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Home My WebLink About3190; Rancho Santa Fe Road Widening; Rancho Santa Fe Road Widening; 1998-08-31^ AGRA Earth & Environmenta AGRA Earth & Environmental, inc. 16760 West Bernardo Drive San Diego, CA 92127 Tel (619) 487-2113 Fax (619) 487-2357 GEOTECHNICAL INVESTIGATION RANCHO SANTA FE ROAD WIDENING SAN MARCOS, CALIFORNIA Submitted To: CITY OF SAN MARCOS 1 CIVIL CENTER DRIVE SAN MARCOS, CALIFORNIA 92069 Submitted By: AGRA EARTH & ENVIRONMENTAL 16760 WEST BERNARDO DRIVE SAN DIEGO, CALIFORNIA 92127-1904 August 31, 1998 Job No. 8-252-102600 RecyclPd Paper ^ AGRA Earth & Environmental ENGINEERING GLOBAL SOLUTIONS AGRA Earth & Environmental, Inc. 16760 West Bernardo Drive San Diego, CA 92127 Tel (619) 487-2113 Fax (619) 487-2357 1. I Recycled Paper GEOTECHNICAL INVESTIGATION RANCHO SANTA FE ROAD WIDENING SAN MARCOS, CALIFORNIA Submitted To: CITY OF SAN MARCOS 1 CIVIL CENTER DRIVE SAN MARCOS, CALIFORNIA 92069 Submitted By: AGRA EARTH & ENVIRONMENTAL 16760 WEST BERNARDO DRIVE SAN DIEGO, CALIFORNIA 92127-1904 August 31, 1998 Job No. 8-252-102600 ^ AGRA Earth & Environmental ENGINEERING GLOBAL SOLUTIONS AGRA Earth & Environmental, Inc. 16760 West Bernardo Drive San Diego, CA 92127 Tel {619)487-2113 Fax (619) 487-2357 August 31, 1998 Job No. 8-252-102600 The City of San Marcos 1 Civil Center Drive San Marcos, California 92069 Attention: Mr. Tim Regello RE: GEOTECHNICAL INVESTIGATION RANCHO SANTA FE ROAD WIDENING SAN MARCOS, CALIFORNIA This letter transmits AGRA Earth & Environmental's (AEE) geotechnical investigation report for the planned improvements to Rancho Santa Fe Road in San Marcos, California. The investigation was conducted in general conformance with the scope of work presented in AEE's proposal dated May 20, 1998. We appreciate this opportunity to be of service. Should you have questions concerning this report, please feel free to contact us. Yours truly, AGRA Earth & Environmental Clifford A. Craft, GE 243 ^ Supervising Engineer I Recycled Paper i: I. City of San Marcos Job No. 8-252-102600 Rancho Santa Fe Road Widening August 31, 1998 San Marcos, CA Page (i) TABLE QF CONTENTS Page EXECUTIVE SUMMARY iii 1.0 INTRODUCTION 1 1.1 PROJECT 1 1.2 PROPOSED CONSTRUCTION 1 2.0 SCOPEOFWORK 1 3.0 FIELD EXPLORATION AND LABORATORY TESTING 3 3.1 FIELD EXPLORATION 3 3.2 LABORATORYTESTING 8 4.0 SITE CONDITIONS 8 4.1 SURFACE CONDITIONS 8 4.2 SUBSURFACE CONDITIONS 8 4.3 ENGINEERING SEISMOLOGY 9 5.0 CONCLUSIONS AND RECOMMENDATIONS 9 5.1 GENERAL 9 5.2 SITE PREPARATION AND GRADING 11 5.3 EXCAVATION CONDITIONS 11 5.3.1 Soil and Rock Excavation 11 5.3.2 Permanent Slopes 12 5.3.3 Temporary Slopes 12 5.4 RETAINING WALLS 12 5.4.1 Bearing Capacity 13 5.4.2 Settlement 15 5.4.3 Resistance to Lateral Loads 15 5.5 PAVEMENT 15 5.5.1 Flexible Pavement Structural Section 15 5.5.2 Structural Section Between Stations 306-1-00 and 325+00 .... 16 i: # AGRA Earth & Environmental Recycled Paper EMGINEERING GLOBAL SOLUTIONS City of San Marcos Job No. 8-252-102600 Rancho Santa Fe Road Widening A"9"st 31, 1998 San Marcos, CA 5.6 PIPELINE DESIGN AND CONSTRUCTION RECOMMENDATIONS 16 5.6.1 Bearing Capacity for Pipeline 16 5.6.2 Pipe Bedding 1^ 5.6.3 Trench Backfill 1^ 5.6.4 Temporary Excavation Support 18 5.7 CORROSION POTENTIAL 18 6.0 GEOTECHNICAL AND CONSTRUCTION REVIEW 18 19 7.0 CLOSURE REFERENCES . 20 I IST QF FIGURES Figure 1 - Vicinity Map Figure 2 - Boring Locations Figure 3 - Boring Locations Figure 4 - Boring Locations Figure 5 - Boring Locations Figure 6 - Fault Map Figure 7 - Retaining Wall Drain Detail I'^ 2 4 5 . 6 . 7 10 APPENDICES Appendix A Test Boring Logs ^'^ *° Appendix B Laboratory Testing B-1 to B-4 ^ AGRA Earth & Environmental Recycled Paper ENGINEERING GLOBAL SOLUTIONS [ Citv of San Marcos Job No. 8-252-102600 Rancho Santa Fe Road Widening August 31, 1998 San Marcos, CA Pafle EXECUTIVE SUMMARY This executive summary presents a brief description of the prominent ground conditions, conclusions and recommendations from the geotechnical investigation performed by AGRA Earth & Environmental (AEE) for the widening and realignment of a portion of Rancho Santa Fe Road in San Marcos, California. The proposed widening and realignment of Rancho Santa Fe Road will be from just north of Alga Road to Island Drive, a distance of about 6510 feet. Included in the project will be the installation of a 14-inch water line below new road surface. Melrose Drive will also be realigned and widened from about Corintia Street, west of Rancho Santa Fe Road, to Patton Street, east of Rancho Santa Fe Road, a distance of about 1600 feet. A new intersection will be constructed at Melrose Drive and Rancho Santa Fe Road. Improvements also will be made at the intersection of Rancho Santa Fe Road and Via Allondra. The site is underiain by fill, colluvium, or alluvium over the Escondido Creek Leucogranodiorite or Santiago Formation. Fill and colluvium consist primarily of medium dense silty sand and clayey sand. Alluvial material consists of primarily clayey sand. The Escondido Creek Leucogranodiorite comprises most of the rock along the alignment and consists of light-colored, fine to medium-grained granodiorite or tonalite. Rocks from the Escondido Creek Leucogranodiorite are variably weathered at the near surface, while hard and strong where fresh. The Santiago Formation consists of light-colored, fine to medium-grained clayey sandstone. In general, formational material was encountered at relatively shallow boring depths ranging from about 1 to 9 feet. No groundwater was encountered in the borings. It is anticipated that the permanent groundwater level is below a depth that would influence the project. A majority of the revised roadway alignment will be within a few feet of existing grade. Hard rock is anticipated at shallow depths beneath the proposed construction. Excavations in the upper portion of the rock should be feasible with heavy-duty equipment. Mass grading involving excavations more than a few feet below existing grade will likely require limited blasting for efficient rock removal, particularly in proposed deep cuts. Trench excavation for the proposed pipeline below the revised roadway may need special rock-breaking equipment. Proposed retaining walls can be supported on shallow foundations. Post-construction settlements of spread footings on rock are anticipated to be negligible. Recommendations for earthwork, foundation support and surface drainage are provided in the body of the report. ^ AGRA Earth & Environmenta Recycled Paper ENGINEEflING GLOBAL SOLUTIONS I • [ i: i: i; City of San Marcos Job No. 8-252-102600 Rancho Santa Fe Road Widening August 31, 1998 San Marcos, CA Page (D 1.0 INTRODUCTION 1.1 PROJECT This report presents the results of the geotechnical investigation performed for the planned improvements to Rancho Santa Fe Road to be constructed from just north of Alga Road to [ • Island Drive, a distance of about 6510 feet. The purpose of this study was to investigate 1 . surface and subsurface conditions and develop geotechnical recommendations for paved roadway and retaining wall areas. The relationship to the site with respect to nearby ! topographic features is shown on Figure 1. 1.2 PROPOSED CONSTRUCTION The project consists of widening and realigning the portion of Rancho Santa Fe Road from just north of Alga Road to Island Drive, a distance of about 6510 feet, in addition, Melrose Drive will be realigned and widened from about Corintia Street west of Rancho Santa Fe Road to Patton Street east of Rancho Santa Fe Road, a distance of about 1600 feet. A new intersection wiil be constructed at Melrose Drive and Rancho Santa Fe Road which will include new traffic lights and storm drains. Improvements also will be made at the intersection of Rancho Santa Fe Road and Via Allondra. Most of the revised roadway alignment will be within a few feet of existing grade. A 35-foot cut will be made for the new alignment at approximate Station 300-1-00 on the new road. A 14-inch diameter water line will be installed below the new road surface. The pipe will have approximately 42 inches of cover. New retaining walls may be needed in some areas. In addition, a visual assessment was made of the condition of existing pavements and pavement component thicknesses between approximate Stations 306-t-00 and 325 + 00. 2.0 SCOPE OF WORK This investigation consisted of a review of available geologic data, a site reconnaissance, a field exploration program, laboratory testing, engineering analyses and development of conclusions and recommendations regarding: • Site preparation and grading. • Excavatability of materials anticipated in the cut portion of the new alignment. ^ AGRA Earth & Environmental ENGINEERING GLOBAL SOLUTIONS Recycled Paper Approximate Scale: 1 : 26,510 LOCATION MAP [Ml Reference: Geology Map of the Encinitas and Rancho Santa Fe Quadrangles Eisenberg. 1983 Ranch Santa Fe Road Widening San Marcos, California Figure 1 - VICINITY MAP AGRA Earth & Environmental BAR 8/11/98 I 8-252-102600 JobNo. 8-252-102600 -2- i - [ City of San Marcos Job No. 8-252-102600 Rancho Santa Fe Road Widening August 31, 1998 San Marcos, CA Page (3) • Suitability of excavated materials for use as fill. • Fill material types, placement procedures and compaction criteria. • Temporary and permanent cut and fill slope angles and slope heights. • Lateral loads on retaining walls. • Suitable foundation types and appropriate criteria for foundation support for walls including allowable bearing pressures and resistance to lateral loads. Total and differential foundation settlements are also addressed. • Feasibility of retaining the existing pavement section between approximate Stations 306+00 and 325+00, along with recommendations for improvement or overlay, if needed. • Flexible pavement structural sections for new roadways. • Excavation conditions for the planned new pipeline. • Pipe support, bedding and backfill recommendations for the new water line. • Temporary excavation support and the necessity for shoring along with lateral loads on temporary shoring systems, if needed. • Condition of existing culverts and the corrosivity of on-site soiis with respect to steel and concrete. 3.0 FIELD EXPLORATION AND LABORATORY TESTING 3.1 FIELD EXPLORATION Fourteen test borings were drilled to depths of approximately 2 to 45 feet with 8-inch diameter hollow stem auger equipment. Test boring locations are shown on Figures 2 through 5. Drilling was performed under the supervision of an AEE geologist who also logged the borings and obtained samples for visual examination and laboratory testing. Disturbed samples were obtained from auger cuttings. Disturbed samples were also obtained from cuttings generated by a 6-inch diameter air percussion drill (Boring B-10). Relatively undisturbed samples were obtained by driving a 2.5-inch diameter sampler with a 140-pound hammer falling 30 inches. ^ AGRA Earth & Environmental ENGlNEEIilNG GLOBAL SOLUTIONS Recycled Paper Boring Location RANCHO SANTA FE ROAD WIDENING CITY OF SAN MARCOS SAN MARCOS. CALIFORNIA FIGURE 2 - BORING LOCATIONS AGRA Earth & Envkonmental ittmma Ml en/98 -4- RANCHO SANTA FE ROAD WIDENING CITY OF SAN MARCOS SAN MARCOS. CALIFORNIA FIGURE 3 - BORING LOCATIONS AGRA Earth & Environmental BWT RAR uai M tm. 8/5/98 »-252-102600 -5- RANCHO SANTA FE ROAD WIDENING CITY OF SAN MARCOS SAN MARCOS. CALIFORNIA FIGURE 4 - BORING LOCATIONS AGRA Earth & Environmental ssrr RAR DUI 8/5/98 |8-252-10 102600 -6- RANCHO SANTA FE ROAD WIDENING CITY OF SAN MARCOS SAN MARCOS. CALIFORNIA 200 feet FIGURE 5 - BORING LOCATIONS AGRA Earth & Environmental MmMD 1 tMt JM RAR 1 8/5/98 8-252-102800 -7- [ City of San Marcos Job No. 8-252-102600 Rancho Santa Fe Road Widening August 31, 1998 San Marcos, CA Page (8) The logs of the test borings are contained in Appendix A. Soils are classified in accordance with the Unified Soil Classification System which is explained in Appendix A. Formational materials are described according to their physical characteristics. 3.2 LABORATORYTESTING Selected samples were tested to evaluate pertinent classification and engineering properties. The program included in-situ dry density and moisture content determinations, direct shear tests, grain-size analyses, pH, resistivity, soluble sulfate and chloride content, and R-value. Dry density and moisture content results are shown in the boring logs. Descriptions of test procedures and the results of the tests are contained in Appendix B. 4.0 SITE CONDITIONS 4.1 SURFACE CONDITIONS in general, unimproved areas within the right-of-way are covered by brush and grass, with sparse trees along the slopes of adjacent hills. Existing ground elevations range from about 350 feet above mean sea level (MSL) just south of Melrose Drive to about 580 feet MSL in the vicinity of Island Drive. 4.2 SUBSURFACE CONDITIONS The proposed alignment is underlain by fill soils or colluvium over Escondido Creek Leucogranodiorite or Santiago Formation at relatively shallow depths. Alluvium was also encountered locally. In general, formational material was encountered at shallow depths ranging from approximately 1 foot (boring B-2) to approximately 9 feet (boring B-11). Fill material encountered consisted primarily of silty sand with scattered gravel. To a lesser degree, clayey sand was also encountered as fill. Colluvium encountered consisted of silty and clayey sand. Alluvial material sampled consisted primarily of clayey sand. The Cretaceous-aged Escondido Creek Leucogranodiorite comprises the majority of the rock beneath the proposed alignment. It is composed largely of light-colored, fine to medium- crystalline granodiorite, with locally abundant inclusions. The granodiorite in the near surface ranges from relatively fresh to deeply weathered. Where fresh, it is generally hard and strong. Jointing is common, but the spacing and orientation of joints is highly variable. Commonly, the Escondido Creek Leucogranodiorite presents significantly difficult excavation conditions. ^ AGRA Earth & Environmental ENGINEERING GL08AL SOLUTIONS ' Recycled Paper City of San Marcos Job No. 8-252-102600 Rancho Santa Fe Road Widening August 31, 1998 San Marcos, CA Pao« <9» The southern portion of the alignment, in the vicinity of Melrose Drive, is underlain by rocks of the Santiago Formation. Regionally, this formation is composed largely of light-colored, poorly-bedded, fine- to medium-grained sandstone interbedded with siltstone and claystone. Light-colored, fine- to medium-grained clayey sandstone was encountered in Borings 4 and 11. In exposed slopes, clayey beds within the Santiago Formation commonly give rise to slope instability problems. No groundwater was encountered in the borings. Based on topography, it is likely that the groundwater table is below a depth that would influence the project. 4.3 ENGINEERING SEISMOLOGY The site is within the regional influence of a number of active fault zones, as indicated on Figure 6. The most severe ground motions estimated to affect the site result from a maximum credible earthquake event on the Newport-lnglewood/Rose Canyon Fault Zone which lies approximately 7 miles to the southwest. The maximum horizontal ground acceleration on rock due to the maximum credible earthquake (magnitude 7.0) is estimated to be 0.44g, with a repeatable acceleration of 0.29g. A maximum probable event on the same fault (magnitude 6.5) is estimated to yield an acceleration of 0.37g and repeatable acceleration of 0.24g. The alignment is not within a currently established Aiquist-Priolo Earthquake Special Studies Zone. The fill soils underlying the site contain significant quantities of fines and the formational materiais are very dense. In addition, as mentioned previously, the groundwater level is relatively deep. Consequently, the potential for liquefaction is slight. The Uniform Building Code should be followed with respect to seismic design. The soil profile can be considered Type Sl and an S Factor of 1.0 as described in UBC Table 16-J is appropriate for conditions at the subject site. Based on the data assembled, it is concluded that the alignment is not susceptible to collapsible or highly expansive soiis, subsidence, erosion, mudflows, or landsliding. 5.0 CONCLUSIONS AND RECOMMENDATIONS 5.1 GENERAL The investigation found no evidence of unusual or severe geotechnical hazards which would exert a severely adverse influence on timely and economic completion of the proposed improvements, it is concluded that the subject alignment is suitable for the proposed construction. The proposed retaining walls can be supported on shallow foundations. ^ AGRA Earth & Environmental ENGirjEERING GLOBAL SOLUTIONS I Recycled Paper l- JobNo. 8-252-102600 -10- City of San Marcos Job No. 8-252-102600 Rancho Santa Fe Road Widening September 1, 1998 San Marcos, CA Page dD 5.2 SITE PREPARATION AND GRADING Initially, the surface of the site should be cleared of obstructions, debris and the upper few inches of soit containing roots and organic material. All soil containing organic materia! should be disposed of off-site or stockpiled for later use in landscaping. Existing irrigation, drainage and utility lines, or other existing subsurface structures which are not to be utilized should be removed, destroyed or abandoned in compliance with applicable regulations. The exposed ground surface in areas where fill will be placed should be scarified to a depth of 8 inches, brought to a moisture content within 2 percentage points of optimum moisture content, and compacted to 90 or more percent relative compaction based on the ASTM D- 1557-91 laboratory test method. All references to optimum moisture content and relative compaction in this report are based on this test method. On-site or imported materials can be used as fill. Use of the more weathered, upper approximately 1 foot of excavated Escondido Creek Leucogranodiorite or sandstone of the Santiago Formation is feasible. Excavation of the Escondido Creek Leucogranodiorite below the more weathered zone, however, will likely generate larger fragments of rock which would require further processing. Rocks greater than 6 inches in maximum dimension should be removed from on-site soils, if these materials are used. Imported materials, if used, should consist of clean, predominately granular soil containing no vegetation, debris or rocks greater than 6 inches in maximum dimension. Imported materials should have an Expansion Index of 20 or less, and be non-corrosive. In general, fill should be spread in 6- to 8-inch loose lifts, moisture conditioned to within 2 percentage points of optimum moisture content and compacted to 90 or more percent relative compaction. The upper 12 inches of fill and backfill beneath pavement and footing areas should be moisture conditioned and compacted to 95 or more percent relative compaction. 5.3 EXCAVATION CONDITIONS 5.3.1 Soil and Rock Excavation A majority of the revised roadway alignment wil! be within a few feet of existing grade. Hard rock is anticipated at shallow depths beneath the proposed construction. Based on conditions encountered in the borings, excavations in the upper portion of the Escondido Creek Leucogranodiorite should be feasible with heavy-duty equipment. Excavation of the Santiago Formation sandstone should also be feasible with heavy-duty equipment. Mass grading of the roadway involving deeper excavations in the Escondido Creek Leucogranodiorite will likely require limited blasting for efficient removal of the rock, particularly in the proposed 35-foot cut at the approximate Station 300 + 00. Proposed 15- to 22-foot cuts at approximate ^ AGRA Earth & Environmental ENGINEERING GLOBAL SOLUTIONS ' Recycled Paper CitY of San Marcos Job ^o. 8-252-102600 Rancho Santa Fe Road Widening August 31, 1998 San Marcos, CA Page (12) Stations 325+00 and 334 + 00 will likely also require blasting. Trench excavation for the proposed pipeline below the roadway will require the use of special rock-breaking equipment or light blasting. All blasting should be conducted by an experienced and licensed contractor in strict compliance with City, County, State and any district regulations that may apply. 5.3.2 Permanent Slopes Fiil slopes should not be steeper than 2:1 (horizontal to vertical) in accordance with current geotechnical practice. Should cut slopes expose competent Escondido Creek Leucogranodiorite, they may be cut back to a slope of 1 Vail (horizontal to vertical). Cut slopes should be evaluated by an experienced and licensed engineering geologist to check for the presence of adverse bedding planes, fractures, joints or other indications of potential instability. Slopes flatter than those indicated above, or structural support, may be needed if planes of weakness or adverse bedding are encountered. Slope faces should be planted to reduce the potential for erosion. Planting will be difficult to establish and maintain on rock slopes, if topsoil is used to promote growth, significant erosion and resultant maintenance should be anticipated, especially on relatively steep slopes, until plants are well-established. Jute mesh or similar erosion control products can reduce the amount of initial erosion. In general, susceptibility to erosion increases significantly on slopes steeper than about 1 Vi :1. The City of San Marcos "Grading Code" requires cut and fill slopes having a total vertical height of 15 feet or more to include one or more 10-foot wide drainage terraces sloped to a proper outfall. These terraces should be designated and constructed so as to provide a swale or ditch having a depth of 1 or more feet and a grade of 2 or more percent. 5.3.3 Temporary Slopes Temporary cut and fill slope angles should not be steeper than 1:1 (horizontahvertical). Construction excavations in the crystalline rock generally can be made at a Va:! gradient from the standpoint of overall slope stability. Variations in moisture, texture or strength, as well as local geologic structure, may require flatter slopes in some areas. 5.4 RETAINING WALLS Retaining walls capable of rotating 0.001 radian can be designed using active earth pressures. Walls supporting level granular backfill should be designed for an active equivalent fluid pressure of 40 pounds per cubic foot (pcf). Walls supporting backfill with a 2:1 slope should be designed for an active equivalent fluid pressure of 60 pcf. Active earth pressures for walls ^ AGRA Earth & Environmental ENGINEERING GLOBAL SOLUTIONS Recycled Paper City of San Marcos Job No. 8-252-102600 Rancho Santa Fe Road Widening August 31, 1998 San Marcos, CA Pase (13) be designed for an active equivalent fluid pressure of 60 pcf. Active earth pressures for walls supporting backfill with intermediate slopes can be interpolated between these values. Traffic loads can be modeled where appropriate using a surcharge equal to an additional 2 feet of soil. Retaining walls should be provided with adequate drainage systems. Backdrains should consist of a layer of free draining gravel or crushed rock at least 12 inches wide extending nearly the full height of the wall, as shown on Figure 7. A perforated pipe connected to an appropriate outlet should be placed at the bottom of the gravel or crushed rock. Backfill behind retaining walls should consist of imported fill or on-site materials conforming to the recommendations in Section 5.2, Site Preparation and Grading. Backfill should be placed in lifts 6- to 8-inches in loose thickness, moisture conditioned to within 2 percentage points of optimum moisture content and compacted to 90 or more percent relative compaction. The upper 12 inches of backfill immediately behind the wall should consist of predominately clayey soil to reduce the rate of surface water infiltration into the backdrain. Where moisture vapor penetration or efflorescence may be a probtem, commercial waterproofing or a waterproofing membrane should be placed against the back of the wall, as recommended by the project architect. 5.4.1 Bearing Capacity Proposed retaining walls are anticipated to be founded in Escondido Creek Leucogranodiorite. If fill, colluvium, or alluvium are encountered at footing grade, they should be removed to competent formational material, as evaluated by the geotechnical engineer. The resulting excavation should be backfilled with approved granular fill compacted to 90 or more percent compaction. Walls and footings spanning a cut/fill transition should be evaluated by the geotechnical engineer. If a cut/fiti transition is present, the cut portion should be over- excavated 3 or more feet and backfilled with compacted fill in order to reduce the likelihood of abrupt differential settlement at the cut/fill contact. Spread footings can be designed to impose an allowable bearing pressure of 5000 pounds per square foot (psf) for support of the walls. These values are for dead plus long-term live loads and may be increased by ^^ when considering the total of all loads, including wind or seismic forces. ^ AGRA Earth & Environmental ENGINEERING GLOBAL SOLUTIONS I Recycled Paper RETAINING WALL SOIL BACKFILL COMPACTED TO 90 OR MORE PERCENT RELATIVE COMPACTION CLASS 2 PERMEABLE FILTER MATERIAL COMPACTED TO 90 OR MORE PERCENT RELATIVE COMPACTION 12'MIN. WALL FOOTING 4" DIAMETER PERFORATED SCHEDULE 40 PVC PIPE OR EQUIVALENT INSTALLED WITH PERFORATIONS DOWN. MINIMUM 1 PERCENT GRADIENT TO JUST BEYOND WALL AND THEN NON- PERFORATED PIPE STREET OR SUITABLE OUTLET NOT TO SCALE BASED ON ASTM D 1557-78 FILTER MATERIAL Filter material shail be Class 2 permeable materiai per State of Caiifomia Standard Specifications or approved alternate geofabric drain system. Class 2 grading as foiiows SIEVE SIZE r 3/4- 3/8" No. 4 No. 8 No. 30 No. 50 No. 200 PERCENT PASSING 100 90-100 40-100 25-40 18-33 5-15 0-7 0-3 Ranch Santa Fe Road Widening San Marcos, Califomia Figure 7 - RETAINING WALL DRAIN DETAIL AGRA Earth & Environmental RAR 8/25/98 e-252-10260O JobNo. 8-252-102600 -14- City of San Marcos job No. 8-252-102600 Rancho Santa Fe Road Widening August 31, 1998 San Marcos, CA Page (15) 5.4.2 Settlement As mentioned above, proposed retaining wall foundations are likely to bear on relatively hard formational materials. Consequently, foundation settlements are anticipated to be negligible. 5.4.3 Resistence to Lateral Loads Lateral loads wiil be resisted by friction between supporting soils and the bottoms of footings by passive earth pressures acting on the sides of footings and other structural elements below grade. The allowable static horizontal frictional resistance can be taken as 0.5 times the applied vertical load. The allowable horizontal passive earth pressure against formational material is 400 psf per foot of depth of embedment below the lowest adjacent surface. If the ground adjacent to the footing is not covered with asphalt or concrete, the top 12 inches of soil should not be relied upon for passive support. 5.5 PAVEMENT 5.5.1 Flexible Pavement Structural Section R-value tests were performed on samples considered representative of average subgrade conditions. R-values of 62 to 68 were measured in the tests for the proposed roadway and used to develop the flexible pavement structural sections described below. A conservative R-value of 50 was assumed. The Caltrans method of pavement design was used to calculate pavement component thickness for 2 values of the Traffic Index (Tl). Rancho Santa Fe Road (Tl = 8.5) 0.4' AC / 0.55' AB Melrose Drive (Tl = 8) 0.4' AC / 0.5' AB AC = Asphalt Concrete Surface Course AB = Aggregate Base Course (R = 78) The upper 12 inches of subgrade soil below the pavement section in fill areas should be compacted to 95 or more percent relative compaction at a moisture content within 2 percent of the optimum moisture content. Paved areas should be properly sloped and surface drainage facilities established to reduce water infiltration into the pavement subgrade. Curbs adjacent to paved areas should have bases in the subgrade materials, not the aggregate base course. ^ AGRA Earth & Environmental ENGINEERING GLOBAL SOLUTIONS Recycled Paper r City of San Marcos Job No. 8-252-102600 Rancho Santa Fe Road Widening September 1, 1998 San Marcos, CA Page (16) to paved areas should have bases in the subgrade materials, not the aggregate base course, to provide a cut-off to reduce water migration into the pavement base course. 5.5.2 Structural Section Between Stations 306 + 00 and 325 + 00 Based on cores through the existing roadway (see boring logs B-8, B-9, B-13, and B-14), the existing structural section of Rancho Santa Fe Road, except wtthin the vicinity of Station 306 + 00, meet the required criteria discussed in Section 5.5.1 above, which calls for a minimum of 0.4 feet of asphalt concrete over 0.55 feet of aggregate base course. Boring B-9 indicated a full depth 0.75-foot section of asphalt concrete in the vicinity of Station 306 + 00 of Rancho Santa Fe Road. This satisfies a minimum depth criteria of 0.7 feet for a full depth section. The existing roadway surface from Station 306 + 00 to 325 + 00 was observed to have little noticeable distress which would warrant an overlay. Slight to moderate distress was noted at approximate Station 305 + 00, just south of Redwing Street, which was not within the scope of service, for this report. 5.6 PIPELINE DESIGN AND CONSTRUCTION RECOMMENDATIONS 5.6.1 Bearing Capacity for Pipeline It is anticipated that trenching for the proposed pipeline will take place in rock along the entire proposed alignment. Investigation data indicate that the existing rock will have adequate bearing capacity for support of the proposed pipeline. The excavation should be observed by the geotechnical engineer prior to placement of pipe bedding (See Section 5.7,2, below). Construction of the pipeline on Escondido Creek Leucogranodiorite or Santiago Peak Volcanics should result in only slight settlement of the line. 5.6.2 Pipe Bedding Pipe bedding is defined as that material supporting, surrounding and extending to one foot above the top of the pipe, in accordance with the "Greenbook, Standard Specifications for Public Works Construction," 1994 Edition. Where it is necessary to remove boulders or other obstructions at subgrade elevations for bedding in rock areas, the void should be filled with compacted bedding material. If soft, expansive or otherwise unsuitable materials are encountered at subgrade, they should be removed to a depth evaluated by the geotechnical engineer and replaced with compacted sand fill or bedding to the level of the bottom of the trench. The thickness of bedding below the pipe barrel should be 8 or more inches. Bedding material should consist of clean sand or gravel. On-site soils are not suitable for bedding. Sand meeting the gradation listed for portiand cement concrete sand in Standard % AGRA Earth & Environmental Recycled Paper ENGINEERING GLOBAL SOLUIIONS [ City of San Marcos Job No. 8-252-102600 Rancho Santa Fe Road Widening August 31, 1998 San Marcos, CA Page (17) Specifications Table 200-1.5.5(A) is suitable. Alternative materials may be acceptable. Per Standard Specifications Section 306-1.2.1, bedding material shall have a sand equivalent of not tess than 30 or a coefficient of permeability greater than 1.4 inches/hour. Gradation specifications of the imported bedding proposed for use should be reviewed and approved by the engineer before the material is brought to the project alignment. The stiffness of soil backfill placed at the sides of a buried flexible pipeline is characterized by the modulus of soil reaction, E'. E' is used to evaluate deflection attributed to the weight of the backfill over the pipe. A modulus value of 1,500 psi may be utilized for granular material with a sand equivalent of 30 or greater. Soil used as backfill below the bedding, where used to replace unsuitable subgrade material, should be placed in lifts 8 inches or less in loose thickness, moisture conditioned and mechanically compacted to 95 or more percent relative compaction. Bedding compacted to 90 or more percent relative compaction should be placed to at least 1 foot above the top of the pipe. Initially, the required thickness of pipe bedding zone material should be placed over the full width of trench. After placement of the pipe, bedding should be brought up uniformly on both sides of the pipe to reduce the potential for unbalanced loads. No voids or uncompacted areas should be left beneath the pipe. 5.6.3 Trench Backfill Backfill should consist of predominantly granular, non-expansive soil containing no rocks greater than 6 inches in maximum dimension or organic debris. The engineer should evaluate and, if appropriate, test imported materials proposed for use as backfill before placement in the excavation. It should be noted that the Street Excavation Ordinance-Backfill Requirements of the City of San Marcos specify that backfill within existing or proposed paved areas is to have a Sand Equivalent (S.E.) of at least 20. Based on boring logs and the percentage of fines determined from grain-size analyses, the alluvial and colluvial soils encountered along the alignment may have S.E. values of less than 20. It is anticipated that materials generated by excavation of the Escondido Creek Leucogranodiorite and Santiago Formation would require further processing. Consequently, import of backfill material may be necessary, and an allowance in the project budget for importing material with an S.E. of 20 or more is suggested. The quality of materials and placement histories for existing fills along the alignment are not known. Consequently, it is possible that debris, trash or organic materials unsuitable for use could be present within some fill areas. All trench backfill should consist of approved earth materials, free of trash or debris, vegetation, and other deleterious matter. Backfill should be mechanically compacted; ^ AGRA Earth & Environmental Recycled Paper ENGINEtfiING GLOBAL SOLUTIONS [ City of San Marcos Job No. 8-252-102600 Rancho Santa Fe Road Widening September 1, 1998 San Marcos, CA Page (18) flooding or jetting should not be allowed. Expansive soils, as evaluated by the engineer during construction, should not be placed within the trench backfill. As with the general fill recommendations, trench backfill should also be placed in 6- to 8-inch loose lifts within 2 percent of optimum moisture content and compacted to 90 or more percent relative compaction. The upper 12 inches of backfill beneath pavement and slab areas should be moisture conditioned and compacted to 95 or more percent relative compaction beneath paved areas. [ 5.6.4 Temporary Excavation Support In general, the recommended y^:^ (horizontal to vertical) temporary backslope in formational materials should be stable. Temporary excavations in fills, colluvium, or alluvium, if encountered, should be stable at a backslope of 1:1 (horizontal to vertical). Minor sloughing of backslopes is possible. 5.7 CORROSION POTENTIAL Our visual observations of the existing culverts did not indicate corrosive conditions. Corrosive conditions may exist at other areas not accessible for visual observation and at areas where soil is in contact with the culverts. Soluble sulphate tests on two soil samples indicated that concrete will have a negligible exposure to sulfate-containing solutions, with concentrations ranging from 391 ppm to 524 ppm. Measured chloride contents ranging from 48 ppm to 254 ppm classify the tested soils as having a negligible corrosivity due to chloride influence at the same sample locations. However, we recommend that Type ll modified cement be used and that reinforcing bars for concrete in contact with the soil have a cover of 3 or more inches. Resistivity tests indicated that soils classified as severely corrosive (1070 ohm-cm) to ferrous metals exist in the vicinity of the Rancho Santa Fe Road / Melrose Drive intersection, while soils mildly corrosive (4530 ohm-cm) to ferrous metal are found at the north end of the proposed alignment near Island Drive. We recommend that metallic conduit should be avoided if possible and special provisions such as epoxy coating or the use of plastic pipe should be considered. 6.0 GEOTECHNICAL AND CONSTRUCTION REVIEW AEE should review the project plans and specifications prior to foundation construction to evaluate whether the intent of the geotechnical recommendations in this report have been incorporated. It should be anticipated that the materials exposed during construction will differ from those encountered in the borings. AEE's presence on-site during construction will ^ AGRA Earth & Environmental Recycled Paper ENGINEERING GLOBAL SOLUTIONS City of San Marcos Rancho Santa Fe Road Widening San Marcos, CA Job No. 8-252-102600 September 1, 1998 Page (19) enable modification of the geotechnical recommendations in this report or development of additional recommendations on a timely basis. 7.0 CLOSURE This report has been prepared in accordance with generally accepted geotechnical practices in San Diego, California and makes no other warranties, either express or implied, as to the professional advice or data included in it. The report is based on the project as described and the data obtained in the field or from referenced documents. AEE should be notified of any changes in the plans or of any site conditions that differ from those described in this report, since these conditions may necessitate a reevaluation of the recommendations. This report has not been prepared for use by parties or projects other than those named or described above, and may not contain sufficient information for other parties or other purposes. AGRA Earth & Environmental / R. Alan Reyes / Staff Engineer CAC/BHR/RAR/rar Distribution: (6) Client (1) Project Design Consultants Ctifforti A. Craft, RGE 243 Supervising Engineer Brian Reck, CEG 1792 Project Geologist "•*mm^ ^ AGRA Earth & Environmental Recycled Paper ENGINEERING GLOBAL SOLUTIONS City of San Marcos Job No. 8252102600 Rancho Santa Fe Road Widening August 27, 1998 San Marcos, CA Page (20) REFERENCES American Public Works Association, Associated General Contractors of California, "Greenbook" Standard Specifications for Public Works Construction, 739 pp., dated 1994 American Society for Testing and Materials, Annual Book of ASTM Standards, Section 4, Volume 4.08, 970 pp., dated 1997 City of San Marcos, Grading Code, undated City of San Marcos, Street Excavation Ordinance, Backfill Requirements, undated International Conference of Building Officials, Uniform Building Code, Volume 2, 1339 pp., dated 1994 Tan, S.S. and Kennedy, M.P., Geologic Map of the Encinitas and Rancho Santa Fe 7.5' Quadrangles, San Diego County, California, California Division of Mines and Geology Open-File Report 96-02, 1:24,000 scale, dated 1996 ^ AGRA Earth St Environmental Recycled Paper ENGINMRING GLOBAL SOLUTIONS APPENDIX A UNIFIED SOIL CLASSIFICATION Highly Organic soils Silts and days Uquid Umit >50% Silts and days Uquid Umit <50% Rne grained soiis (More than 50% Is smaller than No. 200 sieve) Sands - more than 50% of coarse fraction Is smaller than No. 4 sieve Gravels - moro than 50% of coarse fraction is larger than No. 4 sieve Coarse grained soils (More than 50% is larger than No. 200 sieve) 60 40 20 t H / / CL / / 0\ i& IH ,.l I L-U IL& CL LABORATORY CUSSIFICATION CRITERIA GW and sw - Cu - D «;DW greater than 4 for GW and 6 for SW Cc - Di /(DM XD« ) between 1 and 3 GP and SP - Clean Gravel or sand not meeting requirements for GW and SW GM and SM - Atterberg Umit below "A-UNE" or P.l. less than 4 SILT OR CLAY FINE SANO MEDIUM SAND COARSE SAND BNE GRAVEL COARSE QRAVEL COBBLES BOULDERS SIEVE SIZE 200 40 10 ' v.- r IO- 20 40 BO 80 UQUID UMn*. 100 Classification of earth materials is based on fieid Inspection and should not be constnjed to Imply laboratory analysis unless so stated. MATERIAL SYMBOLS Extrusive Igneous Rock Asphalt Claystone Interbedded Limestone and Shale Limestone Clayey Sandstone Sandy Claystone Clayey Siltstone Metamorphic Rock Concrete Conglomerate intrusive Igneous Rock Sandstone Sandy Siltstone Siltstone Silty Claystone Silty Sandstone LEGEND OF PENETRATION TEST Blows per foot - 25 Blows per foot (using 140 Ib. hammer wrth 30" drop - 350 ft-lb blow) Consistency Classification for Soils According to the Standard Penetration Test Blows/Ft.* Granular Blows/Ft.* CJohesive Very loose 0-5 Very soft 0-5 Very loose 0-5 Very soft 6-10 Soft 6-10 Loose 6-10 11-20 Medium Stiff 11-30 Medium Dense 11-20 21-35 stiff 31-50 Dense 21-35 Very dense 36-70 Very Stiff >50 Very dense 36-70 Very Stiff >70 Hard LEGEND OF BORING G.W.S. Confomiable material change Approximate material change Unconformable material change Bottom of boring •NSR" indicates 'no sampie recovery" A-1 AG RA EARTH & ENVIRONMENTAL, INC. TEST BORING LOG TYPE 8" Hollou Stem Auger 8.4 100+ Bag 2.5 Bag 1 ELEVATION ^-SeS.Q feet sc BORING B-1 PII I Gray-brown fine to coarse SILTY SAMD with gravel, ESCQKDIDQ TRFFlf I FUrOGBAHODIQRlTE: Yellow to gray-green, fine-to medium-crystalline GRANODIORITE; moderately weathered. 1. 2. 3. 4. 5. Total depth of boring 8.25 feet. No groundwater encountered. No caving observed. Elevation obtained from "Public Grading Plans (95% Submittal)" by Project Design Consultants. Boring backfilled with cuttings on 7/7/98. H I-S CO H O)^ 2**-LJ U a Q. > Oi a LJ o o o u. \ tfi o _i CD o z UJ _J z: <i: Hi Qi HO HI a:(/: ocn UC H U-O H Z_] DH o Ui THIS BORING LOG SUtlMfiRY APPLIES ONLY AT TIME AND LOCATION INDICATED. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND TIMES. LOGGED BY TUP DATE 7-7-98 JobNo. 8-252-1026 - August 31, 1998 A-a AG RA EARTH & ENVIRONMENTAL, INC. TEST BORING LOG [ TYPE 8" Hollou Stem Auger 100+ Bag 2.5 Bag ELEVATION ^524.0 feet BORING B-2 tPAVFHFMT 2" of asphaltic concrete. Red brown fine CLAYEY SAND. gSCQMDIDO CBFFIf 1 FUrnRgAMnDIOglTE: Gray-green, fine-to medium-crystalline GRANODIORITE; slightly weathered. 5. Total depth of boring 8.25 feet. No groundwater encountered. No caving observed. Elevation obtained from "Public Grading Plans (95% Sulsmittal)" by Project Design Consultants. Boring backfilled with cuttings on 7/7/98. u I H, Q. H ^ "Q-O H-n UIUJ Qixao. H LU U a a. > Ql Q UJ O 1-O o u. \ O) o _J to LU N UJ Ql -C u (0 UJ -I o. JZ <L tfi UJ, HO xl " (0 0(n UIC H_l U.U H z_l =)H o THIS BORING LOG SUMMARY APPLIES ONLY AT TIME AND LOCATION INDICATEO. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND TIMES. LOGGED BY TMP DATE 7-7-98 JobNo. 8-252-1026 - August 31, 1998 A-3 AGRA EARTH & ENVIRONMENTAL, INC. TEST BORING LOG TYPE 8" Hollou Stem Auger ELEVATION '521.0 feet BORING B-3 100+ 100+ Bag 1.4 Bag 1.4 SM mniivtiiM. Red-brown fine- to medium-grained SILTY SAND with scattered GRAVEL. F^trnunrnn ppFFif i FiirnnpflMnnTnpTTF- Red-brown to yellow-brown, fine- to medium-crystalline GRANODIORITE; slightly weathered. 1. Total depth of boring 7 feet. 2. No grourKlwater encountered. 3. No caving observed. 4. Elevation obtained from "Public Grading Plans (95% Submittal}" by Poject Design Consultants. 5. Boring backfilled with cuttings on 7/7/98. Q S I H \£xu. UJ •H HTIUJUJ! cn' tf) >• H H tfi^ US o a 0. >-0£ O Ul Oi o h-O O U. \ tf) 3, a CO UJ UJ-C CL.E tfi o z Ul -I Q-z: c tfi C-J HO ujx: tfi atn LUC H_I Z-1 =)H o tfi THIS BORING LOG SUMMARY APPLIES ONLY AT TIME AND LOCATION INDICATED. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND TIMES. LOGGED BY TMP DATE 7-7-98 JobNo. 8-252-1026 - August 31, 1998 A-4 AG RA EARTH & ENVIRONMENTAL. INC. TEST BORING LOG TYPE 8" Hollou Stem Auger ELEVATION -361.0 feet BORING B-4 116 125 12.2 8.1 21 46 100+ Bag 2.5 Bag 1.4 1.4 1 10 f-ni iimTMM. Red-brown, medium-dense, fine SILTY SAND. Mottled red-brown and gray CLAYEY SAND. SANTIAGO FOBHATIQM: Light yellow-green, fine- to medium-grained, CLAYEY SANDSTONE. 1. Total depth of boring 12.6 feet. 2. No grouryJwater encountered. 3. No caving observed. 4. Elevation obtained from "Public Grading Plans (95% Submittal)" by Project Design Consultants. 5. Boring baclcfilled with cuttings on 7/8/98. u H. \i:XLL WtKH HT,UJUJS CO tfi H tO^ ZH-UJ U a a > a UJ H^ O O o u. \ CO UJ tfi Ul Q) r. tsi UJ _i 0-r c CO Uj. o. _J c_ HC •X.t£. U CO) (0 OCA UJC H-J U.CJ H Z-S Z)H o CO THIS BORING LOG SUMMARY APPLIES ONLY AT TIME AND LOCATION INDICATED. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND TIMES. LOGGED BY TMP DATE 7-8-98 JobNo. 8-252-1026 - August 31, 1998 A-5 AGRA EARTH & ENVIRONMENTAL, INC. TEST BORING LOG TYPE 8" Hollou Stem Auger ELEVATION '394.0 feet BORING B-5 37 100+ Bag 1.4 Bag 1.4 1 SC fnilllVTMM. Red-brown fine CLAYEY SAND with scattered GRAVEL. FSCQHDIDQ CBFFIC LFUCQGRAMnOIQRlTg; Gray-green, fine- to medium-crystalline GRANODIORITE. Moteai 1. 2. 3. 4. 5. Total depth of boring 8 feet. No groundwater encountered. No caving observed. Elevation obtained from " Public Grading Plans (95% Submittal)" by Project Design Consultants. Boring backfilled with cuttings on 7/8/98. Q S I H, UIQI-H H.n^UJ fll CO ao.' CO H CO^ 2H-UJ U a Q. >-a: a I-o o iL \ to o CO UJ tfi o z Ul _l Q. z: c CO c_ HC uz: CCO CO DCO UJC H_ U.U H z_ 3H O CO THIS BORING LOG SUMMARY APPLIES ONLY AT TIME AND LOCATION INDICATED. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND TIMES. LOGGED BY TMP DATE 7-8-98 JobNo. 8-252-1026 - August 31, 1998 A-6 AG RA EARTH & ENVIRONMENTAL, INC. TEST BORING LOG TYPE 8" Hollou Stem Auger ELEVATION '456.0 feet BORING B-6 Bag 1.4 1 ML Gray-brown, very soft CLAYEY SILT with GRAVEL and COBBLES and BOULDERS; loose. 1. 2. 3. 4. 5. Total depth of boring 7 feet. No groundwater encountered. No caving observed. Elevation obtained from "Public Grading Plans (95% Submittal)" by Project Design Consultants, Boring backfilled with cuttings on 7/8/98. \£xu. WT^I-H u UJ H-nUJUjS CO tfi > I- H tfi^ us o a tL > Oi a Ul O O O u. \ cn CO JZ u 0-.E CO o z Ul -I C CO 0" ^ C_J HO [iSZi <ctr. £1 CO 0(0 UJC H-l U.(J H Z_l Z>H O CO THIS BORING LOG SUMMARY APPLIES ONLY AT TIME AND LOCATION INDICATED. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND TIMES. LOGGED BY TMP DATE 7-8-98 JobNo. 8-252-1026 - August 31, 1998 A-7 AG RA EARTH & ENVIRONMENTAL, INC. TEST BORING LOG TYPE 8" Hoilou Stem Auger ELEVATION '419.0 feet BORING B-7 104 128 8.0 6.2 53 100+ Bag 2.5 2.5 Bag 1.4 1 SC Dark red-brown, loose, fine to coarse CLAYEY SAND with minute voids ESCONDIDQ CRFEIC lEUrnRRAMnninBITg: Light yellow-brown fine- to medium-crystalline GRANODIORITE; moderately weathered. Nntpsi 1. 2. 3. 4. 5. Total depth of boring 10 feet. No groundwater encountered. No caving observed. Elevation obtained from "Public Grading Plans (95% Submittal)" by Project Design Consultants. Boring backfilled with cuttings on 7/8/98. a. H Q H-Oi H co 'to iUJ u I H( XU. I-H! LUUJS to H tO/% ZH-Ul u o a >-Oi a O Q U. \ (O Z3i O _l CD UJ Ss to o z Ul _I CL C tfi tL-i HO OilC H > ^(0 K tfi OCO UJC H_l U.O H Z_l 3H O CO THIS BORING LDG SUMMARY APPLIES ONLY AT TIME AND LOCATION INDICATED. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND TIMES. LOGGED BY TMP DATE 7-8-98 JobNo. 8-252-1026 - August 31, 1998 A-8 AGRA EARTH & ENVIRONMENTAL, INC. TEST BORING LOG TYPE 8" Hollou Stem Auger ELEVATION -497.0 feet CO Q S I H UJ^I-H[;; H-n Ul Uiy CO CO >-I- H ZM-LU U a Q. >-Oi a UJ Oi H O 100+ o o u. to o _J CO Bag 1.4 cn a. i CO C-J HG 'z: CCO E: CO OCO UJC H_l U.U H Z-1 DH Q to BORING B-8 PAVFMFMT 7.0" ASPHALTIC CONCRETE BASF MATgRIAL: Green-gray fine to coarse GRAVELLY SAND. FSCOMDIDQ CRFFIf 1 gUCQGBAMODinBITF; I Gray-green, fine- to medium-crystalline I GRANODIORITE; slightly weathered. 1. Total depth of boring 5 feet. 2. No grourxiuater encountered. 3. No caving observed. 4. Elevation obtained from " Public Grading Plans (95% Submittal}" by Project Design Consultants. 5. Boring backfilled with cuttings on 7/8/98. THIS BORING LOG SUMMARY APPLIES ONLY AT TIME AND LOCATION INDICATED. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND TIMES. LOGGED BY TMP DATE 7-8-98 JobNo. 8-252-1026 - August 3 1998 A-9 AGRA EARTH & ENVIRONMENTAL, INC. TEST BORING LOG TYPE 8" Hollou Stem Auger ELEVATION •459.0 feet BORING B-9 117 4.7 81 Bag 2.5 gig SC PAVFHFMT 9.0" asphaltic concrete. FILL: Yellow-brown and red-brown fine CLAYEY SAND. FSCOMDIDQ PPPFir I FLlCDr.gAMnOIQRITEi Light yellow-brown and gray-green, fine- to medium-crystalline GRANODIORITE; moderately weathered. QJ H to Hy ILU5 CO H CO^ ZH-US o a a >-Oi Q H UJ o Oi o u. (OO H \ (OO H (0 (OO H o o BL UJ IH- Ss Ujt o-.E CO Nnrps: 1. Total depth of boring 4.8 feet. 2. No grourxlwater encountered. 3. No caving observed. 4. Elevation obtained from " Public Grading Plans (95% Submittal)" by Project Design Consultants. Boring backfiUed with cuttings on 7/8/98. 5. o z Ul _l CL E C CO C-J HC U -> CCO E tf) atfi UJC H-l U.U H Z_l 3H O CO THIS BORING LOG SUMMARY APPLIES ONLY AT TIME AND LOCATION INDICATED. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND TIMES. LOGGED BY TMP DATE 7-8-98 JobNo. 8-252-1026 - August 31, 1998 A-10 AG RA EARTH & ENVIRONMENTAL, INC. TEST BORING LOG TYPE 5 7/8" Air Percussion ELEVATION •455.0 feet OL, H h CJ Q S I H \£xu. UJ •H HTIUJUJ^ oi^aa.^ CO CO H tn^ LU U O Q. > Oi a Ul Oi O E 100+ 100+ o o u. \ CO o _l CD 1.4 Bag 1.4 Bag Bag Bag UJ Ss Q..E CO o z UJ -J Q. E C CO 10 15 20 25 30 35 40 -*5- SM 5" -I C_i HO oitn UJE CtO CO OCO LUC H_J U.U H Z_J Z)H O CO BORING B-10 Fill Gray-brown fine to coarse SILTY SAND with GRAVEL. FSrFM0Ti?n ~BPFif LiuC0GgAHDIQ"BITE7 Light gray, fine- to medium-crystalline GRANOIORITE, lightly weathered. 1. 2. 3. 4. 5. Total depth of boring 45 feet. No groundwater encountered. No caving observed. Elevation obtained from " Public Grading Plans (95% Submittal}" by Project Design Consultants. Boring backfilled uith cuttings on 7/9/98. THIS BORING LOG SUMMARY APPLIES ONLY AT TIME AND LOCATION INDICATED. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND TIMES. LOGGED BY TMP DATE 7-9-98 JobNo. 8-252-1026 - August 31, 1998 A-11 AG RA EARTH & ENVIRONMENTAL, INC. TEST BORING LOG TYPE 8" Hollou Stem Auger ELEVATION •350.0 feet BORING B-11 97 109 116 127 20.4 13.7 16.0 10.0 10 17 61 2.5 Bag 2.5 Bag 2.5 Bag 2.5 ML FMI sc Mottled gray-brown CLAYEY SILT. Mottled yellow-green, loose, fine CLAYEY SAND. AtMIVlllM; Gray-brown, loose, fine CLAYEY SAND. SAMTTAfin PngHATinH- Mottled gray, yellow-brown, fine CLAYEY SANDSTONE. 5. Total depth of boring 16 feet. No groundwater encountered. No caving observed. Elevation obtained from " Public Grading Plans (95% Submittal)" by Project Design Consultants. Boring backfilled with cuttings on 7/13/98. Om t H SI (-> UJ-th-HW H-n UJUJ CO CO H tO^ ZH-Ul u a OL >- Q UJ Oi o E o o u. \ CO 3 o -J ta hi Ss Q!.E CO o z UJ -I Q-E C CO THIS BORING LOG SUMMARY APPLIES ONLY AT TIME AND LOCATIDN INDICATED. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND TIMES. LOGGED BY TMP DATE 7-13-98 JobNo. 8-252-1026 - August 31, 1998 A-12 AG RA EARTH & ENVIRONMENTAL, INC. TEST BORING LOG I. TYPE 8" Ho Ilou Stem Auger ELEVATION S« U I H xu. I-H (LU UILU OCL to H tO^ ZH-Ul u O tL >- Oi a hi ta H^ O E O O u. \ to 3 o _l CD Bag UJ Ss 5!.E CO UJ _J Q. E C CO -507.0 feet C-J HO CCT CO QtO LUC H_l U.U H Z-J 3H O CO BORING B-12 eAUEHENI: 8.0" asphaltic concrete. 4.0" BASE HATERIAL: brown, fine- to medium-grained SILTY SAND with gravel. Fgrnuninn TPFFIC I FiirnRBflunninRtTF- Mottled gray-brown GRANODIORITE, slightly weathered. Wntps: 1. 2. 3. 4. 5. Total depth of boring 2 feet. No grourxlwater encountered. No caving observed. Elevation obtained from " Public Grading Plans (95% Submittal}" by Project Design Consultants. Boring backfilled with cuttings on 7/13/98. THIS BORING LOG SUMMARY APPLIES ONLY AT TIME AND LOCATION INDICATED. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND TIMES. ____ LOGGED BY TMP DATE 7-13-98 JobNo. 8-252-1026 - August 31, 1998 A-13 AG RA EARTH & ENVIRONMENTAL, INC. TEST BORING LOG L TYPE 8" Hollou Stem Auger 100+ Bag 1.4 ELEVATION •507.0 feet SH BORING B-13 PAVFHFMT- 6.0" asphaltic concrete. B.O" BASE HATERIAL; Hottled gray-brown fine to coarse SILTY SAND with scattered GRAVEL. FSCOMDIDQ CBFFIf 1 FUCOGBAMOPIOBITF! Gray green, fine- to medium-crystalline, ^ GRANODIORITE; slightly weathered. 1. 2. 3. 4. 5. Total depth of boring 4.5 feet. No groundwater encountered. No caving observed. Elevation obtained from " Public Grading Plans (95% Submittal)" by Project Design Consultants. Boring backfilled with cuttings on 7/13/98. U 1 H, \rxu. UJ •H S"DLO H^^UJU! CO " H CO^ ZH-Ul u o a >- Q LU Oi H o E o o u. \ CO o -J CO Q> u D..E CO O z UJ _J Q-E C CO 5" uj»! az CJ HO XtC LUE cco E CO OCO UIC H-J L.U H Z_ ZDH O CO THIS BORING LOG SUMMARY APPLIES ONLY AT TIME AND LOCATION INDICATED. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND TIMES. LOGGED BY TMP DATE 7-13-98 JobNo. 8-252-1026 - August 31, 1998 A-14 AG RA EARTH & ENVIRONMENTAL, INC. TEST BORING LOG TYPE 8" Hollou Stem Auger 19 Bag 2.5 ELEVATION •"473.0 feet SH SC BORING B-14 PAVFMFWT; 6.0" asphsltic concrete 1?" BASF HATFRIAl : Green-gray, fine to coarse, GRAVELY SAND. Ftll Gray-green fine to coarse SILTY SAND with GRAVEL, Dark yellow-brown, medium dense, fine to coarse CLAYEY SAND. Notes: 1. 2. 3. 4. 5. Total depth of boring 6.5 feet. No groundwater encountered. No caving observed. Elevation obtained from " Pifelic Grading Plans (95% Submittal)" by Project Design Consultants. Boring backfilled w ith cuttings on 7/13/98. :^m^ •I. CL H HTIUJ t— t^ CO u ITI CO CO H CO^ ZH- hl U O Q. Oi a hs Oi r— v. COO H O E O o u. \ CO zz O -I CQ UJ Ss a..E CO UJ -I CL E C CO is^ C_J HO ai<£ LUE h->- cco CO OCO UIC H_J U.U H Z_l 3H O tfi THIS BORING LOG SUMMARY APPLIES ONLY AT TIME AND LOCATION INDICATED. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND TIMES. LOGGED BY TMP DATE 7-13-98 JobNo. 8-252-1026 - August 31, 1998 A-15 APPENDIX B i; i: City of San Marcos Job No. 8252102600 Rancho Santa Fe Road Widening August 31, 1998 San Marcos, CA Page (B-1) LABORATORY TESTING The laboratory test program was designed to fit the specific needs of this project and was limited to testing on-site materials. A brief description of each type of test is presented below. Test results are included in the boring logs in Appendix A and in this appendix. The in-situ dry densities and moisture contents were determined for relatively undisturbed samples. Resuits are listed in the boring logs in Appendix A adjacent to the sample tested. Strength characteristics of the on-site materials were determined in the laboratory by direct shear tests performed on three relatively undisturbed samples. The samples were submerged and each tested under 3 different normal loads in a 2.5-inch I.D. circular shear box, using a controlled displacement rate in general accordance with ASTM D 3080. Results are summarized in Table B-1. Minimum electrical resistivity and pH were measured for 2 samples in accordance with California Test 643. The concentration of soluble sulphate was determined in accordance with California Test 417. Chloride content was determined in accordance with California Test 422 Results are contained in Table B-2. The percentage by weight of soil particles finer than the No. 200 sieve (silt and clay) was determined for three soil samples in accordance with ASTM D 1140. Results are in Table B-3. The grain-size distributions of 3 samples were determined in genera! accordance with ASTM D 422. Resultant data are plotted on page B-4. Resistance (R-value) tests were performed on three samples considered representative of potential subgrade materials. The tests were performed in accordance with California Test 301. Results are in Table B-5. ^ AGRA Earth & Environmental Recycled Paper ENGIWEEBING GLOBAL SOLUTIONS City of San Marcos Rancho Santa Fe Road Widening San Marcos, CA Job No. 8252102600 August 31, 1998 Page (B-2) LABORATORY TEST RESULTS TABLE B-1 SUMMARY OF DIRECT SHEAR TEST RESULTS (ASTM D 3080) Boring No./ Shear Stress as Sample No. Normal Strfi.ss Peak Shear Stress 0.2B Inch Displacement (psf) (psf) (psf) 4/2 1125 2580 1230 2160 2720 2015 3195 4330 3125 7/3 1125 2180 1185 2160 4140 2210 3195 4750 3360 11/5 1125 1765 1340 2160 2430 2035 3195 2785 2700 TABLE B-2 SUMMARY OF CORROSIVITY TEST RESULTS (California Test 417, 422 and 643) i: Boring No./ Sample No. Dh Rfisi.stivity (ohm-cm) Chloride Content (ppm) Soluble Sulphatfi (ppm) 1/3 7.8 4530 50 390 4/3 7.7 1070 255 525 Recycled Paper ^ AGRA Earth & Environnnental EWGlNEERiNG GLOBAL SOLUTIONS City of San Marcos Rancho Santa Fe Road Widening San Marcos, CA Job No. 8252102600 August 31, 1998 Page (B-3) TABLE B-3 SUMMARY OF PERCENTAGE OF PARTICLES FINER THAN NO. 200 SIEVE (ASTM D 1140) [• L Borinn Nn./Samnle No. % Pa.9.<5inq No. 200 Sieve 4/1 30 9/1 38 11/3 48 TABLE B-4 SUMMARY OF LABORATORY R-VALUE TEST RESULTS (California Test 301) Boring No./Sample No. R-Value* 1/3 68 5/1 62 13/1 68 By Exudation '•*»nmr Recycled Paper ^ AGRA Earth & Environmental EMGINEEFimG GLOBAL SOLUTIONS U.S STANDARD SIEVE SIZE 100 50 1.0 0.5 0.1 GRAIN SIZE IN MILLIMETERS 0.005 0.001 B0UU3ERS GRAVEL SAND Fines (Silt and Clay) B0UU3ERS COBBLES Coarse Fine Coarse Medium Fine Fines (Silt and Clay) Sample No. or Location Test Date USCS Description Natural Water LL PL Pl SE Max. Diy Densitv Optimum Water GRAIN SIZE DISTRIBUTION 4/1 7/22/98 SM SILTY SAND 6.2 ^ AGRA Earth & Environmental 9/1 -CH 7/22/98 SC CLAYEY SAND 8.6 ^ AGRA Earth & Environmental 11/3 7/22/98 SC CLAYEY SAND 13.7 Project: Rancho Santa Fe Road Widening By: WMC Date: 07/22/98