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Home My WebLink About; La Costa Major Roads Project; Soils Report; 1981-01-08CEOTECHNICAL INVESTIGATION FOR LA COSTA MAJOR ROADS PROJECT CARLSBAD, CALIFORNIA W.O. 1140 January 8, 1981 ENGINEERING DEPT. LIBRARY City of Carlsbad 2075 Las Palmas Drive Carl&ad CA 92009-4859 0 e EBERHART-AXTEN and ASSOCIATES, INC. GEOTECHNICAL CONSULTANTS 2211 E. WINSTON ROAD, SUITE F . ANAHEIM. CALFORNIA 92806. (114)991-0163 6353 EL CAMNO REAL. SUITE c . CARLSBAD, CAUFORNIA 92008. ,714)438-9416 DAN R. EBERHART. CEG GREGORY W. AXTEN, RCE GERALD L. STONE, RCE W.O. 1140 January 8, 1981 La Costa Land Company 2100 Costa de1 Mar Road La Costa, California 92008 Attention : Subject: Mr. Irv Roston Geotechnical Investigation for the Major Roads Project, Ranch0 La Costa, City of Carlsbad, California; including portions of Alga Road, Melrose Avenue, Corintia Street, La Costa Avenue, Mision Estancia Avenue and Ranch0 Santa Fe Road. Dear Mr. Roston: . Pursuant to your request, we have conducted a geotechnlcal investigation of the planned alignments for the subject roadways. During this investigation at- tention was given to geologic conditions encountered in cut areas, soil types and conditions as they related to fill areas, and anticipated removal of unsuit- able material required within these areas. SCOPE OF SERVICES The scope of services utilized in this investigation consisted of the following: o Review of existing geologic’and soil investigative reports where available o Review of preliminary improvement plans provided by Rick Engineering o Geologic reconnaissance of the proposed roadway alignment and adjacent areas which may affect the roadways o Detailed geologic mapping of existing road cuts and exposures o Seismic refraction surveys for evaluation of excavation characteristics o Excavation of 57 backhoe trenches ranging from 5 feet to 15 feet deep o Use of a dozer to excavate one exploratory trench approximate- ly 400 feet in length, and to construct access roads for drilling equipment o Excavation of nine 22inch bucket-auger borings, up to 69 feet deep, which were sampled and downhole-logged as condi- tions and programmed alignments dictated La Costa Land Company -2- W.O. 1140 0 Subsequent recovery and transportation of selected samples to our laboratory for testing of the major representative soil types O Engineering and geologic analyses and evaluation O Preparation of this report and accompanying maps, providing conclusions and recommendations pertinent to grading and construction of the proposed road alignments PROJECT DESCRIPTION The major roads project is composed of six primary work areas. These areas include widening the existing Alga Road West, completing Alga Road East, minor grading for Melrose Avenue, and a small portion of Corintia Street, mass grading for La Costa and Mision Estancia Avenues, and the widening of Ranch0 Santa Fe Road (see Location Map, Plate I). Because of the variety of geologic conditions, related soil types, and topo- graphic conditions encountered, specific conditions and recommendations will be discussed on an individual basis. General descriptions of the earth materials and conditions encountered will be discussed under the section on Engineering Geology. METHODS OF INVESTIGATION Surface conditions were evaluated during a preliminary reconnaissance of the various road alignments. During this reconnaissance, locations were delineated where excavation of exploratory excavations might best yield pertinent informa- tion regarding subsurface conditions. These conditions were explored by exca- vating 57 pits up to 15 feet in depth, utikzing a backhoe. ‘Deeper conditions were explored by utilizing a bucket-auger drill rig excavating nine borings up to ‘69 feet in depth. Visual and tactile classifications were made of all materials encountered in the field, and these are presented in the Log of Test Pits and Boring Logs, included in the, Appendix to this report. Representative in-place and bulk samples were obtained from the various materials encountered. A D-6 bulldozer was utilized to explore large features and to create access roads and pads for the drill rig. Locations of dozer trenches are presented on the accompanying set of plans by Rick Engineering. SEISMIC REFRACTION SURVEY In areas where the backhoe or drill rig could not excavate, or exposures of rock indicated a potential rippability problem, seismic refraction surveys were performed. Four seismic profiles were surveyed using a signal enhancement seismograph to explore the subsurface velocities and thus obtain an estimate of the velocity of the rock encountered. Graphic results are presented as Plates B-l and B-2 in the Appendix. ENGINEERING GEOLOGY Geologic Setting The site is located on the western flanks of the Peninsular Range Province. e - EEERHART-AXTEN and ASSOCIATES. INC. La Costa Land Company -3- W.O. 1140 Bedrock underlying the site consists of relatively flat-lying marine sedimentary rocks of Eocene age, which lie unconformably upon Cretaceous and Jurassic age igneous and volcanic rocks. Since deposition of sedimentary rocks, only relatively minor folding and faulting has occurred. Earth Units Earth units encountered are briefly described in a general sense below; for a more specific description of the materials exposed in a given area of the project, refer to the Log of Test Pits and Boring Logs. Fill (Qafc) Compacted fill materials generally consisting of onsite materials were encountered along the north flanks of Alga Road West near its intersection with El Camino Real, between stations 24+00 and 29+50, along the entire alignment of Alga Road East, and along the west flank of Ranch0 Santa Fe Road. The fill is composed primarily of clayey silts and silty clays which are medium brown to olive or gray-green, derived from bedrock in the area. Dumped loose fill which is contaminated with debris was noted along the align- ment for La Costa Avenue between stations 122+50 and 126+00. Additionally, numerous piles of end-dumped fill contaminated with debris, were noted along Alga Road East. Alluvium (Qal) Alluvium noted onsite was confined primarily to major canyons and valleys. Significant amounts of alluvium were noted in the valley north of Alga Road West between stations 13 and 18, and at various locations on La Costa Avenue and Mision Estancia Avenue. Smaller, less significant deposits were located along Ranch0 Santa Fe Road, Melrose Avenue, and La Costa Avenue. Soil types encountered were primarily silty clays and clayey silts with inter- bedded sequences of sand. These soils are generally dark brown and moist to wet at depth, and soft to firm in place. Groundwater was encountered in significant amounts on Alga Road West and along Mision Estancia Avenue at stations 7+00 to lO+OO, 33+50 to 35+00, and 42+00 to 43+00. Depths of removal of alluvium will be discussed under the conclusions and recommendations for the specific road conditions. Colluvium (Qco) Colluvium is composed of buildups of topsoil and weathered bedrock along the flanks of natural slopes. Most of these soils consist of silty clays and clayey silts which are dark brown or gray, dry to damp in place, extremely expansive and may reach thicknesses of up to eight feet. Significant amounts of colluvium were noted along Melrose Avenue and Mision Estancia Avenue. Geologic Units Del Mar Formation (Tdm) The Eocene age Del Mar Formation is composed of near-shore and lagoon deposits NOTE: Station numbers are shown on the enclosed preliminary plans. EBERHART-AXTEN and ASSOCIATES. INC. La Costa Land Company -4- W.O. 1140 which are light gray to yellowish, fine to medium grained sandstones, inter- bedded with thick sequences of medium gray to olive gray arenaceous shales and claystones. Shales and claystones are well consolidated and contain con- cretionary beds with occasional mollustan fossils. Cranitic Rocks (Kgr) These Cretaceous age, plutonic, intrusive rocks of the Southern California Batholith were observed south of Alga Road East and probably underly the Del Mar Formation at depth, particularly in the vicinity of Melrose Avenue. Santiago Peak Volcanics (Jspv) The Santiago Peak Volcanics were mapped along the north and south cut slopes near the intersection of Alga Road East with El Fuerte Street. These rocks consist primarily of dark gray to black micro-crystalline rocks with a basaltic to andesitic composition. GEOLOGIC STRUCTURE Bedding Only minor folding and faulting of the sedimentary rock has occurred since their deposition and subsequent consolidation, which has resulted in broad but gentle undulations with varying dips of O” to 15O. In the vicinity of Mision Estancia Road, the Del Mar Formation was observed to be locally massive. Joints Except near minor faults, jointing within the Del Mar Formation was poorly developed. Within the Santiago Peak Volcanics, jointing was moderately to well developed, forming at near right angles with spacing from 3 inches to 2 feet. Jointing in the granitic rock was crudely developed but appeared primarily to be subparallel in an east/west orientation. Faulting Evidence of faulting within the bedrock was expressed in two very different modes. The first occurred at relatively high angles with minor amounts of normal or oblique slippage; the second is generally along the bedding and is thus termed a “bedding plane fault”. Disturbances and offsets along the high angle faults are relatively insignificant and of little concern. Remolded clays observed within bedding plane faults are generally very flat-lying, occurring within the siltstones and claystones. These represent a potential geologic haz- ard for sloping areas, should they be exposed in an unfavorable orientation. SElShllClTY Although no active or potentially active faults are known to cross the site, the proximity of the site to active faults in Southern California makes it reasonable to assume that the site will undergo moderate groundshaking as a result of an earthquake along an active fault. The most likely source of such an event is the Newport Inglewood/Rose Canyon Fault System. Plate II shows the location of the site in relation to the most significant active faults in the region. a EBERHART-AXTEN and ASSOCIATES, INC. La Costa Land Company -5- W.O. 1140 Ground response at the site during a seismic event can be evaluated on the basis of previous ground motion studies, observations of other earthquakes, activity along selected faults and current “state-of-the-art” understanding of seismic forces. Such an evaluation forms the basis for the seismic parameters listed for major active and potentially active faults in Southern California (see Table I). These listingsprovide estimates of seismic conditions which are likely to occur at the site, including accelerations, predominant period, duration of shaking, and possibJe recurrence of probable seismic events along the listed faults. Groundwater In areas of higher elevations, groundwater was not encountered. However, on Alga Road West between stations 13+00 and 17+50 and on Mision Estancia Avenue at stations 7+00 to lO+OO, 33+50 to 35+00 and 42+00 to 43+00, significant amounts of groundwater were encountered, but apparently are confined to the alluvial channels. Perched water conditions may be encountered within the Del Mar Formation. This water is generally confined to sandier beds cut off from perco- lation by impermeable clay beds. CONCLUSIONS AND RECOMMENDATIONS Based upon our investigation and review, it is our opinion that this project may be constructed in accordance with the present plans, provided the recom- mendations and specifications presented in this report are incorporated into project design and construction practice. GRADING Except as specifically noted herein, all grading should conform to the applicable local grading code requirements, the recommendations within this report, and the accompanying.Standard Grading Specifications. Site Preparation Prior to grading, the subject site should be stripped of all deleterious material such as trash, debris and vegetation. These materials should be wasted off- site. Light growths of grasses may be incorporated within the fills, provided they are thoroughly blended with the soils. However, concentrations of vege- tal matter should be avoided. Stripping and wasting of moderate to heavy vegetation is recommended. Incorporation of any vegetal materials in the fills should be considered subject to review by the soil engineer and the governing authority as field conditions dictate. Overexcavations Portions of the site are covered with a 2 foot to 3 foot mantle of topsoil, colluvium, and creep-affected bedrock. These soils are considered unsuitable for support of additional fill or improvements, and overexcavation should be planned. Similarly, the upper 1 foot to 2 feet of existing compacted fill materials will also require overexcavation. In all cases, overexcavation should expose either compe- tent fill or bedrock, and should be inspected and approved by the soil engineer prior to placement of additional fills. In the area onsite where previous borrow operations were conducted, and where significant new cuts are proposed, EBERHART-AXTEN and ASSOCIATES, INC. W.O. 1140 La Costa Land Company overexcavations should be negligible. Due to the water or wet conditions of/or near the ground surface, problems during excavation and placement of compacted fill can be anticipated. In some areas (discussed under the specific conclusions and recommendations section), placement of a rock layer following removals will most likely be required to establish a working base for equipment to place compacted fill. Free drainage below the compacted fill will also be facilitated by the placement of the rock base. Where removals to competent materials are limited and/or a rock base is required due to the depth of unsuitable materials and/or the presence of water, one or two conventional settlement monuments for each area will be recommended, follow- ing achievement of final grades. Such monuments should be established about 3 feet below finished surface and should be surveyed about every two weeks until the completion of grading, or as needed to evaluate future settlement poten- tial. Canyon Subdrains Subdrain systems are recommended for major drainage courses underlying pro- posed fills. These systems should be placed as field conditions dictate. We have indicated on the accompanying plans and under specific road areas where subdrains are anticipated. These designations should be considered preliminary and will be reviewed by the engineering geologist during grading operations. Cut Slope Stabilization Proposed cut slopes should be constructed no steeper than 2:l (horizontal to vertical). Cut slopes within the Del Mar Formation are generally considered grossly stable. However, due to the erodible nature of some of the materials and potential seepage problems in others, long-term surficial stability of some of these slopes is considered marginal. If excavation for cut slopes exposes locally adverse conditions, as determined by the engineering geologist, overexcavation and replacement with compacted fill will be recommended as field conditions dictate. The most significant slopes (i.e., greater than 10 feet high) requiring stabilization or possible stabiliza- tion have been indicated on the accompanying plan. Unless otherwise recom- mended, stabilization fills should be constructed in accordance with the accompany- ing Standard Grading Specifications. As an alternative to cut slope stabilization$, slopes may be laid back at ratios of about 2:5 to 4:l to be determined in the field by the engineering geologist and a representative of the La Costa Land Company. This option will be subject to review of field conditions by the geo- technical consultant. The need for backdrains within stabilization fill slopes will be determined by the engineering geologist based on exposed conditions during grading. Fill Slopes Fill slopes should be constructed no steeper than 2:l (horizontal to vertical)~. Based on the results of laboratory tests, engineering analyses, and experience with similar projects, it is our opinion that compacted fill slopes should perform _ EBERHART-AXTEN and ASSOCIATES, INC. La Costa Land Company -7- W.O. 1140 satisfactorily. Fills should be keyed and benched into competent material ap- proved by the soil engineer or engineering geologist during construction. In order to enhance the probability of future favorable performance, we recom- mend overfilling and cutting back of the slope face to the firm, compacted inner core. Conventional backrolling techniques may also be utilized for slope face compaction, but are considered less desirable. In addition, appropriate land- scaping and maintenance programs should be established as soon as possible. Ideally, slope planting should consist of deep-rooting vegetation requiring little watering. Fill Placement Prior to placement and compaction of fill materials, the exposed ground surface should be inspected and approved by the soil engineer, then scarified, brought to the proper moisture content and compacted to a minimum of 90% of the labora- tory maximum dry density, per ASTM Method of Test D1557-70. Fill should be brought up in thin lifts not exceeding 8 inches in thickness (prior to compaction). The moisture content should be adjusted to near opti- mum, and the material compacted to a minimum of 90% of the laboratory maxi- mum. Oversize Rock Placement within Compacted Fill Where rocks or similar irreducible materiars of greater than 12 inches but less than 3 feet of maximum dimension, are generated during grading, or otherwise desired to be placed within an approved compacted fill, special handling will be required. Rocks greater than 12 inches (maximum dimension) should not be placed in the upper 10 feet of any fill, nor closer than 15 feet to any slope face. Where practical, oversized material should be placed in windrows on clean, over- excavated, approved compacted fill or firm natural ground surface. Select native or imported granular soil should be placed and/or thoroughly flooded over and around all windrows such that no voids remain. Windrows of oversized material should be staggered so that successive windrows of oversized material are not in the same vertical plane. For planning purposes, rocks larger than 3 feet should be disposed of offsite or broken down and incorporated into the deeper fill areas. As field conditions dictate, however, it may be possible to dispose of some of the larger rock onsite. Excavation Characteristics Based on seismic refraction data, it is our opinion that mass excavation within most cut areas may be accomplished by light to moderate ripping within the Del Mar Formation. Within the volcanics, however, cuts will be marginally rip- pable and may ,require blasting below 6 feet. These estimates are based on per- formance specifications of a D-9 dozer traveling in low gear with a single-shank ripper tooth. See Plate B-l for a summary of velocities and depths of rip- pable materials. Shrinkage, Bulking and Subsidence In consideration of the in-place densities and anticipated densification, we would anticipate shrinkage of on the order of 15% to occur for removal and replacement of existing fill, topsoil, alluvium, colluvium and creep-affected materials. Where m EBERHART-AXTEN and ASSOCIATES, INC. La Costa Land Company -8- W.O. 1140 fill material is generated from the more consolidated bedrock, we would anticj- pate bulking to be on the order of 5%. Subsidence of bedrock materials as a result of placement of additional fill should be minimal (i.e., less than t-inch per foot of fill added). These numbers are order of magnitude estimates based upon our field observations and laboratory testing to date, as well as our exper- ience with similar projects and material types. Pavement Section Design Due to significantly varying soil types within the roadway alignments, soil condi- tions at finished grades are also anticipated to vary. In this regard, pavement section requirements can be best evaluated as final grades are achieved. For estimating purposes, however, probable ranges in section requirements have been presented within Table IV. These sections have been based upon the results of R-Value testing of typical soil types and upon traffic index information supplied by Rick Engineering. SPECIFIC CONCLUSIONS AND RECOMMENDATIONS The following conclusions and recommendations are for specific areas. They are based on our field observations and laboratory testing as noted. Materials between test excavations may have different characteristics. Addendum recom- mendations could be required as field conditions dictate. Any changes in plans may affect the soil engineering and geologic engineering aspects of the proposed project and will, therefore, have to be evaluated at that time. Alga Road West Station 5+00 to 9+75 Existing fill : removal of 1 foot, processing of 1 foot, repair slopes from Station 5+00 to 6+00. Sur- ficial slump areas to be repaired per standard detail. 9+75 to 12+75 Proposed 24-foot cut slope: possible stabilization to be determined in field during grading. If stabiliza- tion required, an alternative may be to lay the slope back to 2.5:1 to 4:1 as recommended by the geotechni- cal consultant at the time of grading. 12+75 to 18+00 Alluvial basin: groundwater at depths of 6 feet to 8 feet. Removal of 5 feet required, followed by place- ment of a 3-foot? blanket of 3-inch rock* to establish a base for heavy equipment. Water in the pond should be drained prior to placement of rock. This area may require use of special excavating equipment. Following the placement of compacted fill to the desired grades, conventional settlement monuments should be established below finished grade on each side of the road alignment. Surveying of the settlement monuments should be ac- complished (prior to paving) about every two weeks through the end of the grading period or as needed to evaluate future settlement potential. *This rock may be derived from the Hidden Meadows access road area, provided no rocks larger than 3 feet in diameter are used. m EBERHART.AXTEN and ASSOCIATES, INC. La Costa Land Company -9- W.O. 1140 Alga Road West - Continued Station 18+00 to 21+50 Proposed 88-foot cut slope: local adverse bedding conditions, and highly erodible surface materials. Probable stabilization in two stages (two 25-foot keys and corresponding stability fills, stacked at slope toe and mid height (+) (see typical detail) with back- drains at 20-foot intervals. An alternative to stabilizing the slope is to lay the slope back to a ratio of 3:l or flatter if deemed necessary by the engineering geo- logist during grading. If slope is laid back to a 3:l (+), it should be provided with benches and planted as soon as possible to prevent erosional problems. 21+50 to 23+50 23+50 to 24+50 24+50 to 29t75 Proposed 42-foot cut slope and alluvial cleanout: cut slope will probably require stabilization, 20-foot key x 3-foot depth. Clean out now silted up with 3-foot to 5-foot of recent alluvium and debris which will require removal. This slope, if recommended by the geotechnical consultant at the time of grading, may be laid back to a ratio of 3:l. fitted with benches, and planted as soon as possible to prevent erosional problems. Recent alluvial deposits: removal at 2-feet to 4-feet plus processing prior to fill placement. Existing fill: in proposed cut area, possible removal and replacement of l-foot plus processing. In pro- posed fill area, removal of l-foot plus processing prior to placement of additional fill. 9 Alga Road East All work north of Alga Road East from the property line will be done by developer of this (Meadowbrook) subdivision. lOl+OO to 12975 Existing fill with end-dumped trash: all end-dumped trash and debris to be removed and disposed of offsite. 101+00 to lo@75 Cut slope in Volcanic Rock: may require blasting if road is widened in this area. TO6+75 to 123+75 122+00 to 12969 Removals of l-foot to 2-feet plus processing of l-foot. Excavate fill keys (15 x 3 feet) wherever the road is widened . Locally deeper keys may be required. Benching into existing road fill required. Cut slope in Del Mar siltstone and sandstones on north side of road: will require stabilization (key 20 x 3 feet) with backdrains. Tie fill key to key for stability fill on Alga Road East. Work to be done by developer of the Meadowbrook Subdivision when constructed. EBERHART-AXTEN and ASSOCIATES, INC. La Costa Land Company Melrose Avenue Station 231+50 to 236+50 228+00 to 231+50 226tO0 to 228tO0 205+18 to 226tO0 Melrose E Ranch0 Santa Fe Intersection - Corintia Street uo+oo to 52too La Costa Avenue 122+66 to 127t50 127+50 to 130+25 and 131+15 to 132t10 13ot25 to 131c15 -lO- W.O. 1140 Slopes west of Melrose (east facing slopes) : go-foot cut slope will require 45-foot buttressistabilization fill with backdrains to be done by developer of Meadowbrook project. West facing slope may require stabilizations subject to field inspection or slope may be laid back to 3: l(+). Temporary slope at end of Melrose may require flattening to 3:l or flatter to achieve temporary stability. Three feet to four feet of colluvium overlying Del Mar siltstones: removals will be 2 feet to 3’feet with processing of 1 foot in place. Cut area: may require some additional removal if all unsuitable surficial materials are not removed during cutting operations. Three to four feet of colluvium overlying Del Mar Formation : removals of 3~feet to 4 feet plus process- ing of 1. foot. Two feet to 4 ~feet of colluvium and alluvium overlying Del Mar siltstones: removals may be 3 feet to Y- feet (plus) and processing in place of 1 foot. Three feet to 4feet of coIluvium overlying Del Mar formation siltstones: removals may be 3+ feet with processing of 1 foot. Local areas of cut may require some overexcavation if colluvium is not removed. Cut area with lo-foot slope in Del Mar siltstones and sandstones : area to be cut contains end-dumped fill with debris. All deleterious material should be re- moved and disposed of offsite. Cut may require stabilization, or lay north side of road back to 3:1(+) as field conditions dictate. Fill area: colluvium over Del Mar Formation. Colluvium should be removed with moderate to heavy benching. Fill area in canyon: fill 30 feet in depth. Canyon cleanout required, 5 feet to 6~ feet in north portions of canyon, 7 feet to 9- ,feet in south portions of canyon. Canyon subdrains required. m EBERHARl-AXTEN and ASSOCIATES, INC. La Costa Land Company -ll- W.O. 1140 La Costa Ave.-(continued) Station 132+10 to 136t75 Cut 30 feet in Del Mar siltstones: possible stabilization key dimensions to be determined during grading opera- tions. Alternative, as field conditions dictate, is to lay the slope back to 3:1(t) on north side of road. South side probably acceptable as planned. -, 136+75 to 138+50 138t50 to 144tlOO 144tO0 to 144t80 Mision Estancia Road o+oo to 5t10 5+10 to 6tlO and 12t25 to 13t75 6~10 to 12t25 10+00 to 12+00 Twenty-foot cut slope, volcanic dike: will probably require blasting. Sliver cuts to q-feet in depth and sliver fills to 3~ feet in depth. Within areas of colluvium and Del Mar silt- stones, fill areas may require removals of 3 feet to 4~ feet. Cut area removals may be required but should be determined at the time of grading. Alluvial channel, seepage noted during investigation: Four feet to 6, feet removal to expose bedrock or firm natural soil; subdrain required. Cut area maximum cut lo- feet in Del Mar siltstones. Cuts less than 2- feet may require some processing and/or removals of 1 foot to 2. feet. Cut slope probably acceptable as planned; subject to field inspections. Fill area in colluvium over Del Mar siltstones will require benching to competent material. Fill area in alluvium: depth of fill 9- feet to 10’feet. Free water encountered in B-4 at 8 ~feet (wet from ground surface). Removals of 5 feet to 6 feet and processing will be required. Placement of approximately 3 feet of rock* to provide base for heavy equipment. Specialized excavating equipment may be required. Settlement monuments as specified by the soil engineer. Near station lOtlO, removals to bedrock for future toe of slope will be required. 13t75 to 15+50 Cut/fill combination: 3 feet to 4~ feet of colluvial materials removed from fill areas. Cuts less than 3i feet may also require some removal. Cut slope may require stability fill to be determined at the time of grading. 15t50 to 16t50 Fill area in alluvium/colluvium: removals of 5. feet to 6 feet may be expected in canyon bottom; moderate to heavy benching into canyon walls. 63 m EBERHART-AXTEN and ASSOCIATES, INC. La Costa Land Company Mision Estancia Road (continued) Station -12- W.O. 1140 16t50 to 23t80 Cut slope in Del Mar siltstone: maximum height 2Oi feet. Probably requires stabilization (key 15 x 3 feet) due to weathered, fractured nature of bedrock. Stabilization requirements to be confirmed during grading operations. May be laid back to 3:1+ provided no seriously adverse geolbgic conditions are exposed during grading operations. 23t80 to 33t90 33t90 to 35+60 35+60 to 41t90 41t90 to 42+75 42t75 to 45+00 Ranch0 Santa Fe Road lOOtO to 106+00 Fill or cut/fill transition in colluvium and Del Mar siltstones: removals will range from 2, feet to 4 feet. Fill 17 feet in alluvial-colluvial creep area: this area is saturated with running water and is not accessible with conventional equipment. Removals to bedrock may be on the order of 6 feet to 8, feet. A key (15’ feet wide x 3 feet deep) into competent material will be required. Subdrains will also be required. Cut/fill transition in colluvium and Del Mar Formation: removals 2. feet to 3 feet and processing in fill area and fill key required. May require removals of l- foot to 2 feet in cut areas less than 3~ feet in depth. Fill 18~ feet in stream channel: removal to bedrock (?8-10 ft.) may require special equipment and placement of rock bed to begin fill. Key will be required with subdrains in colluvium over Del Mar Formation. Fill area: 2~ feet to 4 feet removal and heavy benching required. Fill key for west facing slope. Del Mar Formation sandstone: cut slope 35? feet in height, massive sandstones; typical attitude N 45O W 0-15O (neutral to slope). Though not currently an- ticipated, possible stabilization must be evaluated during grading. by the engineering geologist. 106+00 to 109tOO 109+00 to 118t50 Alluvium: removals 3 feet to 5 feet plus processing. Sevenfoot to 20 foot cut slope and small fills: Cuts probably acceptable as planned; removals of 3~ feet to 4 feet may be required in daylight fill and fill slope areas. 118t50 to 129+75 AlluviumlColluvium: probable removals of 2 feet to 4- feet plus processing. * Rock from Hidden Meadows access road may be used provided no rocks larger than 3. inches are used. @ sm. EBERHART-AXTEN and ASSOCIATES, INC. La Costa Land Company -13- W.O. 1140 Ranch0 Santa Fe Road (continued) Station 129+75 to 137+80 137t80 to 139+20 139t20 to 145too 145too to 147too 147tO0 to La Costa Ave. Cut slope in Del Mar Formation: approximate height 30 ~feet, may require stabilization if siltstones are exposed. Slope may, as field conditions dictate, be laid back at 3:1(k) as alternative to stabilization if required. Fill in alluvial area: removals to bedrock may be 3 feet to 5, feet. Cut slope in Del Mar Formation: may require stabili- zation if siltstones are exposed. Maximum cut height 10~ feet to 18 feet. Cut slope may, as field conditions dictate, be laid back to 3:1(f). Fill area in alluvium: removal to ‘bedrock, 3- feet to 5 feet. Tie to existing asphalt. Asphalt below grade will be removed and replaced with compacted fill to achieve grade. Low areas of subgrade may require removals plus processing. These areas are subject to inspection by the soils engineer and engineering geologist during construction. This report presents our conclusions based upon field observations and laboratory testing. Though significant variance between test excavations is not anticipated, it must be recognized that no representations are made as to the quality or ex- tent of material not observed. All recommendations should be considered subject to review by the project geologist during grading operations. Should you have any questions regarding the information contained herein, please do not hesitate to call. Respectfully submitted, EBERHART-AXTEN & ASSOCIATES, INC. SC& Vice President RCE 26098 RKJ/GWA/DRE/mm Reviewed by: Qiizzgg& --~~’ Dan R. Eberhart President CEG 965 Enclosure : Appendix Distribution: (2) Addressee (3) Rick Engineering (4) La Costa Constr. Office @ al EBERHART-AXTEN and ASSOCIATES, INC. La Costa - @ cii‘\ EBERHART-AXTEN and ASSOCIATES, INC. W.O. 1140 APPENDIX La Costa W.O. 1140 References Laboratory Testing Location Map Fault Map Seismicity Information Log of Test Pits TABLE OF CONTENTS Page A-l Page A-2 Plate I Plate II Table I Table II Summary of Laboratory Test Data Summary of Pavement Section Information Boring Logs Seismic Refraction Survey Data Settlement Monument Detail Consolidation Pressure Curves Standard Grading Specifications Map Legend Improvement Plans Table Ill Table IV Plates A-l through A-9 Plates Bl and B2 Plate C Plates D-l through D-4 Pages 1 through 22 Plate E (pocket enclosures) - c3 m EBERHART.AXTEN and ASSOCIATES, INC. La Costa (A-1) W.O. 1140 REFERENCES Creensfelder, R. W., 1974, Maximum Credible Rock Accelerations from Earth- quakes in California, C.D.M.C., MS-23. Housner, C.W., 1970, Strong Ground Motion, Earthquake Engineering, edited by R.W. Wiegel. Leeds, A.J., 1973, The Design Earthquake, A.E.G., Special Publication. Moyle, W.R. Jr., 1974, Ceohyrologic Map of Southern California, U.S.G.S., Water Resources Investigations 48-73 open file. Ploessel, M.R. and Slosson, J.E., 1974, Repeatable High Ground Accelerations from Earthquakes, California Geology. September 1974. Rogers, T.H., 1966, Geologic Atlas of California, Santa scale 1: 250,000. Ana Sheet, C.D.M.G., Schnabel, P.B. and Seed, H.B., 1973, Accelerations in Rock for Earthquakes in Western United States, S.S.A., Vol. 63, No. 2. Weber, F.H. Jr., 1977, Seismic Hazards Related to Geologic Factors, Elsinore and Chino Fault Zones, Northwestern Riverside County, California, C.D.M.C., open file 77-4. AERIAL PHOTOS Flown by Rick Engineering: July 13, 1970, Flight #10-l through 10-6 June 12, 1972, Flight #l-4 and 6 SOIL RELATED REPORTS Final Report on Compacted Filled Ground Extension of Alga Road from El Fuerte Street to Rancho Santa Fe Road, by Benton Engineering, Inc., dated March 9, 1972 (P.N. 72-l-30). Soils Investigation, by Benton Engineering, Inc., dated June 27, 1979 (P.N. 79-4-4F). Supplemental Soils Investigation by Benton Engineering, Inc., dated September 19, 1979 (revised November 16, 1979). (P.N. 79-4-4F). Reports by Benton Engineering, Inc., dated May 27, 1969, October 27, 1970, November 25, 1974 and August 1, 1975 (P.N. 69-4-14D). PLANS Preliminary Improvement Plans for Alga Road, Melrose Avenue, Corintia Street, La Costa Avenue,, Mision Estancia Road, and Rancho Santa Fe Road, by Rick Engineering, 1”=40’, November 9, 1980, EBERHART-AXTEN and ASSOCIATES, INC. - . La Costa (A-2) W.O. 1140 LABORATORY TESTING Bulk samples ~were obtained during trenching and subsequently transported to our laboratory in moisture-resistant containers. During drilling, relatively un- disturbed ring samples were also attempted by pushing and/or driving a split barrel, ring-lined, sampling spoon into soil and bedrock strata. Where recovered, these samples were also transported to our laboratory in moisture-resistant con- tainers. Laboratory tests were performed on samples for subsequent use in engineering evaluations. Brief descriptions of laboratory tests performed have been indicated below. Classification Field classifications were verified in the laboratory by visual and tactile identifi- cation. Moisture-Density Field moisture content and dry unit weight were determined from relatively un- disturbed ring samples obtained during drilling operations. This testing was performed in accordance with conventional laboratory techniques. Compaction Representative samples of onsite soils were tested for maximum density and optimum moisture content in accordance with ASTM Method of Test D1557-70. R-Values Resistance value testing was performed on representative samples of the onsite materials. R-Values were determined in accordance with California Test Method No. 301. Consolidation Consolidation tests were performed on relatively undisturbed ring samples. For these tests, samples were loaded in increments to a specified load at which time water was added. The samples were then allowed to further consolidate or swell prior to proceeding with additional load increments. Upon recording consoli- dation at the maximum load conditions, samples were then unloaded and rebound characteristics recorded. On similar samples, time consolidation tests were performed. For these tests, tools approximately equal to overburden were added and the samples were allowed, under saturated conditions, to stabilize. Additional loads were then added and consolidation recorded over time increments until the samples again stabilized. @ m- EBERHART-AXTEN and ASSOCIATES, INC. . . LOCA-‘NW+J MAF’ From U.S’.G.S. Encinitas and Rancho Santa Fe Quadrangles MAJOR ROADS PROJECT W.O. 1146 Plate I /yw , % . ..I.... . . 1 A, \ \‘. s A c>.t \~ El k :R N A R 0 , N 0 I ,*,..... *..I* - .*%@’ \ -R\ ANGELES \ ‘(-\., / ,,,;,,‘~--- ’ :I -7 t ME.,.“. : \ ACTIVE FAULTS .-.... :ota~ length of fault zone that breaks Holocenr doposIts v that has had ralsmic activity I ’ . . oult eagmant wlth rurtaca rupture during an hiatorlc .: : : QrthquaYe, or with narlrmlc fault weep, N M P E ii3 ‘**. I A LI __#-- I I , / a , , 1 / , 1 . . . ^ --..- La ‘Costa Land ‘Co. TABLE I’ W.U. 114u SEISMIC PARAMETERS FOR NORTHWESTERN SAN DIEGO COUNTY -r Maximum - Age of Credible Most Recent Earthquake Surface Richter Richter Displacement Magnitude Magnitude ,:(approx. 1 (Note 1) (Note 1) 1948 7.50 7.50 to to 8.25 8.00 Holocene 7.50 7.00 I-11,000 yrs. Maximum Probable Earthquake (for design purposes) Peak Horizontal Ground cceleration (Gravity) (Note 2) ?- Predomlnent Period at Site (Seconds) (Note 3) T7: 0 5 i iuratlon f strong shaking 3t Site Seconds: (Note 4 ess than 0.10 0.58 34 ess than or equal to 0.10 0.40 28 Holocene, I-11,000 yrs. 7.7 6.7 0.18 0.3 20 Ground failures, but no definite known rupture 7.5 6.5 0.38 0.28 18 mtential lusative Fault Distance Length from site of to fault fault (miles) (mhes) 310 Richter Magnitude of Historical iarthquakes 8.0 (1857) 6.5 (1948) tstimatc :ecurrenc Interval (years) (Note 5) Ii 1 1 L L I 6.8 (19181’ 6.0 (1937) 6.2 (1954) 6.4 (1958) 6.0 (1910) , 6.3 (1933) I Andrea: >uth 8 :entral) 68 5 40-100 40-100 n Jacinto 46 150 to 200 22 135 to 162 iinore ’ wport- glewood I lose Zanyon go-200 200-300 7 to 8 Between 50 E 120 t I tes: 1) 21 Postulated Fault Rupture Lengths-: Maximum Credible Earthquake = length/2 Maximum Probable Earthquake.= length/l0 Schnabel and Seed, 1972. For sites less than 20 miles from the fault, the peak accelerations may further be reduced to repeatable high ground accelerations by using 65% of the peak acceleration (after Ploessel & Slosson, 1974)~. 3) After Seed, ldriss and Kiefer. 1969. 4) After Housner (1970), Bolt (1973) 5) Recurrence intervals for maximum probable earthquake taken in part from Lamar and others (1973). La Costa Land W.O. 1140 TABLE II LOG OF TEST PITS Test Pit No. (Station) .Depth (ft.) Alga Road West (14 +l75) 0.2-2.5 ‘2.5-5.0 o.o-1;5 1.5-4.0 (7 + io, (5-+ :o, (9 + :5, 6 (6 + 5) 0.0-1.0 1.0-2.0 2.0-5.0 0.0-1.0 1.0-5.0 0.0-3.0 3.0-4.0 0.0-0.5 Field Description ALLUVIUM: Sandy Silt, pale brown, moist, soft; with minor rootlets. ALLUVIUM: Silty Clay, dark brown, wet, very soft. TOPSOIL: Clayey Sand, medium brown, damp, dry. BEDROCK : Clayey Sandstone, orange brown, with mottled spots of gray sand. moist, dense; black magnesium stains (highly weathered), massive, no indication of bedding. FILL: Clayey Sand, medium gray, mottled, dry to damp near surface, firm. FILL: FILL: moist, FILL: dry, hard; desiccated. Clayey Sand, moist, firm. Sandy Silt, pale gray-green, dense. Clayey Sand, medium brown, FILL: Sandy Silt, pale gray-green, occasionally mottled, dry to damp; locally blocky, roots penetrating the upper foot. FILL: Clayey Silt and Silty Clay, medium brown to olive gray or green, dry, porous, loose; desiccated. FILL: Sandy Silt, gray to gray- green, slightly mottled, moist, firm, dense. , FILL: Sandy Silt, pale gray. gray- green or brown, mottled, moist, firm; with fragments of siltstone, and rootlets penetrating to depths of 3-ft. or more. @ m EBERHART-AXTEi and ASSOCIATES, INC. La Costa Land -2- W.O. 1140 Test Pit No. (Station) (ConGt.) (25+0;) Depth (ft.) 8.0-11.0 0.0-1.0 (26+9:) (29+5i) 1.0-2.5 2.5-6.0 0.0-1.0 1.5-5.0 0.0-1.0 1.0-5.0 Alga Road East ( 1 o*+:i, 0.0-1.0 1.0-5.0 (104+::1 0. O-O. 18 ‘Field Description BEDROCK : Siltstone, pale gray-green, moist, dense. FILL: Silty Clay, gray brown, dry, loose; desiccated, containing fragments of volcanic rock 2-in. to 3-in. in diameter. FILL: Clayey Silt, dark brown, moist, firm to stiff, dense; containing minor fragments of the volcanic rock. FILL: Silty Clay, pale gray to green, mottled, moist; containing occasional cobbles and boulders 3-in. to 6-in. in diameter. FILL: Silty Sand, pale brown, dry, loose; desiccated. FILL: Silty Clay, dark brown, moist, firm to very firm; contains scattered cobbles and pebbles 2-in. to 3-in. in diameter. FILL: Silty Sand, pale brown, dry, slightly dense; desiccated and loose within the upper 6-in. to 1-ft. FILL: Silty Clay, pale gray-brown to green, locally mottled with red (iron oxide) stains, moist, stiff; occasional scattered cobbles. FILL: Silty Clay, medium brown to gray, dry, porous; desiccated, roots near the surface. BEDROCK: Clayey Siltstone, dark gray to green, moist; with cobbles, varying in size from 6-in. to 12-in. of volcanic% FILL: Sandy Silt, pale brown, dry, loose; contains numerous roots. @ m. EBERHART-AXTEN and ASSOCIATES, INC. La Costa Land -3- W.O. 1140 Test Pit No. (Station) 11 (Cont.) ( lo,+::) Depth (ft.) Field Description 0.18-2.5 0.0-3.0 3.0-3.5 0. O-7.0 7.0-10.0 10.0-15.0 o-o-4.0 4.0-7.0 7.0-8.0 0.0-5.0 0.0-4.0 BEDROCK : Volcanic, Basalt-Andesite, dark gray, damp, silty sand matrix. FILL: Silty Sand, medium brown, moist, hard; with mottled fragments of siltstone and angular fragments of volcanic rock, locally scattered, ranging from 2-in. to 3-in. in diameter. BEDROCK: Andesite-Basalt, dark gray, very dense. FILL: Silty Sand, medium brown, damp, firm; containing large angular fragments of volcanics 3-in. to 1.5-ft. in diameter. ALLUVIUM: Silty Clay, dark brown to pale brown, slightly reddish, moist, firm, stiff. COLLUVIUM: Silty Clay, medium brown to pale gray, damp to moist, firm to stiff; possibly residual soil from the Delmar Formation, moderately stiff. FILL: Silty Sand, pale brown, moist, slightly dense; with fragments of rock scattered throughout, 2-in. to Gin. in diameter. COLLUVIUM: Silty Clay, dark brown, moist, firm, slightly porous; containing minor rootlets. BEDROCK : Siltstone, orange to gray brown; iron oxide stains. FILL: Silty Sand, medium brown to pale brown, occasionally mottled, dry in the upper I-ft., moist below, loose in the upper 1-ft., firm to stiff below I-ft.;generally the fill appears to be in pretty good condition. FILL: Silty Sand, medium brown, dry at surface, damp to moist below, firm to very stiff; contains some buried debris. % EBERHART-AXTEN and ASSOCIATES, INC. La Costa Land Test Pit No. (Station) 16 (Cont.) f l26+$ Melrose Avenue (230+::) (227+;:) (224+::) (220+::) (215+Zl Depth (ft.) Field Description 4.0-4.5 0.0-4.0 0. O-3.0 3.0-5.0 0. o-3.5 4.5-5.0 0.0-2.5 2.5-4.5 4.5-5.0 0.0-4.5 4.5-5.0 -4- W.O. 1140 BEDROCK: Sandy Siltstone, pale gray to olive gray; massive. BEDROCK: Sandy Siltstone, dark gray- brown, moist, dense. FILL: Silty Sand, pale brown, dry to damp, loose near surface; locally desiccated, porous. COLLUVIUM: Silty Clay, dark brown, moist, stiff; with numerous small rootlets. COLLUVIUM: Silty Clay, gray-brown; dry, expansive; desiccated, becoming moist and stiff and cracks at a depth of 2-ft.~ to 3-ft. RESIDUAL SOIL, BEDROCK: Silty Clay, moist to wet, stfff; highly p~lasfic. COLLUVIUM: Silty Clay, dark gray-brown, dry and desiccated in the upper 2.5-ft., moist below 2-ft., very hard upper 2-ft., soft to firm below 2-ft. to 4.5-ft. BEDROCK: Silty Sandstone, medium green, wet; highly weathered. COLLUVIUM: Silty Clay, gray-brown, dry desiccated, porous, hard and loose. RESIDUAL SOIL: Clayey Silt, medium brown, mottled, moist, firm; slightly porous, con- taining fragments of sandstone t-in. to t-in. in diameter, locally mottling the soil. BEDROCK: Cranitics, Silty Sand, gray, moist, dense; massive. COLLUVIUM: Silty Clay, gray-brown, dry, desiccated, hard in the upper 1-ft., below I-ft. it is medium brown, moist, firm to stiff. BEDROCK: Siltstone, dark gray, moist, stiff, firm. @ c%ilY EBERHART-AXTEN and ASSOCIATES, INC. - La Costa Land -5- W.O. 1140 Test Pit No. (Station) Depth (ft.) Field Description 0.0-1.0 2.0-4.0 (207+::) 0. O-2.0 2.0-4.5 4.5-5.0 (51+0i5 Corintia St.) 0.0-2.0 2.0-4.5 (205+::) 4.5-5.0 0.0-1.5 2.0-5.0 La Costa Avenue ( ,2,+::1 0.0-3.0 3.0-3.5 TOPSOIL: Silty Clay, gray-brown, dry, hard; desiccated. COLLUVIUM: Silty Clay, medium brown, damp to moist, stiff to very hard, expansive; exhibits some caliche staining, hightly plastic. TOPSOIL: Silty Clay, gray-brown, dry; desiccated, coarse, very hard due to desiccation. COLLUVIUM: Silty Clay, medium brown to dark brown, stiff to hard, moist, plastic; expansive. BEDROCK : Clayey Sand, medium brown, moist, moderately dense; medium to coarse grain. TOPSOIL: Silty Clay, gray-brown, dry, desiccated, coarse, very hard due to desiccation. COLLUVIUM: Silty Clay, medium brown to dark brown, stiff to hard, moist, plastic; very expansive. BEDROCK : Clayey Sand, medium brown, moist, moderately dense; medium to coarse grain. TOPSOIL: Silty Sand, pale brown, dry, loose; coarse with numerous roots. ALLUVIUM: Silty Clay, gray-brown to green- brown, moist, soft to firm; extremely porous, minor rootlets. COLLUVIUM: Silty Clay, medium brown, damp to dry, desiccated, porous and loose within the upper l-ft. BEDROCK : Siltstone. duskv vellow inter- beds of sandstone; bedding’s; 6-ft., EW2=‘N. . . @ m EBERHART-AXTEN and ASSOCIATES, INC. La Costa Land -6- W.O. 1140 Test Pit No. (Station) Depth (ft.) Field Description (128~::) 0.0-1.0 1.0-2.5 2.0-4.0 ( 13o+::j 0.0-1.0 1.0-5.0 (128+::) ( 132+::) 0.0-1.5 1.5-5.0 5.0-8.0 0.0-1.0 1.0-5.0 5.0-7.0 0.0-2.5 2.5-6.0 TOPSOIL: Silty Clay, gray-brown, dry desiccated, loose, porous. COLLUVIUM: Silty Clay, red-brown, damp to dry, hard; desiccated. RESIDUAL SOIL: Clayey Sand, medium brown, moist, dense to vely*.‘dense; medium grained to fine grained, minor rootlets. TOPSOIL: Silty Clay, medium brown, dry desiccated, porous, loose and hard due to desiccation. ALLUVIUM: Silty Clay, medium to dark brown, stiff to hard, expansive, highly plastic; containing some caliche stains with- in the bedrock. TOPSOIL: Sandy Silt, pale brown, dry, loose; porous and blocky in the upper 18-in. ALLUVIUM: Silty Clay, medium brown, firm to stiff, damp, moderately plastic; slightly porous, with incltisions of small pebbles, some fragments of bedrock. BEDROCK : Siltstone, dusky green, moist, dense; no groundwater. ALLUVIUM: Silty Sand, pale brown, dry porous; containing numerous roots, loose, slightly blocky. ALLUVIUM: Silty Clay, dark gray-brown, to gray, green-brown, moist, firm; porous, mottled in nature, occasional roots. BEDROCK : Siltstone, dusky green, moist, dense. COLLUVIUM: Silty Clay, dry, hard; desiccated, porous, blocky. BEDROCK: Siltstone, dusky, olive green, dense; blocky, occasional slicken sides. @ %l EBERHART-AXTEN ond ASSOCIATES, INC. La Costa Land -7- W.O. 1140 Test Pit No. (Station) Depth (ft.) Field Description Mi.sion Estancia Road ( 144+:;) 0. O-3.0 COLLUVIUM: Silty Clay, gray brown. dry. hard; desiccated, porous. ( 144+Z) ( 140+~~) fl38+::1 ( 142+::) (44+0031L (39+0:; 3.0-5.0 0.0-4.0 BEDROCK: Siltstone, brown and dusky green; extremely weathered. COLLUVIUM: Silty Clay, medium brown, dry at surface, moist to wet below I-ft. 4. O-5.0 RESIDUAL SOIL: Silty Clay, dusky green, moist, soft. 5.0-6.0 BEDROCK : Siltstone, dark green, moist, stiff. 0.0-5.0 ALLUVIUM: Silty Clay to Sandy Clay, medium brown, dry to damp, stiff to hard; porous near the surface. o-o-1.5 COLLUVIUM: Silty Clay, dark gray-brown, dry, porous. 1.5-1.75 0.0-1.5 BEDROCK : Andesite, white to gray, dense. TOPSOiL: Silty Clay, gray-brown, loose, hard; blocky, porous. 1.5-3.5 COLLUVIUM: Medium brown grading to pale gray with streaks of red, damp to moist, stiff to hard; slightly porous, highly expan- sive and plastic, occasional stains of caliche and minor rootlets. 0.0-1.0 TOPSOIL: Clayey Sand, medium brown, dry, hard; desiccated, minor roots in the upper I-ft. 1.0-3.0 COLLUVIUM: Clayey Sand, reddish brown, moist, very dense; can not make any impres- sion at all with thumb or fingernail. 0.0-3.5 COLLUVIUM: Silty Clay, dark brown, dry at surface, damp below 2-ft., stiff to hard; hard surface due to desiccation, porous, expansive,~ large cracks in the topsoil. s EBERHART-AXTEN and ASSOCIATES. INC. La Costa Land -a- W.O. 1140 Test Pit No. (Station) fCont3.9, Depth (ft.) 3.5-5.0 (35+7ZP 0.0-4.5 4.5-5.0 (33,+G, (29+0ftf (24+5:: (18+1:; (16+0:; 0.0-5.0 5.0-5.5 0.0-5.0 0.0-3.5 3.5-5.0 0.0-4.5 4.5-7.0 0.0-4.0 Field Description BEDROCK : Siltstone, dusky gray to gray- green, moist, dense; massive, caliche stained, weathered. COLLUVIUM: Silty Clay, dark gray-brown, dry at surface, moist to wet below, hard at surface, stiff to firm below 2-ft.; blocky, expansive. BEDROCK: Siltstone, pale brown to green or green-gold, moist, stiff; highly weathered, fragments of volcanics scattered in the upper zones of the bedrock. COLLUVIUM: Silty Clay, dark gray-brown, dry at the surface, moist to wet below 2-ft., highly expansive in the upper 2-ft., soft to firm where it is moist below 2.5-ft. BEDROCK: ,‘Dusky gray to yellow-gray with mottled streaks of green and red, moist and soft; weathered. COLLUVIUM: Silty Clay, gray-brown to medium brown, dry at surface, moist to wet below, hard at surface, stiff to hard below; porous and rooty in the upper I-ft., highly plastic and extremely expansive. COLLUVIUM: Silty Clay, dark gray-brown, dry, hard; desiccated, becoming damp at 2-ft. to 3.5-ft., becoming moist near 3.5-ft. BEDROCK: Silty Claystone, olive to dusky green, soft to firm, moist to wet. COLLUVIUM: Silty Clay, dark gray-brown, desiccated, extremely porous, extremely expansive. BEDROCK : Clayey Siltstone, dusky green, moist, wet, very soft; highly weathered. COLLUVIUM: Silty Clay, dark gray-brown, moist below 2-ft., hard in upper 2-ft., stiff to firm below; porous, rooty, extremely expansive. e EBERHART-AXTEN and ASSOCIATES, INC. - La Costa Land -9-. W.O. 1140 Test Pit No. (Station) 45 (Cont.) (lo+7:; (l4+2$ (5+50P8 Depth (ft.) Field Description 4.0-5.0 BEDROCK : SiltstonelSandstone, green and red-brown to bright orange-red, moist, medium dense; highly weathered. 0.0-5.0 ALLUVIUM: Silty Clay, gray-brown, dry in the upper 2-ft., moist, becoming wet near 5-ft., hard in the upper 2-ft. where it is dry, firm to stiff below 2-ft.; roots penetrating to approximately I-ft., extremely expansive. 0.0-2.0 2.0-8.0 0. O-5.0 [ 3+25; ,o.o-2.0 2.0-8.0 Ranch0 Santa Fe Road 0.0-2.0 ( 152+80) 2.0-5.5 (107+:& 0. O-4.0 ALLUVIUM: Silty Clay, dark gray-brown, dry, dense; desiccated. Siltstone, green; .highly weathered with num- erous iron oxide stains, fractures and gypsum seam*. COLLUVIUM: Silty Clay, dark gray-brown, dry in the upper 2-ft., moist, hard near surface due to desiccation, firm to stiff from 3-ft. to 5-ft.; occasional caliche stains, highly expansive, porous with roots penetrating approximately 3-in. to 6-in. TOPSOIL: Sandy Clay, dark gray-brown, dry to damps, hard; expansive, locally porous, roots to 6-in., expansion cracks &-in. to t-in., locally with sand, orange-brown, moist, dense. BEDROCK : Siltstone, dark green with inter- beds of red, damp, dense; numerous caliche stains, occasional animal infills and rootlets to 6-ft. Silty To Sandy Clay, medium gray-brown, dry to slightly damp in the upper 2-ft., hard; desiccated, expansion cracks, brittle, abundant rootlets to 2-ft. BEDROCK : Clayey Sandstone, gray-green to orange-brown, damp to moist; slightly friable, with minor lionite and iron oxidation staining, minor caliche within the upper 1-ft. ALLUVIUM: Sand, light to medium brown, dry to slightly damp, medium dense; friable, with abundant rootlets to 2-ft., fine grained. dT., EBERHART-AXTEN and ASSOCIATES, INC. La Costa Land -lO- W.O. 1140 Test Pit No. (Station) 51 (Cont.) 52 ( 114+00) 53 (115+25) 54 (120+25’) 55 (123+50) 56 (128+00) 57 ( 138+00) Depth (ft.) 4.0-12.0 Field Description BEDROCK : Sandstone, orange-brown, becoming damp, dense; appears massive. 0.0-1.5 TOPSOIL: Silty Clay, medium gray-brown, dry, desiccated, with abundant rootlets, at 18-in. becomes stiff and moist, medium reddish brown. 1.5-4.0 4.0-5.0 0.0-6.0 0.0-4.5 4.5-6.0 0.0-3.0 0.0-2.0 0. O-3.0 3. O-4.0 4.0-5.0 COLLUVIUhl: dark brown, moist, fine, porous. BEDROCK: Siltstone, medium to dark green, damp, stiff, damp to moist and stiff; weathered, with iron and limonite staining. COLLUVIUM: Silty Clay, medium brown to y-J;b,srodwm; ,“,“~~gIp,l~~~~,““,“,“rr,l~~~;s, desiccated, with abundant rootlets to 12-in., hard, becoming damp, firm to stiff. COLLUVIUM: Silty Clay,, dark brown, dry to damp, firm to hard; desrccated. BEDROCK : Siltstone, dark gray-green, moist firm to stiff; highly weathered. ALLUVIUM: Silty Sand, light brown, dry loose, grades to medium brown to gray-brown silty sandstone; minor limonite staining. COLLUVIUM: Sandy Clay, medium grayish brown, dry to slightly dame, hard; dessicated, brittle, porous., rootlets to 18-in.,; becoming damp at.~2;ft.; very hard, clayey sand. Silty Sand And Sandy Clay, medium green, medium brown to reddish brown, dry, slightly damp at 2-ft., loose to 1.5-ft., with minor fragments of sandstone and siltstone. ALLUVIUM: Silty Sand, medium gray-brown, damp, medium dense. ALLUVIUM: Silty Clay, brownish gray, damp to moist, slightly firm to firm. m EBERHART-AXTEN and ASSOCIATES, INC. La Costa W.O. 1140 TEST EXCA. TP-1 TP-2 TP-3 TP-4 TP-5 TP-6 TP-7 TP-8 TP-9 TP-10 TP-11 TP-12 TP-13 TP-14 TP-15 TP-16 TP-18 TP-19 TPI20 TP-21 TABLE Ill SUMMARY OF LABORATORY TEST DATA DEPTH (feet) 1.0 3.0 5.0 1.0 3.0 1.0 3.0 5.0 1.0 1.0 3.0 O-8 1.0 3.0 5.0 3.0 5.0 O-2.5 1.0 3.0 5.0 1.0 1.0 1.0 1.0 3.0 5.0 2.0 4.0 1.0 3.0 5.0 2.0 4.0 1.0 3.0 5.0 3.0 5.0 1.0 3.0 5.0 o-3 3.0 5.0 uses CL CL :lrl CL CL CL C,H ML ML ML ML CL ML ML CL CL SM /SC CL CL CH ML SM CL CL CH CH CL SM CH ML CL CL ML ML Eli CH CH CH CH CH CH CH CL - s? EBERHART-AXTEN and ASSOCIATES. INC. IN SITU DRY DENSITY (pcf) IN SITU MOISTURE CONTENT (‘3) 89 92 100 99 106 110 108 112 109 105 105 18 18 25 7 12 14 15 17 16 13 16 117 9 108 16 111 12 114 12 106 13 113 10 100 16 108 16 102 17 104 10 103 14 108 11 110 14 105 17 108 13 90 6 103 17 96 19 100 20 106 15 104 17 99 11 99 16 96 19 101 15 96 23 105 11 98 18 87 29 101 95 20 24 MAX. DRY* OPTIMUM* DENSITY MOISTURE (pcf) (3 115 13.5 121.5 12 117 12 - . La Costa W.O. 1140 TEST EXCA. TP-22 TP-23 TP-24 :~ . I, TP-26 ?P-28 TP-29 TP-30 TP-32 TP- 33 TP-34 TP-37 TP-40 TP-41 TP-42 TP-43 TP-45 TP-46 TP-48 TP-50 TABLE III SUMMARY OF LABORATORY TEST DATA DEPTH (feet) 1.0 3.0 5.0 3.0 5.0 1.0 3.0 5.0 1.0 3.0 5.0 1.0 3.0 5.0 1.0 3.0 5.0 2.0 ~4.0 2.0 4.0 4.0 6.0 1.0 5.0 2.0 4.0 3.0 5.0 1.5 4.0 3.0 5.0 1~.5-~.~; .4.0 3.0 5.0 3.0 .5.0 3.0 5.0 2.0 3.5 3.0 5.0 uses CL .- CL CL CH CL CH CL CL ML CL CL CL CL ML SMIML CL CH CL CH CH CL CL CL CL CL/CH CL CL CL ML CH CH CH CH. CH CH CL ML z! CH CH :H” SM CL .- e ET(FPl-lP.DT.aYTcM “l.4 ACCnrlATCC lhll- IN SITU DRY DENSITY (PCf) IN SITU MOISTURE CONTENT (8 105 14 112 13 ;112 13 .108 15 109 13 101 16 110 16 105 15 103 4 lOl!., 17 112 16 99 18 86 17 99 14 97 13 100 20 100 23 104 18 98 23 91 23 102 20 112 17 115 15 107 14 105 21 105 19 101 18 107 16 119 15 95 25 98 23 99 23 100 22 92 22 98 26 99 22 105 15 99 22 89 26 100 22 102 21 96 .23 98 21 101 18 93 21 MAX. DRY* OPTIMUhJ* DENSITY MOISTURE (pcf) (%I La Costa TEST EXCA. TP-52 TP-53 1 . 0 TP-54 TP-55 TP-56 TP-57 W.O. 1140 TABLE Ill SUMMARY OF LABORATORY TEST DATA IN SITU IN SITU MOISTURE MAX. DRY* OPTIMUM* DEPTH DRY DENSITY CONTENT DENSITY MOISTURE (feet) uses (pcf) (%I (pcf) (%I 3.0 5.0 1.0 3.0 5.0 3.0 1.0 3.0 1.0 1.0 3.0 5.0 ML 96 CL 98 SM 100 CH 99 CH 98 CH 104 SM 91 SM 98 SM 91 SM 86 SM 97 ML 98 12 19 8 20 20 15 10 7 5 12 9 17 * ASTM D1557-JO. @ - EBERHART-AXTEN q nd ASSOCIATES. INC. , - La Costa W.O. 1140 TABLE IV SUMMARY OF PAVEMENT SECTION INFORMATION TEST DATA: R-Value Expansion Test Exca. Depth (ft.) Exudation , TI = 5.5 , TI = 7.0 1 0.0-2.5 33 39 41 11 0.0-1.0 43 52 54 49 3.0-8.0 25 23 25 Estimated Range of Pavement Section: Street Street Name Class ALGA Major Rd. CORINTIA Res. Coil. LA COSTA Coil. Rd. MELROSE Prime Art. MIS. EST. Coil. Rd. RHO. SF. Major Rd. Pavement Sections (in. 1 TI from TI for Rick Eng. this est. R=20 R=40 J-min. 7 3+AC I1 3AB 3tAC /8AB 5.5 5.5 2;ACIlOAB 2;AC l6AB 7 7 3iACl13AB 3fAC /8AB J-min. 7 3$AC I1 3AB 3jACI8AB 7 7 3iAC I1 3AB 3+AC l8AB J-min. 7 34AC113AB 3iACl8AB - e m EBERHART-AXTEN and ASSOCIATES, INC. Location Alga Road West CORING LOG Boring No. 1 W.O. 1140 Date: 10-16-80 - By: MJ -- Surface Elevation g 2 A Ll.. c: ,c Is! : 5 L oU 0” ~5” &b 58. 0.. 5.L 5f F P P i 56-ft. Total Depth 25-ft. Driller 6 Rig TommyIAlrov I FIELD DESCRIPTION Surface Conditions: Marsh-Like Area: Heavy Vegetation Phreatophytes Subsurface Conditions: Soft and Wet Remarks ALLUVIUM: Silty Clay, dark gray-brown, soft. wet, t ALLUVIUM: Silty Clay, dark gray-brown, wet,-- soft. . Seepage ’ Seepage ’ 4. s-ft . 4. s-ft . Silty Clay, dark brown, very wet, very soft. Silty Clay, dark brown, very wet, very soft. Occasional sand ‘lenses Occasional sand ‘lenses - Standing Water 8-ft. Becoming firm Becoming firm Clayey Sand, medium brown, wet, loose to slightly dense; mottled. 1 Clayey Sand, medium brown, wet, loose to slightly dense; mottled. Sand, medium brc---- ~~~-. nvn, wer. 1 Caving badly I 4 Fnrl nf Dnrinr. ,2-&c EORINC LOG w.0 1140 Earing No. B-2 Date’: 10-16-80 Location Melrose Avenue By: RKJ Surface Elevation _ 342-ft. Total Depth 1 I-ft. Driller 6 Rig TommylAlroy f FIELD DESCRIPTION Surface Conditions: Meadow area, dry at surface Subsurface Conditions: Remarks Clayey Silt, dark gray-brown, dry at surface,-~ moist below 1.05-ft., stiff-firm, porous, expansive. ia. __ . _ _. BEDROCK: Siltstone, pale gray, moist, denser R 3 120 9 __ End of Boring 11-ft. r,-,rn.i.nr A”Tr-k, c ACcnrlATrC IF.IP “l-l- A-3 EORINC LOG W.O. 1140 Earing No. B-3 Date: 19-16-99 _ Location Melrose Avenue - By: RKJ - Surface Elevation _342-ft ~~ i Total Depth 15-ft. Driller t Riq Tommy/Alroy 2 L”. c 5 tit 3 5-p 0’ 5.. 1 z FIELD DESCRIPTION Surface Conditions: Meadow area, dry at surface v ;:z rp.z.2.g Subsurface Conditions: Remarks 2 ;r;z 00 v x.& CH Silty Clay, dark gray-brown, dry at surface, -- moist below 1.5-ft., porous, firm-stiff . . & R P 111 17 Slightly sandy --SC- _. -. R 2 Clayey Sand, medium brown, moist,dense; water at 9-ft. Seepage at - 9-ft. BEDROCK: siltstone, gray, very weathered. - R 7 End of Boring 15-ft. -- _^.. -. ^_ ..*v-.. - .--A-. .-r- . ..I ^. . A-1 BORING LOG W.O. 1140 Earing No. B-4 Date: 10-16-80 Location Mission Estawd By: RKJ Surface Elevatior z : Q) - k. ‘ ,s z- .s : -,G 0” 5-m Ita, 13’ 0’ L - h’ c : a8 0 2. 0: - ll( 114 13 - - = w ii G’ 5, z, 13 60-ft. Total Depth 16-ft. Driller t Rig Tommy/Alro FIELD DESCRIPTION Surface Conditions: 25-ft. away. Marshy areas with running water Subsurface Conditions: Wet Remarks ALLUVIUM: Silty Clay, dark gray-brown, / moist, wet, very soft, mottled. I Becoming firm ! sandy Clay, orange-brown, moist to wet, soft to firm. 11 14 - < ;ravel in sample, l-in. to 2-in. rounded. C Ilay, dark gray. wet, stiff, extremely plastic a lnd slick. BEDROCK: Siltstone, gray-green, moist, wet, ‘cry stiff; mottled. :nd of Boring 16-ft. BORING LOG - . W.O. 1140 Boring No. B-5 Date: 18-16-88 - Location Rancho Santa Fe Road By: RKJ Surface Elevation 122-ft. Total Depth lo-ft. - Driller t Rig Tommv/Alrov FIELD DESCRIPTION Surface Conditions: Alluvia1 channel, very sandy Subsurface Conditions: Sandy, dense Remarks R7102 6 ‘- .. ALLUVIUM: Sand, medium brown, moist, loose, with porous roots. BEDROCK : Sandstone, medium brown, moist, very dense; contains small, well-rounded pebbles and clasts. End of Boring lo-ft. EORINC LOG W.O. 1146 Earing No. B-6 Date: 10-16-66 Location Alga Road West By: 7 Surface Elevation 1 Total Depth 6g-ft. - - Driller & Rig w FIELD DESCRIPTION lo- 5 : t .z 2; JE ;; ‘i z: I- - L - G :: -1 I?!. ” 7 t rz * .- 0. j s z ZV : 0” ” E SN 5.. ._ Y’ -3M1 SP 0.. -. Sh ‘5- _. , iT x i I -4 4 ,X-i ‘ji I ii= 0 x! LT 3: 113 109 114 - Surface Conditions: Sparse vegetation on filled ground Subsurface Conditions: Firm. dry-damp Remarks FILL: Silty Sand, dark brown, dry in upper _- 6-in., loose in upper l-in. Becoming olive gray; damp to moist. 3ecoming very sandy; pale gray, slightly tense. Silty Sand, Sandy Silt, pale gray-olive green, iamp to moist, firm; composed of siltstone/ sandstone bedrock. rorntirns IVTI-h, c Accnf-l~.TrC IhIP “l-r- A-csl ,. CORING LOG Location Alga Road West Earing No. B-6 Surface Elcvatiol b m 3 .u 0. V 9 : WY u” F R R R 11 11: 16 16 17 - CA? 2 J z;: ‘6 , zz. - 12. 8. 2.t 1.6 10 ZZZ -ft. - E J ;; ‘5 z 5 E i= : 4-w ). 4 - W.O. 1lip-J Date: 10-16-80 - By: RKJ l- Surface Conditions: Subsurface Conditions: Remarks iilty Sand, Sandy Silt, pale gray to olive Ireen, damp-moist, firm. tme as above; no changes in material. . \_ ___^.. ..^_ ..,__.. - .PCc.A. .--- . ..- 2400 Ibs. 1650 Ibs. - Location Alga Road Surface Elevation z fz -A 2. ” ,s 2 0. 5 z av 0” 5U’ 55. fie* 69’ ?Q- R LIB L __ R R R R . . (I i 2 1’ 11 21 2 . : I L : : > 1 L 3 1 I I -1 109 113 117 ;26 13 -2 EORlNG LOG W.O. 1140 Boring No. B-6 Date: 10-16-80 West By: BK, Total Depth 69-ft. Driller & Riq Tommy/Al z 1 FIELD DESCRIPTION 10-i B f 3 .a *= J5 3’ .E VI- ‘6 0” Z- 9 . .A 14.! Surface Conditions: Subsurface Conditions: Remarks 1650 Ibs. 850 Ibs. - TOPSOIL: Silty Clay, dark gray-brown, moist-w&t, firm, slightly porous, organic smell. Topsoil at 53-ft. sample’ at 54-ft. ALLUVIUM: Clayey Sand, Sandy Clay, medium brown, wet, firm to stiff. Seepage at 53.5-ft. to 55-ft. 3.7 2.1 2.1 - BEDROCK: weathered, clayey siltstone, pale gray-green, moist, wet, very stiff; mottled. Weathered bedrock at 68-ft. to 69- ft. lroy . EORIRC LOG - W.O. 1140 Doring No. D-7 Date: 10-17-80 Location Rancho Santa Fe Road BY: RKJ Surface -5 ; G’ 2i I u”,: 5 C - R Total Depth 40-ft. Driller t Rig Tommy /Alroy - FIELD DESCRIPTION Surface Conditions: Dry on ‘natural pad; ridge top Subsurface Conditions: TOPSOIL: Clayey Sand, dark brown, dry to noist at 2-ft., loose to slightly firm. SANDSTONE: Gold brown, moist, dense; abundant FED2 staining. Remarks Zolor change to pale gray, highly oxidized. Ilay seam, t-in. thickness, discontinuous. ‘oorly developed bedding, l/16-in. to i-in. hickness, near horizontal within highly xidized siltstone and sandstone. : N30E lertical - andstone continues (massive). hln sequence of coarse grained and fine - rained sandstone; cross bedding. andstone continues, damp; dense, massive. - I: NlOW,6E - -.:. -- .._--.. _ .---- .._I ^ . ..- -. A-7a BORING LOG W.O. 1140 Earing No. B-7 Date: 10-17-80 Location Rancho Santa Fe Road - By: RKJ Surface Elevation rn Gj If!. ” T CZ .- 0. z ?I- ‘;v 0” - ,x Gi : 3 ? 3: - - 62 = - - - Total Depth qO-ft. Driller t Rig TommylAlroy FIELD DESCRIPTION Surface Conditions: Subsurface Conditions: Remarks I ,.. A-7b SANDSTONE, orange-brown to dark gray- brown, moist; dense to very dense, fine to medium grained. Concretion, locally, well indurated,. Siltstone, dark olive green, damp, hard:,. l/16-in. to t-in. remolded; clay seam along contact, undulatory, oxidized with inclusions C: N45W,l5W - B: N5W,19W - 3f gypsum. ind of Boring 40-ft. BORING LOG w.0 ‘140 . Earing NO. 0-a Date: 10-17-80 Location LaCosta Avenue By: RKJ Surface Elevation 298-ft. Total Depth 30-ft. Driller G Rig Tommy/Alroy I FIELD DESCRIPTION Lii : 2. - ‘ c r - c 5 : QC z i IQ 5.. 0.. ; , i 5 Surface Conditions: Subsurface Conditions: TOPSOIL: Clayey Sand, light brown, damp; slightly dense. SILTSTONE: olive green, moist, stiff to hard Dxidized, massive, locally desiccated, blocky t-in. to l-in.; caliche. Becoming lighter in cofor, with random sfick- oolished surfaces. More massive, less fractured. jiltstone continues, dark olive-green, damp, tiery hard, more massive, slight polished surface along bedding. c :lay seam, greenish gray, moist, firm;highly Ilastic, $-in. thick, siliceous -bed, 2-in. to ,-in. thickness, very hard. I Remarks B: N25E,2f B: EW,,lSN _. GOf~INC LOG WC). 1148 Earing No. B-8 Date: lU7’-m Location LaCosta Avenue By: Y Surface Elevatic = - - 2 3 Tii ‘6 I E : 0” = Total Depth Driller & Rig Tommy/AIroy - FIELD DESCRIPTION Stirface Conditions: Subsurface Conditions: Continues siltstone, massive, very hard. ind of Boring 30-ft. Remarks Location - z IL” .c 5 ii 3 - 5. 10 I5 !a !S - 6ORlNC LOG Earing No. B-9 Mission Estancia Road 254-ft. Total Depth 45-ft. - Surface Elevation W.O. “40 Date: 10-17-80 By: RKJ Driller 6 Rig Tommy/Alro Y - FIELD DESCRIPTION Surface Conditions: Subsurface Conditions: TOPSOIL: Clayey Silt, medium brown, damp, stiff. Remarks SILTSTONE: Olive green, damp, hard, zaliche, minor clay. ‘i Becoming slightly sandy and lighter in color. iighly oxidized (FE02) with abundant gypsum itringers, clayey siltstone. Concretion with i-in. gypsum stringer above, pale orange-brown; very hard .’ well indurated. SILTSTONE: Gray to dark green, damp, har to very hard, massive, blocky. 0011 ING LOG Earing No. B-9 Location Mission Estancia Road W.O. ‘140 Date: 10-17-80 - By: RKJ Surface Elevatior - : c z !i ; - - - - xi .z s1 a 2 3: - - - - . . = _ Total Depth 45-ft. Driller & Rig TommyIAlrc FIELD DESCRIPTION Surface Conditions: Subsurface Conditions: Remarks Zontinues, siltstone, light gray, damp to noist, very hard, massive. Ind of Boring 45-ft. ~~~- ---~-- ~.__ J-&I_SI.IIC REFRACTION SURVH Line Number SL-1 W.O. 1140 Date :m78tT By: RKJ ‘Location: La Costa Avenue Bearing (Hammer to Ceophone): N 15’W Notes: Length: 100’ Outcrops of Volcanic.RoclkLongBoadwayAlignmen~----.-- /-f$-& -- I .I 6~0--.--..-.- ~~--‘5:2_L 16.7 70 16.9 18.0 80 18.0 20.3 90 19.2 20.6 1 .A00 20.1 20.8 - -~l.lQ--. __ 120 I 130 t -..I511 1.40 Cain I---- Range Eorward;Reverse Forward-Rever: 20 20 20 25 25 ._ ~.~. -__ 25 ._ ___ ..,--- .~--.. .-- .~ -.- . ..__ ~--~-..~ 1 ..~._ -..- ~----~ ;RAPHIC REPRESENTATION Delay %rwarbRevers Sta. kWZ.KS 10R 2OR ~.- 30R 40R -- 50-R 66R Am - -. 8pR -9OR 1OOR .llOR 120R 130R 14OR J50R SL-1 O-4’ V=1528 ft/sec SL-1R 0-4’ V=ll23 ft lsec > 4’ V=10,044 ftlsec z- 4’ V=B, 500 ft lsec Plate El I-?kllC REFRACTION SURVEY 1 Line Number SI;~C,) W.O.jJqQ .__ Date:)2/24/80 -~__ By: RKJ kcation: Melrose Avenue Bearing (Hammer to Ceophone) : Notes: Length: 100’ De1 Mar kmation ---- __~__ _.._..__._ ~_~_.-~~__~-_-~~_. ..~-. _~- .~ --..- __- Delay Wwar.d~~Revers _------- 50. .~~.506 -------- -------- -------- -------- Sta. kvers 10R 20R -~ 30R _ 4oR ,-.. S@ -~2~0--~.~~._- ZL- _---_--_ --- _ GRAPHIC REPRESENTATION JloR- 1 20RI . 0’ to 7.5’ Vl =650 Ft.lsec. to 1200 ft.Isec. 7.5’ to 4O’*V2 =2000 ft. /sec. to 2200 ft. /sec. 40’ to unknown velocities, may range from 2000-5000 ft. /sec. *40’ is estimated minimum No third layer encountered. Plato B-2 I3tmlL ; I lwpLL&flOd IIJfbleMBflO~ (5keCA - do 5Lble ) _/ .,~ , civwnd&-cev \ 1 DATE: lo/&& 1 PLATE C CONSOLIDATION +a PRESSURE CURVE Normal Load - KSF Excavation No. p-1 ; Depth 4’ CIassification $,&q C (6~ I cl Remolded Sample $1 Relatively Undisturbed Sample :5* UVd 44 @ EBERHART-AXTEN ond ASSOCIATES. INC. Date \O 2 l&a PI AT6~ P-14 / 1 / 1 1 / / 2 ,f--Y ‘\ I’ 1, 1 r$,[, CONSOLIDATION c~ PRESSURE CURVE Normal Load m KSF 1.0 , CONSOLIDATIONS PRESSURE CURVE Normal Load - KSF Excavation .No. 63 , Depth 5’ Classification -5-4$ Clsti III Remolded Sample lx Relatively Undisturbed Sample 5&&4 EBERHART-AXTEN and ASSOCIATES, INC. W.O. 1140 Date lo/~&~ o-= / 1 / FE /--- / . i id h lil CONSOLIDATION w PRESSURE CURVE Normal Load - KSF - Excavation .No. 3 , Depth Classification ek&& Cl Remolded Sample Ia Relatively Undisturbed Sample , .&& I @ EBERHART-AXTEN and ASSOCIATES. INC. 1.0 1.1 1.2 1.3 1.4 1.5 2.0 2.1 2.2 2.3 2.4 -l- STANDAXD SPECIFICATIONS FOR GRADING PROJECTS GENERAL The specifications contained herein and the standard details attached hereto represent this firm’s minimum requirements for grading and other associated operations on construction projects. These specifications should be considered a portion of the pro- ject specifications. These recommendations should not be considered to preclude more restrictive requirements of the regulating agencies. The contractor, prior to any site preparation or prading, should arrange a meeting onsite among himself, the developer, the design engineer, the geotechnical consultant, and representatives of the appropriate governinq authorities. at least 48 hours no&e. All parties should be given The contractor shall be responsible for the satisfactory completion of all grading and other associated operations on construction projects, includinq, but not limited to, all earth work in accord- ance with the project plans, specifications and controlling agency requirements. All plates attached hereto shall be considered as part of these specifications. These Standard Specifications for Grading Projects may be modified and/or superseded in part or all by recommendations contained in the text offs the preliminary geotechnical report and/or sub- sequent reports as a result of engineering analyses and evalu- ations of laboratory data and/or grading plan changes, or con- ditions found during grading. DEFINITION OF TERMS BEDROCK- a relatively solid, undisturbed or in-place rock existing at either the ground surface or beneath surficial deposits (old or recent alluvium, colluvium) of soils. Bedrock will be identified in the field by the engineering geologist. COLLUVttJM-loose, incoherent deposits usually found at the toeyof- slopes and brought there chiefly by gravity. RECENT ALLUVIUM-unconsolidated detrital deposits resulting from operations of modern rivers, including sediments laid down in river beds, flood plains, lakes, fans at the foot of slopes and estuaries. OLDER ALL”Vl”b,- sameorigin as recent alluvium,except that it iS older anahas been Iithified. EBERHART-AXTEN and ASSOCIATES, INC. -2- SLIDE DEBRIS - material (bedrock, colluvium,alluvium) produced from instability of natural or manmade slopes, usually fractured, porous and of low density. DEBRIS - all products of clearing, grubbing, demolition, contamin- ated soil material unsuitable for reuse as compacted fill. - 2.5 2.6 2.7 2.8 2.9 2.10 FILL - anv deaosits of soil. rock. soil-rock blends or other . ~~~~~. similar maieriais placed by man. IMPORTED OR BORROW MATERIAL the project site from offsite areas. ENGINEERED FILL - a fill of which - any fill material hauled to the soil engineer or his repre- sentative during grading has made sufficient observations and taken sufficient tests to enable him to conclude that the fill has been placed in substantial compliance with these specifications and the governing agency requirements. RELATIVE COMPACTION - the degree of compaction (expressed as a percentage) of dry unit weight of a material as compared to the maximum dry unit weight of the material. Unless otherwise speci- fied, the maximum dry unit weight shall be determined in accordance with ASTM Method of Test D1557-70. 2.11 GRADING - any operation consisting of excavation, filling or combinations thereof and associated operations. 2.12 CLIENT - The developer or his awthorized representative shall have the responsibility of reviewing recommendations made by the geotechnical consultant and shall authorize or cause to ha,ve authorized the contractor to perform such work as required to comply with said recommendations. 2.13 2.14 2.15 2.16 2.17 CONTRACTOR - a person or company under contract or other- wise retained by the client to perform demolition, grading, and other site improvements. TRACT ENGINEER - a licensed civil engineer experienced in sub- division planning design and preparation of construction plans and overall coordination of all engineering, surveying, and construction of the project. ENGINEERING GEOLOGIST - a geologist holding a valid certificate of registration in the specialty of engineering geology. SOIL ENGINEER - a licensed civil engineer experienced in soil mechanics. GEOTECHNICAL CONSULTANT - the soil engineering and engineer- ing geology consulting firm retained to provide technical services for the project. For the purpose of these specifications ,including observations by the soil engineer, engineering geologist, and those performed by persons employed by and responsible to the geotechnical consultant. m EBERHART-AXTEN and ASSOCIATES, INC. 3.0 3.1 3.2 3.3 3.4 3.5 4.0 4.1 4.2 4.3 -3- SITE PREPARATION Clearing and grubbing should consist of the removal of all vegetation such as brush, grass, woods, stumps, trees, roots of trees and all otherwise deleterious natural materials from the areas to be graded. Clearing and grubbing should extend to the outside of all proposed excavation and fill areas. Demolition should include removal of all buildings, structures, reservoirs, utilities (including septic tank, leach field, seepage pit, cisterns, mining shafts, tunnels,etc.), and all other manmade surface and subsurface improvements from the areas to be graded. Demolition of utilities should include proper capping or re-routing at the project perimeter and cutoff and capping of wells in ac- cordance with the requirements of the governing authorities and the recommendations of the soil engineer at the time of demolition. Trees, plants or manmade improvements not planned to be removed or demolished should be protected by the contractor from damage or injury. All deleterious material generated during clearing, grubbing and/or demolition operations should be wasted from areas to be graded and disposed offsite. All clearing, grubbing and demolition opera- tions should be performed under the observation of the geotechnical consultant. Where applicable, the contractor should obtain approval from the controlling authorities for the project, prior, during, and/or after demolition, site preparation, and removals, etc. The appropri- ate approvals should be obtained prior to proceeding with grading operations. SITE PROTECTION The contractor shall be responsible for the stability of all temporary excavations. Recommendations by the geotechnical consultant should not be considered to preclude those requirements of the regulating agencies. Precautions should be taken during the performance of all site clearing earthwork, excavations and grading to protect the work site from flooding, ponding or inundation by poor or improper surface drainage. Temporary provisions should be made during the rainy season to adequately direct surface drainage from all sources away from and off the work site. Where low areas cannot be avoided, pumps should be kept on hand to continually remove water during periods of rainfall. During periods of rainfall, plastic sheeting should be kept on hand to prevent unprotected slopes from becoming saturated. Where neces- sary during periods of rainfall, the contractor should install check- dams, desilting basins, riprap , sandbags or other devices or methods necessary to control erosion and provide safe conditions. - @ m- EBERHART-AXTEN and ASSOCIATES, INC. -4- During periods of rainfall, the geotechnical consultant should be kept continually informed by the contractor as to the nature of any work being performed (e.g., pumping, placement of sandbags or plastic sheeting, other hand labor, dozing, etc.). 4.4 4.5 Following periods of rainfall, the contractor should contact the geotechnical consultant and arrange a walk-over of the site in order to visually assess rain-;-elated damage. The geotechnical consultant may also suggest supplemental testing in order to complete his assessments. At the request of the geotechnical consultant, the contractor shall make all excavations as necessary to evaluate the extent of rain -related damage. 4.6 Rain-related damage should be considered to include erosion, silting, saturation, swelling, structural distress, and any other adverse condition delineated by the soil engineer. Soil adversely affected should be classified as unsuitable materials, referred to herein under Section 5.1, and should be subject to over-excavation and replacement as compacted fill or other remedial grading as directed by the soil engin- eer. a) Relatively level areas, where saturated soils and/or erosion- gullies exist to depths of greater than 1.0 foot., should be over- excavated to unaffected, competent material. Where less than 1.0 foot in depth, unsuitable materials may be processed in place to achieve near-optimum moisture conditions, then thoroughly re- compacted in accordance with the applicable specifications. If the desired results are not achieved, the affected materials should be over-excavated, then replaced in accordance with the applicable specifications. b) In slope areas, where saturated soil and/or erosion-gullies exist to depths of greater than 1.0 foot., they should be overexcavated and replaced as compacted fill in accordance with the slope repair specifications herein. Where affected materials exist to depths of 1.0 foot or less below proposed finished grade, remedial grad- ing by moisture conditioning in place followed by thorough re- compaction in accordance with the applicable specifications may be attempted. If the desired results are not achieved, all af- fected materials should be overexcavated and replaced as com- pacted fill in accordance with the slope repair specifications herein. As field conditions dictate, slope repair may be recommended by the soil engineer in accordance with the accompanying specifi- cations for stabilization fills. 5.0 EXCAVATIONS 5.1 a) Unsuitable Materials: Materials which are unsuitable should be excavated under observation and recommendations of the geo- technical consultant. Unsuitable materials include, but may not be limited to,dry, loose, soft, wet, compressible natural soils and fractured, weathered, soft bedrock and non-engineered or otherwise non-approved fill materials. - .@ m EBERHART-AXTEN and ASSOCIATES, INC. -5- Material identified by the geotechnical consultant as unsatis- factory due to its moisture conditions should be overexcavated, watered or dried.as needed,and thoroughly blended to a uniform near-optimum moisture condition (as per guidelines in these specifications) prior to placement as compacted fill. Slopes : Unless otherwise recommended by the geotechnical consultant and approved by the regulating agencies, perma- nent cut slopes should not be steeper than 2:l [horizontal to vertical). If excavations for cut slopes expose loose, cohesionless, sig- nificantly fractured or otherwise unsuitable material, overex- cavation and replacement of the unsuitable materials with a compacted stabilization fill should be accomplished and recom- _~. ,..- - mended by the geotechnical consultant. Unless otherwise spec- ified by the geotechnical .consultsnt; stabilization fillcon.struction shou!d conform to the requirements of Plate 3 of these specifications. The engineering geologist should inspect all cut slopes at ver- tical intervals not exceeding 10 feet and shall be notified by the contractor when cut slopes are started and when the lo- foot intervals are anticipated. If, during the course of grading, adverse or potentially ad- verse geotechnical conditions are encountered which were not anticipated in the preliminary report, the geotechnical consultant should investigate, analyze, and make recommendations to treat these problems. For cut slopes made in the direction of the prevailing drainage, a non-erodrble diversion swale [brow ditch) should be provided at the topiof-cut.~ Lot Pads: All lot pad areas, including side yard terraces, above stabilization fills or buttresses should be overexcavated to pro- vide for a minimum of 3 feet (Plate 5) of compacted fill over the entire-pad areaD Ceotechnicalconditions may require greater depth of overexcavation and should be delineated by the geo- technical consultant during grading. Pad areas with both fill and cut materials exposed and pad areas containing both very shallow (less than 3 feet) and deeper fill should be overexca- vated to provide for a uniform compacted fill blanket of a min- imum of 3 feet in thickness (Plate 5). Cut areas exposing. significantly varying material types should also be overexca- vated to provide for at least a 3-foot thick compacted fill blanket. For pad areas created above cut or natural slopes, positive drainage should be established away from the, top-of-slope.~ This may be accomplished utilizing a berm and/or an appro- priate pad gradient. An overall gradient away from top-of- slope of 2% or greater should be maintained. 5.1 5.2 a) 5.2 b) 5.2 cl 5.2 d) 5.2 e) 5.3 5.3 a) bl b) EBERHART-AXT;EN and ASSOCIATES, INC. -_ -6- 6.0 COMPACTED FILL 6.1 Compaction : All fill materials should be compacted as specified below or by other methods specifically approved by the geotech- nical consultant. Unless otherwise specified, the minimum degree of compaction (relative compaction) should be 90% of the laboratory maximum density. 6.2 a) Placement: Prior to placement of compacted fill, the contractor should request a review by the geotechnical consultant of the exposed ground surface. Unless otherwise recommended, the exposed ground surface should then be scarified (6-inch minimum), watered or dried as needed, thoroughly blended to achieve near-pptimum moisture conditions, then thoroughly compacted to a minimum of 90% of the laboratory dry density. The review by the geotechnical consultant should not be con- sidered to preclude requirement of review and evaluation by the controlling agency. 6.2 b) Compacted fill should be placed in thin horizontal lifts not exceeding eight inches (bulk) in thickness prior to compaction. Each lift should be watered or dried as needed, thoroughly blended to achieve moisture conditions within the range of optimum moisture content and optimum moisture content plus 3% (by dry soil weight), then thoroughly compacted by mechanical methods to a minimum of 90% of laboratory maximum dry density. Each lift should be treated in a like manner until the desired finished grades are achieved. 6.2 c) The contractor shall have suitable and sufficient compaction equipment and watering apparatus on the job site to handle the amount of fill being placed in consideration of moisture retention properties of the materials. If necessary, excavation equipment will be “shut down” temporarily in order to permit proper compaction of fills. 6.2 d) When placing fill in horizontal lifts adjacent to areas sloping steeper than 5:l (horizontal to vertical), horizontal keys and vertical benches should be excavated into the adjacent slope area. Keying and benching should be sufficient to provide at least five-foot wide benches and a minimum of three feet of vertical bench height within firm natural ground, firm bed: rock or approved compacted fill. No compacted fill should be placed in an area subsequent to keying and benching until the area has been evaluated by the geotechnical consultant. Typical keying and benching details have been included on the accompanying Plate 4. 6.2 e) Within a single fill area where grading procedures dictate two or more separate fills, temporary slopes (false slopes) may be created. When placing fill adjacent to a false slope, EBERHART-AXTEN and ASSOCIATES, INC. - . -7- beEhing,shaII be conductedin the same manner as the above described. At least a three-foot vertical bench should be established within the firm core of adjacent approved’com- pacted fill (i.e., the material underlying the surficial loose material) prior to placement of additional fill. Benching should proceed in approximately 3-foot to 4-foot increments until the desired finished grades are achieved. 6.2 f) All fill should be tested for compliance with the required rel- ative compaction and moisture conditions as recommended. Field density testing should conform to ASTM Method of Test D1556, D2922 and/or D2937. Tests should be provided for about every 2 feet or’ 1,000 cubic yards of fill placed. Fill found not to be.in conformance with the specifications should be removed, then replaced in accordance with the specifications. 6.2 6.3 g) The contractor shall assist the geotechnical consultant and/or his representative in digging test pits for removal determin- ations and/or testing as compacted fill progresses, and will remove from test area, or shut down temporarily, the equip- ment during “sand cone” testina _- a) Moisture: For field testing purposes, “near-optimum” moisture should be considered to mean optimum moisture to 3% above optimum moisture. 6.3 b) Prior to placement of additional compacted fill following an overnight, or other grading delay, the exposed surface of previously compacted fill should be processed by scarification, watered or dried as needed, thoroughly blended to near- optimum moisture conditions, then recompacted to a minimum of 90% of laboratory maximum dry density. Where wet or dry or other unsuitable materials exist to depths of greater than 1 foot., the unsuitable materials should be overexcavated. 6.3 c) Following a period of flooding, rainfall or overwatering by other means, no additional fill should be placed until damage assessments have been made and remedial grading performed as described under Section 4.0 herein. 6.4 a) Fill Material: Excavated onsite materials which are acceptable to the geotechnical consultant may be utilized as compacted. fill, provided all trash, vegetation and other deleterious materials are removed prior to placement. 6.4 b) Where import materials are required for use onsite, the oeo- technical consultant should be notified at least 72 hours <n advance of importing. in order to sample and test materials from proposed borrow sites. No import materials shall be delivered for use onsite without prior sampling and testing by geotechnical consultant. EBERHART-AXTEN and ASSOCIATES, INC. - -8- 6.4 c) Rocks 8 inches in maximum dimension and smaller may be utilized within the compacted fill, provided they are placed in such a manner that nesting of the rock is avoided. Fill should be placed and thoroughly compacted to the minumum requirement over and around all rock. 6. 4 d) During the course of grading operations, rocks, or similar irreducible materials greater than 8 inches maximum dimension (oversized material), nay be generated. These rocks should not be placed withirl the compacted fill unless placed as rec- ommended by the geotechnical consultant. 6. 4 e) Where rocks or similar irreducible materials of greater than 12 inches, but less than 3 feet,of maximum dimension are generated during grading, or otherwise desired to be placed within an approved compacted fill, special handling, in accor- dance with the accompanying Plate 6 is recommended. Rocks greater than 3 feet should be broken down or disposed offsite. Rocks up to 3 feet maximum dimension should be placed below the upper 13 feet of any fill and should not be closer than 15 feet to any slope face. Where practical, oversized material should not be .placed ~below areas where structures or deep utilities are proposed. Oversized material should be placed in windrows on a clean, overexcavated or unyielding compacted fill or firm natural ground surface. Select native or imported granular soil (S.E=30 or better) should be placed and/or thoroughly flooded over and around all windrowed rock, such that no voids remain. Windrows of oversized material should be stagaered so that successive strata of oversized material are not-in the same vertical plane. 6.4 f) Material that is considered unsuitable by the geotechnical con- consultant should not be utilized in the compacted fill. 6.4 g) During grading operations, placing and mixing the materials from the cut (borrow) areas may result in soil mixtures which may possess different physical properties. Additional testing may be required of samples obtained directly from the fill areas in order to verify conformance with the intentions of the recommendations of the preliminary report. Processing of these additional samples may take two or more working days. The contractor may elect to move theoperation to other areas within the project, or may continue placing compacted fill, pending laboratory test results. Should he elect this second alternative, fill placed is done so at the contractor’s risk. 6.4 h) Any fill placed in areas not previously reviewed and evaluated by the geotechnical consultant, and/or in other areas, with- out.prior notification to the geotechnical consultant of his in- tentions of placing the compacted fill, may require removal and recompaction at the contractor’s expense. Determination of overexcacations should be made upon review of field con- ditions by the peotechnical consultant. c2 m EBERHART-AXTEN q nd ASSOCIATES, INC. 6.4 1) 6.5 b) 6.5 cl 6.5 d) 6.5 e) Plan locations of field density tests (horizontal and vertical) should only be considered approximate. The contractor shall provide sufficient grading stakes with elevations to serve as guidelines for test loca,tion identification. w: Compacted fill slopes should be limited to a slope ratio of no steeper than 2:l (horizontal to vertical). All compacted fill slopes shall be overbuilt and citt back to grade, exposing the firm, compacted fill inner core. The actual amount of overbuilding may vary as field conditions dictate. If the desired results are not achieved, the existing slopes should be overexcavated and reconstructed under the guidelines of the geotechnical consultant. The degree of over- building shall be increased until the desired compacted slope surface condition is achieved. Carestiould be taken by the contractor to provide thorough mechanical compaction to the outer edge of the overbuilt slope surface. Beginning in the early stages of fill slope construction, the con- tractor shall, upon the request of the geotechnical consultant, make excavations through the overbuilt section to the proposed finished slope surface in order for the geotechnical consultant to test for conformance with these specifications. Care should be taken by the contractor not to excavate beyond the proposed finished slope surface. Following.the attainment of the desired slope height, the outer surface of overbuilt slopes should be cut back to a desired finished surface contour. Care should be taken by the con- tractor not to excavate beyond the desired finished slope surface. Where economicconsiderations, and/or other pertinent consider- ations,preclude overfilling and cutting back, alternative con- ventional construction procedures may be attempted. If other methods, including backrolling, are adopted, it should be recognized by all interested parties that the slopes cannot be expected to perform as well as slopes which are overbuilt and cut back. Unless slopes are overfilled and cut back to grade, the outer faces of all fill slopes shall be at least back- rolled,utilizing a sheepsfoot roller at intervals not exceeding 4 feet of vertical slope height. Vibratory methods may be required., During construction of the fill slopes, care should be taken to maintain near-optimum moisture conditions over the entire slope height. Following achievement of the desired slope height, the entire slope face may require thorough com- paction, utilizing a vibratory sheepsfoot roller. Upon completion of the above procedures, the faces of all fill slopes should be grid-rolled over the entire slope height with standard grid- rolling equipment. During all above operations, near-optimum moisture conditions should be maintained. EBERHART-AXTEN and ASSOCIATES, INC. - -10. 6.5 f) Following slope construction in the manner described above, if the desired uniformly compacted fill slope condition is not achieved, overfillinq .and cutting back, as set forth~ in these. specifications; should be adopted. Completed slopes found by the-geotechnical consultant to be below the standards [moisture and density) should be overexcavated a minimum of 12 feet (horizontal) and replaced by the overfilling and cutting back procedure described above. 6.5 g) Where placement of fill above a natural slope or above a cut slope is proposed, the fill slope configuration presented on the accompanying Plate 4, Figures 1 and 2, respectively, should be adopted. 6.5 h) For pad areas above fill slopes, positive drainage shall be established away from the top-of-slope. This may be ac- complished utilizing a berm and an overall pad gradient of at least 2%. 6. B a) Offsite Fill: Offsite fill, in general, should be treated in the same manner as recommended in these specifications for site preparation, excavation, drains, compaction, etc. 6.6 b) Offsite canyon fill should be placed in preparation for future additional fill, as shown on Plates 7 and 8. 6.6 c) Offsite fill subdrains temporarily terminated (up canyon) should be carefully surveyed for future relocation and connection. 6.6 d) Surface drainage of offsite fill areas should be planned to be collected and discharged by convenient storm drain devices. 7.0 7.1 STAKING In all fill areas, the fill should be compacted prior to the placement of the stakes. This is particularly important on fill slopes. Slope stakes should not be placed until the slope is thoroughly compacted (backiolled). 7.2 In order to allow for remedial grading operations, which could include overexcavations or slope stabilization, appropriate staking offsets should be provided. For finished slope and stabilization backcut areas, we recommend at least a lo-foot setback from pro- posed toes and tops-of-cut. 8.0 8.1 SLOPE MAINTENANCE Landscaping : In order to enhance surficial slope stability, slope planting should consist of deep-rooted vegetation requiring little wattering. Plants native to the Southern California area G9 m EBERHART-AXTEN and ASSOCIATES, INC. - . . 8.2 8.2 8.2 8.2 8.3 8.3 8.3 8.3 8.4 8.4 -II- and plants relative to native plants are generally desirable. Plants native to other semi-arid and arid areas may also be appropriate. A landscape architect would be the best party to consult regarding actual types of plants and planting configuration. a) b) cl 4 a) b) cl dl a) b) Irrigation: Slope irrigation should be minimized. If auto- matic timing devices are utilized on irrigation systems, pro- visions should be made for interrupting normal irrigation during periods of rainfall. Drip-irrigation systems may be utilized as an alternative to con- ventional irrigation systems. Though not a requirement, consideration should be given to the installation of near-surface moisture monitoring control devices. Such devices can aid in the maintenance of relatively uniform and reasonably constant moisture conditions. Property owners should be made aware that overwatering of slopes is detrimental to slope stability. Maintenance: Periodic inspections of landscaped slope areas should be planned and appropriate measures, consistent with the provisions of these Standard Specifications, should be taken to control weeds and enhance growth of the landscape plants. Some areas may require occasional replanting and/or reseeding. Terrace drains and downdrains should be periodically inspected and maintained free of debris. Damage to drainage improve- ments should be repaired immediately. Property owners should be made aware than burrowing animals can be detrimental to slope stability. A preventative program should be established to control burrowing animals. As a precautionary measure, plastic sheeting should be readily available, or kept on hand, to protect all slope areas from saturation by periods of heavy or prolonged rainfall. This measure is strongly recommended, beginning with the period of time prior to’landscape planting and before becoming well established. Repairs:~ If slope failures occur, the geotechnical consultant should be contacted for a field review of site conditions. If slope failures occur, apparently as a result of exposure to peri’ods of heavy rainfall, the failure area and currently unaffected areas should be covered with plastic sheeting to protect against additional rain. @ 5-m. ERERHART-AXTEN and ASSOCIATES, INC. - . . , -12- c) Plate 9 illustrates appropriate repair procedures for super- ficial slope failures (i.e., occurring typically within the outer 1 foot to 3 feet-t of a slope face) during grading. These failures generally occur as a result of failure to comply with the in- tentions of Specification Sections 8.0 and/or 9.0 herein. 8.4 9.0 9.1 9.2 9. 3 9.4 10.0 10.1 10.2 10.3 DRAINAGE Canyon subdrain systems specified by the geotechnical consultant should be installed in accordance with the specifications on the accompanying Plate 1. Typical subdrains for compacted fill buttresses, slope stabilizations, or sidehill masses, should be installed in accordance with the specifications on the accompanying Plate 2. All roof, pad and slope drainage should be directed away from slope area structures to approved disposal areas by way of non- erodible devices, (i.e., gutter, down spout, concrete swales). For drainage immediately away from structures, a minimum 5% gradient should be maintained. Overall, pad drainage of at least 2% should be maintained. Overall, pad drainage may be reduced to at least 1% for projects where no slopes exist, either natural or manmade, of greater than 10 feet in height and where no slopes are planned, either natural or manmade, steeper than 2:l (hor- izontal to vertical slope ratio). Trench Backfill: Utility trench backfill can be best placed by mechanical compaction. Unless otherwise specified, degree of com- paction shall be a minimum of 90% of the laboratory maximum density. As an alternative, where specifically approved by the soil engineer, granular material (sand equivalent greater than 30) may be thoroughly jetted in-place. Jetting should only be considered to apply to trenches no qreater than 2 feet in width and 4 feet in depth. Following jeti;‘ng operations, trench backfill should be thoroughly and mechanically compacted and/or wheelrolled from the surface. Exterior and interior trenches extending below a 1 :l projection from the outer edge of foundations should be mechanically com- pacted to a minimum of 90% of the laboratory maximum density. Within slab areas, but outside the influence of foundations, trenches up to 1 foot wide and 2 feet deep may be backfilled with sand and consolidated by jetting, flooding, or by mechanical means. If on- site materials are utilized, they should be wheelrolled, tamped or otherwise compacted to a firm condition. For these minor interior trenches, density testing may be deleted or spot testing may be elected if deemed necessary, based upon review of backfill oper- ations during construction. If utility contractors indicate that it is undesirable to use com- paction equipment in close proximity to a buried conduit, the con- tractor may elect the utilization of light weight mechanical @ m. EBERHART-AXTEN and ASSOCIATES, INC. -13- compaction equipment and/or shading of the conduit with clean, granular material, which could be thoroughly jetted in-place above the conduit, prior to initiating mechanical compaction procedures. Other methods of utility trench compaction may also be appropriate, upon review by the geotechnical consultant at the time of con- struction. 11.0 STATUS OF GRADING Prior to proceeding with any grading operation, the geotechnical consultant should be notified at least 2 working days in advance in order to schedule the necessary observation and testing services. 11.1 Prior to any significant expansion or cut back in the grading op- eration, the geotechnical consultant should be provided with adequate notice (i.e., 2 days) in order to make appropriate adjustments in observation and testing services. 11.2 Following completion of grading operations and/or between phases of a grading operation, the geotechnical consultant should be pro- vided with at least 2 working days notice in advance of commence- ment of additional grading operations. 12.0 VARIANCES FROM SPECIFICATIONS The contractor should not vary from these specifications without prior written recommendation by the geotechnical consultant and the approval of the client and/or his authorized representative. The above should not be considered to preclude requirements for approval by the controlling agency prior to the excecution of any changes. EBERHART-AXTEN end ASSOCIATES, INC. TYPICAL CANYON SUBDRAIN c CANYON PROFILE Cou.u”/AL AND ALLuLL/AL R&yOVAL ALTERNATIVE A- PREFERED BACKHOE TRENCH ALTERNATIVE C DOZER V TRENCH N OTES : 1. F,#aL 20+x OF Fw=.. SflOULD BE Atw-+?ER-.4TE~ PoS,T,VE cdNN.EcT,o.v6youLo am PROV,D.zD es~es.sN -Y7 OF F/P.sS. 2. ARFOAlrmvs SHOULD 3.E 47 5vbvBLE 3/ /“Cry 4fAf. O,.q?t7ER WT” .y,‘v. OF e “.w,.wRsYLv 3P-D +?s&=se*TIo, ALTERNATIVE 8 PER FceT,N LO*VaR ,-067/a+, of PlpE. 2-v .&MY c&d LxbySTE> OR /=ERFO&4T/Lw 5rHzwLD 0.z c D& OF .=,‘T.ER WTWIL. BACKHOE TRENCH 3. P/,-E ATLLNIL Lhsc!.E~ OT..M,5E APPROVED. a*c1LILD aas /=&z OR A& 4. F~?LT.~R /~ATER/IL SYOULD ca.w~~si- a= s~.w.s OF ClL,FOR.wA CLA.55 2 PEx?“.c*dL& .=,.LT.ER rl/x. 5. F& ALTLRAIA~~~~~ a 3/4” ROCK I.W A F/L+ER FA~R/C CEosr70) SNOULD DE “se. GRADING DETAIL IzeR P,%- ..^.,A, @ EBERHART-AXTEN and ASSOCIATES, INC. ‘wG-7i a= c‘zN%eAL GEOTECHNICAL CONSULTANTS De4,u c zecY> n,, EAST WINSTON ROAD.S”ITE F.ANAHEIM.CALIFORNI~ Plaa STANDARD GRADING--SPEClFlCATlONS 1 PLATE 2 TYPICAL SUBDRAIN FOR BUTTRESS. STABILIZATION I OR SIDEHILL FILL MASSES NIT.%? 2 ,e,M CY *7..mAL (SCE “OTS I cy/MhY”h7 OF /2 tc .J3zET OF F,LTS sy.4?-zFR/*L FXR --- ^_ ^.^_ ,., I,_., ^- e,,-c^ _.....?m,., B*LX.=,LLEo Ic//sw oK.sITE 50,L. 3. FOR T.RRAC&IID .¶LOP.Es BACKDRNNS .4”B c%rrL~73 SXOUID c3.s P‘AHNED TO OUTldT ABOYE 7w.E 7-EAR*cE. GRAOING DETAIL @ EBERHART-AXTEN and ASSOCIATES, INC. a GEOTECHNICAL CONSULTANTS 1212 EASTWMTON RO)ID.S”ITE~.*N*“EIU.CILIFORIII~ DITn6 STANDARD GRADING SPECIFICATIONS IPLATE 2 TYPICAL STABILIZATION FILL FIG. I TYPICAL BUTTRESS FILL FIG. 2 BAcKcz”T /:I 3ft.,.pM CIP F/L/.. SLoph a:1 OR F..nsR IS PR TSll .4J OF RAZS-ORT BLrycI: /ER.T,CAL aft.‘y.M u*.qzc”rAL 5fLylM. GRADING DETAIL @ EBERHART-AXTEN and ASSOCIATES, INC. a GEOTECHNICAL CONSULTANTS 111 I EAST WINSTON ROAD. SUITE F . ANA”EIY. CALlrORHln OZBO STANDARD GRADING SPECIFICATIONS IPLATE 3 I I / 1 I I ‘1’ 1 /. ! * I i i TYPICAL FILL OVER NATURAL SLOPE Couuv/“,.j AmcJ 07-IIIJc W5wT”BLb .+n=.wacs bwcY: Awm~avnL sft.q/,u ~k%mzAL 3&.*e! I:1 (wg d"LccyT ,y",//NTAN /6/t. .y". .=Au WZJT" + ‘CVWhSLC.=Z sor7aycFx~"r7 KEV - Daws- YDC. N 07,!zs:* SC1 ,+onrl TYPICAL FILL OVER CUT SLOPE ;,: ;,. ; : tl-----z.,.. : . . ,:::: ccyPrcsr/J ,=,LL JLOPS t ;. . . ‘. : . . . : .: T by.Elicavmr.. TO,-sac, co.u&% WD o- “~s4/nBL.s 44,wILs i’>,<.T . :....-a 1 - 0ENcy : HomzoM4L SfLwd -... v~*T,eILdft..yA+! GRADING DETAIL I 63 EBERHART-AXTEN and ASSOCIATES, INC. a GEOTECHNICAL CONSVLTANTS 2211 EASTWNSTON ROAD.S”,TE F.ANAHEIM.CAILIFORNI/\ 928(1 GRADING SPECIFICATIONS IPlATE +f TYPICAL REMOVAL OF TRANSITION LOTS JJJ- LOT ‘RANSITION- UNSUITABLE TO FIRM IATURAL MATERIAU GRADING DE TAIL e? EBERHART-AXTEN and ASSOCIATES, INC a GEOTECHNICAL CONWLTANTS 2111 EPST WlNSTON ROAO.S”ITL F.I\NIHEIH.CILI~ORLII~P18 STANDARD GRADING SPECIFICATIONS PLATE 5 TYPICAL ROCK WINDROW PRO.-JS‘cD ,=,MS”.GD GR1DS ,ELati’lnoN DEPT” FOR i Fo”Na4ncaNs, “T/L,T/EL rwII JU,~.y~O - “CCEPT**LP TO 7i*.E Gz=OT.GWN/c”L CO,./WLTA,vT: TYPICAL WINDROW DETAIL (edge vi‘ew) oyE.+s,~zD nf” T.aR,/*L Ge”.u”L1R ,yrr*,uAI. 56 - 30 w nmTTe.+ .$“ouLD ac WaTcnhs/JL. .%eo-c, 7s F//L I.-/m 4”P I-Am - 1s coypaclro p M,p&4T UP AP,Ac&wT * ICYW D.-x4 \ PROFILE VIEW r Ov..S,ZED .7”7E,wAL I I G2 EBERHART-AXTEN and ASSOCIATES, INC. m4 GEOTECHNICAL CONSULTANTS 1111 EAST WlNsJDN ROAD.S”ITE ~.~N*HEIU,C~LIFORNI/\9180 STANDARD GRADING SPECIFICATIONS [PLATE 6 ADDITIONAL COMPACTED FILL ON EXISTING CANYON FILL (VIEW UP CANYON AXIS) BroRacK 0.4 z?fAT-,/AL ACCEPTA- TO LsEOT.=LHN/CAL coNs”LTAN7 L GRADING DETAIL @ EBERHART-AXTEN and ASSOCIATES, INC. a GEOTECHNICAL CONSULTANTS 2111 ElSTWlNSTON ROAD.S”ITE F~ANAHtlM.C*LIFORNIA 92ea STANDARD GRADING SPEClFlCATlOfk IPLATE 7 / , : j 1,. I I 1 ADDITIONAL COMPACTED FILL ON EXISTING CANYON FILL (VIEW OF CANYON SIDE) M4VIT”RAL OROUNO ON CNNON SID& -7 * BE.=oRE P.LciClNo AD*n-mh%u CofPAC” F/y GRADING DETAIL EBERHART-AXTEN and ASSOCIATES, INC. GEOTECHNKA, CONSULTANTS 211, E&SIT WINSTON RDAD.S”ITE F ~)I*“~IY,CL~I~ORNI~IP18a SPECIFICATIONS 1 ,i - i 1. , / I , I I ! t. TYPICAL MINOR SLOPE FAILURE REP) ID ncTnif , I I~\ UL I HlL Provide min. I - ft. hIOh earth berm or approved alternative, Original slope surface Bockdrain; recommended vertical spacing 6 ft., see detail below. Failure surface Mlnlthum 3ft. wide by Zft. high horitotitol and vertical benches into firm undisturbed material (IS approved by the geotechnicd consultant at ,time’ of grading. Excavate key Into firm underlying unaffected material Replace excavated orea with fill I” 6-ln.(max.J loose Ilfts adjusted to near optimum moisture and compact= to Q mlnlmum of 90% of the laboratory maxlmum density o?1 determined I” accordance with method of test Dl557- 70. Slope surface co” be best constructed by overfllllnq and cutting bock to the IfIrm compacted Inner core. TYPICAL SLOPE REPAIR BACKDRAIN DETAIL / of two cubic. feet of filter materlal pa- foot of pipe consisting of state of colifornio doss 2 per&able filter. 1; lieu of flltsr mate&l “se 3/4” rock encased I” filter fabric (EOS _z 70) IZ-in. ml”. Z-ln(mln.J PVC (or equ1v.J perforated pipe fperforatlons down1 with mlnlmum 4% gradient to dml” wth tee or elbow. Provide 2~ln.(mln.J “onperforated pipe wlth minimum 4% drolnoge. Horizontal spacing to be determined by geotechnical consultant during constructiwu. NOTE: Bock drolns ore often &tted frcen slope’repolrs. Where Installed, however, they serve to mitigate the potentlol for reoccuring follures. 22lI E1\5T WWSTOH ROAo.*“lTC F .~NI\HEIU,CI\LI~ORNI~I418a STANDARD GRADING SPECIFICATIONS PLATE 9 I - I / 1. 1. I ! / I ! . La Costa W.O. 1140 a 9% + s-9 JS /sm Qaf Qal COI c l/H 0 M Td M J3P 4 r MAP LEGEND Cut slope Fill & stability key, width & depth indicated Slump Approximate test pit location Approximate boring location Proposed sub-drain location Possible blasting area Location of seismic line Geologic attitude Artificial fill Alluvium Colluvium Colluvium concealing Delmar Formation Delmar Formation Santiago Peak Volcanics Granitic Rock a EBERHART-AXTEN and ASSOCIATES, INC. Plate E