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HomeMy WebLinkAbout3956; Water Transmission Pipeline Replacement Project; Geotechnical Evaluation; 2004-11-19Geotechnical and Environmental Sciences Consultants GEOTECHNICAL EVALUATION SAN MARCOS BOULEVARD WATER TRANSMISSION PIPELINE REPLACEMENT PROJECT SAN MARCOS, CALIFORNIA PREPARED FOR Daniel Boyle Engineering 3142 Vista Way, Suite 303 Oceanside, California 92056 PREPARED BY Ninyo & Moore Geotechnical and Environmental Sciences Consultants 5710 Ruffin Road San Diego, California 92123 November 19, 2004 Project No. 105372001 5710 Ruffin Road • San Diego, California 92! 23 - Phone (858) 576-1000 • Fax (858J 576-9600 San Diego • Irvine • Ontario • Los Angeles • Oakland • Las Vegas • Salt Lake City • Phoenix Environmental Sciences Consultants November 19,2004 Project No. 105372001 Mr. Dan Smith Daniel Boyle Engineering 3142 Vista Way, Suite 303 Oceanside, California 92056 Subject: Geotechnical Evaluation San Marcos Boulevard Water Transmission Pipeline Replacement Project San Marcos, California Dear Mr. Smith: In accordance with your authorization, we have prepared this geotechnical evaluation report for the proposed San Marcos Boulevard Water Transmission Pipeline Replacement Project. This re- port presents our geotechnical findings, conclusions, and recommendations regarding the proposed improvements. We appreciate the opportunity to be of service on this project. If you have any questions or comments regarding our report, please contact the undersigned. Sincerely, NINYO & MOORE Robert T. Wheeler Project Geologist Erik Olsen, G.E. Chief Geotechnical Engineer Randal L. Irwin, C.E.G. Chief Engineering Geologist RTW/FOM/RI/EO/GTF/atf Distribution: (6) Addressee Gregory T. Farrand, C.E.G. Principal Geologist 5710 Ruffin Road • San Diego, California 92123 - Phone (858) 576-1000 • Fax [858J 576-9600 San Diego • Irvine • Ontario • Los Angeles • Oakland • Las Vegas • Salt Lake City • Phoenix San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 TABLE OF CONTENTS Page 1. INTRODUCTION 1 2. SCOPE OF SERVICES 1 3. PROJECT DESCRIPTION . 1 4. SITE DESCRIPTION 2 5. FIELD EXPLORATION AND LABORATORY TESTING 2 6. GEOLOGY AND SUBSURFACE CONDITIONS 3 6.1. Regional Geologic Setting 3 6.2. Site Geology 3 6.2.1. Fill 4 6.2.2. Colluvium 4 6.2.3. Santiago Formation 4 6.3. Rippability 4 6.4. Groundwater 5 6.5. Faulting and Seismicity 5 6.5.1. Strong Ground Motion 5 6.5.2. Surface Rupture 6 6.6. Landsliding 6 6.7. Liquefaction 6 7. CONCLUSIONS 6 8. RECOMMENDATIONS 7 8.1. Earthwork 7 8.1.1. Site Preparation 7 8.1.2. Temporary Excavations and Shoring 8 8.1.3. Excavation Characteristics 9 8.1.4. Microtunneling/Jack-and-Bore 9 8.2. Pipe Bedding and Modulus of Soil Reaction (E1) 10 8.3. Import Soil 11 8.4. Trench Backfill 11 8.5. Soil Corrosivity 12 8.6. Thrust Blocks 12 8.7. Pavement 13 8.8. Concrete 13 8.9. Construction Dewatering 14 8.10. Pre-Construction Conference 14 8.11. Construction Observation 14 9. LIMITATIONS 15 10. SELECTED REFERENCES 17 105372001 R San Marcos B1vd.doc ty/nyo San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 Table Table 1 - Pipe Zone Backfill 10 Table 2 - Recommended Pavement Section 13 Figures Figure 1 - Site Location Map Figure 2 - Boring Location Map Figure 3 - Fault Location Map Figure 4 - Shoring Lateral Earth Pressure Diagram Figure 5 - Thrust Block/Jacking Pit Reaction Lateral Earth Pressure Diagram Appendices Appendix A - Boring Logs Appendix B - Laboratory Testing Appendix C - Typical Earthwork Guidelines 105372001 R San Marcos Blvd.doc San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 1. INTRODUCTION In accordance with your request, we have completed a geotechnical evaluation for the design of the San Marcos Boulevard Water Transmission Pipeline Replacement Project. The project study area is located in San Marcos, California (Figure 1). The purpose of this evaluation was to pro- vide design recommendations regarding the geotechnical aspects of the proposed project. This report presents the results of our background review, subsurface evaluation, laboratory testing, geotechnical analyses, our conclusions regarding the geotechnical conditions along the subject alignment, and our recommendations for design. 2. SCOPE OF SERVICES Ninyo & Moore's scope of services for this project included the following: • Review of in-house data on the alignment vicinity and readily available published geotech- nical literature, including geologic maps, geologic reports, and aerial photographs. • Geologic reconnaissance of the pipeline alignment. • Coordination and mobilization for the subsurface exploration. Mark-out of existing under- ground utilities was conducted through Underground Service Alert • Performing a subsurface evaluation consisting of the excavating, logging, and sampling of five borings to evaluate the subsurface soils. • Performing laboratory testing on selected samples. • Geotechnical analysis of the data obtained. • Preparing this geotechnical report presenting our findings, conclusions, and recommenda- tions for the design and construction of the proposed project. 3. PROJECT DESCRIPTION It is our understanding that the project will include the replacement of approximately 4,000 lin- ear feet of existing water pipelines with a new 30-inch diameter steel cement mortar lined pipeline. The pipeline alignment begins at the Second San Diego Aqueduct located near the southeast corner of West San Marcos Boulevard and Rancho Santa Fe Road and extends along 105372001 R San Marcos Blvd.doc San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 West San Marcos Boulevard to the intersection of Avenida de las Rosas/Acacia Drive near the San Marcos/Carlsbad city boundary. Due to traffic considerations, a jack-and-bore crossing un- der Rancho Santa Fe Road is also planned with access pits located on either side of the intersection. The pipeline depth is assumed to be less than 15 feet except for the jack-and-bore crossing where it is assumed to be less than 35 feet in depth. 4. SITE DESCRIPTION The new pipeline will generally be constructed along the southern side of the existing West San Marcos Boulevard. Elevations along the alignment range from approximately 450 feet Mean Sea Level (MSL) at the western end of the alignment to approximately 588 feet MSL approximately 800 feet west of Rancho Santa Fe Road. The eastern end of the alignment is at an approximate elevation of 565 feet MSL. 5. FIELD EXPLORATION AND LABORATORY TESTING Five borings were drilled on October 23 and 26, 2004 using 8-inch diameter, hollow-stem augers on a truck-mounted drill rig. The borings were excavated to depths of up to approximately 41.5 feet below the ground surface (bgs). Relatively undisturbed and bulk samples were collected from the borings. The approximate locations of the borings are shown on Figure 2. The boring logs are presented in Appendix A. Laboratory testing of representative soil samples included in-situ moisture content and dry den- sity, gradation analyses, Atterberg limits, shear strength, R-value, and soil corrosivity. The results of the in-situ moisture content and dry density tests are shown at the corresponding sample depth on the boring logs in Appendix A. The results of the other laboratory tests performed are pre- sented in Appendix B. 105372001 R San Marcos Blvd doc San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 6. GEOLOGY AND SUBSURFACE CONDITIONS Our findings regarding regional and local geology, including faulting and seismicity, landslides, and groundwater conditions along the proposed pipeline route are provided in the following sec- tions. 6.1. Regional Geologic Setting The project area is situated in the western San Diego County section of the Peninsular Ranges Geomorphic Province. This geomorphic province encompasses an area that extends approximately 900 miles from the Transverse Ranges and the Los Angeles Basin south to the southern tip of Baja California (Norris and Webb, 1990). The province varies in width from approximately 30 to 100 miles, hi general, the province consists of rugged mountains underlain by Jurassic metavolcanic and metasedimentary rocks, and Cretaceous igneous rocks of the southern California batholith. The portion of the province in San Diego County, in which the project area is situated, generally consists of uplifted and dissected Tertiary-age sedimentary rocks. The Peninsular Ranges Province is traversed by a group of sub-parallel faults and fault zones trending roughly northwest. Several of these faults are considered active faults. The Whit- tier-Elsinore, San Jacinto, and San Andreas faults are active fault systems located northeast of the project area and the Agua Blanca-Coronado Bank, San Clemente, and Rose Canyon faults are active faults located west of the project area. Major tectonic activity associated with these and other faults within this regional tectonic framework consists primarily of right-lateral, strike-slip movement. Further discussion of faulting relative to the site is provided in the Faulting and Seismicity section of this report. 6.2. Site Geology Geologic units encountered during our subsurface evaluation include fill, colluvium, and materials of the middle Eocene Santiago Formation. Generalized descriptions of the earth units encountered are provided in the subsequent sections. More detailed descriptions are 105372001 R San Marcos Blvd. doc San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 provided on the boring logs in Appendix A. The approximate limits of units greater than " feet thick, encountered during our evaluation are shown on Figure 2.5 6.2.1. Fill Fill materials were encountered in our borings from the surface (beneath pavements), and ranged from depths 2 to 11 feet below the existing grade. In general, these materials consisted of damp to moist, very stiff, silty clay, and medium dense to dense, clayey and silty sand. 6.2.2. Colluvium Colluvium was encountered in boring B-l below fill (4 feet) to a depth of approxi- mately 6 feet below the existing ground surface. In general, the colluvium consisted of moist, very stiff, fine to medium, sandy clay. 6.2.3. Santiago Formation Eocene-age Santiago Formation was encountered in our borings below the fill and col- luvium to the depths explored. In general, the materials of the Santiago Formation consisted of moist to saturated, weakly to moderately indurated, silty claystone and clayey siltstone, and moderately to strongly cemented sandstone with some gravel and cobble lenses and concretions. 6.3. Rippability Our evaluation of the excavation characteristics of the on-site materials is based on the re- sults of our exploratory borings, our site reconnaissance, and our experience with similar materials. Our borings at the site encountered fill, colluvium, and materials of the Santiago Formation, hi our opinion, excavation to the anticipated depths of pipe placement for pipe- line construction can generally be performed with conventional, heavy-duty construction equipment. Strongly cemented zones, concretions, and cobble layers, however, will be en- countered during trenching operations within the Santiago Formation, and may require the use of breakout equipment. 105372001 R San Marcos Blvddoc San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 6.4. Groundwater Groundwater was encountered during our subsurface exploration in borings B-l and B-2 at depths of approximately 21 and 23 feet below the ground surface, respectively. Based on our experience, we anticipate that the groundwater table along the proposed alignment will gen- erally be below the depths of the proposed pipeline excavations. Water seepage into the trench may occur as the result of perched water zones in some areas. Seasonal fluctuations in groundwater conditions should also be anticipated. The proposed jack-and-bore pits are expected to extend below the encountered water table and the need for dewatering should be expected. 6.5. Faulting and Seismicity The project area is considered to be seisniically active. Based on our review of the refer- enced geologic maps and stereoscopic aerial photographs, as well as on our geologic field mapping, the subject alignment is not underlain by known active or potentially active faults (i.e., faults that exhibit evidence of ground displacement in the last 11,000 years and 2,000,000 years, respectively) (see Figure 3). The Rose Canyon Fault has been mapped ap- proximately 10 miles west of the alignment. In general, hazards associated with seismic activity include strong ground motion, ground surface rupture, liquefaction, seismically induced settlement, and tsunamis. These hazards are discussed in the following sections. 6.5.1. Strong Ground Motion Based on a Probabilistic Seismic Hazard Assessment for California, issued by the United States Geological Survey/California Geological Survey (2003), the project is lo- cated in a zone where the horizontal peak ground acceleration having a 10 percent probability of exceedance in 50 years is 0.27g (27 percent of the acceleration of grav- ity). The requirements of the governing jurisdictions and applicable building codes should be considered in the project design. 105372001 R San Marcos Blvd doc San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 6.5.2. Surface Rupture Ground surface rupture due to faulting is considered unlikely in the project area, as there are no known underlying active faults. Lurching or cracking of the ground surface as a result of nearby or distant seismic events is also considered unlikely. 6.6. Landsliding No landslides or indications of deep-seated landsliding were noted along the proposed alignment during our field exploration or our review of available geologic literature, topog- raphic maps, and stereoscopic aerial photographs. 6.7. Liquefaction Liquefaction of cohesionless soils can be caused by strong vibratory motion due to earth- quakes. Research and historical data indicate that loose, granular soils with clay contents of less than 20 percent, and saturated by a relatively shallow groundwater table, are susceptible to liquefaction. Based on the relatively dense nature of the subsurface materials encountered in our exploratory borings, it is our opinion that the potential for liquefaction at the site is not a design consideration. 7. CONCLUSIONS Based on our review of the referenced background data and subsurface evaluation, it is our opin- ion that the proposed pipeline project is feasible from a geotechnical standpoint, provided the conclusions and recommendations in this report are considered during the design and construc- tion of the project. In our opinion, the following will be significant in the planning, design, and construction of the proposed project: • The study alignment is underlain by fill, colluvium, and materials of the Santiago Forma- tion. • Subsurface conditions along the alignments should not preclude cut-and-cover and/or microtunneling/jack-and-bore construction methods. In general, the trench and jacking pit locations are likely to be rippable with standard heavy-duty excavation equipment. Gravel 105372001 RSanMarcosBlvd.doc San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 and cobble lenses and strongly cemented zones and concretions, are likely to be encountered during trenching and microtunneling/jack-and-bore construction operations within the Santi- ago Formation which the contractor should be made aware of. Shoring is anticipated for the jacking and receiving pit excavations, and is discussed in the recommendations section of this report. The materials encountered during our subsurface exploration, are considered suitable for reuse as backfill within the proposed trench zone. In addition, excavations in the Santiago Formation are anticipated to generate some quantities of cobbles and concretions greater than 3 inches in dimension. Disposal or crushing of this material should be anticipated. Deleterious material, such as trash, was generally not encountered during our reconnaissance or subsurface exploration. Trench zone materials should be in accordance with governing ju- risdictions. Groundwater was encountered at depths of 21 and 23 feet in our exploratory borings in the vicinity of the proposed jack-and-bore pits. Due to the anticipated depth of groundwater and proposed jack-and-bore pit depths, it is expected that dewatering will be needed. The con- tractor should be made aware of the potential need for dewatering. 8. RECOMMENDATIONS Recommendations pertaining to the geotechnical aspects of the project are based on the results of the engineering analysis, and our understanding of the project. Should the proposed project plans change, a supplemental geotechnical evaluation may be needed. 8.1. Earthwork In general, earthwork should be performed in accordance with the recommendations pre- sented in this report. The geotechnical consultant should be contacted for questions regarding the recommendations or guidelines presented herein. In addition, Typical Earth- work Guidelines for the project are included as Appendix C. In the event of a conflict in recommendations, the recommendations presented in the text of this report supersede those in Appendix C. 8.1.1. Site Preparation The project alignment should be cleared and grubbed prior to grading. Clearing and grub- bing should consist of the removal of asphalt concrete and other deleterious materials from 105372001 R San Marcos Blvd.doc San Marcos Boulevard Water Transmission November 19,2004 Pipeline Replacement Project Project No. 105372001 the areas to be graded. Clearing and grubbing should extend to the outside of the proposed excavation areas. The debris generated during clearing and grubbing should be removed from areas to be graded and disposed of off site at a legal dumpsite. 8.1.2. Temporary Excavations and Shoring We recommend that trenches and excavations be designed and constructed in accor- dance with Occupational Safety and Health Administration (OSHA) regulations. These regulations provide trench sloping and shoring design parameters for trenches up to 20 feet deep based on a description of the soil types encountered. Trenches over 20 feet deep should be designed by the Contractor's engineer based on site-specific geotechni- cal analyses. For planning purposes, we recommend that the following OSHA soil classifications be used: Fill and Colluvium Type C Santiago Formation Type B Upon making the excavations, the soil classifications and excavation performance should be evaluated in the field by the geotechnical consultant in accordance with the OSHA regulations. Temporary excavations should be constructed in accordance with OSHA recommenda- tions. For trench or other excavations, OSHA requirements regarding personnel safety should be met by laying back the slopes no steeper than 1.5:1 for fill or colluvium, and 1:1 for materials of the Santiago Formation. Temporary excavations that encounter seepage may be stabilized by placing sandbags or gravel along the base of the seepage zone. Excavations encountering seepage should be evaluated on a case-by-case basis. As an alternative to laying back the side walls, the excavations may be shored or braced. Temporary earth retaining systems will be subjected to lateral loads resulting from earth pressures. Shoring systems for excavations may be designed using the lateral earth pressure parameters indicated on Figure 4. 105372001 R San Marcos Blvd. doc San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 The design of the earth pressure diagram assumes that spoils from the excavation or other surcharge loads will not be placed above the excavation within a 1; 1 plane extend- ing up and back from the excavation. If spoil piles are placed closer than this to the braced excavation, the resulting surcharge loads should be considered in the bracing de- sign. We recommend that an experienced structural engineer design the shoring systems. The shoring parameters presented in this report should be considered as guide- lines. We recommend that completed sections of excavated areas be backfilled as soon as practicable. The stability of the excavations decreases over time as the soil dries and weathers. On-site safety of personnel is the responsibility of the contractor. 8.1.3. Excavation Characteristics Our evaluation of the excavation characteristics of the on-site materials is based on the results of our exploratory borings, our site observations, and our experience with similar materials. Our borings at the site encountered fill, colluvium, and materials of the Santi- ago Formation. In our opinion, excavation to the anticipated depths of pipe placement for pipeline construction can generally be performed with conventional equipment. Strongly cemented zones, concretions and cobbles, however, will likely be encountered during trenching operations within the Santiago Formation requiring the use of breakout equipment. 8.1.4. Microtunneling/Jack-and-Bore Design of shaft shapes, dimensions, and ground support systems for microtunnel- ing/jack-and-bore excavations will be at the contractor's option in order to be compatible with his construction equipment and methods. Soldier piles with lagging or shored excavations may serve as a suitable support system for rectangular shafts, while circular steel ribs in conjunction with steel or timber lagging or liner plates may be suit- able for circular shafts. 105372001 R San Marcos Blvddoc San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 Jacking reaction force is developed by the action of the micro-tunneling/jack-and-bore operation against the surface of the opposite wall of the jacking pit. The jacking force is resisted by the bearing of the wall. The allowable jacking force may be calculated using the lateral earth pressures shown on Figure 5. These earth pressures are applicable to Santiago Formation materials. Strongly cemented zones, concretions and cobbles, up to approximately 12 inches or more in size will likely be encountered in the Santiago Formation. Microtunneling and jack-and-bore equipment selected for tunneling through this material should be capable of processing these materials. 8.2. Pipe Bedding and Modulus of Soil Reaction (£') It is our recommendation that the new pipeline, where constructed in open excavations, be supported on 4 or more inches of granular bedding material. Granular pipe bedding should be provided to distribute vertical loads around the pipe. Bedding material and compaction re- quirements should be in accordance with this report, and the Standard Specifications for Public Works Construction (Public Works Standards, Inc., 2000), known as the "Greenbook." Section 306-1.2.1 in the Greenbook defines bedding requirements for the installation of pipe. The trench excavation should provide 6 to 8 inches of lateral clearance between the trench wall and the side of the pipe. Pipe bedding typically consists of graded aggregate. The pipe bedding and pipe zone backfill should conform to the following gradation limits: Table 1 - Pipe Zone Backfill Sieve Sizes 1" 3/4" No. 4 No. 30 No. 200 Percentage Passing Sieves 100% 90-100% 50-95% 25-45% 3-9% Mint/a 105372001 R San Marcos Blvd.doc 1Q T •* San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 Pipe bedding and pipe zone backfill should have a Sand Equivalent (SE) of 30 or greater, and be placed around the sides and top of the pipe. In addition, the pipe zone backfill should extend 1 foot or more above the top of the pipe. The modulus of soil reaction (E1) is used to characterize the stiffness of soil backfill placed at the sides of buried flexible pipes for the purpose of evaluating deflection caused by the weight of the backfill over the pipe. A soil reaction modulus of 1,000 pounds per square inch (psi) may be used for a 0- to 5-foot deep excavation backfilled with granular soil compacted to 90 percent based on the latest version of ASTM D 1557. A soil reaction modulus of 1,400 psi may be used for trenches 5 to 10 feet deep, a modulus of 1,600 psi for trenches 10 to 15 feet deep, and a modulus of 1,800 psi for trenches deeper than 15 feet. 8.3. Import Soil We recommend that import material, if any, consist of granular, very low to low expansive material (Uniform Building Code Expansion Index of 50 or less). The import material should have an organic content of less than 3 percent by volume (1 percent by weight), not contain rocks or lumps over 3 inches in largest dimension, and not more than 40 percent larger than 3/4 inches. The import material should also have low corrosion potential (electrical resistiv- ity greater than 1,000 ohm-cm, and soluble sulfate content of less than 0.2 percent). Import material should be evaluated by the geotechnical consultant at the borrow site for its suit- ability as fill prior to importation to the project site. 8.4. Trench Backfill The soils encountered in the borings should be generally suitable for reuse as backfill of the trench zone provided they are free of organic material (less than 3 percent by volume or 1 percent by weight), contaminated material, clay lumps, debris, and rocks greater than 3 inches in diameter. Rocks greater than 3/4 inches in diameter should not exceed 40 percent of the backfill volume. Trench zone materials should be in accordance with governing juris- dictions. Moore 105372001 R San Marcos Blvd doc JJ f San Marcos Boulevard Water Transmission November 19,2004 Pipeline Replacement Project Project No. 105372001 Backfill should be moisture conditioned to within approximately 2 percent of the optimum moisture content, placed, and compacted to 90 percent or greater relative compaction, as evaluated by the latest version of ASTM D 1557. Wet soils, if encountered, should be mois- ture conditioned to within approximately 2 percent of optimum prior to their placement as backfill. Backfill lift thickness will be dependent upon the type of compaction equipment util- ized. Backfill should generally be placed in uniform lifts not exceeding 8 inches in loose thickness. The upper 1 foot of pavement subgrade, base, and asphalt concrete should be com- pacted to 95 percent or more relative compaction. Special care should be exercised to avoid damaging the pipes during compaction of the backfill. 8.5. Soil Corrosivity Laboratory testing was performed on samples of the on-site soils to evaluate pH and electri- cal resistivity, as well as chloride and sulfate contents. The pH and electrical resistivity tests were performed in accordance with California Test Method 643, and the sulfate and chloride tests were performed in accordance with California Test Methods 416 and 422, respectively. These laboratory test results are presented in Appendix B. The results of the corrosivity testing indicated an electrical resistivity of the sample tested of approximately 620 ohm-cm. The soil pH of the sample was approximately 7.9, which is considered nearly neutral. The chloride content of the tested sample was approximately 270 ppm. The sulfate content of the tested sample was approximately 0.01 percent. Based on the laboratory test results and California Department of Transportation (Caltrans) criteria, the alignment would not be classified as a corrpsive site, which is defined as soil with more than 500 ppm chlorides, more than 0.20 percent sulfates, or pH less than 5.5. 8.6. Thrust Blocks Thrust blocks should be designed for the support of pipes in accordance with the pressure diagram on Figure 5. Thrust block excavations should be backfilled with compacted granu- lar material in accordance with the recommendations included in Section 8.4. 105372001 R San Marcos Blvd.doc 12 San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 8.7. Pavement Based on our understanding of the project, new pavement will include flexible (asphalt con- crete) pavement that will be subjected to heavy traffic on San Marcos Boulevard. Our laboratory test results indicated an R-value of less than 5, and a Traffic Index (TI) of 8.5 and 9. The following section describes our recommendations for the proposed pavement. Table 2 presents preliminary pavement section designs for the assumed traffic conditions. Table 2 - Recommended Pavement Section Traffic Index 8.5 9.0 Thickness Asphalt Concrete (inches) 5.0 5.5 Thickness Class II Aggregate Base (inches) 21.0 22.0 The pavement subgrade soils should be scarified to a depth of 12 inches or more, moisture conditioned and compacted to 95 percent or more of the specified laboratory dry density, as evaluated by the latest version of ASTM D 1557. Aggregate base material should be com- pacted to a relative compaction of 95 percent or more. The pavement sections are based on a preliminary soil R-value of less than 5. Final design of pavement sections should be based on R-value testing of finish grade soils after completion of the trench backfilling. 8.8. Concrete Concrete in contact with soil or water that contains high concentrations of soluble sulfates can be subject to chemical deterioration. Based on CBC criteria (CBC, 2001), the potential for sulfate attack is negligible for water-soluble sulfate contents in soil ranging from 0.00 to 0.10 percent by weight, and moderate for water-soluble sulfate contents ranging from 0.10 to 0.20 percent by weight. The potential for sulfate attack is severe for water-soluble sulfate con- tents ranging from 0.20 to 2.00 percent by weight and very severe for water-soluble sulfate contents over 2.00 percent by weight. Laboratory testing indicated the sulfate content of the samples tested was approximately 0.01 percent, which is considered a negligible potential for sulfate attack. Although our laboratory testing did not indicate a significant sulfate content, N/nuo 105372001 R San Marcos Blvddoc t -} T ** San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 due to the potential for variable conditions at the site, we recommend that Type V cement be used for concrete structures in contact with soil. The concrete should have a water-cement ra- tio no greater than 0.45 by weight for normal-weight aggregate concrete, and a slump no greater than 4 inches. 8.9. Construction Dewatering As discussed, groundwater was encountered in boring B-l and B-2 during our subsurface exploration. Accordingly, construction dewatering should be anticipated, particularly near the east end of the alignment, in the vicinity of the proposed tunnel excavation. Groundwater levels can fluctuate due to seasonal precipitation, irrigation, groundwater withdrawal or in- jection, and other factors. Discharge of water from excavations may require securing a National Pollution Discharge Elimination System (NPDES) permit. Compliance with the permit requirements may require testing and treatment of the water prior to discharge to storm drains. 8.10. Pre-Construction Conference We recommend that a pre-construction conference be held. Owner representatives, the civil engineer, geotechnical consultant, and contractor should be in attendance to discuss the plans and the project. 8.11. Construction Observation The conclusions and recommendations presented in this report are based on analysis of ob- served conditions encountered in our exploratory borings. If conditions are found to vary from those described in this report, the geotechnical consultant should be notified and addi- tional recommendations will be provided upon request. The project geotechnical consultant should review the final project drawings and specifications prior to the commencement of construction. The geotechnical consultant should perform appropriate observation and test- ing services during construction operations. fJinuo 105372001 R San Marcos Blvddoc J4 f «* San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 The recommendations provided in this report are based on the assumption that Ninyo & Moore will provide geotechnical observation and testing services during construction. In the event that it is decided not to utilize the services of Ninyo & Moore during construction, we request that the selected consultant provide the client with a letter (with a copy to Ninyo & Moore) indicating that they fully understand Ninyo & Moore's recommendations, and that they are in full agreement with the design parameters and recommendations contained in this report. Construction of proposed improvements should be performed by qualified subcon- tractors utilizing appropriate techniques and construction materials. 9. LIMITATIONS The field evaluation, laboratory testing, and geotechnical analyses presented in this geotechnical report have been conducted in general accordance with current practice and the standard of care exercised by geotechnical consultants performing similar tasks in the project area. No warranty, expressed or implied, is made regarding the conclusions, recommendations, and opinions pre- sented in this report. There is no evaluation detailed enough to reveal every subsurface condition. Variations may exist and conditions not observed or described in this report may be encountered during construction. Uncertainties relative to subsurface conditions can be reduced through addi- tional subsurface exploration. Additional subsurface evaluation will be performed upon request. Please also note that our evaluation was limited to assessment of the geotechnical aspects of the project, and did not include evaluation of structural issues, environmental concerns, or the pres- ence of hazardous materials. This document is intended to be used only in its entirety. No portion of the document, by itself, is designed to completely represent any aspect of the project described herein. Ninyo & Moore should be contacted if the reader requires additional information or has questions regarding the content, interpretations presented, or completeness of this document. This report is intended for design purposes only. It does not provide sufficient data to prepare an accurate bid by contractors. It is suggested that the bidders and their geotechnical consultant per- form an independent evaluation of the subsurface conditions in the project areas. The 105372001 R San Marcos Blvddoc i c San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 independent evaluations may include, but not be limited to, review of other geotechnical reports prepared for the adjacent areas, site reconnaissance, and additional exploration and laboratory testing. Our conclusions, recommendations, and opinions are based on an analysis of the observed site conditions. If geotechnical conditions different from those described in this report are encoun- tered, our office should be notified and additional recommendations, if warranted, will be provided upon request. It should be understood that the conditions of a site will change with time as a result of natural processes or the activities of man at the subject site or nearby sites. In addi- tion, changes to the applicable laws, regulations, codes, and standards of practice may occur due to government action or the broadening of knowledge. The findings of this report may, therefore, be invalidated over time, in part or in whole, by changes over which Ninyo & Moore has no con- trol. This report is intended exclusively for use by the client. Any use or reuse of the findings, conclu- sions, and/or recommendations of this report by parties other than the client is undertaken at said parties' sole risk. Ninuo 105372001 R San Marcos Blvddoc jg T *» San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 10. SELECTED REFERENCES American Public Works Association and Associated General Contractors of California (APWA), 1991, Standard Specifications for Public Works Construction: BNI Building News, Los Angeles, California. California Building Standards Commission, 2001, California Building Code, Title 24, Part 2, Volumes 1 and 2. California Division of Mines and Geology (CDMG), 1998, Maps of Known Active Fault Near- Source Zones in California and Adjacent Portions of Nevada: International Conference of Building Officials. Jennings, C.W, 1994, Fault Activity Map of California and Adjacent Areas: California Division of Mines and Geology, California Geologic Data Map Series, Map No. 6, Scale 1:750,000. Tan, S.S., and Kennedy, M.P, 1996, Geologic Maps of the Northwestern Part of San Diego County California: California Division of Mines and Geology, Open File Report 96-02. Norris, R.M., and Webb, R.W, 1990, Geology of California, Second Edition: John Wiley & Sons, Inc. United States Department of the Interior, Bureau of Reclamation, 1989, Engineering Geology Field Manual. United States Geological Survey, 1968 (photo-revised 1983), San Marcos Quadrangle, Califor- nia, San Diego County, 7.5-Minute Series (Topographic): Scale 1:24,000. United States Geological Survey, 2002, National Seismic Hazard Mapping Project, World Wide Web, http://geohazards.cr.usgs.gov/eq. Source USDA AERIAL PHOTOGRAPHS Date Flight Numbers 3-31-53 AXN-4M 68 and 69 Scale 1:20,000 Moore 105372001 R San Marcos Blvddoc J7 ' " 1900 Approximate Scale in Feet 3800 \REFERENCE: 2004 THOMAS GUIDE FOR SAN DIEGO COUNTY, STREET GUIDE AND DIRECTORY SITE LOCATION MAP SAN MARCOS BOULEVARD WATER PIPELINE REPLACEMENT SAN MARCOS, CALIFORNIA PROJECT NO. 105372001 DATE 11/04 X FIGURE A 1 ) 1 )105372001 blm fig 2 ) 1 1 ! I 1 I 1 1 1 1 LEGEND B-5 Approximate location of exploratory boring NOTE: ALL DIMENSIONS ARE APPROXIMATE 400 Approximate Scale in Feet 800 BORING LOCATION MAP SAN MARCOS BOULEVARD WATER PIPELINE SAN MARCOS, CALIFORNIA e PROJECT NO. 105372001 DATE 11/04 FIGURE 2 3 \ scale After Morris and Webb, 1990. r i FAULT LOCATION MAP SAN MARCOS BOULEVARD WATER PIPELINE REPLACEMENT SAN MARCOS, CALIFORNIA f PROJECT NO. I 105372001 DATE 11/04 \T FIGURE AJ GROUND SURFACE C H INCHES OR MORE 12 INCHES OR MORE f/ Pp D NOTES: 1. APPARENT LATERAL EARTH PRESSURE, P Pa = 29 H psf 2. CONSTRUCTION TRAFFIC INDUCED SURCHARGE PRESSURE, P P, =120 psf 3. PASSIVE LATERAL EARTH PRESSURE, P Pp = 300 D psf 4. ASSUMES GROUNDWATER NOT PRESENT 5. SURCHARGES FROM EXCAVATED SOIL OR CONSTRUCTION MATERIALS ARE NOT INCLUDED NOT TO SCALE SHORING LATERAL EARTH PRESSURES FOR BRACED EXCAVATION SAN MARCOS BOULEVARD WATER PIPELINE REPLACEMENT SAN MARCOS, CALIFORNIA r PROJECT NO. ^ 105372001 DATE "N 11/04 J FIGURE 4 ) GROUND SURFACE THRUST BLOCK/ JACKING PIT Dt (VARIES) D7(VARIES) Rr ASSUMPTIONS AND NOTES 1.= 27 2. Kp= 2.65 3. 7t = 120 pcf 4. No groundwater 5. Rp =(1/2)Kp7f (D|-D RP =160 (of-D?) pif fig 5 /y\oore THRUST BLOCK LATERAL EARTH PRESSURE (FILL MATERIAL) SAN MARCOS BOULEVARD WATER PIPELINE REPLACEMENT SAN MARCOS, CALIFORNIA r PROJECT NO. ^ 105372001 DATE "N 1 1/04 J FIGURED 5 ) San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 APPENDIX A BORING LOGS Field Procedure for the Collection of Disturbed Samples Disturbed soil samples were obtained in the field using the following methods. Bulk Samples Bulk samples of representative earth materials were obtained from the exploratory excava- tions. The samples were bagged and transported to the laboratory for testing. Field Procedure for the Collection of Relatively Undisturbed Samples Relatively undisturbed soil samples were obtained in the field using the following methods. The Modified Split-Barrel Drive Sampler The sampler, with an external diameter of 3.0 inches, was lined with 1-inch long, thin brass rings with inside diameters of approximately 2.4 inches. The sample barrel was driven into the ground with the weight of a hammer in general accordance with ASTM D 3550-01. The driving weight was permitted to fall freely. The approximate length of the fall, the weight of the hammer, and the number of blows per foot of driving are presented on the boring logs as an index to the relative resistance of the materials sampled. The samples were removed from the sample barrel in the brass rings, sealed, and transported to the laboratory for testing. 105372001 R San Marcos Blvddoc X LUQ 0 5-SAMPLES 1BulkDriven:!I Ii I\\ 0 BLOWS/FOOTxx/xx MOISTURE (%)9 *DRY DENSfTY (PCF)SYMBOL |II CLASSIFICATIONU.S.C.S.SM BORING LOG EXPLANATION SHEET Bulk sample. Modified split-barrel drive sampler. No recovery with modified split-barrel drive sampler. Sample retained by others. Standard Penetration Test (SPT). No recovery with a SPT. Shelby tube sample. Distance pushed in inches/length of sample recovered in inches. No recovery with Shelby tube sampler. Continuous Push Sample. Seepage. Groundwater encountered during drilling. Groundwater measured after drilling. ALLUVIUM: Solid line denotes unit change. T)ashed~!ine Senotes matenaFcGange. Attitudes: Strike/Dip b: Bedding c: Contact j: Joint f: Fracture F: Fault cs: Clay Seam s: Shear bss: Basal Slide Surface sf : Shear Fracture sz: Shear Zone sbs: Sheared Bedding Surface The total depth line is a solid line that is drawn at the bottom of the boring. mrt mm BORING LOG •ml^mmmmmmM' '^^^WPWHHHl^l '^Hi EXPLANATION OF BORING LOG SYMBOLSY ** f PROJECT NO. DA Rev. TE FIGURE 01/03 U.S.C.S. METHOD OF SOIL CLASSIFICATION MAJOR DIVISIONS SYMBOL TYPICAL NAMES COARSE-GRAINED SOILS(More than 1/2 of soil>No. 200 sieve size)FINE-GRAINED SOILS(More than 1/2 of soil<No. 200 sieve size)GRAVELS (More than 1/2 of coarse fraction > No. 4 sieve size) SANDS (More than 1/2 of coarse fraction <No. 4 sieve size) SILTS & CLAYS Liquid Limit <50 SILTS & CLAYS ft Liquid Limit >50 B ?:*:*••»:•»:«•'•**-?'• • • « m\ ..•" , i I i •i'" <j^? I it P PI 1H HIGHLY ORGANIC SOILS r; GW • GP ' GM ^ GC Y sw SP SM % sc ^ ML | CL 1°L MH ^ CH \ OH3 Pt Well graded gravels or gravel-sand mixtures, little or no fines Poorly graded gravels or gravel-sand mixtures, little or no fines Silty gravels, gravel-sand-silt mixtures Clayey gravels, gravel-sand-clay mixtures Well graded sands or gravelly sands, little or no fines Poorly graded sands or gravelly sands, little or no fines Silty sands, sand-silt mixtures Clayey sands, sand-clay mixtures Inorganic silts and very fine sands, rock flour, silty or clayey fine sands or clayey silts with Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean Organic silts and organic silty clays of low plasticity Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, elastic silts Inorganic clays of high plasticity, fat clays Organic clays of medium to high plasticity, organic silty clays, organic silts Peat and other highly organic soils GRAIN SIZE CHART CLASSIFICATION BOULDERS COBBLES GRAVEL Coarse Fine SAND Coarse Medium Fine SILT & CLAY RANGE OF GRAIN SIZE U.S. Standard Sieve Size Above 12" 12" to 3" 3" to No. 4 3" to 3/4" 3/4" to No. 4 No. 4 to No. 200 No. 4 to No. 10 No. 10 to No. 40 No. 40 to No. 200 Below No. 200 Grain Size in Millimeters Above 305 305 to 76.2 76.2 to 4.76 76.2 to 19.1 19.1 to 4.76 4.76 to 0.074 4.76 to 2,00 2.00 to 0.420 0.420 to 0.074 Below 0.074 PLASTICITY CHART j ft / CL-M / L V' / CL /f ML / ',<X / / / CH / ^ MH, > X OH X D 10 2O 30 40 SO 60 TO 3D 90 *)Q UQ U1D LIMIT (IX), % U.S.C.S. METHOD OF SOIL CLASSIFICATION Revised U.S.C.S. Clasmfication Chart Oo O CD III(T Z) W O u_oa. toz LU D a 3o DATE DRILLED 10/23/04 BORING NO.B-l GROUND ELEVATION Existing Grade SHEET OF METHOD OF DRILLING 8" Hollow-Stem Auger DRIVE WEIGHT 140 Ibs. Auto-Trip Hammer DROP SAMPLED BY RTW LOGGED BY RTW REVIEWED BY RJ_ DESCRIPTION/INTERPRETATION sc FILL:ryyjm Dark brown, moist, medium dense, silty to clayey fine to coarse SAND; few gravel. CL 10/6"14.6 118.3 COLLUVIUM: Dark brown, moist, very stiff, fine to medium sandy CLAY. 15 50/6" 12.1 114.9 SANTIAGO FORMATION: Dark yellowish to grayish brown, damp, weakly to moderately cemented, silty fine-grained SANDSTONE; weathered. Less weathered. Dark reddish brown; moist; weakly to moderately cemented; silty fine- to coarse-grained. Light green, moist, weaHylndurated, clayey SlLTSTONE. BORING LOG SAN MARCOS BOULEVARD WATER PIPELINE REPLACEMENT SAN MARCOS, CALIFORNIA PROJECT NO. 105372001 DATE 11/04 FIGURE A-1 "S X Q.UJ Q 20 25- 30- 35- 4.0 SAMPLESin c > Dii :1 ! i BLOWS/FOOT147 90 135 MOISTURE {%)21.8 19.3 DRY DENSITY (PCF)- —116.5 104.7 , 112.9 SYMBOL |LLL ill ;i|i| iHH CLASSIFICATIONu.s.c.s.— — Ninya&M^ DATE DRILLED 10/23/04 BORING NO. B-l GROUND ELEVATION ExistingGrade SHEET 2 OF 3 METHOD OF DRILLING 8" Hollow-Stem Auger DRIVE WEIGHT 140 Ibs. Auto-Trip Hammer DROP 30" SAMPLED BY RTW LOGGED BY RTW REVIEWED BY RI DESCRIPTION/INTERPRETATION SANTIAGO FORMATION: (Continued) Gray, saturated, weakly to moderately cemented, silty fine- to coarse-grained SANDSTONE. Dark gray and dark reddish brown; weakly cemented; silty fine- to medium- grained. Dark olive brown, moist, weakly to moderately indurated, silty CLAYSTONE. (Mive~brown, moist, moderately mSurateB, clayey SILTSTONE; trace~fine san3. BORING LOG •%•• ^& SAN MARCOS BOULEVARD WATER PIPELINE REPLACEMENT imBm ^5 SAN MARCOS, CALIFORNIA PROJECT NO. DATE FIGURE 105372001 11/04 A-2 a & I a.wa 40 fifl SAMPLES |^3CD as 1 BLOWS/FOOTn 85 MOISTURE (%)DRY DENSITY (PCF)SYMBOL |ill CLASSIFICATIONU.S.C.S.flf/nyo typ DATE DRILLED 10/23/04 BORING NO. B-I GROUND ELEVATION Existing Grade SHEET 3 OF 3 METHOD OF DRILLING 8" Hollow-Stem Auger DRIVE WEIGHT 140 Ibs. Auto-Trip Hammer DROP 30" SAMPLED BY RTW LOGGED BY RTW REVIEWED BY RI DESCRIPTION/INTERPRETATION SANTIAGO FORMATION: (Continued) Olive brown, moist, moderately to strongly indurated, clayey SILTSTONE. Total Depth = 41 feet. Groundwater encountered during drilling at approximately 20 feet. Groundwater measured after drilling at approximately 21 feet. Backfilled with approximately 13 cubic feet of bentonite grout, tremie method, and capped with 2 feet of concrete on 10/23/04. BORING LOG • ••• ^m SAN MARCOS BOULEVARD WATER PIPELINE REPLACEMENT imlM ^B SAN MARCOS, CALIFORNIA PROJECT NO. DATE FIGURE 105372001 11/04 A-3 •£ I 0.LUQ 0 - 10- 15- 0u " < 0 "5 " _ 1 - ! 3J 0 1 O 1 - I i J Oou.w5o 43 40 -M& T g HIo:13 wo 24.8 18.0 ftL «/ - oa. i i § 2>.fcQ 1 1 i"S : 99.8 = „ - || 107.9 || IH I J0& 11 •" zoj i— .3 < WJa oo^ ^w; WT0 (0 -35O 1 I t:i::"3 fe SM |! il I ^^AU^ DATE DRILLED 10/23/04 BORING NO. B-2 GROUND ELEVATION Existing Grade SHEET 1 OF 3 METHOD OF DRILLING 8" Hollow-Stem Auger DRIVE WEIGHT 140 Ibs. Auto-Trip Hammer DROP 30" SAMPLED BY RTW LOGGED BY RTW REVIEWED BY Rl DESCRIPTION/INTERPRETATION ASPHALT CONCRETE: Approximately 10" thick. BA&b: Brown, damp, dense, fine to medium SAND; with gravel. FILL: Brown, damp to moist, medium dense, silty fine to medium SAND; little gravel. SANTIAGO FORMATION: Light gray and dark reddish brown, damp, weakly indurated, silty CLAYSTONE. Gray, moist, weakly to mocferately indurated, clayey SILTSTONE, Driller reported gravel/cobbles at approximately 12'-18'. Fine-grained sandy siltstone with scattered interbeds of dark yellowish brown, damp, weakly cemented, silty fine-grained sandstone. BORING LOG • •*• *m SAN MARCOS BOULEVARD WATER PIPELINE REPLACEMENT !%•• ^S SAN MARCOS, CALIFORNIA PROJECT NO. DATE FIGURE 105372001 11/04 A-4 "3 &i Q.LUQ 20 25- 30- 35- 4f) I Vu ^^<V ^ 3 1 " : " - 3JJ • 3 1 Q ' ' 1 , — j oou. 35 O 60/4" 50/3" 50/5" 57/5" m mMMi7 g LUCCz> wo 14.0 ^16.3 7£ •/ OQ. t CO L1Ja £a 108.6 111.8 r/7 oCOp CO tt111 jiji SJ-V^H. . rrr^rrr kJ ~z.o1- . < CO9d"-coco^CO ->3o M|QT DATE DRILLED 10/23/04 BORING NO. B-2 GROUND ELEVATION Existing Grade SHEET 2 OF 3 METHOD OF DRILLING 8" Hollow-Stem Auger DRIVE WEIGHT 1 40 Ibs. Auto-Trip Hammer DROP 30" SAMPLED BY RTW LOGGED BY RTW REVIEWED BY RJ DESCRIPTION/INTERPRETATION SANTIAGO FORMATION: (Continued) Light grayish brown, moist, weakly cemented, silty fine- to coarse-grained SANDSTONE, Dark yellowish brown; saturated; weakly cemented; scattered gravel. Brown,~3ark yellbwisH Brown and gray, moist, wealdy induratedTclayey SILTSTONE; few fine sand. Dark gray, damp, moderately indurated, silty CLAYSTONE. BORING LOG (%V*^& SAN MARCOS BOULEVARD WATER PIPELINE REPLACEMENT imB% V5 SAN MARCOS, CALIFORNIA PROJECT NO. DATE FIGURE 105372001 11/04 A-5 & X Q.UJQ 40 fin Vu • <c * 3 J 0 1O > ooLLig 28 m m3Mi7 2 UJKU wo M«J oQ-, £ CO UJo £ Q f0 — OCO?fc &j zo1— . < OT2d"-« w^w -1 5o JM JMMof DATE DRILLED 10/23/04 BORING NO. B-2 GROUND ELEVATION Existing Grade SHEET 3 OF 3 METHOD OF DRILLING 8" Hollow-Stem Auger DRIVE WEIGHT 140 Ibs. Auto-Trip Hammer DROP 30" SAMPLED BY RTW LOGGED BY RTW REVIEWED BY RI DESCRIPTION/INTERPRETATION SANTIAGO FORMATION: (Continued) Light brown to light gray, moist to wet, moderately indurated, silty CLAYSTONE. Total Depth = 41.5 feet. Groundwater encountered during drilling at approximately 25 feet. Groundwater measured after drilling at approximately 23 feet. Backfilled with approximately 13 square feet of bentonite grout and patched with approximately 2 feet of concrete on 10/23/04. BORING LOG •%•* ^& SAN MARCOS BOULEVARD WATER PIPELINE REPLACEMENT imlM «S SAN MARCOS, CALIFORNIA PROJECT NO. DATE FIGURE 105372001 11/04 A-6 "55 X Q.WO 0 5- ?n SAMPLESCO 1 0 O ,BLOWS/FOOT63/6" 20/3"MOISTURE (%)DRY DENSITY (PCF)CLASSIFICATIONU.S.C.S.•• E 1 * !5T SM : :I j 1; DATE DRILLED 10/26/04 BORING NO. GROUND ELEVATION Existing Grade SHEET B-3 1 OF 1 METHOD OF DRILLING 8" Hollow-Stem Auger DRIVE WEIGHT 140 Ibs. Spooling Cable DROP 30" SAMPLED BY RTW LOGGED BY RTW REVIEWED BY RI DESCRIPTION/INTERPRETATION ASPHALT CONCRETE: Approximately 6" thick. BASE: Approximately 8" thick. FILL: Grayish brown, damp, dense, silty fine to coarse SAND; few gravel. SANTIAGO FORMATION: Light brown and dark yellowish brown, damp, moderately cemen SILTSTONE; and, scattered interbeds of gray, strongly cementec SANDSTONE. Layer of strongly cemented sandstone. Auger refusal. ted, fine-grained sandy ., fine- to coarse-grained Total Depth = 8.2 feet (Refiisal). Groundwater not encountered during drilling. Backfilled with bentonite grout and patched with concrete on 10/26/04. • BORING LOGjy/nya«typ•%•* ^& SAN MARCOS BOULEVARD WATER PIPELINE REPLACEMENT >mB V ^3 SAN MARCOS, CALIFORNIA PROJECT NO. DATE 105372001 11/04 FIGURE A-7 "S I Q.UJO 0 5- 10- 15- 90 CLJ « <C := J - 1 0J ) 1 Q I | 1 - ' J OOu. OT 3 29 - A *JMi7 g Ula:z> to O 12.5 23.2 . "fiu O ^£w LJa Vfra 116.6 96.7 1O OCD S W • •m:H! : i ******'**********'**** 1j?W?"WiHjdVd*?1 t*l*¥*rt*5fftuu Cj ~z.O1- .< COy<J "-to W-SCO =>5o SM sc Mpf DATE DRILLED 10/26/04 BORING NO. B-4 GROUND ELEVATION Existing Grade SHEET I OF 1 METHOD OF DRILLING 8" Hollow-Stem Auger DRIVE WEIGHT 140 Ibs. Spooling Cable DROP 30" SAMPLED BY RTW LOGGED BY RTW REVIEWED BY Rl DESCRIPTION/INTERPRETATION ASPHALT CONCRETE: Approximately 8" thick. BASE: Approximately 12" thick. FILL: Brown, damp to moist, medium dense, silty fine to medium SAND. Reddish brown; moist; medium dense; clayey fine to medium SAND. SANTIAGO FORMATION: Mottled dark reddish brown, yellowish brown, and gray, moist, weakly indurated, silty CLAYSTONE; weathered. Light yellowish brown and gray; less weathered. Total Depth =16.5 feet. Groundwater not encountered during drilling. Backfilled with bentonite grout and patched with concrete on 10/26/04. BORING LOG ff%V*^ft SAN MARCOS BOULEVARD WATER PIPELINE REPLACEMENT imBl ^3 SAN MARCOS, CALIFORNIA PROJECT NO. DATE FIGURE 105372001 11/04 A-8 c- I a.UJa 0 5- • 10- 15- "••CjLJ • < & "5 \ ~' - - •-r>LJj 0 a: O 1 1 11 i — j Oou.w o CO 45 . 27 50/5" m M£Mi7 ^s HIa: Z> w O 18.5 19.5 ^ C/ ot- £w HI O > 2Q 105.4 95.5 r/y<^ oCQ ?>(O 1 JB*^K^*rt"ft*t*r*t*t*tt*t*r**•**»t*t*r*l*t*¥)*t*r*t*t*Yrt*r*rr\rrr*t*}*¥\nin *j ~z.o1- . < CO ^d"-coW-SCO D 5o SP J SC r CH * vv°F DATE DRILLED 10/26/04 BORING NO. B-5 GROUND ELEVATION Existing Grade SHEET 1 OF 1 METHOD OF DRILLING 8" Hollow-Stem Auger DRIVE WEIGHT 140 Ibs. Spooling Cable DROP 30" SAMPLED BY RTW LOGGED BY RTW REVIEWED BY RI DESCRIPTION/INTERPRETATION ASPHALT CONCRETE: Approximated 8" thick. BASE: Grayish brown to dark gray, dense, fine to coarse SAND with GRAVEL. FILL: Grayish brown, moist, medium dense, clayey fine to coarse SAND; little gravel. Dark gray, moist, very stift7sllty CLAY. SANTIAGO FORMATION: Light brown, damp to moist, weakly cemented; fine-grained sandy SILTSTONE. Total Depth- 15.9 feet. Groundwater not encountered during drilling. Backfilled with bentonite grout and patched with concrete on 10/26/04. BORING LOG (%•* ^& SAN MARCOS BOULEVARD WATER PIPELINE REPLACEMENT «• • ^5 SAN MARCOS, CALIFORNIA PROJECT NO. DATE FIGURE 105372001 11/04 A-9 San Marcos Boulevard Water Transmission November 19,2004 Pipeline Replacement Project Project No. 105372001 APPENDIX B LABORATORY TESTING Classification Soils were visually and texturally classified in accordance with the Unified Soil Classification System (USCS) in general accordance with ASTM D 2488-00. Soil classifications are indicated on the logs of the exploratory excavations in Appendix A. ID-Place Moisture and Density Tests The moisture content and dry density of relatively undisturbed samples obtained from the ex- ploratory excavations were evaluated in general accordance with ASTM D 2937-00. The test results are presented on the logs of the exploratory excavations in Appendix A. Gradation Analysis Gradation analysis tests were performed on a selected representative soil sample in general ac- cordance with ASTM D 422-63. The grain size distribution curve is shown on Figure B-l. The test results were utilized in evaluating the soil classifications in accordance with the Unified Soil Classification System. Atterberg Limits A test was performed on a selected representative fine-grained soil sample to evaluate the liquid limit, plastic limit, and plasticity index in general accordance with ASTM D 4318-00. The test results were utilized to evaluate the soil classification in accordance with the Unified Soil Classi- fication System. The test results and classifications are shown on Figure B-2. Shear Strength Test Shear strength tests were performed on undisturbed samples in general accordance with ASTM D 3080-98 to evaluate the shear strength characteristics of selected materials. The samples were inundated during shearing to represent adverse field conditions. The results are shown on Figures B-3 and B-4. Soil Corrosivitv Tests Soil pH, and minimum resistivity tests were performed on representative samples in general ac- cordance with California Test (CT) 643. The chloride content of selected samples was evaluated in general accordance with CT 422. The sulfate content of selected samples was evaluated in general accordance with CT 417. The test results are presented on Figure B-5. 105372001 R San Marcos Blvd.doc San Marcos Boulevard Water Transmission November 19, 2004 Pipeline Replacement Project Project No. 105372001 R-Vahie The resistance value, or R-value, for site soils was evaluated in general accordance with Califor- nia Test Method 301. Samples were prepared and evaluated for exudation pressure and expansion pressure. The equilibrium R-value is reported as the lesser or more conservative of the two calculated results. The test results are shown on Figure B-6. 105372001 R San Marcos Blvddoc GRAVEL Coarse Fine SAND Coarse Medium Fine FINES Silt U.S. STANDARD SIEVE NUMBERS 3* 1-1/2- 1" 3/4" 1/2- 3/8-4 8 16 30 50 100 200 i- Oy eo S zLJ- LU£UJ I I I I t I 100 Symbol . • T I ^i 10 Hole No. B-1 Depth (ft) 10.0-11.0 \ \\ \ \\i v\ S \ ^i Clay HYDROMETER 1 0.1 GRAIN SIZE IN MILLIMETERS Liquid Limit _ Plastic Limit - Plasticity Index - D,o - D, - PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 422-63 (02) ^ r ^ J 0.01 0.001 0.0001 *, ~ cu - Passing c= No. 200 18 U.S.C.S SM J r GRADATION TEST RESULTS San Marcos Boulevard Water Pipeline Replacement L San Marcos, California ^ r PROJECT NO. ^ 105372001 DATE A r FIGURED 11/04 J V B-1 J 105372001 Sieve, SYMBOL • LOCATION B-5 DEPTH (FT) 6.0-9.0 LL (%) 56 PL {%) 18 PI (%) 38 U.S.C.S. CLASSIFICATION (Minus No. 40 Sieve Fraction) CH U.S.C.S. (Entire Sample) CH NP - Indicates non-plastic 70 60 ^ 50XIII I 40 t 30o w 20 10 ^r / -11. / M/ / CL / ML / >X orOL / • X / CH X /^ MH >X X or OH 0 10 20 30 40 50 60 70 80 90 100 LIQUID LIMIT (LL), % PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 431 &-00 ATTERBERG LIMITS TEST RESULTS San Marcos Boulevard Water Pipeline Replacement San Marcos, California (PROJECT NO. 105372001 DATE A 11/04 J FIGURED B-2 V 1DS372001 ANertwro Pfll 2000 1500 w£.. wwui (0 1000 500 500 1000 NORMAL STRESS (PSF) 1500 2000 Description Sandy CLAY Symbol Boring Number B-1 Depth (ft) 5.0-6.0 Shear Strength Peak Cohesion (psf) 520 Friction Angle (deg) 27 Soil Type CL Performed in general accordance with ASTM D 3080-03. SHEAR STRENGTH TEST RESULTS 1 San Marcos Boulevard Water Pipeline Replacement San Marcos, California r PROJECT NO. L 105372001 DATE A 11/04 J FIGURE B-3 105372001 Shear, B-1 @ 5-6.0 2500 2000 u_ 1500 WtoUJa: a)a:5 1000ICO 500 500 1000 1500 NORMAL STRESS (PSF) 2000 2500 Description Silty CLAYSTONE Symbol Boring Number B-2 Depth (ft) 5.0-6.5 Shear Strength Peak Cohesion (psf) 250 Friction Angle (deg) 28 Soil Type Formation Performed in general accordance with ASTM D 3080-03. SHEAR STRENGTH TEST RESULTS! San Marcos Boulevard Water Pipeline Replacement San Marcos, California r PROJECT NO. ^ 105372001 DATE ^ 11/04 J FIGUREJ 105372001 Shear, B-2 @ 5-6.5' CORROSIVITY TEST RESULTS SAMPLE LOCATION B-5 SAMPLE DEPTH (FT) 6.0-9.0 pH« 7.9 RESISTIVITY' (ohm-cm) 620 WATER-SOLUBLE SULFATE CONTENT IN SOIL ** {%) 0.01 CHLORIDE CONTENT *" (ppm) 270 * PERFORMED IN GENERAL ACCORDANCE WITH CALIFORNIA TEST METHOD 643 ** PERFORMED IN GENERAL ACCORDANCE WITH CALIFORNIA TEST METHOD 417 ... PERFORMED IN GENERAL ACCORDANCE WITH CALIFORNIA TEST METHOD 422 CORROSIVITY TEST RESULTS San Marcos Boulevard Water Pipeline Replacement San Marcos, California r PROJECT NO. L 105372001 DATE "A 11/04 J FIGURED B-5 105373001 Cwrosion Pal R-VALUE TEST RESULTS SAMPLE LOCATION B-5 SAMPLE DEPTH (FT) 6.0-9.0 SOIL TYPE CH R-VALUE Less than 5 PERFORMED IN GENERAL ACCORDANCE WITH CALIFORNIA TEST METHOD 301 R-VALUE TEST RESULTS San Marcos Boulevard Water Pipeline Replacement San Marcos, California r PROJECT NO. V 105372001 DATE ^ 11/04 J FIGURE B-6 D J 105372001 R-Value San Marcos Boulevard Water Transmission Appendix C Pipeline Replacement Project Project No. 105372001 APPENDIX C TYPICAL EARTHWORK GUIDELINES San Marcos Boulevard Water Transmission Appendix C Pipeline Replacement Project Project No. 105372001 TABLE OF CONTENTS Page 1. GENERAL 1 2. OBLIGATIONS OF PARTIES 2 3. SITE PREPARATION 3 4. TRENCH BACKFILL 3 5. SITE PROTECTION 4 6. DEFINITIONS OF TERMS 6 105372001 eanhworks.doc i Rev. 05/03 San Marcos Boulevard Water Transmission Appendix C Pipeline Replacement Project Project No. 105372001 TYPICAL EARTHWORK GUIDELINES 1. GENERAL These Guidelines are presented as general procedures for earthwork construction. They are to be utilized in conjunction with the project plans. These Guidelines are considered a part of the geo- technical report, but are superseded by recommendations in the geotechnical report in the case of conflict. Evaluations performed by the consultant during the course of pipeline installation may result in new recommendations which could supersede these specifications and/or the recom- mendations of the geotechnical report. It is the responsibility of the contractor to read and understand these Guidelines as well as the geotechnical report and project plans. 1.1. The contractor shall not vary from these Guidelines without prior recommendations by the geotechnical consultant and the approval of the client or the client's authorized rep- resentative. Recommendations by the geotechnical consultant and/or client shall not be considered to preclude requirements for approval by the jurisdictional agency prior to the execution of any changes. 1.2. The contractor shall perform the earthwork operations in accordance with these speci- fications, and shall be responsible for the quality of the finished product notwithstanding the fact that earthwork will be observed and tested by the geotechnical consultant. 1.3. It is the responsibility of the contractor to notify the geotechnical consultant and the jurisdictional agencies, as needed, prior to the start of work at the site and at any time that earthwork resumes after interruption. Each step of the earthwork operations shall be observed and documented by the geotechnical consultant and, where needed, re- viewed by the appropriate jurisdictional agency prior to proceeding with subsequent work. 1.4. If, during the earthwork operations, geotechnical conditions are encountered which were not anticipated or described in the geotechnical report, the geotechnical consult- ant shall be notified immediately and additional recommendations, if applicable, may be provided. 1.5. An as-built geotechnical report shall be prepared by the geotechnical consultant and signed by a registered engineer. The report documents the geotechnical consultants' observations, and field and laboratory test results, and provides conclusions regarding whether or not earthwork construction was performed in accordance with the geotech- nical recommendations and the plans. 105372001 earthworks.doc San Marcos Boulevard Water Transmission Appendix C Pipeline Replacement Proj ect Proj ect No. 105 3 72001 1.6. Definitions of terms utilized in the remainder of these specifications have been pro- vided in Section 6. 2. OBLIGATIONS OF PARTIES The parties involved in the projects earthwork activities shall be responsible as outlined in the following sections. 2.1. The client is ultimately responsible for each of the aspects of the project. The client or the client's authorized representative has a responsibility to review the findings and recommendations of the geotechnical consultant. The client shall authorize the contrac- tor and/or other consultants to perform work and/or provide services. During earthwork the client or the client's authorized representative shall remain on site or remain rea- sonably accessible to the concerned parties to make the decisions that may be needed to maintain the flow of the project. 2.2. The contractor is responsible for the safety of the project and satisfactory completion of pipeline installation and other associated operations, including, but not limited to, earthwork in accordance with the project plans, specifications, and jurisdictional agency requirements. The contractor shall further remain accessible during non- working hours times, including at night and during days off. 2.3. The geotechnical consultant shall provide observation and testing services and shall make evaluations to advise the client on geotechnical matters. The geotechnical con- sultant shall report findings and recommendations to the client or the client's authorized representative. 2.4. Prior to proceeding with any earthwork operations, the geotechnical consultant shall be notified two working days in advance to schedule the needed observation and test- ing services. 2.4.1. Prior to any significant expansion or reduction in the grading operation, the geotechnical consultant shall be provided with two working days notice to make appropriate adjustments in scheduling of on-site personnel. 2.4.2. Between phases of earthwork operations, the geotechnical consultant shall be provided with two working days notice in advance of commencement of ad- ditional operations. 10S372001 carthworks.doc San Marcos Boulevard Water Transmission Appendix C Pipeline Replacement Project Project No. 105372001 3. SITE PREPARATION Site preparation shall be performed in accordance with the recommendations presented in the following sections. 3.1. The client, prior to any site preparation or earthwork, shall arrange and attend a pre-construction meeting between the contractor, the design engineer., the geotechnical consultant, and representatives of appropriate governing authorities, as well as any other involved parties. The parties shall be given two working days notice. 3.2. Demolition in the areas to be graded shall include removal of pavements, and other manmade surface and subsurface improvements. Demolition of utilities shall include capping or rerouting of pipelines at the project perimeter. 3.3. The debris generated during demolition operations shall be removed from areas to be graded and disposed of off site at a legal dump site. Demolition operations shall be per- formed under the observation of the geotechnical consultant. 4. TRENCH BACKFILL The following sections provide recommendations for backfilling of trenches. 4.1. Trench backfill shall consist of granular soils (bedding) extending from the trench bot- tom to 1 or more feet above the pipe. On-site or imported fill which has been evaluated by the geotechnical consultant may be used above the granular backfill. The cover soils directly in contact with the pipe shall be classified as having a very low expansion po- tential, in accordance with UBC Standard 18-2, and shall contain no rocks or chunks of hard soil larger than 3/4-inch in diameter. 4.2. Trench backfill shall, unless otherwise recommended, be compacted by mechanical means to 90 percent or greater relative compaction as evaluated by ASTM D 1557-02. Backfill soils shall be placed in loose lifts 8-inches thick or thinner, moisture condi- tioned, and compacted in accordance with the recommendations of the geotechnical report and of these guidelines. The backfill shall be tested by the geotechnical consult- ant at vertical intervals of approximately 2 feet of backfill placed and at spacings along the trench of approximately 100 feet in the same lift. 4.3. Jetting of trench backfill materials is generally not a recommended method of densifi- cation, unless the on-site soils are sufficiently free-draining and provisions have been made for adequate dissipation of the water utilized in the jetting process. 4.4. If it is decided that jetting may be utilized, granular material with a sand equivalent greater than 30 shall be used for backfilling in the areas to be jetted. Jetting shall gener- 105372001 earthworks doc San Marcos Boulevard Water Transmission Appendix C Pipeline Replacement Project Project No. 105372001 ally be considered for trenches 2 feet or narrower in width and 4 feet or shallower in depth. Following jetting operations, trench backfill shall be mechanically compacted to the specified compaction to finish grade. 4.5. Trench backfill which underlies the zone of influence of foundations shall be mechani- cally compacted to a relative compaction of 90 percent or greater as evaluated by ASTM D 1557-02. The zone of influence of the foundations is generally defined as the roughly triangular area within the limits of a 1:1 (horizontal:vertical) projection from the inner and outer edges of the foundation, projected down and out from both edges. 4.6. Trench backfill within slab areas shall be compacted by mechanical means to a relative compaction of 90 percent or greater as evaluated by ASTM D 1557-02. For minor inte- rior trenches, density testing may be omitted or spot testing may be performed, as deemed appropriate by the geotechnical consultant. 4.7. When compacting soil in close proximity to utilities, care shall be taken by the contrac- tor so that mechanical methods used to compact the soils do not damage the utilities. 4.8. Clean granular backfill and/or bedding materials are not recommended for use in slope areas unless provisions are made for a drainage system to mitigate the potential for buildup of seepage forces or piping of backfill materials. 4.9. The contractor shall exercise the specified safety precautions, in accordance with OSHA Trench Safety Regulations, while conducting trenching operations. Such pre- cautions include shoring or laying back trench excavations at 1:1 or flatter, depending on material type, for trenches in excess of 5 feet in depth. The geotechnical consultant is not responsible for the safety of trench operations or stability of the trenches. 5. SITE PROTECTION The site shall be protected as outlined in the following sections. 5.1. Protection of the site during the period of construction shall be the responsibility of the contractor unless other provisions are made hi writing and agreed upon among the concerned parties. Completion of a portion of the project shall not be considered to preclude that portion or adjacent areas from the need for site protection, until such time as the project is finished as agreed upon by the geotechnical consultant, the client, and the regulatory agency. 5.2. The contractor is responsible for the stability of temporary excavations. Recommenda- tions by the geotechnical consultant pertaining to temporary excavations are made in consideration of stability of the finished project and, therefore, shall not be considered to preclude the responsibilities of the contractor. Recommendations by the geotechni- 105372001 carthworks.doc San Marcos Boulevard Water Transmission Appendix C Pipeline Replacement Project Project No. 105372001 cal consultant shall also not be considered to preclude more restrictive requirements by the applicable regulatory agencies. 5.3. Precautions shall be taken during the performance of site clearing, excavation, and grading to protect the site from flooding, ponding, or inundation by surface runoff. Temporary provisions shall be made during the rainy season so that surface runoff is away from and off the working site. Where low areas cannot be avoided, pumps shall be provided to remove water as needed during periods of rainfall. 5.4. Following periods of rainfall, the contractor shall contact the geotechnical consultant and arrange a walk-over of the site in order to visually assess rain-related damage. The geotechnical consultant may also recommend excavation and testing in order to aid in the evaluation. At the request of the geotechnical consultant, the contractor shall make excavations in order to aid in evaluation of the extent of rain-related damage. 5.5. Rain- or irrigation-related damage shall be considered to include, but may not be lim- ited to, erosion, silting, saturation, swelling, structural distress, and other adverse conditions noted by the geotechnical consultant. Soil adversely affected shall be classi- fied as "Unsuitable Material" and shall be subject to overexcavation and replacement with compacted fill or to other remedial grading as recommended by the geotechnical consultant. 105372001 eaithworks.doc San Marcos Boulevard Water Transmission Pipeline Replacement Project Appendix C Project No. 105372001 6. DEFINITIONS OF TERMS ALLUVIUM: AS-GRADED (AS-BUILT): BEDROCK: BORROW (IMPORT): CIVIL ENGINEER: CLIENT: COLLUVIUM: COMPACTION: CONTRACTOR: DEBRIS: ENGINEERED FELL: Unconsolidated detrital deposits deposited by flowing water; includes sediments deposited in river beds, canyons, flood plains, lakes, fans at the foot of slopes, and in estuaries. The site conditions upon completion of grading. Relatively undisturbed in-place rock, either at the surface or beneath surficial deposits of soil. Any fill material hauled to the project site from off-site areas. The Registered Civil Engineer or consulting firm responsible for preparation of the grading plans and surveying, and evaluating as-graded topographic conditions. The developer or a project-responsible authorized represen- tative. The client has the responsibility of reviewing the findings and recommendations made by the geotechnical consultant and authorizing the contractor and/or other con- sultants to perform work and/or provide services. Generally loose deposits, usually found on the face or near the base of slopes and brought there chiefly by gravity through slow continuous downhill creep (see also Slope Wash). The densification of a fill by mechanical means. A person or company under contract or otherwise retained by the client to perform, excavation, pipeline installation, and other site improvements. The products of clearing, grubbing, and/or demolition, or contaminated soil material unsuitable for reuse as compacted backfill, and/or any other material so designated by the geo- technical consultant. A fill which the geotechnical consultant or the consultant's representative has observed and/or tested during placement, enabling the consultant to conclude that the fill has been placed in substantial compliance with the recommendations of the geotechnical consultant and the governing agency re- quirements. 103372001 earthworks.**Rev- 5/03 San Marcos Boulevard Water Transmission Pipeline Replacement Project Appendix C Project No. 105372001 ENGINEERING GEOLOGIST: EROSION: EXCAVATION: EXISTING GRADE: FILL: FINISH GRADE: GEOFABRIC: GEOTECHNICAL CONSULTANT: GEOTECHNICAL ENGINEER: GRADING: LANDSLIDE DEPOSITS: A geologist registered by the state licensing agency who ap- plies geologic knowledge and principles to the exploration and evaluation of naturally occurring rock and soil, as re- lated to the design of civil works. The wearing away of the ground surface as a result of the movement of wind, water, and/or ice. The mechanical removal of earth materials. The ground surface configuration prior to grading; original grade. Any deposit of soil, rock, soil-rock blends, or other similar materials placed by man. The as-graded ground surface elevation that conforms to the grading plan. An engineering textile utilized in geotechnical applications such as subgrade stabilization and filtering. The geotechnical engineering and engineering geology con- sulting firm retained to provide technical services for the project. For the purpose of these specifications, observations by the geotechnical consultant include observations by the geotechnical engineer, engineering geologist and other per- sons employed by and responsible to the geotechnical consultant. A licensed civil engineer and geotechnical engineer, regis- tered by the state licensing agency, who applies scientific methods, engineering principles, and professional experience to the acquisition, interpretation, and use of knowledge of materials of the earth's crust to the resolution of engineering problems. Geotechnical engineering encompasses many of the engineering aspects of soil mechanics, rock mechanics, geology, geophysics, hydrology, and related sciences. Any operation consisting of excavation, filling, or combina- tions thereof and associated operations. Material, often porous and of low density, produced from instability of natural or manmade slopes. 105372001 eanhworks.doc San Marcos Boulevard Water Transmission Pipeline Replacement Project Appendix C Project No. 105372001 OPTIMUM MOISTURE: RELATIVE COMPACTION: SITE: SLOPE WASH: SLOUGH: SOIL: The moisture content that is considered optimum relative to compaction operations. The degree of compaction (expressed as a percentage) of a material as compared to the dry density obtained from ASTM test method D 1557-91. The particular parcel of land where earthwork is being per- formed. Soil and/or rock material that has been transported down a slope by gravity assisted by the action of water not confined to channels (see also Colluvium). Loose, uncompacted fill material generated during grading operations. Naturally occurring deposits of sand, silt, clay, etc., or com- binations thereof. 105372001 earthworks.doc