever retaining walls should be designed for an active earth pressure approximated by an equivalent fluid pressure of 35 Ibs/fe. The active pressure should be used for walls free to yield at the top at least 0.2 percent of the wall height. For walls restrained so that such movement is not permitted, an equivalent fluid pressure of 45 Ibs/fe should be used based on at-rest soil conditions. The above pressures do not consider any sloping backfill, surcharge loads, or hydrostatic pressures. If these are applicable, they will increase the lateral pressures on the wall and we should be contacted for additional recommendations. Retaining wall backfill should be compacted to at least 90 percent relative compaction, based on ASTM 01557. Backfill should not be placed until walls have achieved adequate structural strength. Heavy compaction equipment which could cause distress to walls should not be used. 8.0 LIMITATIONS OF INVESTIGATION This investigation was performed using the degree of care and skill ordinarily exercised, under similar circumstances, by reputable geotechnical consultants practicing in this or similar localities. No other warranty, expressed or implied, is made as to the conclusions and professional opinions included in this report. The samples taken and used for testing and the observations made are believed representative of the project site; however, soil and geologic conditions can vary significantly between borings. As in most projects, conditions revealed by excavation may be at variance with preliminary findings. If this occurs, the changed conditions must be evaluated by the geotechnical consultant and additional recommendations made, if warranted. Gcotcchnics IncoqJOratctl I I I I I I I I I I I I I I I I I I I Mr. Dennis Franson January 16, 1996 Project No. 0261-002-00 Doc. # 6-0009 12 This report is issued with the understanding that it is the responsibility of the owner, or of his representative, to ensure that the information and recommendations contained herein are brought to the attention of the necessary design consultants for the project and incorporated into the plans, and the necessary steps are taken to see that the contractors carry out such recommenda- tions in the field. The findings of this report are valid as of the present date. However, changes in the condition of a property can occur with the passage of time, whether due to natural processes or the work of man on this or adjacent properties. In addition, changes in applicable or appropriate standards of practice may occur from legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and should not be relied upon after a period of three years. *** GEOTECHNICS INCORPORATED ~;?ð~ Anthony F. Belfast, P.E. 40333 Principal W. Lee Vanderhurst, C.E.G. 1125 Principal Geotechnics Incorporated I I I I I I I I I I I I I I I I I I I APPENDIX A REFERENCES American Society for Testing and Materials, 1992, Annual Book of ASTM Standards, Section 4, Construction, Volume 04.08 Soil and Rock; Dimension Stone; Geosynthetics: ASTM, Philadelphia, PA, 1296 p. Bowles, J.E. 1988, Foundation Analysis and Design: 4th ed., New York, McGraw Hill, 816p. California Division of Mines and Geology, 1975, Recommended Guidelines for Determining the Maximum Credible and the Maximum Probable Earthquakes: California Division of Mines and Geology Notes, Number 43. California Department of Conservation, 1993, The Rose Canyon Fault Zone, Southern California: Division of Mines and Geology, Open File Report 93-02. Geotechnics Incorporated, 1995, Report of Geotechnical Reconnaissance, 3453 Bumann Road, Encinitas, California: Project No. 0261-001-00, dated August 16. Hall, S.W., 1995, Preliminary Site Plan, New Home for Barbara and Dennis Franson, 3453 Bumann Road, Encinitas, California: Job Number 94306, dated December 1. Jennings, C.W., 1994, Fault Map of California: California Department of Conservation, Division of Mines and Geology, California Geologic Data Map Series, Map No.6. Mualchin, L, and Jones, AL, 1982, Peak Accelerations from Maximum Credible Earthquakes in California (Rock and Stiff Soil Sites): California Division of Mines and Geology, Open- File Report 92-1. Treiman, J.A., 1984, The Rose Canyon Fault Zone, A Review and Analysis: California Division of Mines and Geology. USDA, 1953, Stereoscopic Aerial Photographs: Flight No. AXN-4M-73 and 74, dated March 31. I I I I I I I I I I I I I I I I I I I APPENDIX B FIELD EXPLORATION Field exploration consisted of a visual reconnaissance of the site and subsurface exploration. Eight test pits were excavated using a John Deere 710 backhoe. The test pits were excavated to a maximum depth of 8-1/2 feet. Bulk samples were collected from the excavated soils. The approximate locations of the test pits are shown on Plate 1. Logs describing the subsurface conditions encountered are presented as Figures B-1 through 8-4. Test pit locations were approximately located using the plans provided for the proposed development. The locations shown should not be considered more accurate than is implied by the method of measurement used. The lines designating the interface between soil and rock material on the test pit logs are determined by interpolation and are therefore approximations. The transition between the materials may be abrupt or gradual. Further, soil and rock conditions at locations between the test pits may be substantially different from those at the specific locations explored. It should be recognized that the passage of time can result in changes in the soil conditions reported in our logs. I I I I I I I I I I I I I I I I I I I LOG OF EXPLORATION TEST PIT NO.1 Logged by: DR Date: 1/5/96 Method of Excavation: John Deere 710 Backhoe with 24-inch Bucket Elevation: 333' MSL DEPTH DESCRIPTION TOPSOIL: Red-brown sandy CLAY (CU. moderately Dlastic, dry to moist, firm. 1 ft. SANTIAGO PEAK VOLCANICS: Yellow-brown METAVOLCANIC ROCK, dry. moderately to intensely weathered, moderately fractured. Fault oriented N27En8W, offset 2 ft. undetermined. Topsoil not offset. Rock is moderately to intensely weathered on down-dropped side, slightly to moderately weathered on up-thrown side. 3 ft. 4 ft. 5 ft. 6 ft. 7 ft. 8 ft. 9 ft. Total depth: 8-1/2 feet 10 ft. No groundwater encountered No caving LOG OF EXPLORATION TEST PIT NO.2 Logged by: DR Date: 1/5/96 Method of Excavation: John Deere 710 Backhoe with 24-inch Bucket Elevation: 330' MSL DEPTH DESCRIPTION FILL: Red-brown sandy CLAY (CL) with gravel, moderately plastic, dry to moist, soft to firm, 1 ft. porous. (Bag Sample) 2 ft. SANTIAGO PEAK VOLCANICS: Yellow-brown and red-brown METAVOLCANIC ROCK, dry 3 ft. to moist, moderately weathered. Slightly weathered. 4 ft. Total depth: 3 feet 5 ft. No groundwater encountered No caving 6 ft. 7 ft. 8 ft. 9 ft. 10 ft. ¡PROJECT NO. 0261-002-00 GEOTECHNICS INCORPORATED FIGURE: B-1 I I I I I I I I I I I I I I I I I I I LOG OF EXPLORATION TEST PIT NO.3 Logged by: DR Date: 1/5/96 Method of Excavation: John Deere 710 Backhoe with 24-inch Bucket Elevation: 330' MSL DEPTH DESCRIPTION FILL: Red-brown clayey SAND (SC) with gravel, medium grained, moist, loose to medium dense. 1 ft. 2 ft. TOPSOIL: Red-brown fat CLAY (CH), highly plastic, moist to wet, soft. 3 ft. SANTIAGO PEAK VOLCANICS: Yellow-brown METAVOLCANIC ROCK, dry to moist, 4 ft. intensely to moderately weathered. 5 ft. 6 ft. Total depth: 5 feet No groundwater encountered 7 ft. No caving 8 ft. 9 ft. 10 ft. LOG OF EXPLORATION TEST PIT NO.4 Logged by: DR Date: 1/5/96 Method of Excavation: John Deere 710 Backhoe with 24-inch Bucket Elevation: 315' MSL DEPTH DESCRIPTION TOPSOIL: Red-brown sandy fat CLAY (CH), highly plastic, dry to moist, soft to firm. 1 ft. (Bag Sample) 2 ft. SANTIAGO PEAK VOLCANICS: Yellow-brown METAVOLCANIC ROCK, dry, intensely to 3 ft. moderately weathered. (Bag Sample) 4 ft. 5 ft. 6 ft. Slightly weathered. 7 ft. Total depth: 6 feet No grounddwater encountered 8 ft. No caving 9 ft. 10 ft. ¡PROJECT NO. 0261-002-00 GEOTECHNICS INCORPORATED FIGURE: B-2 I I I I I I I I I I I I I I I I I I I LOG OF EXPLORATION TEST PIT NO.5 Logged by: DR Method of Excavation: John Deere 710 Backhoe with 24-inch Bucket Date: 1/5/96 Elevation: 307' MSL DEPTH DESCRIPTION TOPSOIL: Red-brown sandy CLAY (CH), moderately to highly plastic, dry to moist, soft to firm. 1 ft. 2 ft. SANTIAGO PEAK VOLCANICS: Yellow-brown and red-brown METAVOLCANIC ROCK, dry to moist, moderately weathered. 3 ft. Slightly weathered. 4 ft. 5 ft. Total depth: 3 feet No groundwater encountered No caving 6 ft. 7 ft. 8 ft. 9 ft. 10 ft. LOG OF EXPLORATION TEST PIT NO.6 Logged by: DR Method of Excavation: John Deere 710 Backhoe with 24-inch Bucket DEPTH DESCRIPTION TOPSOIL: Red-brown sandy CLAY (CH), moderately to highly plastic, dry to moist, firm. Date: 1/5/96 Elevation: 307' MSL 1 ft. 2 ft. SANTIAGO PEAK VOLCANICS: Gray METAVOLCANIC ROCK, dry to moist, intensely to moderately weathered. 3 ft. 4 ft. 5 ft. Slightly weathered. 6 ft. 7 ft. Total depth: 5-1/2 feet No groundwater encountered No caving 8 ft. 9 ft. 10 ft. PROJECT NO. 0261-002-00 GEOTECHNICS INCORPORATED FIGURE: B-3 _n~--- I I I I I I I I I I I I I I I I I I I LOG OF EXPLORATION TEST PIT NO.7 Logged by: DR Date: 1/5/96 Method of Excavation: John Deere 710 Backhoe with 24-inch Bucket Elevation: 295' MSL DEPTH DESCRIPTION TOPSOIL: Red-brown sandy CLAY (CH), moderately to highly plastic, dry to moist, firm. 1 ft. (Bag Sample) 2 ft. 3 ft. SANTIAGO PEAK VOLCANICS: Yellow-brown and red-brown METAVOLCANIC ROCK, dry to moist, Intensely weathered. 4 ft. Moderately weathered. 5 ft. Slightly weathered. 6 ft. Total depth: 5 feet No groundwater encountered 7 ft. No caving 8 ft. 9 ft. 10 ft. LOG OF EXPLORATION TEST PIT NO.8 Logged by: DR Date: 1/5/96 Method of Excavation: John Deere 710 Backhoe with 24-inch Bucket Elevation: 276' MSL DEPTH DESCRIPTION TOPSOIUCOLLUVIUM: Red-brown sandy CLAY (CH), moderately to highly plastic, dry 1 ft. to moist, firm. 2 ft. 3 ft. SANTIAGO PEAK VOLCANICS: Yellow-brown METAVOLCANIC ROCK, dry to moist, intensely 4 ft. weathered. 5 ft. 6 ft. 7 ft. 8 ft. Total depth: 7 feet No groundwater encountered 9 ft. No caving 10 ft. ¡PROJECT NO. 0261-002-00 GEOTECHNICS INCORPORATED FIGURE: B-4 I I I I I I I I I I I I I I I I I I I APPENDIX C LABORATORY TESTING Samples typical of the soils encountered were selected for laboratory testing. Testing was performed in accordance with methods of ASTM or other commonly accepted methods. Classification: Soils were classified visually according to the Unified Soil Classification System. Visual classification was supplemented by laboratory testing of selected samples and clas- sification in accordance with ASTM D2487-90. The soil classifications are shown on the Test Pit Logs. Particle Size AnalYSis: Particle size analyses were performed in accordance with ASTM D422-63. The grain size distribution was used to determine presumptive strength parameters and to develop foundation design criteria. The results are provided on the following Figure C-1. Atterbera LImits: ASTM 04318-84 was used to determine the liquid limit, plastic limit, and plasticity index of selected fine-grained samples. The results are summarized in Figure C-1. Expansion Index: The expansion potential of selected soils was characterized by using the test method ASTM D4829. The results are presented in Figure C-2. pH and Resistivity: To assess their potential for reactivity with metal pipe, a representative sample was tested for pH and resistivity, using CAL TRANS method 643. The results are listed in Figure C-2. Sulfate Content: To assess their potential for reactivity with concrete, a representative sample was tested for content of water-soluble sulfate minerals using CAL TRANS method 417 (Part I). The results are listed in Figure C-2 - - - - - - - - - - - - - - :ë 70 c ã: ~ 60 :> .c ~ 50 c ¡¡: ë 40 Q; ~ .. 3. 30 - - - - - 10ð" 1-1/Z' 314" U.S. Standard Sieve Sizes 3/8" #4 #8 #16 #30 #50 #100 #200 Hydrometer 90 . ..- - -. . u- --- .. .-- .. -- "'r--. ""I ...... ""'¡"""'" -. " . 80 20 10 0 100 10 1 0.1 0.01 Grain Size in Millimeters COARSE GRAVEL FINE MEDIUM SAND FINE SILT AND CLAY COARSE 0 10 201: ,g 40 t ! CIS 0 50° - c 0 60 t:! l. 70 80 90 100 0.001 UNIFIED SOIL CLASSIFICATION: CH I SAMP~ I TP-4 @ 0 to 2 ft. ATTERBERG LIMITS LIQUID LIMIT: 54 PLASTIC LIMIT: 22 PLASTICITY INDEX: 32 DESCRIPTION: Sandy fat CLAY Geotechnics Incorporated PROJECT NO. 0261-002-00 DOC. # 6-0009 PARTICLE SIZE ANALYSIS AND A TTERBERG LIMITS FIGURE C-1 I I I I I I I I I I I I I I I I I I I EXPANSION TEST RESULTS (ASTM D4829) SAMPLE EXPANSION EXPANSION INDEX POTENTIAL TP-4 @ 0 to 4 ft. 134 VERY HIGH CORROSIVITY TEST RESULTS (Caltrans Test Method 417 and 643) SULFATE G SAMPLE CONTENT RESISTIVITY (PPM) (ohm-cm) TP-4 @ 0 to 4 ft. 1,600 7.4 800 Geotechnics Incorporated Laboratory Test Results 3453 Bumann Road Encinitas, California Project No. 0261-002-00 Document No. 6-0009 Figure C-2 I I I I I I I I I I I I I I I I I I I ~eotechnics Incorporated Principals: Anthony F. Belfast Michael P. Imbriglio W. Lee Vanderhurst AS-GRADED GEOTECHNICAL REPORT SINGLE FAMILY RESIDENCE ANÓ STABLES 3453 BUMANN ROAD. ENCINITAS, CAUFORNIA PREPARED FOR Mr. Dennis Franson c/o Design West Builders 3328 Piragua Carlsbad, California 92009 .~/ , ) ,? \~ ~ ~ B~\Q ~~ //"', \<.- ~ ~ ~,<,~\~c:, , '~" ~"'\::>, " ~ c:';' "t. .,) 0.J~.' '.. \, ~~ ~(j'\ \.> .~~«) ~ X;. ~(}~~ 0 ~ G~' Project No. 0261-002-02 Doc. #6-0464 9951 Business Park Ave., Ste. B . San Diego California. 92131 Phone (619) 536-1000 . Fax (619) 536-8311 I I I I I I I I I I I I I I I I I I I ~eotechnics Incorpora ted July 23, 1996 Principals: Anthony F. Belfast Michael P. Imbriglio W. Lee Vanderhurst Mr. Dennis Franson c/o Design West 3328 Piragua Carlsbad, California 92009 Project No. 0261-002-02 Doc. #6-0464 SUBJECT: AS GRADED GEOTECHNICAL REPORT Single Family Residence and Stables 3453 Bumann Road Encinitas, California Reference: Geotechnics Incorporated, January 16, 1996, Report of Geotechnical Investigation, 3453 Bumann Road, Encinitas, California, Project No. 0261-002-00, Doc. #6-0009. Dear Mr. Franson: This report summarizes the observation and testing performed by Geotechnics Incorporated at the subject site during construction of building pads for the proposed new single family residence, and adjacent stables. Our services were performed between March 18, 1996 and July 11, 1996. This report and the associated services were performed in accordance with the provisions of our Proposals No. 6-054 and 6-098, dated March 3 and May 21, 1996, respectively. 1.0 SCOPE OF SERVICES Field personnel were provided for this project to perform observation and testing of site preparation, and fill compaction operations so that we could develop the professional opinions contained herein. Our services did not include supervision or direction of the actual work by the contractor, his employees, or agents. 2.0 AS-GRADED GEOLOGY The geology exposed during grading was generally as anticipated. Jurassic age Santiago Peak Metavolcanic rock was found to underlie the entire site. The rock is a dark green to greenish gray meta-dacite and meta-tuff with a predominant steeply dipping, east-west trending wide spaced joint pattern. Two shear zones interpreted to be ancient faults were exposed in the rock slope immediately south of the residential pad. The faults are considered inactive and do not represent a seismic hazard. The rock was overlain by a variable thickness of soil and local zones of severely weathered rock. The rock was very hard and locally could not be ripped economically using the equipment used for grading. As a result, blasting was used to loosen the rock prior to excavation. 9951 Business Park Ave., Ste. B . San Diego California. 92131 Phone (619) 536-1000 . Fax (619) 536-8311 I I I I I I I I I I I I I I I I I I I Mr. Dennis Franson July 23, 1996 Project No. 0261-002-02 Doc. #6-0464 Page 2 3.0 EARTHWORK OPERATIONS Earthwork construction at the subject site consisted of two phases of grading. The initial phase occurred in the western portion of the property and consisted of the construction of a pad and adjacent fill slope for a horse stable. The second phase involved construction of pads and slopes for a single family residence and a second stable. Construction of the residential pad required blasting to cut the pad to design grade. The blasting created a large amount of oversized rock. A portion of the rock was hauled off-site. The majority of the rock, however, was disposed in a corral area just north of the second stable. The disposal area and other localized areas at the site are not considered suitable for the support of structures. The areas of structural fills as well as the location of, density tests, and geologic features are shown on the As-Graded Geotechnical Map (Plate 1). A Caterpillar D-7 bulldozer, Caterpillar 980 rubber tire loader, dump trucks, and a backhoe were used to mix and compact the soil. Moisture was supplied by a fire hose. 3.1 Structural Fills Following clearing of the fill areas, remedial grading consisting of removal of approximately 1 to 3 feet of top soil and cutting keyways at the toes of slopes. The bottom of the excavations exposed bedrock of the Santiago Peak Metavolcanics. Following excavation, the stockpiled onsite soil was mixed and moisture conditioned to at least 5% above optimum moisture, spread in approximately 4- to 6-inch thick lifts and compacted within the stable areas. The onsite soil consisted of dark reddish brown silty clay (CL - Unified Soil Classification). To facilitate construction of foundations and to eliminate transitions between bedrock and fill within the building area, the building pad was filled with a minimum of three feet of import fill. The import fill consisted of silty sand (SM). The structural fill areas are delineated on the As-Graded Geotechnical Map, Plate 1. 3.2 Non-Structural Fill Rock and soil were used to fill a "riding rink" area in the northeast corner of the property. Topsoil was removed to bedrock and oversized rock was dumped into the fill area. The rock was spread into 1- to 3-foot thick lifts, and moisture conditioned. The fill was observed to see that large voids were not created. However, this fill was not tested and is not considered suitable for the support of structures due to the potential for uncontrolled settlement. The 3: 1 (horizontal to vertical) or shallower slope immediately to the north of the residential pad was constructed without observation or testing. The fill is no more than 2-feet thick and has been "track walked" into place. This fill is subject to uncontrolled settlement and is therefore not suitable for support of structures. 3.0 TESTING The maximum density and optimum moisture of representative samples of on site and import soil were determined in the laboratory by the ASTM D 1557-91 (Modified Proctor) method. The laboratory test results are presented on Figure 2. Density tests were made by the Nuclear Gauge Geotechnics Incorporated I I I I I I I I I I I I I I I I I I I Mr. Dennis Franson July 23, 1996 Project No. 0261-002-02 Doc. #6-0464 Page 3 Method (ASTM D 2922-91, D 3017-88). Results of the density tests are provided in Appendix A. Test locations are shown on the attached As-Graded Geotechnical Map (Plate 1). Geotechnics Incorporated I I I I I I I I I I I I I I I I I I I Mr. Dennis Franson July 23, 1996 Project No. 0261-002-02 Doc. #6-0464 Page 4 5.0 CONCLUSIONS AND RECOMMENDATIONS Our descriptions of the compaction operations, as well as observations and testing services, are limited to work performed between March 18, and July 11, 1996. The conclusions contained in this report are based on our observations and testing as noted. No representations are made as to the quality or extent of any materials or operations that were not observed. Based upon our observations and testing, it is our professional opinion that the onsite fill soil with in the prescribed structural areas was moisture conditioned to above optimum moisture content and compacted to at least 90% of ASTM D 1557 in accordance with the referenced report. 5.1 Slope Stability In general, slopes should be stable with regard to deep-seated failure with a factor of safety of at least 1.5. Slope analysis was based on our best estimate of the prevailing geologic conditions, groundwater conditions and soil strength characteristics. It should be realized that site conditions can be complex and variable due to changes in stratigraphy, geologic structure, and changes in groundwater. It is possible that conditions can differ from those anticipated in our analysis. In addition, cuts or retaining walls constructed at the toe of slopes could decrease slope stability. Any changes to constructed slope heights, ratios, retaining walls, or addition of surcharge should be evaluated by the geotechnical consultant. Man-made and natural slopes will weather over time as a result of wetting and drying, biologic forces and gravity. As a result, the outer 5 feet of slope face may experience minor down-slope creep over the years. While it is not possible to completely eliminate this effect,' it can be minimized by establishing deep-rooted vegetation on the slope, maintaining the drainage patterns established during construction, and by rodent control. We recommend vegetation that is adapted to semi-arid climates and therefore requiring minimal irrigation. Vertical and near vertical rock slopes to a maximum height of 6 feet are present locally at the southern edge of the residential pad. Geologic mapping of the slope did not reveal adverse structure or close spaced, loose fractures. These slopes are therefore considered grossly stable. 5.2 Site Drainaae Foundation and slab performance depends greatly on how well the runoff waters drain from the site. This is true both during construction and over the entire life of the structure. The ground surface around structures should be graded so that water flows rapidly away from the structures without ponding. The surface gradient needed to achieve this depends on the prevailing landscape. In general, we recommend that pavement and lawn areas within 5 feet of buildings slope away at gradients of at least two percent. Densely vegetated areas should have minimum gradients of at least 5 percent away from buildings Geotechnics Incorporated I I I I I I I I I I I I I I I I I I I Mr. Dennis Franson July 23, 1996 Project No. 0261-002-02 Doc. #6-0464 Page 5 within 5 feet of the structure's perimeter. Densely vegetated areas are considered those in which the planting type and spacing is such that the flow of water is impeded. Planters should be built so that water from them will not seep into the foundation, slab, or pavement areas. Site irrigation should be limited to the minimum necessary to sustain landscaping plants. Should excessive irrigation, water line breaks, or unusually high rainfall occur, saturated zones or "perched" groundwater may develop in fill soils. This condition may result in excessive moisture migration into and through foundations and slabs and possible damage to vegetation. 5.3 Foundations The following recommendations are based on our testing and observation of the grading, and the laboratory testing of the soil near finish grade. The recommendations are considered generally consistent with methods typically used in southern California, although other alternatives may be available. The foundation recommendations herein should not be considered to preclude more restrictive criteria of governing agencies or by the structural engineer. The design of the foundation system should be performed by the project structural engineer incorporating the geotechnical parameters described in the following sections. In general, the expansion index testing indicated that the soils exhibit a low expansion potential. The following parameters assume an expansion index of less than 30. Conventional shallow foundations are considered suitable to support the proposed structures. The following recommendations assume that all foundations bear completely in compacted structural fill prepared as previously described. Allowable Soil Bearing: 2,000 psf (allow a one-third increase for short-term wind or seismic loads) Minimum Footing Width: 12 inches Minimum Footing Depth: 18 inches below lowest adjacent soil grade. Minimum Reinforcement: Two No.4 bars at both top and bottom in continuous footings. 5.5.1 Lateral Resistance Lateral loads against structures may be resisted by friction between the bottoms of footings or slabs and the supporting soil. A coefficient of friction of 0.25 is recommended. Alternatively, a passive pressure of 250 pcf is recommended for the portion of vertical foundation members embedded into formational soil. If Geotechnics Incorporated I I I I I I I I I I I I I I I I I I I Mr. Dennis Franson July 23. 1996 Project No. 0261-002-02 Doc. #6-0464 Page 6 friction and passive pressure are combined, the passive pressure value should be reduced by one-third. 5.5.2 Slope Setback Footings on slopes should be founded at a depth such that at the distance between the lower outside edge of the footing and the face of any slope is at least 8 feet. 5.5.3 Settlement Settlement resulting from the bearing loads recommended are not expected to exceed 1 inch and 3/4-inch, respectively for total and differential settlements across the length of the structure. These settlements are applicable to structural fills areas shown on Plate 1 only. Graded and natural ground outside these areas are subject to unpredictable amounts of differential settlement that may result in distress to settlement sensitive structures. Settlement sensitive structures planned for non-structural fill areas will need specific foundation recommendations to mitioate the effects of differential settlement. 5.6 Conventional Interior On-Grade Slabs Slabs should be designed for the anticipated loading. If an elastic design is used, a modules of subgrade reaction of 250 kips/fe should be suitable. As a minimum, slabs should be at least 5 inches in thickness and be reinforced with at least No.3 bars on 24- inch centers, each way. 5.7 Moisture Protection for Slabs Concrete slabs constructed on soil ultimately cause the moisture content to rise in the underlying soil. It is our understanding that the planned moisture protection for slabs on grade is to consist of 1-% inches of sand, over 10-mil visqueen, over an additional 1-% inches of sand. It has been our experience that such systems will transmit from approximately 6 to 12 pounds of moisture per 1000 square feet per day. It is our opinion that soil conditions do not exist that would preclude the use of the indicated moisture protection on this project. It should be recognized that this system relies entirely on the integrity of the visqueen membrane. Accordingly, care should be taken to protect the visqueen against all punctures and to provide adequate overlap at all seams. 5.8 Exterior Slabs Because of the presence of moderately expansive soil on the site, there is a risk of minor movement and cracking of exterior slabs. Reinforcement and the use of crack control joints should help reduce random cracking and differential movement. Slabs should be at least 4 inches in thickness and should be reinforced with at least 6-inch by 6-inch, W1.4 by W1.4, welded-wire fabric. Slabs may bear directly on compacted subgrade. Crack Geotechnics Incorporated I I I I I I I I I I I I I I I I I I I Mr. Dennis Franson July 23, 1996 Project No. 0261-002-02 Doc. #6-0464 Page 7 control joints should be provided on no greater than 5-foot centers for sidewalks, and not greater than a-foot centers, each way. 6.0 LIMITATIONS Our services were performed using the degree of care and skill ordinarily exercised, under similar circumstances, by reputable soils engineers and geologists practicing in this or similar localities. No other warranty, expressed or implied, is made as to the conclusions and professional advice included in this report. The samples taken and used for testing, the observations made, and the in-place field testing performed are believed representative of the project; however, soil and geologic conditions can vary significantly between tested or observed locations. This report is issued with the understanding that it is the responsibility of the owner, or of his representative, to ensure that the information and recommendations contained herein are brought to the attention of the architect and engineer for the project and incorporated into the plans, and that the necessary steps are taken to see that the contractçr and subcontractors carry out such recommendations in the field. As in most major projects, conditions revealed by excavation may be at variance with preliminary findings. If this occurs, the changed conditions must be evaluated by Geotechnics Incorporated and designs adjusted as required or alternate designs recommended. The findings of this report are valid as of the present date. However, changes in the conditions of a property can occur with the passage of time, whether they be due to natural processes or the works of man on this or adjacent properties. In addition, changes in applicable or appropriate standards may occur, whether they result from legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and should not be relied upon after a period of three years. This opportunity to be of service is appreciated. If you should have any further questions, please do not hesitate to contact the undersigned at your convenience. Very truly yours, ".f. Anthony F. Be Principal Attachments: Plate 1, As-Graded Geotechnical Map Appendix A, Field Density Test Results and Laboratory Test Results Geotechnics Incorporated I I I I I I I I I I I I I I I I I I I APPENDIX A FIELD DENSITY TEST RESULTS (ASTM D 1556) TEST TEST ELEVATION MAXIMUM OPTIMUM TEST TEST RELATIVE NO. DATE (FEET) DRY MOISTURE DRY MOISTURE COMPAC- DENSITY (%) DENSITY (%) TION (PCF) (PCF) (%) 1 3/19/96 294 124.7 11.7 113.2 15.4 90.8 2 3/19/96 300 124.7 11.7 110.1 14.9 88.3 3 3/19/96 300 124.7 11.7 111.6 17.4 89.5 4 3/19/96 300 124.7 11.7 115.5 16.9 92.6* 5 3/19/96 302 124.7 11.7 112.7 16.1 90.3 6 3/28/96 309 124.7 11.7 113.6 13.1 92 7 3/28/96 310 124.7 11.7 114.7 10.0 92 8 3/28/96 311 124.7 11.7 117.9 11.5 94 9 3/28/96 312 124.7 11.7 116.0 11.9 93 10 3/28/96 313 124.7 11.7 115.5 12.2 93 11 3/28/96 314 124.7 11.7 114.4 12.3 92 12 6/13/96 288 130.1 8.0 125.4 10.5 96.3 13 6/13/96 287 130.1 8.0 122.8 13.1 94.3 14 6/13/96 288 130.1 8.0 124.6 11.3 95.7 15 6/13/96 290 130.1 8.0 123.0 11.1 94.5 16 6/13/96 291 130.1 8.0 119.1 11.0 91.5 17 6/13/96 292 130.1 8.0 121.4 11.0 93.3 18 6/13/96 293 130.1 8.0 120.8 12.2 92.8 19 6/13/96 294 130.1 8.0 125.0 7.7 96.0 20 6/13/96 294 122.7 12.1 110.8 17.2 90.3 21 6/14/96 296 122.7 12.1 110.6 16.4 90.2 22 6/14/96 296 124.7 11.7 116.0 10.2 90 I I I I I I I I I I I I I I I I I I I TEST TEST ELEVATION MAXIMUM OPTIMUM TEST TEST RELATIVE NO. DATE (FEET DRY MOISTURE DENSITY MOISTURE COMPAC- BELOW DENSITY (%) (PCF) (%) TION F.G.) (PCF) (%) 23 7/3/96 322 111.8 13.0 104.6 8.3 93.5 24 7/3/96 322 111.8 13.0 107.8 15.4 96.4 25 7/11/96 322 111.8 13.0 105.7 5.9 94.6 26 7/11/96 322 111.8 13.0 106.2 9.6 95.0 27 7/11/96 322 111.8 13.0 107.8 10.1 96.5 28 7/11/96 323 127.5 9.0 118.1 9.8 92.6 29 7/11/96 323 127.5 9.0 116.5 6.7 91.4 30 7/11/96 F/G 127.5 9.0 115.7 9.6 90.7 31 7/19/94 F/G 127.5 9.0 117.1 9.5 91.8 32 7/19/94 F/G 127.5 9.0 116.3 9.5 91.2 * Retest of Test 2 and 3 LABORATORY MAXIMUM DENSITY (ASTM D 1557) NO. CLASSIFICATION MAXIMUM OPTIMUM DENSITY (PCF) MOISTURE (%) 1 DARK BROWN CLAY, (CL) 124.7 11.7 2 BROWN SANDY, CLAY (CL) 122.7 12.1 3 BROWN GRAVELY CLAY (CL) 130.1 8.0 4 REDDISH BROWN SAND (SP) (IMPORT) 123.8 10.5 5 LIGHT BROWN SAND (SP) (IMPORT) 111.8 13.0 6 LIGHT BROWN SILTY SAND (SM) (IMPORT) 127.5 9.0 EXPANSION INDEX (ASTM 4829) SAMPLE LOCATION EXPANSION INDEX EXPANSION POTENTIAL 1 Residential Pad 15 Very Low Geotechnics Incorporated .?~ ,'.,,,,,,<!.;.. " :'Ch ~' "., ~ ~~....:~ --~ ' . .,'~~ ,.................~ ..,..... . \ ., .,., "',' -t, ~ ""'<>;""" ~~~~~;;;. ~'\ d, . . ~ - - ~ . .{o ,J." ~ . , ~ - , .,.,,- -. - ,- - ~,. ~. 1.,1 . ~ , .~ . ' .. 'i .r r:l l J - '1' ft:' ,,:ai . gSlJ'.... ~ ..- ......... ~." < " - -' -- - . - ,- , )I - -- ...- -' - - - - - 'jJ: -:r"!~ "~~~ :1 : ~ ~ " \ ", "V ..... .-J - .. , ..- if "''1'91 M!'Tl!A , ) , 1" i; i" 'f' .. ...-d. t - ... ~cNER .. ~ I.' -- ~- .,~ .......~ - .- ~ ,- '-:::::a:-::...;r'-::==.~=:::.:-: - " '''~ .'8v - '"103M" ~ .- - . "'7" __ .,a....... ~ ..'~ ..-- ......... - - ..---- - ~ - - ""'"- /:T, - -" -- - --... - - .. ... ..-- .... . .- ~ .~ ~. '!1 I I ~" -I t .~.". ., r ,,/ , - ~ , f)"?,y}. -- /' ......- .i-'" ___ -- - -- ~ ~/"-- '&', ,..".., . .I' ~ /. ..- ~~ ;....>- - / ---- ; --- .-4 .....-' .- / /' r --- .r - -- - ~ -- - ...,..... (../ /(fl "0/ "" ... ,I .J.: ~ .... J" ,~ ~--. .- /' /' /- --- / /' ~,..., -- -- ./ ---- . /' /' /' ~ ~-~..; I j - \0 --- -' / ,/ - .-"- - , ~. -' , ~ - ;..,; ~-- -- /' .' 'O?>> .-- ~" _1..-" ~'-~ -./ ",./ _/ - -, -/- ~- ....... .....<"' --- - ~ ','II 'ill, l .. ,It...g " 1 , ~ .' _,4' .: . " - I Modified f m ndated untitled ,t~ ~ Inc, ' > .,. i- ,. EXPLANA lION SCALE 1"=40' ':f Fill Fill Jsp Santiago Peak Vo!?nics --- Approximate location of geologic contact ~, i" . . T78 Approximate location of fault showi~g orientation and dip i . M. TP-8 D' ~proximate location of , exploratory test pit t ~, ~I GEOTECHNICAL" 3453 Brumann Roa Franson Residenc ..'" , . .. . ,t.\... PROJECT NO, 0261.002-00 ~ ~JnFif"l()('lq JA'