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Home My WebLink AboutCT 82-15; ALICANTE HILLS CROSSROADS; GEOTECHNICAL SUMMARY REPORT; 1981-11-11I 4 I I '4 I H I .1 I '4 u I 4 I ,døt4 : ,-1T I Geo-so ,Is Inc. UI .. I Soil Mechanics • Geoiog • Foundation Engineering p 1 1 1 i '.• L.i 4IPIII. I - - I 1 i 1__ I!LJI 0 .•0_00 -" - - I I 1 I I I I I - I - 0 • :. S. I I.. 0• I I I: . GEOTECHNICAL SUMMARY REPORT ALICANTE HILLS SUBDIVISION LA COSTA, CITY OF CARLSBAD I . CALIFORNIA FOR I DAON CORPORATION '. W.O. 845-OC NOVEMBER 11, 1981 I I I I I I .1. •., . I I I GeoSolls, Inc. Soil Mechanics' Geology Foundation Engineering 15801 Bockfield Boulevard, Suite C Irvine, California 92718 • (714) 859-4599 I H.., .. November 1i, 1981 I .. - -: - -, - - •- - Daon Corporation I 4041 MacArthur Boulevard I Newport Beach, California 92660 I Attention: Mr. Bill Storm Subject: Geotechnical Summary Report Alicante Hills Subdivision I La Costa, City of Caribad, California I Gentlemen: The following presents a summary ,report of our geotechnicai I study of the subject property. This investigation as initiated by Daon'Corporation as,a part of a 1anning team, including consultants in site planning; civil engineering, traffic, marketirg and soils engineering. Planning meetings were I held from August through November, 1981 and geotechnical, data was 'supplied periodically as exp1orationandtesting ., * progressed.- Our field exploration includes borings 'conducted - • in January, 1981 as part of the La" Costa Lana Company I . purchase. Additionally, borings and pits were performed .' during August and September, 1981. . I This report includes-a discussion of site conditions, soils and geologic parameters, boring and pit logs and a."gëotéchn-idal I map. The general site development 'concept isdiscissed and recommendations are provided for site development and foundation I parameters. -A Geotechnical Map (Plate 1) is provided which' uses U a base 100-scale map prepared by Rick Engineering. . . . Los Angeles County Office: (818) 785-2158 • San Diego County Office: (619) 438-3155 I ' Daon Corporation . Page 2 W.O. 845-OC November 11, 1981 I SITE DESCRIPTION Location I . The subject property is located within the community of La Costa I in the City of Carlsbad, California. Specifically, the site lies along the north side of the La Costa Golf course, westerly I of San Marcos Creek. Access to the site is via existing Alicante Road, Aif ii Way and Altiva Place. Past History I Most of the property has been previously graded, producing a series of flattened pads of various sizes and various cut, fill. 1 and natural slopes. Originally, the site consisted of broad, rolling to irregular hills, descending from the north toward I the golf course area. A major canyon cut across the property in the westerly third of the site and other canyons and swales draining south were present. I Borrow grading for the gOlf course and other development was the first major activity on the site. This produced some cut slopes and roads and possibly minor filling. Later, as a part I of actual development, the canyons and swales were filled and ridges were excavated. Minor dump filling has occurred I through the years. I Topography . I The site generally falls from north to south through a series of graded pads and intervening slopes. A major slope runs along the southeast perimeter varying from a steep natural slope I along San Marcos Canyon to natural and fill slopes along I'. . . GeoSoils, Inc. I I Daon Corporation Page 3 W.O. 845-OC November 11,' 1981 I ,.. I the golf course. The latter vary in gradient from 3;1 to 1-1/2:1 (horizontal to vertical) and are 40 to 60 feet high. .Slopes between pads are generally five to ten feet high with localized slopes varying up to 40 feet. I The west portion of the site is mostly low, being at golf course level to 15 feet higher. Along Altiva Place, grading has I produced smaller pads with 10.to 30 foot high slopes between pads and along the edges. The slopes were all graded at 1-1/2:1. The highest elevations occur along the northern edge; 130 to 140 feet. The southern margin, along the golf course, lies I at 20 to 30 feet.' Relief varies from approximately 90 to 120 feet. I What remains of the major canyon lies along the northwest margin. I The canyon has been, somewhat modified with a desilting basin and fill encroaches upon portions of the sides. Local relief here is up to approximately 35'feet,'with 171/2:1 and 2:1 slopes. Improvements ' Alicante Road, Alfil Way and Altiva Place are existing paved I . roads and contain various underground utilities. A storm drain passes under Alicante Road as a drainage extension of I the major canyon and a paved channel continues this system toward the golf course. A storm drain/sewer easement also I passes under. Alfil Way and continues south toward the golf course in the center of the property. Other easements include a sewer I . easement just east of the paved channel, a drainage and water easement at the southwest corner and a sewer easement along the edge 'of the golf course. ' I . . GeoSoils, Inc. I I Daon Corporation Page 4 W.O. 845-OC November 11, 1981 I Drainage and Vegetation I All the site eventually drains toward the golf course, either directly as runoff or by improved systems. The easterly half I the of the site utilizes surface drainage toward top of the slope. a "V"-ditch along Vegetation on the site is mostly sparce to lacking as a result of previous grading. Groundwater and scattered trees occur on the slope above the golf course and local'patches of grass and weeds exist. The open portion of the major canyon contains phreatophytes. Proposed Development The current planning indicates a regrading of the property 'to produce building. sites for' condominium and townhouse type residential structures. Single family custom lots are also proposed to'border the golf 'course along the western edge of the parcel. A ,recreation area will occupy the area between, the custom lots and townhouses. Grading would mostly include excavation of the easterly two thirds of the site, lowering the grades, to produce golf course oriented views. ' For similar reasons, grades in the westerly portion would be raised. The area along Altiva Place has not been planned at this' time. 'Slopes are planned at 2:1 or flatter to heights up to 50 feet. GeoSoils, Inc. Daon Corporation Page 5 W.O. 845-OC November 11, 1981 Field Exploration Our study has included excavating 26 backhoe pits and 20 exploratory bbrings. Pits varied in depth from four to eighteen feet and borings ranged from five to. forty-seven feet. Most borings were drilled with a 24-inch diameter bucket auger drill. Borings 5 to 9 and 20, however, were accomplished with a 36-inch diameter crane auger. Several borings were limited in depth due to encountering large volcanic rock fragments. The crane auger was used to get better penetration. The locations of borings and pits are plotted.-on the enclosed Geotechnical Map (Plate 1). Logs of Pits and Borings are included herein as Plates A-1 through -A-8 and B-1 through B-20, respectively. Borings were also performed with a 67inch diameter flight auger, however, rock prevented penetration greater than five feet. Later drilling duplicated this information. Site analyses was also performed using aerial photographs, I available topographic coverage prior to grading and original grading plans for the site. Maps were made available through Rick Engineering. . I Three shallow seismic refraction profiles were performed on the site in order to estimate rock hardness.. The lines were I confined to suspected hard areas which were already in a cut condition. I I . . GeoSoili, Inc. Daon Corporation Page 6 W.O. 845-OC November 11, 1981 SURFICIAL DESPOSITS Fill More than half of the subject property is underlain with fill generated through past grading activities. The fill generally occurs within three canyon areas and varies up to possibly 50 feet deep below existing grades. The approximate limits of the fill and fill depths are shown on the enclosed Geotech- nical Map. The approximate axes of the original canyons are also shown. I The fill generally consists of a mixture of gravels and rock fragments with a silt and sand matrix. Rock fragments have been generated from local volcanic materials which have been I noted up to 24 inches in size. Larger rocks may exist. The I percentage of rock varied with exposure, from 25 to 75 percent. The high percentage of rock materials makes actual testing of I the fill difficult to impractical. Our excavation, however, noted loose and soft materials. The rock content itself further I suggests that the fill would be irregularly compacted and may be subject to settlement. This is especially important when con- sidering large, multi-level structures. Local areas of dump fill exist in the areas on both sides of the I storm drain channel and along the golf course. Dump trash occurs along the golf course and pipe has been stored at one location. Topsoil/Colluvium U Since most of the site has been graded, there is very little top- soil or colluvium.remaining at the surface. Surficial soils would still remain along the naturalslope along the golf course. These I GeoSoils, Inc. I Daon Corporation Page 7 W.O. 845-OC I November 11, 1981 I materials are derived from sedimentary bedrock and consist of cohesive soils estimated at two to three feet thick. Topsoil/colluvium was encountered within pits and borings, I at depth, beneath the fill. Zones of probably reworked surficial soils were also observed. These soils were dark, colored, had an organic odor and varied from moist to nearly I dry and soft to firm. These soils were encountered in Test Pits 13, 14?, 15 and 24? and Borings 5?, 7, 8, 15 and 20, Alluvium - Alluvial soils were encountered in several borings and pits I .in the area on either side of the existing concrete 'channel, These soils consisted of mixtures of sands, silts and'clays I predominately with an organic content. Portions resemble highly organic embayment deposits. , The soils are moist to wet and soft to firm. The alluvium is overlain with four I toeleven feet of.fill.' Settlement of the alluvium is anticipated. Earlier maps and photos of the site suggest alluvium extending up into the area of Altiva Place and, within the lower portions of the other canyons. (See approximate canyon locations on I .Geotechnical Map.) It is not known if these deposits were removed prior to filling. BEDROCK I Bedrock materials underlying the subject property are varied, consisting of sediments of the Delmar Formation and volcanic I ' bedrock representing a portion of the Santiago Peak Volcanics. The approximate distribution of materials is shown on Plate 1. I ' GeoSoils,' Inc. I Daon Corporation Page 8 U W.O. 845-OC November 11, 1981 Delmar Formation Most of the westerly half of the site is underlain with inter- bedded sandstones and siltstones. These materials are dense defined layers feet thick. The layers with poorly several are near horizontal. I.. Sediments continue easterly through mOst. of the remainder of the site as a massive deposit of breccia-conglomerate. Materials - include rounded granitic, metamorphic and volcanic pebbles and I cobbles, mixed with angular volcanic fragments, This deposit 'has a silty sand matrix and is very dense. The steep natural I slope at the southeast corner is composed Of these materials, indicating a relatively stable condition. Volcanics I Hard basaltic volcanic rock is locally exposed near Alfil Road and was encountered at a shallow depth in Test Pits 23 and 24, I and Boring 6. The basalt.is locally fractured and weathered,, although difficult excavation would be expected. Additionally, this, deposit would generate oversize rock. Faults,'Landslide-s, Surficial Failures, Erosion - No faults or deep seated landslides were encountered within the I subject property. Photo study indicated a topographic break, however, this feature appears to correspond to the soft sediment/ - I conglomerate contact. Exploration did not reveal any bedrock disturbance. I' I - GeoS oils, Inc. Daon Corporation I Page W.O. 845-OC November 11, 1981 I Surf±ial slope failures were observed in the natural slope along the golf course. These appear as shallow rotational slumps I in fill and natural soils and as sloughing along steep cut slopes bordering an access road at the southeast corner of the site. I A surficial, rotational type failure has occurred in the fill portion of the -slope along Alicante Road just southwest of II Alf ii Way. • Minor slumping has also occurred along an old access west of I Altiva Place, above the canyon. These have occurred in fill and surficial soils as a result of cutting in the road. I • Erosion has cut into sandy sediments in the central portion I • of the site along one of the access roads. Minor erosion has affected other sandy slopes. Groundwater and Caving I • Both groundwater and caving ground conditions were encountered • in the alluvium and in sedimentary bedrock materials west I of the major canyon. The groundwater va'ies from 4.5 to 14 feet below ground surface. Caving was encountered within many I of the borings, related to saturated ground conditions. I Groundwater, in the alluvial soils would be related to storm drain runoff and golf course watering. Within the bedrock, water is I contained within sand and gravel layers and is probably related to north of the site. landscape irrigation I -• I I • • • GeoSoils, Inc. I I Daon Corporation Page 10 W.O. 845-OC November 11, 1981 I The potential for groundwater level increases related to onsite irrigation is present and dewatering through the use of sub- drains is advised. I Seismicity Although no active faults occur within or nearby the property, I it, as well as Southern California. as a whole, would be affected by earthquake activity. The affects would include ground shaking and vibrations indicating the necessity for earthquake resistance in structures as directed by. the Uniform Building Code. A liquefaction potential may exist in the vicinity of Boring 17. This may be mitigated through the use of a subdrainage system. Excavation Character The sedimentary and fill materials should be relatively easy to excavate with conventional grading equipment. The volcanics, .. however, may require heavy ripping to blasting at depths of 8 to 20 feet. The results of three shallow seismic refraction surveys are presented below: SUMMARY OF SEISMIC REFRACTION LINES Seismic Approximate Average Seismic Line Depth (ft.) Velocity (ft./sec.) Comments 1 • 0-20 . 31,200 I . • .2030 2 0-17 14,500 5,500 17-30 8,000 I 3 0-15 . 3,600 15-30 10,500 I • . GeoSoits, Inc. Moderate Ripping Non-Rippable Difficult Ripping Non-Rippable Moderate Ripping Non-Rippable Daon Corporation Page 11 W.O. 845-OC November 11, 1981 I The above velocities represent actual measurements at the specific locations of the seismic lines. Variations in I velocities may occur at other locations. The comments re- garding rippability are based upon the Catapiller Performance Handbook, Edition 9, 1978. - CONCLUSIONS I General I , -- 1. Based upon the foregoing study and the current development plan, development of the subjecE property for residential purposes is feasible from a geotechnical viewpoint. No evidence of existing landslides or other forms of gross instability was encountered. The conclusions and recommendations do not apply to the I area along Altiva Place, north of Alicante Road since this area is not in the current planning. Earth Materials 1. Sedimentary rocks of the Del Mar Formation and portions of U the fill are suitable for reuse in properly controlled fills placed as recommended below. • 2. Oversize rock contained within the fill and that generated by grading in the volcanics should be removed from the site. I Limited amounts may be placed carefully within the deeper fill areas as recommended-below. Oversize rock is generally I regarded as larger than eight inches. I - • GeoSoils, Inc. • • Daon Corporation Page 12 W.O. 845-OC November 11, 1981 Alluvial soils in the vicinity ofthe paved storm drain channel are subject to settlement. Based upon the soil types encountered, the settlement may be considered as long term. - Shallow groundwater conditions exist in the westerly portion of the site. A subdrain system should be established to permit a relief mechanism to facilitate settlement and to mitigate potential liquefaction. The existing fills within, the project site are considered unsuitable for support of the proposed grading and structures. Based on the latest land plan, approximately 175,000 cubic yards are to be exported from the project. We recommend that much of the material to be exported consist of oversize rock as it is separated from the fills and what oversize rock is generated from the volcanics. Rock Hardness Rock Units of the Del Mar Formation should excavate with light to moderate ripping. I Volcanic rocks should generally excavate to-moderate depth (± 20 feet deep) with moderate to heavy ripping. Deeper excavations I should require blasting. It may be beneficial to preblast to the proposed-.grade 'to facilitate excavation. - - I I I GeoSoils, Inc. Daon Corporation Page 13 S W.O. 845-OC - S November 11, 1981 RECOMMENDATIONS The recommendations given below have' resulted from the foregoing site investigation and are consistant with the indicated geotech- nical conditions. The recommendations should be reflected in finalized development plans and implemented during the construction phase. Graded Slope Design Graded fill slopes should be planned and constructed at 2:1 gradients, no greater than 50, feet in height. Higher slopes may be flatter or provided with mid slope benches. Cut slopes may be programmed for 2:1 gradients to the desired heights. • S S All cut pads should be inspected by the engineering geologist for geologic conditions. Areas of significant fracturing and/or differential soil conditions may be subject to over- excavation and rebuilding with compacted fill. All cut slopes should be inspected by an engineering geologist during and at the completion of grading. Stabilization fills maybe recommended depending upon the exposed conditions. Cut and fill slopes shouldbe planted as soon as possible after excavation with fast'growing,' deep rooting vegetation. Shrubs and trees are considered as the best deep rooted types. S GeoSoils, Inc. Daon Corporation Page 14 W.O. 845-OC November 11, 1981 Cut Slope Stabilization The possibility exists that cut slopes in the sedimentary materials may expose unfavorable geology and/or soil types for the conditions. In this event, a stabilization fill may be recommended to support the adverse feature. For estimating purposes, the stabilization fill should be at a minimum width of 15 feet or at a width equal to one half the slope height, with a key depth of two feet below the toe grade. An underdrain system is recommended for all, stablization, fills. Subdrain limits can be determined in the field when actual conditions are exposed. Canyon and Stabilization Fill Underdrains Canyon subdrain systems should consist of six inch diameter perforated pipe embedded in nine square feet of Class 2 permeable filter per foot. A 50-50 mix of clean concrete sand and pea gravel may be substituted as a filter. The subdrain' pipe may be plastic provided a minimum of schedule 40 pipe is used and it is placed within a narrow square cut trench according to manufacturer specifications. Internal subdrainage for buttresses and stabilization fills is required. These will consist of 4-inch diameter perfor- ated pipe embedded in 3 square feet of filter material per foot along the back of the keyway. Schedule 40 plastic pipe may be used provided precautions are taken not to crush the pipe. Outlet pipes should be placed within square-cut trenches. Depending on the height-of the slope, more than one tier may be necessary. GeoSoils, Inc. I. I I I I I I I I I I The drainage systems would be intended to collect rising groundwater and/or water from landscape irrigation. During grading, the engineering geologist should evaluate the necessary of placing additional drains. All subdrainage systems should be inspected by the engineer- ing geologist and soils engineer prior to covering with compacted fill. Treatment of Existing Ground A. Major Canyon and Area to West Debris, major vegetation and other deleterious materials should be removed from the site. All existing fill and loose surface soils should be removed. Alluvium may be left in place, although it would be subject to consolidation. Oversize rock materials encountered should be wasted from the site -or if possible carefully placed in accordance with recommendations below. A network of canyon type subdrains should be installed beneath all structural areas where water exists, extending at an approximate depth and draining into the existing channel or other convenient location. An actual subdrain design may be defined later. These subdrains may consider. filter cloth wrapped drains or other applicable systems. GeoSoils, Inc. Daon Corporation Page 15 W.O. 845-CC November 11, 1981 Daon Corporation Page 16 W.O. 845-OC November 11, 1981 B. Area East of Major Canyon 1. Debris, major vegetation, stockpiled pipe and other deleterious materials should be removed from the site. 2.. All existing fill should be removed, along with any buried topsoil, colluvium or 'alluvium. The estimated depth of-fill-is shown on the enclosed Geotechnica1 Map (Plate I). These depths may not include topsoil or alluvial removal, if required. Subdrains should be installed in the canyon areas once they are established. Placement of Compacted Fill Prior to placing fill, subsequent to removals, the bottom surface should be processed, watered if necessary and compacted. - All fills shOuld be keyed and benched into competent materials. Keys should.by initially excavated at least two feet into competent materials and at a height estimated at one half the height of the slope with a 15 foot minimum. The keys should be tipped slightly so that they are one foot deeper at the, heel of the key. Benching should be continued as the filling progresses to remove unsuitable overburden. GeoSoils, Inc. Daon Corporation Page 17 W.O. 845-OC November 11, 1981 3. The excavated soils should be placed in reasonably uniform, thin lifts (± 6 inches or less),.Oleañed if necessary, watered or air dried to approximate optimum moisture con- ditions and compacted to a minimum relative compaction of 90 percent of the laboratory standard.: The recommended laboratory standard is ASTM D-1557-70. 4.. Grading should be performed in accordance with the require- ments of the grading code of the City of Carlsbad and the Uniform Building CodeS. Generally, all site materials may be reused for compacted fill, except oversize rock. I Materials in excess-of eight inches in size should be I . separated from the fill and either exported from the site or placed carefully within deep fills as directed by the I . soils engineer. A recommended practice is provided below. 7.. Compaction tests should be performed periodically by the I soils engineer to verify the -compaction and moisture content. - These results should be provided to the contractor as an I aid in completion of his work. I .8. The cut portion of cut/fill transition pads should be over- excavated a depth of three feet to provide uniform foundation I - support conditions. This may include any transition produced as a result of previous grading. . . . Where the original ground slope is very steep in cut/fill transition areas, deeper undercuts of the cut portion or I - layback of the original ground slope may be necessary. -I.. GeoSoils, Inc. . . Daon Corporation Page 18 W.O. 845-OC November 11, 1981 9. All exploratory backhoe trenches still remaining after site removals should be excavated and filledwith compacted fill. Settlement Considerations - West Portion of Site The area of the major canyon in the westerly portion of the site is subject to settlement. Anticipated grading at this time calls for approximately 20 feet of fill. Settlement would occur with the alluvial soils which are wet and soft. We recommend that fill be placed in stages consisting of five foot layers, at intervals of abOut.one week. A ten foot surcharge should then be placed over the above finished grade until the majority of settlement has occurred. Survey or instrumental control would be necessary to monitor settlement. Settlement on the order of 12 to 18 inches may be anticipated, U which may occur over a 6 to 12 month time period. A subdrain system is required for this area to facilitate settlement. Estimated time/settlement values for this area should be ' determined when final grading plans are completed. Additional subsurface exploration and laboratory testing ' 'may be necessary at this time Earthwork Balance The following bulking and shrinkage factors are estimated for the various earth units:' Existing Fill -.5-100-6 Shrinkage • Volcanics --0-5% Bülking Sediments ' +1% Bulking • ' ' GeoSoils, Inc. Daon Corporation Page 19 W.O. 845-OC November 11, 1981 The above assumes that the fill is compacted to 90-93 percent relative compaction. Appreciable amounts of oversize materials could increase the bedrock bulking factor. It is also anticipated that 20-25 percent of the existing fill would be oversize rock requiring export to a disposal area. Rock Disposal Since excavation of the volcanic rocks and the existing fill may yield a variable quantity of oversize rock, export or special handling may be required for disposal. Although alternatives may be developed in the field, the following methods of onsite rock disposal are recommended on a preliminary basis. The actual method used should be detailed in the field. Oversize rock should be placed in windrows that. are not more than '5 feet wide or 4 feet high. The wind- rows should be at least 15 feet or equipment width apart. The maximum size rock allowed in the windrows is 4 feet. Larger rocks should be broken down, if possible. Should some of the rocks not break down, they may be buried in: pits with granular material flooded intothe surrounding space. The void spaces between rocks in a windrow should be filled with the more granular soils by flooding them into place. A minimum vertical distance of 3 feet between lifts should be maintained. Also, the windrows should be staggered from lift to lift. Rock windrows should not be placed closer than 15 feet from the face of fill slopes. . GeoSoils, Inc. Daon Corporation Page 20 I W.O. 845-OC November 11, 1981 5. Rocks greater than 8 inches in diameter should not be allowed within 5 feet of finished pad grade for structures, or within I 12° feet of finished grade for recreation areas or utility areas. This will allow easier trenching for foundations, I utility lines and pools.. I 6. Rocks greater than 4 feet should be placed within a dozer trench. Each trench should be excavated into the compacted fill a minimum of one foot deeper than the size of the rock I to be buried. After the rocks are placed in the trench (not immediately adjacent to each other), granular fill materials I should be flooded into the trench to fill the voids. The o'er- size rock trenches should be no closer together than 15 feet I at a particular elevationand 15 feet from any slope face. Trenches at higher elevations should be staggered and there I . should be four feet of compacted fill between the top of one trench and the bottom of the next higher trench. Fill Slopes 1. The outer surface of the fill slopes should be thoroughly back-rolled every3 to 4 feet with a sheepsfoot roller as the slopes are constructed. ° I . When the slopes reach their design height,. they should be shaped, sheepsfooted and then grid-rolled.. The contractor I . should obtain a minimum relative compaction of 90 percent out to the finished slope surface. I 2. All fill, slopes should be keyed into competent bedrock. The key should be at least 15 feet wide for slopes up to I ° 30 feet high, two. feetdeep;. and tipped.one foot deeper at the back of the key. For slopes higher than 30 feet, 1 ° the key width should be equal to 1/2 the height. Additional I . GeoSoils, Inc. . . I . Daon Corporation Page 21 I . W.O. 845-OC November 11, 1981 I excavation may be required to obtain this width along the base of some of the fill slopes in order to penetrate I unsuitable oberburden materials. Where fill over cut slopes are programmed, the cut portion should be made first to determine the depth of the fill key and t0 preclude the possibility of stabilization. Where fill is placed upon slopes steeper than 5:111 the slopes should be benched to remove unsuitable materials and to form irregular horizontal surfaces to support the fill. All fill keys should be inspected by the soils engineer and/or engineering geologist. ..FOUNDATION DESIGN Bearing Value 1.• An allowable bearing value of 1500 lbs./sq, ft, may be used for design of continuous footings 12 inches wide and 12 inches deep. This value may be increased.by 200 lbs./sq. ft. for each additional 12 inches in depth and by 100 lbs./sq. ft. for each additional 1,2 inches in width to a maximum value of 2000 lbs./sq. ft. 2. The above values may be increased by one-third when considering short duration seismic or wind loads. I, .. . GeoSosis, Inc. I Daôn Corporation Page 22 W.O. 845-OC November 11, 1981 I Lateral Pressure I 1. The active earth pressure to be utilized for.retaining wall design may be computed as an equivalent fluid having I a density of 35 pounds per, cubic foot when the slope of .the backfill behind th wall is level.. Where the slope I .. of the backfill is 2:1, an equivalent fluid pressure of 45 pounds per cubic foot may be used. Passive earth pressure may be computed as an equivalent fluid having a density of 250 pounds per ,cubic foot, with.a maximum' earth pressure of 1500'pounds per square foot. An allowable coefficient of friction between soil and concrete of 0.4 may be used with the dead load forces. When combining passive pressure and frictional resistance,, the passive pressure component should be reduced by one- third. , FOUNDATION CONSTRUCTION The' soils on the site are expected to vary from non-expansive to highly expansive in'nature, with the major portion being slightly to moderately expansive. The following construction procedures are recommended asan aid to budgeting: Non-Expansive to Slightly Expansive Soils 1. Footings may be constructed according to standard building code requirements regarding width and depth. No reinforce- ment is necessary' from a soils engineering standpoint. GeoSoils, Inc. I Daon Corporation I Page 23 W.O. 845-OC November 11, 1981 Concrete slabs, ,except in garage areas, shall be ündér- lain with a vapor barrier consisting of a minimum of 6 mil polyvinyl chloride membrane with all laps sealed. This membrane shall be covered with a minimum of one inch of sand to aid in uniform curing of the concrete. I . Concrete slabs, except in garage areas should be reinforced 6 inch 6 inch, with by No. 10 by No. 10 welded wire mesh. All slab reinforcement should be supported to ensure proper I positioning during placement of concrete. Garage slabs should be poured separately from the residence footings. I A positive separation should be maintained with expansion joint material to permit relative movement. Moderately Expansive Soils 1. Exterior footings should be founded at a minimum depth of 18 inches below the lowest adjacent 'ground surface.' I . Interior footings may be founded at a depth of 12 inches below the lowest adjacent ground surface. All footings . should have one No. 4 reinforcing bar placed at the top. and bottom of the footing. A tie beam 12 inches by 12 inches, reinforced as above, I should be provided across the garage entrances. The base of the tie beam should be at the same elevation as the adjoining footings. Concrete slabs, except in garage areas, shall be underlain I with a vapor barrier consisting of a minimum of 6 mil polyvinyl chloride membrane with -all laps sealed. This I • membrane shall be covered with a minimum of one inch of sand to aid in uniform curing of the concrete.. • I . I . • • GeoSoils, Inc. I . Daon Corporation Page 23 I W.O. 845-OC November 11, 1981 Concrete slabs, ,except in garage areas, shall be under- lain with a vapor barrier consisting of a minimum of 6 mil polyvinyl chloride membrane with all laps sealed. This membrane shall be covered with a minimum of one inch of sand to aid in uniform curing of the concrete. I . • Concrete slabs, except in garage areas should be reinforced with 6 inch by 6 inch, No. 10 by No. 10 welded wire mesh. All slab reinforcement should be supported to ensure proper I positioning during placement of concrete. Garage slabs should be poured separately from the residence footings, I A positive separation should be maintained with expansion joint material to permit relative movement. Moderately Expansive Soils Exterior footings should be founded at a minimum depth of 18 inches below the lowest adjacent ground surface. j Interior footings may be founded at a depth of 12 inches below the lowest adjacent ground surface. All footings should have one No. 4 reinforcing bar placed at the top. and bottom of the footing. A tie beam 12 inches by 12 inches, reinforced as above, should be provided across the garage entrances. The base of the tie beam should be at the same elevation as the adjoining footings. Concrete slabs, except in garage areas, shall be underlain I with a vapor.barrier consisting of a minimum of 6 mu polyvinyl chloride membrane with all laps sealed. This I - membrane shall be covered with a, minimum of one inch of sand to aid in uniform curing of the concrete. I I , . GeoSoils, Inc. I . : I Daon Corporation - Page 24 W.P. 845-aC November 11, 1981 Concrete slabs should be reinforced with 6 inch by 6 inches, I No. 10 by No. 10 welded wire mesh. All slab reinforcement should be supported to ensure proper positioning during. placement of. concrete. Presaturation is recommended for these soil conditions. The moisture content of,the subgrade soils should be greater than optimum moisture to a depth of 18 inches below grade in the slab areas. I Highly Expansive Soils I l. Exterior footings should be founded at a minimum depth of 18 inches below the lowest adjacent ground surface. I Interior footings may have a minimum embedment of 18 inches below the top of the lowest adjacent concrete slab s.urface. I However, a minimum penetration of 12 inches into the soil is required. Interior isolated piers are not recommended. All footings shall be reinforced with a minimum of one I .No. 5 reinforcing bar at the top and one No. 5 reinforcing bar at the bottom. Exterior post support should be founded at a dpeth of 24 inches below adjacent grade and be tied to.the main I foundation. I - 2. A tie beam, 12, inches by 12 inches, should be utilized across garage entrances. The base of this reinforced - I tie beam should be at the same elevation as the bottom of the - adjoining footings. I. I . GeoSoils, Inc. 4. Daon Corporation Page 25 W.O. 845-OC November 11, 1981 Concrete slabs in residential areas shall be underlain with 4 inches of washed sand or crushed rock. In addition,. a vapor barrier consisting of a minimum of 6 mil polyvinyl chloride membrane with 'all laps sealed shall be provided. One inch of the sand shall be placed over the membrane to aid in uniform curing of the concrete. Concrete slabs shall be reinforced, with 6 inch by 6 inch, No. 6 by No. 6 welded wire mesh or its equivalent. All slab reinforcement should be properly supported to ensure the desired placement. Presaturation is recommended for these soil conditions, The moisture condition of each slab area shall be 120 percent or greater above optimum and verified by this office to, a depth of '18'inches below slab grade prior to pouring of slabs. Alternatively, post-tensioned foundation and slab systems may be utilized. UTILITY TRENCH BACKFILL 1'. Utility trench backfill' shall be placed to'-.the-following standards: 90 percent of the laboratory' standard if native material is used as .backf ill. 2. As an alternative, clean sand may be utilized and -flooded in place. No specific relative compaction will be required; however, inspection, probing, and if deemed necessary1 ' testing shall be required. , GeoSoils, Inc. I Daon Corporation ,. Page 26 W.O. 845-OC November 11, 1981 3. Exterior trenches, paralleling a footing and extending I below a 1:1 plane projected from the outside bottom edge of the fpoting shall be compacted to 90 percent of the laboratory standard. Sand backfill, unless it is similar I •to the inpiace fill, will not be allowed in these trench backfill areas. Density testing along with probing shall I be accomplished to verify the desired results. INVESTIGATION LIMITATIONS The materials encountered on the project site and utilized in I our laboratory investigation are believed representative of the total area; however, soil and bedrock materials vary in I characteristics between excavations and natural outcrops. I Since our investigation is based upon the site materials observed,. selective, laboratory testing and engineering analyses, the con- clusions and recommendations are professional opinions. These opinions have been derived in accordance with current standards I .. of practice and no warranty is expressed or implied. This opportunity to be of continued service is sincerely I appreciated, and if you' have any questions pertaining to this report, please call. I Respectfully submitted, GeoSoils, Inc., I By k. .4. S By Sayers G 907 351 ± eering G olo ist Civil Engineer I ARK/JAS/se . End: Geotechnical Map - Plate 1 (in pocket) I .Logs of Test--Pits - Plates-A-1 to A-8 Logs of Borings - Plates B-i to B-20 Dist: (2) Addressee I . (1) Rick Engineering, Attn: Bob Ladwig (1) Florian-Escobar-Martinez, Attn: Mr. Gil Martinez . GeoSoils, Inc. Daon Corporation W.O. 845-OC LOGS OF. EXPLORATORY TRENCHES T. P. # DEPTH (feet) DESCRIPTION @ 8' 11.0 - 18.0 0.0 - 5.0 5.0 -11.0 11.0 -. 16•:0 3.0 8.0 FILL: Silty fine Sand (SM), light brown with up to 40% volcanic rock fragments up to 8 inches, moist, moderately compact at 5 to 7 feet, rock fragment content increases to 60% up to 2 feet in size. Locally wet. ALLUVIUM: Clayey to Sandy Silt, (MH/ML) bluish •gray, wet, soft, organic odor. Water seepage at upper contact. T.D. at 18 feet. No caving, water seepage at 11 feet. FILL: ClayeySand (SC) with 10% rock-fragments, moist, medium dense. large volcanic rock fragments to 3 feet at base. FILL(?): •Fine Sandy Silt (ML), medium brown, moist, soft. ALLUVIUM: Fine Sandy Silt (ML), mottled gray and brown,moist, firm. Heavy water seepage at 13 feet and grades to brown. T.D. at 16 feet. No caving, groundwater at 13 feet. FILL: 75% volcanic rock fragments up to 8 inches with a brown Silty Sand matrix, moderately compact, moist. FILL(?): Sandy Silt (ML), brown, soft to firm,moist with local areas of wet sand. 1 0.0 - 11.0 3 0.0 - 3.0 Geo Soils, Inc. PLATE A-i Daon Corporation . W.O. 845-OC T.P. # ..DEPTH (feet) DESCRIPTION 3 (cont'd) 8.0 - 15.0 ALLUVIUM: Sandy Silt (ML), bluish graym moist, soft with minor caving. @ 11' Dark gray, organic odor. T.D. at 15. feet. Minor caving below 8 feet, no groundwater.. 4 0.0 - 3.0 FILL(?): . .Clayey Silt (MH), brown, damp, firm. @ 1.5' Sand (SP), fine to medium grained, moist, dense, friable. 3.0 -. 8.0 BEDROCK: Sandy gravel with Silt, up to 70% rounded and angular volcanic fragments, brown, moist, dense. . @ 7 1 . Heavy groundwater seepage and caving prevents further digging. T.D. at. 8 feet.. Groundwater and caving below 7 feet. 5 . - 2.5 FILL(?): Sandy Clay (CL), brown, damp, firm. @1.5' Sand (SP), fine to medium grained, light gray, moist, dense, friable. 2.5 - 10.0 BEDROCK: Clayey Siltstone (weathered), dark gray, moist, stiff. @ 8' Sandstone-Siltstone, light grayish- green, moist, dense to stiff. T.D. at 10 feet. No caving or water. GeoSoils, Inc. PLATE A-2 Daon Corporation W.O. 845-OC T.P. # - DEPTH (feet) DESCRIPTION 6 0.0 - 10.0 BEDROCK: Gravelly sand, up to 50% rounded and angular rock fragments, brown, damp, dense, no cementation. Sand with thin strata of Silt, gray, • moist, dense. Heavy groundwater • seepage at 9 feet and caving, unable to penetrate deeper. T.D. at 10 feet. Groundwater and caving at .9 feet. 7 0.0 - 2.0 FILL(?): Clayey Silt (MH), brown, • dry to damp, hard at surface to firm. 2.0 - 17.0 BEDROCK: Clayey Siltstone (weatherd) mottled reddish-brown and gray, moist and hard. - @ 5' Silty Sandstone, light brown, moist, . dense. @ 14' Water seepage. T.D. at 17 feet. • No caving, -water seepage at 14 feet. 8 0.0 - 4.5 FILL: Irregular layers of Silty Sand and Clay, brown to gray, moist, soft. • • • 4.5 - 13.0 ALLUVIUM: Silty Sand (SM), dark gray, organic odor, moist, soft, water - • seeps and minor caving near top. 13.0 - 15.0 • BEDROCK: Sandy gravel with up tp 70% ,rounded and angular rock fragments, very dense, moist. • • T,D. at. 15 feet. • • • Water seepage and minor. caving •at • • 4.5 to 15 feet. GeoSoils, Inc. PLATE A-3 Daon Corporation W.O. 845-OC T.P. # 'DEPTH (feet) . DESCRIPTION I 9 0.0 - 5.0 , FILL: Sandy Silt (ML) with 100-, angular rock fragments, brown, moist, firm. 5.0 10.0 ALLUVIUM(?): Fine Sandy Silt (ML), brown, moist, soft. 10.0 - 17.0 ALLUVIUM: Silty Sand (SM), brown, moist, medium dense. Heavy water seepage and minor caving. . 15.' Grades to gravelly. Sand, wet, dense. T.D. at 17 feet. I S Groundwater and caving at 11 feet. 10 0.0 - 2.0 FILL(?): Clayey Silt (MH), dark I S S brown, dry to moist, firm to stiff. 2.0 - 5.0 BEDROCK:,. Sandstone, light brown, somewhat cemented, damp, hard. T.D. at 5 feet. No caving or groundwater. 11 0.0 - 15.0 BEDROCK (WEATHERED): Silty Clay with Sand, brown, dry to damp, hard, scattered caliche. Upper', 18 inches I . disturbed. I @ Becoming moist. . @ Silty fine Sand; brown, moist, medium dense. I @ 14' . , Sandy gravel, heavy water seepage. at 15-feet. S I T.D. S , Groundwater and caving at 14 feet. I 55 I ' ' GeoSoils, Inc. S S , ' PLATE A-4 Daon Corporation W.O. 845-OC 13.0 -.14.0 DESCRIPTION / BEDROCK: Silty Sand, light brown to gray, dry to damp, dense,upper 18 inches disturbed. Sandstone, white, medium grained, moderately cemented and hard. T.D. at 7. feet. No water or caving. FILL: Sandy to Silty Clay (CL), brown )with up to 35% angular rock fragments to 12 inches, moderately compact, moist. Sandy Silt (ML), brown, moist, stiff. . Silty Sand (SM), brown, moist, medium dense. Clayey Silt (MH), dark brown, organic odor, moist, firm. (Probable Topsoil) BEDROCK: Sandstone, white, damp, very dense. . T.D. at 14' feet. No caving or water. FILL: Silty Sand (SM), light brown, moist, dense with 10% volcanic rock fragments, moist, dense. Mixed Silt (ML) and Silty Sand (SM), brown, moist, dense. @ 12' Clayey Silt (MH), dark brown, moist, stiff. (Possible reworked Topsoil) ., Becomes damp to dry. (Possible natural Topsoil,.) WEATHERED BEDROCK(?): Clayey Silt, light gray, hard, damp. T.D. at 17 feet. • . No water or caving. 13 0.0 - 13.0 14 0.0 - 16.0 T. P. DEPTH (feet) 12 0.0 - 7.0 @ 4' @ 4' @ 14' 16.0 - 17.0 GeoSoils, Inc. PLATE A-5 Daon Corporation W.O. 845-OC T.P.# DEPTH (feet) DESCRIPTION 15 0.0 - 7.0 FILL: Clayey Silt (MH), brown, dry to moist, variably stiff to slightly soft. @ 3-5' Volcanic rock fragments up.-to 24 inches. 7.0 - 9.0 TOPSOIL: Clayey Silt (MH), reddish- brown, moist, firm. 9.0 - 12.0 BEDROCK: Silty Sandstone, light gray, moist, dense, friable. T.D. at 12 feet. No groundwater or caving. 16 0.0 - 7.0 FILL: Fine Sandy Silt with scat- tered-rock fragments, medium • brown, dry to damp-,,'firm. 7.0 - 18.0 BEDROCK: Silty Sand, light brown, - coarse grained, moist, dense. • @12' Sandy Silt, light brown, moist, hard. @ 7' Cobbles. • • T.D. at 18 feet. - No groundwater or caving.' 17 0.0 7.0 FILL: Clayey Silt (MH),. brown, up to 50% volcanic rock fragments. to 24 inches, dry to damp, moderately compact. 7.0 - 10.0 • BEDROCK: Clayey Silt (MH),light - ' • brown, moist, hard.- Upper 2 feet appears disturbed. - T.D. at 10 feet. • - No groundwater or-caving. - GéoSoils, Inc. - PLATE A-6 Daon Corporation - W.O. 845-OC T. P. # II] 19 21 DEPTH (feet) DESCRIPTION 0.0 - 10.0 BEDROCK: Sandy Silt to Silty Sand (ML-SM), light to dark brown, moist, stiff/dense. 10.0 - 13.0 Clayey Silt with Sand (MH), brown, - moist, firm. 13.0 - 14.0 Sandstone, brown, friable, dense, moist. T.D. at 14 feet. . No water or caving. 0.0 - 4.0 BEDROCK: Silty gravel with Clay, light brown, up to 75 percent rock fragments and rounded pebbles. Cobbles and occasional boulders to 12 inches, dense, damp. T.D. at 4 feet. No Groundwater. No Caving. 0.0 - 12.0 FILL: Clayey Silt (ML) with Sand,- -reddish -brown, moist, stiff. @ 3' Becomes greenish-brown and contains up. to 15% volcanic rock. fragments. @ 12' Very large rockin bottom, unable to • penetrate. T.D. at 12 feet. No groundwater or caving. 0.0 - 10.0 BEDROCK: Silty Sandstone reddish- brown, massive, damp, dense. @ 3' • Becomes brown. T.-D. at 10 feet. • No groundwater or caving. GeoSoils, Znc. PLATE A-7 I Daon Corporation W.O. 845-OC I T.P. it DEPTH (feet) . DESCRIPTION I 22 0.0 - 10.0 FILL: Sandy Silt (ML) with up to 30% rock fragments, damp, compact. I . @ 8' Clayey Sand (SC) with 30% rock frag- ments, gray-brown, moist, somewhat I loose, organic odor. @ 19' Large rock, unable to penetrate. I . T.D'.T.lo. feet. No caving or groundwater. 23 0.0 - 9.0 BEDROCK: Gravelly Clay with Sand, I reddish-brown, moist stiff, up to 30% volcani.c rock fragments. 81 Basalt, very hard, blocky, reddish staining of fracture surfaces, dark gray on fresh breaks. I T.D. at 9 feet. No groundwater or caving. I 24 0.0 - 8.0 FILL: Silty Sand (SM) with some Clay (S. End) and up to 40% rock fragments, moist, I . dense. @ 5'1 . Silty Sand, light brown, dry to slightly damp, hard. (Possible natural ground) 8.0 - 8.5 BEDROCK: Basalt, dark reddish-brown, hard damp. T.D. at 8.5 feet. No caving or groundwater. 25 0.0. - 17.0 FILL: Sand-Silt mixture with variable Clay and up to 25%, rock fragments to .24 inches... Reddish-brown to brown, moist, moderately compact. T.D'. at 17 feet. I . .. No caving or -groundwater. 26 - 0.0 , - 17.0 FILL: Clayey Silt (MH) with Sand and .up 'to 15% volcanic rock fragments from . I 6 to 24 inches, moist, soft to loose. T.D. at 17 feet. I . No water, sides sloughing slightly. GeoSoils, Inc. . . . . PLATE A-8 _ - - - - - .SEigir -N 1':r .. = BORING LOG' CLIENT_Daon Corp. w.o._L45-OCDATE DRILLEb11281 LOGGED BY DM PROJECT _Alicante Hills SURFACE ELEV ± 27 DRIVING WT. T.? CCi IL. LU I- < --n- W IL. T a. LU - CD a. '-' c __ $ - S >, . Cl) o im CD (n_,•' (oc Cl) W w Cl)O,.o Q.&)O'0 LU O4 'I . c.>- -Wo (I)Ir - I-. I-W Co '-'0 I — --0- FILL(af): Light brown Clayey Silt with Sand. Dry to very slightly moist, loose. From 4 feet; up to 50% hard volcanic rock fragments, slow drilling. -... ! - - - - - - - - - - - - - 5- End of boring at 8 feet. Drill bucket refused by numerous rock. No water or caving. PLATE B-I co BORING LOG CLIENT _Daon Corp. W.0.845—OC DATE DRILLEb _______ LOGGED BY_RZ PROJECT- Alicante Hills SURFACE ELEV.± DRIVING WT. 2400# T rrc4- W 311: U.- . _-Cr 'in I o_ 0 0 - (fluwu.CL C,)CL I- 0 CD >-Q)° DWO< zo 0.1n IQ Owl U00 U). Z >. - a z - __5 Red-brown Silty Sand, dry to slightly moist, dense, rock fragments to 8 inches - 40%. _______________________________ - - - CL - - - -- - - 3 102.5 - - 21.- - - - - - - - - - - ____ Light brown Sandy Clay, dense, 40% rock fragments to 8 inches. Rock to 12 inches, extremely difficult drilling. Easier drilling - 20% rock fragments to 8 inches. --10- Dark brown Silty Clay with Sand, rock fragments to 4 inches, very dense, mottled. Rocks to 12 ihches. 15 - - End Boring at 18 feet, rock refusal.• Note: Moved boring - Refused at 12 feet Moved again - Refused at 13 feet No water. - - - - - - - - - - - - - PLATE B- ci BORING LOG,- CLIENT W. Corp. W.O.4SOC DATE DRILLEb 1138OGGED BY_______ PROJECT Alicante Hills SURFACE ELEV. 35 DRIVING WT. T. ('rc!+ it Lu --p- W Lu F,ir (L 0 --0- - ,CflC.)UJIL(A D Cr W O< Cl) Z 0 CL -; U) __5 FILL (af): Brown, fine to medium Clayey Sand, moderate amount of pebbles to small boulder sizes, angular and subrounded volcanics;. moist, medium dense, large rock at .6 feet. Rock bucket and Gad used, abundant rocks slows drilling. - - SP - - — End boring at 7.5 feet. Drill bucket.refused by large rocks. No water. - - - - - - - - - - PLATE I I I 1 1 I I I I I I S I I I I I I I ce BORING LOG 089 E 1-21 & CLIENT__DAON CORP. w.o:84S_C DATE DRILLEb122_81LOGGED BY_RZ PROJECT Alicante Hills SURFACE ELEV._+ 36 DRIVING WT. 2400# La CccF --v- IL. - X W 0 CD 4J ° ZCL M 0 CD >..Cl)O ILl ' zcU jr w°4 0.00 010 , >- _ 0 _ Z cF 0 NATURAL GROUND: Light brown Silty Sand, moist, dense, mottled. • — Dark brown Sandy Silt, moist, stiff. - 1 IC L07.3 118.6 - - - - Green Silty Clay, moist, hard, slightly porous. __10_ Light green Sandy Clay, moist, I hard. - 3 C 110.1 10.8 Clayey Sand, light green, moist Clayey to very moist, very dense, mottled. - 15_ — — - - - - - - Brown Clayey Sand with rock I fragments to 8 inches, moist, I mottled, difficult drilling. — -- Red-brown Silty fine Sand with fragments to 8 inches, t. LDifficult drilling. ht water seepage at 17 feet — — - - - - 3 15 —s- C C 114.E 108.2 15.7.. - 18.9 25_ Light gray slightly Silty Sandstone, very dense. — - - — - - - — End boring at 25 feet. Slight water seepage at 17 feet. No caving. - - —, PLATE -C — sh1S . BORING LOG ____ CLIENT_DAON CORP. W.0.8450C DATE DRILLEb 827 -83LOGGED BY DM PROJECT Alicante Hills SURFACE ELEV. +118 DRIVING WT. La Costa W 4 --p.- L&J W IL. — Id 0 0_ C.) - __ C a. 0 (no 4J Cr - > U) 0 U)0 - U)0 w zo om 04 om0 - Cl) z >- - we D z -w Cl) 0 I • - FILL(af): Light brown fine Sandy Silt with up to 50% volcanic rock fragments (up to 12°inches diameter). Slightly moist to dry in upper 6 foot, moist below. From 7 feet, local deposits of red-brown Clayey Silt, soft.; - - - - -Iv11i - - - - - - - - - - - 5 FFrom brown to red-brown Clayey with Sand and 20% rock uding cobbles. Moist, nic odor. 18 feet, rock fraction consists of sizes iito 6 inches. - MH IL - - - - - - 20 [NATULGROUND(?): From 24 feet, soil is darker and locally dry. Patches of gray-brown Clay. From 27 feet, larger rock slows drilling. - 25- - CH - - - - IOUTWASHDEPOSIT: Gray-brown Silty Sand with high percentage of cobbles. Slightly moist, very dense. From 32 feet, color grades to light gray. — - - - - - - - - - - - - --30- • • — — --35- PLATE B-a I CLIENT W. W.O.845_OC DATE DRILLEb 82783L0GGED BY _DM I PROJECT A1icane Hills SURFACE ELEV.± 118 DRIVING WT. - La Costa U. I.- ___ (1)CL D o 00 O4 0 ° 39 >- U) cr1- From 32-35 feet, cobbles give way to pebbles. Remains dense and slightly moist. \ At 36 feet, large rock slows \ drilling. - = - - - = = - - - - • End boring at 37 feet. Drill refused by hard, tight rock in bottom. No water or caving __45_ PLATE B5b I ce BORING LOG CLIENT_DAON CORP. W.O.845 -OC DATE DRILLEb 8-27-81 LOGGED BY DM PROJECT_Alicante Hills SURFACE ELEV. + 122 DRIVING W.T. T.. --p--. La(L W ui Li W Cr C.) CD .. . . >UL'J ILD D 0 U)O IL U) zo Ocol Cr C •; - VI) W - a z FILL (af): Dark brown Sandy Silt with Clay and up to 30% volcanic rock fragments and cobbles, moist.- . ----5- ML - - - --10- ,VOLCANIC BEDROCK: Light brown, hard, drilling slow. . - - --15- - 20 — . . End boring at 19 feet; Drill refused by hard rock.- No water or caving. 35 - - - - - - __25- --30- PLATE b0 BORING LOG 7 0#9 9 CLIENT_DAON CORP. W.O.8450C DATE DRILLED 827 -B1LOGGED By DM PROJECT Alicante Hills SURFACE ELEV. 104 DRIVING WT. T t--+- ILiI --c- V.; W W LIL — T a.0 0 --0- () a. j S I . >Cl) (flU DW°< 0a0a30 U)c — ii U. U >- I- — U) Z _ - I-U o — FILL (af): Light brown Sandy Silt with Clay and 30% volcanic rock . fragments, up to 5 inches in diameter. Slightly moist in upper 5 feet, moist below. - - ML - - - — — 5 - - .. Grades to brown Clayey Silt with Sand. and volcanic rock fragments with cobbles (40%), moist. At 13 feet, abundant large rock slows drilling. Up to 14 inches in diameter from 14 feet, color is dark gray-brown, slight . organic odor. ML - - - - - GM - - - - - - - -10- - - - 15 — — ( NATURAL.GROUND: Red-brown, fine Sandy Silt to Silty Sand with Clay and 10% large volcanic rock. Slightly moist to very slightly moist, firm. --20- - S - - - - ( OUTWASH DEPOSIT: Light gray Sandy Silt with high percentage of pebbles to cobbles. Slightly moist, very compact and firm. Drilling is slowed. — __25 - - — - - - - - - - - End boring at 27 feet. No water or caving. --30- --35 - PLATE B-I -r ce BOR IN G L OG : LL 8-27 & CLIENT_DAON CORP. W.045-OC DATE DRILLEb 8-28-8 LOGGED BY DMIRCK PROJECT Alicante Hills SURFACE ELEV.+93 DRIVING WT. T.; (r+- . --'g-• W - LU hi - Z i 0 --0- - 0.0 CD W (00 Ole '. (I) CD >0(1)0 (flOWU. .W. U)• U acn - cr- FILL (af): Light brown fine Silty Sand with 30% large volcanic rock fragments and cobbles, slightly moist. From 8 feet, soil is moist. s - - - - - Grades .to brown Clayey Silt with Sand and high percentage of 10- large volcanic rock fragments. At 11 feet, drilling.slowed by large rock. - . . l - - - - - - - — / NATURALGROUND; Reddish-brown to ( dark brown Clayey Silt, damp, firm, slight.organic odor, scattered rock fragments. . At 22 feet, Dark brown Silt with slight Clay,-damp, soft to, firm, organic smell stronger, rock Percentage 20-30%. - --15- - - - MH . - - - --20. - - - -25. - . OUTWASH DEPOSIT: Dark brown Clayey Silt with 10% rounded cobbles, stiff to' very stiff, damp, cobbles up to 3 inch in diame - - - - - - ____ - -. - . . ... -. - - - Dark brown Clayey Silt, stiff to very stiff, damp, 30% angular fragments (some cobbles) up to 8 inches in diameter. At 30 feet, slight coarsening of the Clayey Silt (some Sand), Silt is_ now _moist, - - — - — _35.. PLATE. I I I I I I I I I I I I I Ce BORING LOG 8 0S 9 -27 & CLIENT _DAON CORP. w.o._84SOCDATE DRILLEb 8-28-8 'LOGGEDBY_ DM, RCK PROJECT Alicante Hills SURFACE ELEV._± 93 DRIVING WT. La Costa Cr Id --p.- L&J Iii U - -. . X 0 CL 4_i __ . I.(D_c_)0 > (I) 'I- COO Cl)-' wo4 zc"jml Id - U) >' - ole D Co At 37 feet, dark brown gravelly Silt, small angular pebbles to rock fragments (to .6 inches) firm, moist. At 38 feet, rock fragments to 12 inches. - - — -40- - - - - - - - Greenish-gray Clayey Silt and Sand, very stiff, moist, pebbles and larger rock frag- ments (to 12 inches in diameter) rock fragments comprise about 20-30% of material. __45- - - End boring at 47 feet. Drill refused by hard, dense rock. No water or caving. 5 PLATE DO1I (-j_ G C. • B 0 R I N G L OG.- CLIENT_DAON CORP. W.0?45C DATE DRILLEb 8-28-8 LOGGED BY_RCK PROJECT Alicante Hills SURFACE ELEV± DRIVING WT. T --T:'- WI- W Ui _ Z a. ' 0 4 .j CD W - ZCUm>.49 >.Cl) U) (I) 0 DW°< 0 Ui .. U) ø >- - Z , • wt-- I- I- 0 • - FILL .(af): Reddish light brown fine Sandy Silt, very stiff to hard, dry to damp, .volcanic rock f rag- ments 40% of composition, up to 12 inches in diameter. At 7 feet, grades to light yellow-brown Sandy Silt, soft to firm, slight dampness, large * rock fragments still present. At 9.5 feet, grades to yellowish- brown Clayey Silt, very stiff damp, rock fragments still present (up to 12 inch diameter). - - - - - ML - GM - - - - - - — — - 5 --15- . NATURAL GROUND: Dark brown Clayey Silt to Silty Clay, very stiff, damp, high percentage of rock fragments which slows drilling. Grading to medium brown Clayey Silt, stiff to very stiff, damp, slight organic odor, rock frag- ments about 20% of composition, some cobbles present..- GM - - - - - - - - - - - - - OUTWASH.DEPOSIT: At 27 feet, grading to light greenish-gray Sandy Silt, very 'stiff to hard, damp, pebbles and cobbles (to 3 inch diameter). At 35 feet, hard tight rock encountered,' .no progress with 12: inch auger, drilling halted. --25- • - - - - - - - - - -30- [TotalDepth at 35 feet. No water or caving. __35_ BOR IN G L OG _,_U 'Ii C LIEN TDAON CORP.. W.O.84SOCDATE DRILLEb82681LOGGED BY_RCK PROJECTAlicante Hills SURFACE ELEV.+ 25 DRIVING WT. 21504 La Costa - 4 3C --p- U. - T 0 0 G_o 4_i __ . 0 I >j cl,(nw 00 CI) W o< >- 0 CL u,F we - FILL: Clayey Silt, medium orange- brown, stiff, damp. — - - NATURAL GROUND*(?): Medium to dark brown Clayey Silt, firm, damp. Dark, brown Silty Clay, moist, orange mottling. At 10 feet, seepage, firm,. wet dark brown Silty Clay, orange mottling. Mottled grayish-green and dark brown Clayey Silt, moist, firm. Medium to dark 'brown Sandy Silt, soft, very moist. Angular rock fragments (2 inches in diameter) in orangish-brown Silty Sand, wet, caving, drillinq' 0 \ haulted. . - - - - - - — - - T P 4 C C C 115 .3 103. L08.1 16.9- - - 23.0- - 18.5- - -10-. ._ - — — __15- — — — __20- - 0 0 — - - — Total Depth at 19.5 feet. Water at 10 feet. Caving at 19 feet. - — __25- --30- PLATE PLATE B-b I I I I I I I I I I I I I I I I I 0 BORING LOG 11 CLIENT_DAON CORP. w.o.845-OC DATE DRILLEb 8-26-8 LOGGED BY_RCK PROJECTAlicante Hills SURFACE ELEV. 22 DRIVING WT. 2150# La Costa • UI 39 - --p-- ILl W C.) U. ' Q. UI Cr 0 Q. __ 0 c : D o -(,0 >-0ur W-J' z0 c.m> O4 0 U) - CL - 0 • -a.. - - FILL (af.): Medium brown Sandy Silt with some Clay, soft, damp. At 2 feet, gray Silty Sand with 'angular rock fragments, damp, soft. ML 7 - - — - - -5- ' ' - - - - - P i 3 C C C EL 109.5 L03.8 L12.4 19.9— - - - 21.0— - - L.8,..3 ALLUVIUM: Black organic Sandy Silt with Clay, soft, damp to moist. At 5 feet, medium to dark brown Sandy Silt with Clay, orange .' mottling, soft, moist, seepage. ,At 8 feet, black organic Clayey Silt with some Sand, firm, moist. At 10 feet, black organic Silty. Clay with some Sand and pebble- size rock fragments, firm, moist. At 13 feet, gray Sandy Silt with slight Clay, firm, very moist. 'At 15 feet, dark brown Silty Clay, organic odor with some Sand \ and pebble-size. rock fragments, / caving. ' J 1 • - - — -10- - — — - --15--, ' CH - - - - - - - • - - - - - - - - - - - --2o- - — Total Depth 15 feet. Water at 5 feet. Caving at 13-15 feet. • --25- --30- - ' PLATE B-il ce B.ORING LOG 12 CLIENT_DAON CORP. W.O. 845-0 DATE DRILLEb 8-26-8 LOGGED BY_RCK PROJECT Alicante Hills SURFACE ELEV.± 27 DRIVING WT. 2150# Li - T 0 U CL 0 ___ 4.J cro C,) D 0 CD COO ___ .., Ui39 zo QjOQ).0 W O< - in _ IM Lii crl-• z U' - — - DELMAR FORMATION: Medium brown Clayey Silt with Sand, desiccated rock fragments (1 to 2 inches diameter). At 2 feet, dark brown Silty Clay, very.stiff, damp to moist, white caliche. At 5 feet, dark brown Silty Clay, very stiff, damp to moist, calich pebble-size rock fragments. At 9 feet, dark reddish-brown Sandy Silt, with slight Clay, firm to stiff, moist. At 10 feet, medium to dark brown/ Sandy Silt, fine grained, stif f,/ moist. / At 12 feet, orangish-brown Silty Sand, fine grained, (.no binder), water seepage, caving. ,7 - - - - - - 4 2 C C 110 5 104.4 - - 16.6— - - - 20.6- - - - - 5 — - - - — -10- - - . - - - - - - - - S. - - - - - - - - - - - - — --20 - - Total Depth 12 feet. Unable to continue due to caving. Water at 10.5 feet. --25- —€5- — — PLATE b1 ce 0S ___ B OR IN G L OG 13 CLIENT CORP. W.O.- DATE DRILLEb82781 LOGGED BY PROJECT Alicante Hills SURFACE ELEV;________ DRIVING WT. 21504 La Costa Cr Ui ILl Iii IL. - X Ui. _ <_j CD 0_ S 5, COa. Cl) Q 0 CD CI)O - CI) ,,. WZ cnWu zo> omc.'' w I— - U) _ - Cr l-.w 0 I - FILL (af):ML Light brown Sandy Silt, desiccated, cobble-size rock frag- ments "(up to 12 inch diameter). At 3 feet, medium brown Sandy Silt with orange-mottles, irregularly mixed with medium brown Clayey Silt, very stiff, damp- At 5 feet, dark brown Silty Clay, pebble-size rock fragments, firm to stiff, damp. At 6 feet, orangish-brown Sandy Si with Clay, cobble-size-rock frag- ments, stiff,' damp. At 8 feet, cobble-size fragments too numerous, drilling halted.' - I - C 109.7 - 18.L. - - - - - - - - ' 7t - - - - --10- -15- --20- Total Depth at 8 feet. No water, no caving —0- PLATE B-13 - BORING LO.G 14 CLIENT_DAON CORP. W.0.845-0C DATE DRILLEb82681 LOGGED BYRCK PROJECT Alicante Hills SURFACE ELEV.± 65 DRIVING WT. 2150# La Costa I I 4 3C I_I-CL U_ - a 4 C9 0 . - . WO I, W , Q. 0 >-co9 (QjOGO .Cl) w0< w 0 Co z U - W Cfl C) FILL (af): Medium orangish-brown, Sandy Silt, desiccated, rootlets. At 2-4 feet, medium brown Sandy Silt., medium dense, damp. . . At 4.5 feet, grades to dark brown Clayey Silt to Silty. Clay with .. large rock fragments (8-12 inches. in diameter), very stiff, damp. At 5 feet, dark brown Silty Clay, very stiff, damp, carbon bits, rock fragments. At 7.5 feet, organic fragments in fill. At 9 feet, grades to light gray- ish green Clayey Silt with Sand and Siltstone derived rock frag- ments (4 inch diam.), very stiff. to hard, damp. . At 13 feet, increase in rock \ fragment size to 12.inch diameter, \ maximum. \ At 15 feet, dark brown Clayey. I Silt, plant matter (twigs), rock \_fragments, very stiff, damp. J ML - - = - - 2 9 4 . C C C - L05.9-17.8 .15.1 L18.7 . - - - 12.0- - - 8.9- _-5- --15- __20- - - - - 5 15 = - C C L13.6 .16.3 5.3- - L3.3- __25- ____ - = \ At 19 feet, (BEDROCK WEATHER ZONE?1 \ light grayish-buff Siltstone \ \ with Sand, hard, dry. \ \t 20 feet, sample, same as 19 ft. - - --30- BEDROCK: Sandy Siltstone, light greenish-gray, hard, dry. Total Depth 26. feet. No Caving. NWM-r. __35- -- PLATE _____ CLIENTDAON CORP. W.O.845-OC DATE DRILLEb 8-26-8 LOGGED BY_RCK PROJECTAlicante Hills SURFACE ELEV._ +75 ________ DRIVING WI. 2150#. La Costa - - T 0 0 "0 <.J .° S - ' > ()o CL (D (00 CLM w o< (9 O CO >- U) Z W 0 - I- DZ IW c_) - • FILL (af): Orangish-brown Sandy Silt with Clay, stiff, damp. = ML BEDROCK: Dark orangish-brown Clayey Silt with some Sand, stiff, damp. At 7 feet, changes to light greenish brown Sandy Silt, Siltstone fragments present, medium dense, dry. At 10 feet, medium orangish- brown Sandy Silt to Silty Sand, medium dense, dry to damp, carbon bits. At 13 feet, medium orangish-brown Silty Sand, medium dense to dense \ damp, pebble-size rock fragments, present. At 15 feet, medium orangish't- \ brown. Sand, coarse, dense, damp, pebbles present. - - - - - - - - - -. - - 3 5 7 C C C 970 103.2 • 95.8'11.2 - - - - 6.3- - - 4.7- - - - - - - - - -10- - - • -15- - -20- — • --30- Total Depth 15 feet. No Water. . • No Caving. •5 • • .. . 5.. •- --25- 5- PLATE i-i5 BORING LOG 16 CLIENT_DAON CORP. W. 0. 845-0 DATE DRILLEbE-27-8ILOGGED BY_RCK PROJECTAlicante Hills SURFACE ELEV.+60 DRIVING WT. 2150# La Costa W -4 31: U. T — 0 I W __ C.) CD _ CL - wo4a. >- Cl) Cl) 0 CD co W zoO. a.aO0 ' w ct >- C) z Q.Cfl1 - -' z i-w 3 — --0- FILL (af): Light buff Sandy Silt, desiccated, with cobble-size fragments of fossiliferous limestone (up to 10 inch). At 2 feet, medium greenish- brown Clayey Silt, stiff, damp, some Sand with orange mottles,; Pebble-size rock fragments. At 10 feet, medium orangish brown Silty coarse Sand with Clay, poorly sorted, stiff to very stiff, damp, small rock fragments. At 11 feet, grading to light \ brown coarse Sand with small I \ (pebble-size) rock fragments, dense, damp, grades to, ML - - - - - 2 5 C C MH 99.3 121.7 - - 18.0.. - - - 10. 4, - -ao- - - - - - - - 6 5 C C MH 106.5 119.6 7.5- - - - - 8.Q- NATURAL GROUND (?) Medium brown Clayey Silt, stiff to very stiff, damp, small rock fragments. At 13 feet, orangish-brown 'Sandy Silt toSilty Sand, medium dense, damp to moist. At 15 feet, light greenish brown Sandy Siltstone, hard, dry to dam]).- At 16 feet, light grayish brown Sandy Silt, stiff, damp. At 20 feet, grading to dark brown Clayey Silt, with some pebbly fragments, very stiff to hard, damp. At 22 feet,' large cobble-size rock fragments in the dark brown Clayey Silt cause refusal drillin --20- ' - L - - - - - - - === - - - - - - - - - --25- - — --30- - - — — halted. T.D. 22 feet, no water, no caving PLATE B16 ce 0 BORING LOG oig# CLIENT DAON CORP. W.O.845-OC DATE DRILLEbB-27-R1LOGGED BY_RCT( PROJECT Alicante Hills SURFACE ELEV.± 23 DRIVING WI. La Costa 141 UJ U. T C.) 0. 4_I 0 . - - -, . . ., . --0- ,, >o) Cl) D 0 Co c')o• - ___ W zoO C l) D.Cl)CU 04 000 - - Cl) z Uj C,C#)I Lii W I FILL (af) C?): Light brown Sandy' -- Silt, with clay, desiccated. At 2 to 4 feet, medium brown Clayey Silt, stiff, small rock fragments, with some cobble-'size fragments, damp with increasing moisture downward. At 5 feet, soil material quickens - dark brown Silty Sand (with little or no binder), very soft, wet \ material flows out of bucket drilling halted. - - - - - - - - - - - - - - - - - - — Total Depth ', 6 feet. Water at 5 feet. Soil Liquefied at 5 feet. - - PLATE B-17 0 BORING LOG 18 CLIENT_DAON CORP. W.O.845-OCDATE DRILLEb827-81LOGGED BY_RCK PROJECTAlicante Hills SURFACE ELEV._+ 22 DRIVING WT. La Costa 31: IL - Z a. C3 I 0 4.J Cl) o CD WLw w39 (L.Cl)0 z0O> O4 U) z _ aCfl - ,-w 0 __ FILL (af): Dark brown Silty Clay, desiccated. At 1.5 feet, grading to medium orangish brown Sandy Silt, desic- cated with cobble-size rock fragments, some subround cobbles present. At 4 feet, medium brown Clayey Silt, very stiff, damp, subround \ to angular rock fragments (up to 2 inches) present in large numbers) At 5 feet, rock fragments cause refusal drilling ha1ted. - - - - - - - - - - - • - • - - - - - - - --10 - • as- Total Depth 5 'feet. No Water. No Caving. - PLATE B-18 CUENTDAON CORP. W.O.845OCDATE DRILLEb 8-27-8 LOGGED BY_RCK PROJECT Alicante Hills SURFACE ELEV. DRIVING WT. 2150# La Costa- - Ir W F- W w U.- T 0.CD 0 , - - a. 4.J - - Cl, Cl) 0 CD >-Cl)° co - W- 0.a3C.):0 F- -. (1) z aCl)F-I-W - C) - - FILL (af): Light brown Sandy Silt, with clay, desiccated, numerous subround• t0 angular rock fragments (cobble-size)-present. At 2 to 4 feet, dark brown-Clayey Silt,- very stiff, damp, numerous rock fragments. At 5 feet, medium orangish brown, Sandy Silt, very stiff, damp, - numerous (cobble-size) rock fragments. BEDROCK \ At .8 feet, Sandy Siltstone, light grayish buff, hard, damp. - - - - - 5 12 C -C 7 0 • 113.6 - - 10. - - - L6.0_ — - 5 - - — - - .- ____ - - - \-15- - - - - - - - - 17 - - - - - - - - - = - — BEDROCK:, - \ At 10 •fe.et ,.Sandy Siltstone, -light grayish buff, hard, dry, biotite evident, massive. — — Total Depth-11 feet. No. Water. No Caving. - • PLATE B-19 BORING LOG 20 CLIENT W. CORP. WÔ845OCDATEDRILLEbB288lLOGGED BY_RCK PROJECT Alicante Hills SURFACE ELEV.± 76 DRIVING WT. La Costa I-. 4 --p- WI— W_ I CL W C. 0.0 4—J __ U.>-u(n;: D 0 CD cnc,,W U)0 W39 w-'1 0.0 p.>- ciCQu zOOm>- 04 C)'0 I- - Z, - Z I_W U)' 0 I 0__FILL: - Light tannish brown Clayéy Silt, with pebbles and rock fragments (to 8 inches) hard, dry At 3 feet, grades to medium brown Clayey Silt, very stiff, damp, 40% rock fragments. _10- At 15 feet, Rock percentage drops to 20% drilling downward speeds up. At 24 feet, Medium yellowish brown Clayey Silt, some sand, stiff to very stiff, damp rock fragments down to 10% and smaller (4 inch :max imum diameter). - - - - - - - - - - - - - - - - - - - - - - - - - - - — — - __5_ — -15- --20- -25- --30- —.35- - PLATE B-20 a CLIENT.DAON CORP. Wb845-OCDATE DRILLEb8-28-81L0GGED BYRCK PROJECT Alicante Hills SURFACE ELEV.-4-76 DRIVING WT. La Costa 4 Li. - W 0 --35- (D 4 .J __ D 0 0 )..CI)u,O ZO w-i'' W°< CLM 0M, >- Z a > DZ 4-- W 0 NATURAL GROUND: Grayish brown sandy Silt, firm to stiff and black organic Silty Clay, moist, firm. - -40- - - - — - - - - __45- DELMAR FORMATION: Light greenish gray Sandy Siltstone, very stiff, damp, carbonaceous bits. Auger spinning on hard tight \ rock at bottom of borehole drilling halted. - - - - — __50- - - - - - - - - — - — Total Depth 49 feet refusal. No water or caving. — --55- 41 PLATE B-20 b