Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Home
My WebLink
About
5508; BUENA VISTA LIFT STATION FORCE MAIN VC-4; GEOTECHNICAL EVALUATION; 2007-04-21
GEOTECHNICAL EVALUATION BUENA VISTA LIFT STATION FORCE MAIN (VC-4) CARLSBAD, CALIFORNIA PREPARED FOR: Brown and Caldwell 9665 Chesapeake Drive, Suite 201 San Diego, California 92123 PREPARED BY: Ninyo & Moore Geotechnical and Environmental Sciences Consultants 5710 Ruffin Road San Diego, California 92123 April 21, 2007 Project No. 106289001 ~1fln9o&~oore~2' .·•-tr;::= Geotechrncal and Enwonmental Sciences Consult,mts 5710 Ruffin Road • San Diego, California 92123 • Phone (858) 576-1000 • Fax (858) 576-9600 San Diego • Irvine • Rancho Cucamonga • Los Angeles • Oakland • Las Vegas • Phoenix • Denver • El Paso Mr. Ed Matthews Brown and Caldwell 9665 Chesapeake Drive, Suite 201 San Diego, California 92123 Subject: Geotechnical Evaluation Buena Vista Lift Station Force Main (VC-4) Carslbad, California Dear Mr. Matthews: April 21, 2007 Project No. 106289001 In accordance with your authorization, we have performed a geotechnical evaluation for the new pipeline alignment for the Buena Vista Lift Station Force Main (VC-4) project in Carlsbad, California. This report presents our geotechnical findings, conclusions, and recommendations regarding the proposed project. This report addresses the portion of the pipeline alignment along Jefferson Street from its intersection with Interstate 5, northeast toward its intersection with Mar-ron Road. This report does not address the portion of the alignment at the Jefferson Street Bridge. We appreciate the opportunity to be of service on this project. Respectfully submitted, NINYO & MOORE Emily Lindstrom, P.G. 8483 Project Geologist Distribution: (5) Addresse t;;;~P.E Project Engineer 571 0 Ruffin Road • San Diego, California 92123 • Phone (858) 576-1000 • Fax (858) 576-9600 San Diego • Irvine • Rancho Cucamonga • Los Angeles • Oakland • Las Vegas • Phoenix • Denver • El Paso Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc i TABLE OF CONTENTS Page 1. INTRODUCTION....................................................................................................................1 2. SCOPE OF SERVICES............................................................................................................1 3. PROJECT AND SITE DESCRIPTION ...................................................................................2 4. SUBSURFACE EXPLORATION AND LABORATORY TESTING....................................2 5. GEOLOGY AND SUBSURFACE CONDITIONS.................................................................3 5.1. Regional Geologic Setting............................................................................................3 5.2. Site Geology.................................................................................................................4 5.2.1. Fill.......................................................................................................................4 5.2.2. Alluvium .............................................................................................................4 5.2.3. Santiago Formation.............................................................................................4 5.2.4. Landslide Deposits..............................................................................................5 5.3. Groundwater.................................................................................................................5 5.4. Excavation Characteristics............................................................................................5 6. GEOLOGIC HAZARDS..........................................................................................................5 6.1. Landslides.....................................................................................................................5 6.2. Faulting and Seismicity................................................................................................6 6.2.1. Strong Ground Motion........................................................................................6 6.2.2. Surface Rupture...................................................................................................6 6.2.3. Liquefaction........................................................................................................6 7. CONCLUSIONS ......................................................................................................................7 8. RECOMMENDATIONS..........................................................................................................7 8.1. Shoring..........................................................................................................................8 8.2. Excavation Bottom Stability.........................................................................................9 8.3. Construction Dewatering..............................................................................................9 8.4. Lateral Pressures for Thrust Blocks..............................................................................9 8.5. Modulus of Soil Reaction.............................................................................................9 8.6. Pipe Bedding...............................................................................................................10 8.7. Trench Backfill...........................................................................................................10 8.8. Fill Placement and Compaction..................................................................................11 8.9. Corrosion....................................................................................................................11 8.10. Concrete......................................................................................................................12 8.11. Pre-Construction Conference......................................................................................12 8.12. Construction Observation...........................................................................................12 9. LIMITATIONS.......................................................................................................................13 10. SELECTED REFERENCES..................................................................................................15 Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc ii Figures Figure 1 – Site Location Map Figure 2 – Boring Location Map Figure 3 – Regional Geologic Map Figure 4 – Fault Location Map Figure 5 – Lateral Earth Pressures for Braced Excavation Below Groundwater Figure 6 – Thrust Block Lateral Earth Pressure Diagram Appendices Appendix A – Boring Logs Appendix B – Laboratory Testing Appendix C – Typical Earthwork Guidelines Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 1 1. INTRODUCTION In accordance with your request and our proposal dated November 1, 2007, we have performed a geotechnical evaluation for the proposed Buena Vista Lift Station Force Main (VC-4) project in Carlsbad, California (Figure 1). The report addresses the portion of the pipeline alignment along Jefferson Street from its intersection with Interstate 5 northeast toward its intersection with Mar- ron Road. This report does not address the portion of the alignment at the Jefferson Street Bridge. The purpose of our study was to evaluate the geotechnical conditions at the site and provide rec- ommendations for the design and construction of the subject project. This report presents our findings, conclusions, and recommendations. 2. SCOPE OF SERVICES The scope of services for this study included the following: • Reviewing background information including available geotechnical reports, geologic maps, topographic maps, and aerial photographs. • Reviewing “as-built” project plans provided by Brown and Caldwell. • Coordinating with the County of San Diego Department of Environmental Health (DEH) to obtain boring permits. Work was conducted under DEH boring permit #LMON105570. • Meeting with City of Carlsbad personnel to acquire a Right-of-Way permit that included the preparation of traffic controls plans and providing traffic control during field exploration. Work was conducted under the City of Carlsbad Right-of-Way Permit No. RW080055. • Performing a geologic reconnaissance of the site. • Visiting the site to mark the boring locations. • Coordinating with Underground Service Alert (USA) to clear the boring locations for the presence of underground utilities. • Drilling, logging, and sampling of three exploratory borings with a truck-mounted rig equipped with 8-inch diameter hollow-stem augers. Borings were advanced to depths of up to approximately 16.5 feet the below ground surface. Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 2 • Collecting bulk and relatively undisturbed samples of the soils encountered during the perform- ance of the exploratory borings. Samples were then transported to our in-house geotechnical laboratory for testing. • Performing geotechnical laboratory testing on selected samples to evaluate appropriate de- sign parameters. • Compiling and analyzing the data obtained from our background review, subsurface evalua- tion, and laboratory testing. • Preparing this geotechnical report for preliminary design of the proposed pipeline alignment. 3. PROJECT AND SITE DESCRIPTION This portion of the proposed Buena Vista Lift Station Force Main project consists of a new sewer pipeline alignment. The proposed sewer pipeline alignment is found between Interstate 5 on the west side and the Buena Vista Lift Station on the east side of Jefferson Street in Carlsbad, California. We anticipate construction of the pipeline alignment will predominantly use conventional “cut and cover” trenching techniques. The project site is bordered to the northwest by Buena Vista Lagoon and to the southeast by com- mercial and residential areas, and a city park. The Buena Vista Lagoon is an ecological reserve, owned by the California Department of Fish and Game. The site is relatively flat adjacent to the la- goon, with a slope up from the roadway to the southeast. The site elevation is approximately 30 feet above mean sea level (MSL) at the subject portion of Jefferson Street (Figure 1). 4. SUBSURFACE EXPLORATION AND LABORATORY TESTING Our subsurface exploration was conducted on March 28, 2008 and consisted of the drilling, logging, and sampling of three small diameter exploratory borings. The borings were drilled with a truck- mounted drill rig equipped with an 8-inch diameter continuous-flight, hollow-stem auger. Borings were drilled to depths of approximately 16.5 feet. Borings B-1 and B-2 were located on the northwest side of Jefferson Street and boring B-3 was located on the southeast side of Jefferson Street; spaced along the proposed alignment. The purpose of the exploratory borings was to observe and sample the Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 3 underlying earth materials. Relatively undisturbed and bulk samples were obtained from the borings at selected intervals. The approximate locations of the borings are shown on Figure 2 and the corre- sponding logs are presented in Appendix A. Borings were backfilled with bentonite grout. Laboratory testing of samples obtained during our subsurface exploration included an evaluation of in-situ moisture content and dry density, gradation (sieve) analysis, No. 200 sieve analysis, Atterberg limits, shear strength, and soil corrosivity. The laboratory tests were performed at our in-house geotechnical laboratory. The results of the in-situ moisture content and dry density tests are shown at the corresponding sample depths on the boring logs in Appendix A. The results of the other laboratory tests performed are presented in Appendix B. 5. GEOLOGY AND SUBSURFACE CONDITIONS Our findings regarding regional and local geology for the subject site are provided in the follow- ing sections. 5.1. Regional Geologic Setting The project area is situated in the coastal section of the Peninsular Ranges Geomorphic Prov- ince. 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 Cali- fornia (Norris and Webb, 1990). The province varies in width from approximately 30 to 100 miles. In general, the province consists of rugged mountains underlain by Jurassic and Cretaceous metavolcanic and metasedimentary rocks, and Cretaceous igneous rocks of the southern California batholith. In the coastal portion of the province in San Diego County, that includes the project area, the metamorphic and granitic basement rocks are overlain by sedi- mentary materials that are Cretaceous, Tertiary, and Quaternary age (Figure 3). The Peninsular Ranges Province is traversed by a group of sub-parallel faults and fault zones trending roughly northwest. Several of these faults, which are shown on Figure 4, Fault Location Map, are considered active faults. The Whittier–Elsinore, and San Jacinto faults are active fault systems located northeast of the project area and the Rose Canyon, Agua Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 4 Blanca–Coronado Bank and San Clemente faults are active faults located west of the project area. Major tectonic activity associated with these and other faults within this regional tec- tonic 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. 5.2. Site Geology Based on our literature review, including published geologic maps, and on our field reconnais- sance, the project site is generally underlain by fill, alluvium, Santiago Formation, and landslide deposits. Fill is presumed to have been placed in conjunction with grading for the adjacent roadway. The landslide deposits were not located in the boring sites and therefore were not en- countered during drilling activities. More detailed descriptions of the geologic units encountered are provided on the boring logs in Appendix A. The regional geologic map details the geologic units in the project area (Figure 3). 5.2.1. Fill Fill material was encountered in all three exploratory borings to depths of approxi- mately 1.5 feet. As encountered, the fill material generally consisted of brown to reddish brown, damp, loose, silty, clayey sand with scattered gravel and pieces of asphalt. 5.2.2. Alluvium Alluvium was encountered underlying the fill in borings B-1 and B-2. The alluvium encoun- tered in boring B-1 extended to a depth of approximately 4.5 feet. The alluvium in boring B-2 was encountered to the total depth explored of 16.5 feet. As encountered, the alluvium gener- ally consisted of grayish brown to dark brown, damp, loose, silty sand with scattered gravel. 5.2.3. Santiago Formation The middle Eocene-age Santiago Formation was encountered underlying the alluvium and fill materials in borings B-1 and B-3 to the total depths explored. As encountered, the formational materials consisted of claystone, siltstone, sandstone and conglomerate. Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 5 5.2.4. Landslide Deposits Quaternary-age landslide deposits are located along the proposed alignment (Figure 3). The landslide deposits are classified as highly fragmented to largely coherent, uncon- solidated to moderately well consolidated. 5.3. Groundwater Groundwater was encountered during our subsurface exploration in borings B-2 and B-3 at approximate depths of 9 feet and 8 feet, respectively, corresponding to approximate eleva- tion of 21 and 22 feet above MSL. Variations in groundwater level may occur due to tidal influence, variations in ground surface topography, subsurface geologic conditions and structure, rainfall, and other factors. Due to the depth of the proposed alignment, it is anticipated that groundwater will be encountered during construction. 5.4. Excavation Characteristics Based on our review of published geologic maps and on our site reconnaissance, the on-site fill materials, alluvium, landslide deposits and Santiago Formation are expected to be generally ex- cavatable with normal heavy-duty earthmoving equipment. Drilling refusal was encountered within boring B-1. Difficulty excavation formational materials should be anticipated. 6. GEOLOGIC HAZARDS In general, geologic hazards include landsliding and those associated with seismic activity in- cluding strong ground motion, ground surface rupture, liquefaction, seismically induced dynamic settlement, and lateral spread. These hazards are discussed in the following sections. 6.1. Landslides Based on our review of referenced geologic maps, literature, topographic maps, stereoscopic aerial photographs, and our subsurface evaluation, Quaternary-age landslide deposits are lo- cated in the proposed site (Figure 3). As such, the potential for significant large-scale slope instability at the site is a design consideration. Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 6 6.2. Faulting and Seismicity The subject site is considered to be in a seismically active area. Our review of readily avail- able published geological maps and literature indicates that there are no 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), underlying the proposed site. The closest known active fault is the Rose Canyon-Newport-Inglewood Fault, which is ca- pable of generating an earthquake magnitude of 7.2 (SCEDC, 2008). The fault is located approximately 5.4 miles west of the site (Treiman, 1993). In general, hazards associated with seismic activity include strong ground motion, ground sur- face rupture, liquefaction, and tsunamis. These hazards are discussed in the following sections. 6.2.1. Strong Ground Motion Based on a Probabilistic Earthquake Hazard Analysis computer program by Blake (FRISKSP, 2001), the calculated peak ground acceleration for the Maximum Consid- ered Earthquake (PGAMCE) at the site, defined as having a 2 percent probability of exceedance in 50 years, with a statistical return period of approximately 2,475 years, is 0.31g (31 percent of the acceleration of gravity). The calculated peak ground accelera- tion for the Design Earthquake (PGADE), defined as two-thirds of PGAMCE is 0.21g. The requirements of the governing jurisdictions and applicable building codes should be considered in the design of structures. 6.2.2. Surface Rupture Ground surface rupture due to active faulting is not considered likely in the project area due to the absence of any known active faults underlying the site. Lurching or cracking of the ground surface as a result of nearby or distant seismic events is also considered unlikely. 6.2.3. Liquefaction Based on the dense formational material encountered in boring B-1, the potential for liquefaction at this location is low. However, based on the shallow groundwater and Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 7 loose granular soil encountered in borings B-2 and B-3, the potential for liquefaction at these locations is moderate. 7. CONCLUSIONS Based on our review of the referenced background data, geologic field reconnaissance, subsurface evaluation, and laboratory testing, it is our opinion that the proposed construction is feasible from a geotechnical standpoint, provided that the recommendations of this report are incorporated into the design and construction of the projects. Geotechnical considerations include the following: • The on-site materials are expected to be generally excavatable with conventional heavy-duty earthmoving equipment in good working condition. Difficulty in the Santiago Formation en- countered in boring B-1, in addition to difficulty excavating and rock breaking, should be anticipated. • Groundwater was encountered at depths of approximately 8 feet during drilling. The contrac- tor should be prepared to take appropriate measures to address the presence of shallow groundwater in excavations. • No active faults are reported underlying or adjacent to the site. The active Rose Canyon - Newport Inglewood Fault has been mapped approximately 5.4 miles east of the site. • Materials derived from on-site excavations are generally considered suitable for reused as trench backfill. However, the contractor should be prepared to perform additional processing of the material including aerating and/or moisture conditioning. • Based on our laboratory testing presented in the following sections and Caltrans (2006) cor- rosion guidelines, the site would be classified as corrosive. • Our subsurface evaluation encountered potentially liquefiable soils within borings B-2 and B-3. The pipeline should be designed to accommodate additional movements due to dy- namic settlement associated with soil liquefaction. 8. RECOMMENDATIONS The following sections include our geotechnical recommendations for the design and construc- tion of the proposed sewer pipelines. These recommendations are based on our evaluation of the site geotechnical conditions and our understanding of the planned construction. We recommend that the site earthwork and construction be performed in accordance with the following recom- Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 8 mendations, the applicable requirements of governing agencies, and the Typical Earthwork Guidelines included in Appendix C. In the event there are conflicting earthwork specifications between applicable standards and the following recommendations, we recommend that the more stringent requirements be followed. 8.1. Shoring It is anticipated that a portion of the alignment will be installed with conventional “cut and cover” trench techniques. We anticipate that shoring systems with bracings will be installed for trenches over 4 feet deep. The shoring system should be designed using the lateral earth pressures shown on Figure 5. The recommended design pressures are based on the assumptions that the shoring system is constructed without raising the ground surface elevation, that there are no surcharge loads, such as soil stockpiles and construction materials, and that no loads act above a 1:1 (horizontal:vertical) plane extending up and back from the base of the shoring system. The contractor should include the effect of any surcharge loads on the lateral pressures against the shoring. We anticipate that settlement of the ground surface will occur behind the shoring wall during ex- cavation. The amount of settlement depends heavily on the type of shoring system, the shoring contractor’s workmanship, and soil conditions. We recommend that structures/improvements in the vicinity of the planned shoring installation be reviewed with regard to foundation support and tolerance to settlement. To reduce the potential for distress to adjacent improvements, we recommend that the shoring system be designed to reduce the ground settlement behind the shoring system to ½ inch or less. Possible causes of settlement that should be addressed include settlement during shoring installation, excavations, construction vibrations, dewatering, and re- moval of the support system. The contractor should retain a qualified and experienced engineer to design the shoring sys- tem, evaluate the adequacy of these parameters and provide modifications for the design. Shoring plans should be reviewed by the district design engineer. We recommend that the contractor take appropriate measures to protect workers. Occupational Safety and Health Administration (OSHA) requirements pertaining to worker safety should be observed. Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 9 8.2. Excavation Bottom Stability In general, we anticipate that the bottom of the excavations will be stable and should provide suitable support to the proposed improvements. However, excavations that are close to or below the water table may be unstable. In general, unstable bottom conditions may be miti- gated by overexcavating the excavation bottom to suitable depths and replacing with compacted fill. Recommendations for stabilizing excavation bottoms should be based on evaluation in the field by Ninyo & Moore at the time of construction. 8.3. Construction Dewatering Groundwater was encountered in our exploratory borings and should be anticipated during construction. In addition, significant fluctuations in the groundwater level may occur. A spe- cialty dewatering contractor should be consulted. Dewatering measures during excavation operations should be prepared by the contractor’s engineer and reviewed by the district design engineer. Considerations for construction dewatering should include anticipated drawdown, volume of pumping, potential for settlement, and groundwater discharge. Disposal of ground- water should be performed in accordance with guidelines of the Regional Water Quality Control Board (RWQCB). 8.4. Lateral Pressures for Thrust Blocks Thrust restraint for buried pipelines may be achieved by transferring the thrust force to the soil outside the pipe through a thrust block. Thrust blocks may be designed using the lateral pas- sive earth pressures presented on Figure 6. Thrust blocks should be backfilled with granular backfill material, and compacted in accordance with recommendations presented in this report. 8.5. Modulus of Soil Reaction We anticipate some trenching will be used on this project. The modulus of soil reaction is used to characterize the stiffness of soil backfill placed at the sides of buried flexible pipe- lines for the purpose of evaluating deflection caused by the weight of the backfill above the pipe. For pipelines constructed in fill and lake deposit materials, we recommend that a Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 10 modulus of soil reaction of 1,000 pounds per square inch (psi) be used for design, provided that granular bedding material is placed adjacent to the pipe, as recommended in this report. 8.6. Pipe Bedding We recommend that pipes be supported on 6 inches or more of granular bedding material such as sand with a Sand Equivalent (SE) value of 30 or more. Bedding material should be placed around the pipe and 12 inches or more above the top of the pipe in accordance with the recent edition of the Standard Specifications for Public Works Construction (“Green- book”). We do not recommend the use of crushed rock as bedding material. It has been our experience that the voids within a crushed rock material are sufficiently large to allow fines to migrate into the voids, thereby creating the potential for sinkholes and depressions to de- velop at the ground surface. Where wet and loose or soft soil conditions are encountered, the trench excavation should be extended to approximately 1 foot or more below the pipe invert elevation and should be backfilled with gravel wrapped in filter fabric. Special care should be taken not to allow voids beneath and around the pipe. Compaction of the bedding material and backfill should proceed up both sides of the pipe. Trench backfill, including bedding material, should be placed in accordance with the recommendations pre- sented in this report. 8.7. Trench Backfill Trench backfill material should be comprised of low-expansion-potential granular soil and should be free of trash, debris, roots, vegetation, or deleterious materials. Backfill should generally be free of rocks or hard lumps of material in excess of 3 inches in diameter. Rocks or hard lumps larger than about 3 inches in diameter should be broken into smaller pieces or should be removed from the site. Wet materials generated from on-site excavations should be aerated to a moisture content near the laboratory optimum to allow compaction. Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 11 On-site clayey and organic soils encountered during excavation should be selectively re- moved and stockpiled separately. The clayey and organic soils are not considered suitable for trench backfill and should be disposed of off site. Imported materials should consist of clean, granular materials with a low expansion potential, corresponding to an expansion index of 50 or less as evaluated in accordance with the Uni- form Building Code (UBC) Standard 18-2. The corrosion potential of proposed imported soils should also be evaluated if structures will be in contact with the imported soils. Import mate- rial should be submitted to the geotechnical consultant for review prior to importing to the site. The contractor should be responsible for the uniformity of import material brought to the site. 8.8. Fill Placement and Compaction Fill and trench backfill should be compacted in horizontal lifts to a relative compaction of 90 percent or more as evaluated by the latest edition of the American Society for Testing and Materials (ASTM) D 1557. Aggregate base and the upper 12 inches of subgrade beneath pave- ment areas should be compacted to a relative compaction of 95 percent or more. Fill soils should be placed at or above the laboratory optimum moisture content as evaluated by the latest edition of ASTM D 1557. The optimum lift thickness of fill will depend on the type of compaction equipment used, but generally should not exceed 8 inches in loose thickness. Special care should be taken to avoid pipe damage when compacting trench backfill above the pipe. 8.9. Corrosion Laboratory testing was performed on a representative sample of the on-site earth materials to evaluate pH and electrical resistivity, as well as chloride and sulfate contents. The pH and electrical resistivity tests were performed in accordance with California Test (CT) 643 and the sulfate and chloride content tests were performed in accordance with CT 417 and CT 422, respectively. These laboratory test results are presented in Appendix B. The results of the corrosivity testing indicated an electrical resistivity of 370 ohm-cm, a soil pH of 6.1, a chloride content of 940 parts per million (ppm), and a sulfate content of Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 12 0.035 percent (i.e., 350 ppm). Based on our laboratory test results, the site would be classi- fied as a corrosive site, which is defined as soil with more than 500 ppm chlorides, more than 0.2 percent sulfates, or pH less than 5.5. We recommend that corrosion protection for im- provements in contact with site soils be designed by a corrosion engineer. 8.10. Concrete Concrete in contact with soil or water that contains high concentrations of water-soluble sulfates can be subject to premature chemical and/or physical deterioration. The soil sample tested in this evaluation indicated a water-soluble sulfate content of 0.035 percent by weight (i.e., about 350 ppm). According to the American Concrete Institute (ACI) 318-05 building code, the poten- tial for sulfate attack is negligible. Due to the potential variability of site soils and the proximity of the site to a marine environment, consideration should be given to using Type V cement and concrete with a water-cement ratio no higher than 0.45 by weight for normal weight aggregate concrete and a 28-day compressive strength of 4,500 psi or more for the project. 8.11. Pre-Construction Conference We recommend that a pre-construction conference be held. The owner and/or their represen- tative, the governing agencies’ representatives, the civil engineer, Ninyo & Moore, and the contractor should be in attendance to discuss the plans and the project. 8.12. 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, Ninyo & Moore should be notified, and additional rec- ommendations will be provided upon request. Ninyo & Moore should review the project drawings and specifications prior to the commencement of construction. Ninyo & Moore should perform the needed observation and testing services during construction operations. Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 13 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 im- plied, is made regarding the conclusions, recommendations, and opinions presented 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. Uncertain- ties relative to subsurface conditions can be reduced through additional subsurface exploration. Additional subsurface evaluation will be performed upon request. Also, note that our evaluation was limited to assessment of the geotechnical aspects of the project, and did not include evaluation of struc- tural issues, environmental concerns, or the presence 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 independent Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 14 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 encountered, 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 could change with time as a result of natural processes or the activities of man at the subject site or nearby sites. In addition, changes to the applicable laws, regulations, codes, and standards of practice may occur due to government ac- tion 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 control. 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. Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 15 10. SELECTED REFERENCES American Concrete Institute (ACI), 2005, ACI 318-05 Building Code requirements for Structural Concrete and Commentary.. Blake, T.F., 2001, FRISKSP (Version 4.00) A Computer Program for the Probabilistic Estimation of Peak Acceleration and Uniform Hazard Spectra Using 3-D Faults as Earthquake Sources. Boore, D.M., Joyner. W.B., and Fumal, T.E., 1997, Equations for estimating horizontal response spectra and peak acceleration from western North American earthquakes: a summary of recent work: Seismological Research Letters, v. 68, p. 128-153. California Building Standards Commission (CBSC), 2007, California Building Code (CBC), Ti- tle 24, Part 2, Volumes 1 and 2. California Division of Mines and Geology, 1998, Maps of Known Active Fault Near-Source Zones in California and Adjacent Portions of Nevada: International Conference of Build- ing Officials: dated February. California Geological Survey, 1999, Seismic Shaking Hazards Maps of California: Map Sheet 48. California Department of Transportation (Caltrans), 2006, Corrosion Guidelines, Division of Engi- neering and Testing Services, Corrosion Technology Branch: dated September. Cao, Tianqing, Bryant, William A., Rowshandel, Badie, Branum, David, and Wills, Christopher J., 2003, The Revised 2002 California Probabilistic Seismic Hazard Maps: dated June. 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. Kennedy, M.R. and Tan, S.S, 2005, Geologic Map of the Oceanside 30’ x 60’ Quadrangle, California. Ninyo & Moore, In-house proprietary information. Ninyo & Moore, 2007, Proposal for Geotechnical Evaluation, Buena Vista Lift Station Force Main (VC-4), Carlsbad, California, Proposal No. P-7838, dated November 1. Norris, R. M. and Webb, R. W., 1990, Geology of California, Second Edition: John Wiley & Sons, Inc. Public Works Standards, Inc., 2006, Greenbook, Standard Specifications for Public Works Con- struction. Southern California Earthquake Data Center, (SCEDC), http://www.data.scec.org/ Tan, S.S. and Kennedy, M.R., 1996, Geologic Map of the Oceanside, San Luis Rey, and San Mar- cos 7.5-Minute Quadrangle, San Diego County, California. Treiman, J.A., 1993, The Rose Canyon Fault Zone, Southern California: California Division of Mines and Geology, Open-File Report 93-02. Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 16 United State Geological Survey (USGS), 2007, Seismic Hazard Curves and Uniform Hazard Re- sponse Spectra, Version 5.0.8, dated November 20. AERIAL PHOTOGRAPHS Source Date Flight Numbers Scale USDA 4/14/53 AXN-9M 45 and 46 1:20,000 SEE J2 1 US1AIW Vltua.i. 2 PirStt~aA l PASOCMl!A$ 4 PAS DC al.Oe:J • IWOC) "' 6 PAS DC 7 PAS DC 8 PAS DC ITA 9 PAS IX SO) 10 MS CE l5 U.URWIINCi SEE HJ 1 ~IAOnm 2 VIA JW( lVIA~ 4¥1Af0:AS S VIASMIICA.5. 6 YIA,YEAA 7VIACIS:OCL • vu, oonsc 41 VlAtt:IU IO'tlA.ltlWJ, H CLWCID(lA l2 YIA(IJJf,' (FIIA1££ 8(,<CH) REFERENCE: 2005 THOMAS GUIDE FOR SAN DIEGO COUNTY, STREET GUIDE AND DIRECTORY. 0 2400 4800 APPROXIMATE SCALE IN FEET .g> NOTE: ALL DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATE. E Map©Rand McNally, R.L.07-S-129 "iii g ~ SITE LOCATION MAP ~1----------~~----------+---------------------------------1 PROJECT NO. 106289001 DATE 4/08 BUENA VISTA LIFT STATION FORCE MAIN CARLSBAD, CALIFORNIA FIGURE 1 N OJ "' 0 APPROXIMATE SCALE 500 1000 FEET E NOTE: ALL DIMENSIONS. DIRECTIONS AND LOCATIONS ARE APPROXIMATE. LEGEND -4'-B-3 APPROXIMATE LOCATION OF -EXPLORATORY BORING TD-15·5 TD=TOTAL DEPTH IN FEET BORING LOCATION MAP I l(in90&/ft&&~e ~1---_ ___:. ____ ~___:. _______ --4-________________________ --I PROJECT NO. 106289001 DATE 4/08 BUENA VISTA LIFT STATION FORCE MAIN CARLSBAD, CALIFORNIA FIGURE 2 (') APPROXIMATE SCALE .g> " ·g, 0 2000 4000 FEET \"• I • I I \ ,, ( t\ \ \ \ \ ··,. l., \ \ t.~ ' \ ._... -. \ ... ~,•, ~ ---~ .. ..,., ', '-r' \ \ \ \ . ' \ ~ \, \. LEGEND \•:Ql!i' I l~~I \oop6-1 (0op2-3 I Tsa I ~ LANDSLIDE DEPOSITS MARINE BEACH DEPOSITS OLD PARALIC DEPOSITS, UNIT 6-7 OLD PARALIC DEPOSITS, UNIT 2-4 SANTIAGO FORMATION TONALITE, UNDIVIDED ) r 75 FAULT -SOLID WHERE ACCURATELY _________ _L LOCATED, DASHED WHERE APPROXIMATE, DOTTED WHERE CONCEALED. ARROW AND NUMBER INDICATE DIRECTION AND ANGLE OF DIP OF FAULT PLANE 5 -L STRIKE AND DIP OF BEDS g o, NOTE: ALL DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATE. REFERENCE: KENNEDY, M.P. AND TAN, S.S .. 2005, GEOLOGIC MAP OF THE OCEANSIDE 30' X 60' QUAORANGLE, CALIFORNIA. ~1--------------------...----------------------------------t REGIONAL GEOLOGIC MAP ; 1(in90&1(too~e :g t----------,-----------+----------------------------, PROJECT NO. 106289001 DATE 4/08 BUENA VISTA LIFT STATION FORCE MAIN CARLSBAD, CALIFORNIA FIGURE 3 MALIBU COAST ... :·:·:·:·:·::.:.~~ .. ···:.~.······: '1,,,_ 'Pi~ ............. . ..., ~ SANTA CATALINA "?~~ '~t~tip ........ . '1,4tj,,,. ·•:•::.: .. \: ...... \:\ ~~"k. ............... .. '"Y .......... .. Riocc APPROXIMATE SCALE 0 30 0~i!t:\ .. \\\~~ \' \ 60 MILES ' ---i.._ "' ' ~-\ SAN BERNARDINO CO. \ t' \BA:ER \ AMBOY • DESERT CENTER • ~ RIVERSIDE CO. -IMPERIAL -CO:- g ~ ~ ._N_o_TE_: A_LL_o_1M_EN_s_10N_s_. 0_1R_ECT_1_0N_s_AN_D_Lo_c_ATI_o_Ns_A_RE_A_PP_Ro_x_1M_AT_E __________________________ A_FTE_R N..,o .... RR_1s_A_ND_WE_BB_, 1-99--10 l(ln9o&·••re PROJECT NO. DATE 106289001 4/08 FAULT LOCATION MAP BUENA VISTA LIFT STATION FORCE MAIN CARLSBAD, CALIFORNIA FIGURE 4 IO "' "' ~ a. g 0, a, "' :g r i i ~•---Pa1---•~1 GROUND SURFACE SHORING ~ ------------i I 7----0 BAACEJ 12 INCHES OR MORE T NOT TO SCALE + + NOTES: 1. APPARENT LATERAL EARTH PRESSURES, Pa1 AND Pa2 fl,1 = 24 H psf Pa2 = 12 H psf 2. CONSTRUCTION TRAFFIC INDUCED SURCHARGE PRESSURE, P5 P5 = 120 psf 3. WATER PRESSURE, Pw Pw= 62.4 h2 psf 4. PASSIVE PRESSURE, PP Pp= 250 D psf 5. SURCHARGES FROM EXCAVATED SOIL OR CONSTRUCTION MATERIALS ARE NOT INCLUDED 6. H, h1 , h2 AND DARE IN FEET 7. + GROUNDWATER TABLE H 12 INCHES OR MORE T D 1 ------------------------------------------------ PROJECT NO. DATE 106289001 4/08 LATERAL EARTH PRESSURES FOR BRACED EXCAVATION BELOW GROUNDWATER BUENA VISTA LIFT STATION FORCE MAIN CARLSBAD, CALIFORNIA FIGURE 5 -"' 2 :S 5 0 Ol IX) N ID GROUND SURFACE~ . ~I I fwl I fillffi3Tt ~ ··•-111-111-11 NOT TO SCALE THRUST BLOCK I\ I \ I \ d (VARIES) \ \ \ '--1 •--Pp2 • I NOTES: 1. GROUNDWATER BELOW BLOCK Pp= 250(D2.d2 ) lb/ft 2. GROUNDWATER ABOVE BLOCK Pp= 250 ( D - d )I 124.8h + 58 ( D+d )lib/ft 3. ASSUMES BACKFILL IS GRANULAR MATERIAL D (VARIES) 4. ASSUMES THRUST BLOCK IS ADJACENT TO COMPETENT MATERIAL 5. D, d AND h ARE IN FEET 6. -!-GROUNDWATER TABLE OL-------------------,,.....------------------------,~-----t PROJECT NO. DATE 106289001 4/08 THRUST BLOCK LATERAL EARTH PRESSURE DIAGRAM BUENA VISTA LIFT STATION FORCE MAIN CARLSBAD, CALIFORNIA FIGURE 6 Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 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. The Standard Penetration Test (SPT) Sampler Disturbed drive samples of earth materials were obtained by means of a Standard Penetra- tion Test sampler. The sampler is composed of a split barrel with an external diameter of 2 inches and an unlined internal diameter of 13/8 inches. The sampler was driven into the ground 12 to 18 inches with a 140-pound hammer free-falling from a height of 30 inches in general accordance with ASTM D 1586-99. The blow counts were recorded for every 6 inches of penetration; the blow counts reported on the logs are those for the last 12 inches of penetration. Soil samples were observed and removed from the sampler, bagged, sealed, 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 the hammer of the drill rig in general accordance with ASTM D 3550. 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 in- dex 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. 10 15 t5 I ·o ...I co XX/XX SM BORING LOG EXPLANATION SHEET Bu sampe. 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. DashedTine aenotes materialchange. ------------------- 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 boring. BORING LOG EXPLANATION OF BORING LOG SYMBOLS PROJECT NO. DATE FIGURE Rev. 01/03 U.S.C.S. METHOD OF SOIL CLASSIFICATION MAJOR DIVISIONS SYMBOL TYPICAL NAMES Well graded gravels or gravel-sand mixtures, little or no fines GRAVELS Poorly graded gravels or gravel-sand (More than 1/2 of coarse mixtures little or no fines 1r-r-,.;:-.-,,..,..,..t---+------------------------------1 fraction > No. 4 sieve size) SANDS (More than 1/2 of coarse fraction <No. 4 sieve size) SIL TS & CLAYS Liquid Limit <SO SILTS& CLAYS Liquid Limit >50 HIGHLY ORGANIC SOILS GRAIN SIZE CHART RANGE OF GRAIN SIZE CLASSIFICATION U.S. Standard Grain Size in Sieve Size Millimeters BOULDERS Above 12" Above 305 COBBLES 12" lo 3" 305 to 76.2 GRAVEL 3" to No. 4 76.2 to 4.76 Coarse 3" to 3/4" 76.2 to 19. l Fine 3/4" to No. 4 19.1 to4.76 SAND No. 4 to No. 200 4.76 to 0,075 Coarse No. 4 to No. 10 4.76 lo 2.00 Medium No. 10 to No. 40 2.00 to 0.420 Fine No. 40 to No. 200 0.420to0.G75 SILT&CLAY Below No. 200 Below0.075 USCS Soil Classification 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, silt or cla e fine sands or cla e silts with Inorganic clays of low to medium plasticity, ravell cla s sand cla s silt cla s lean Organic silts and organic silty clays of low lasticit Inorganic silts, micaceous or diatomaceous fine sand or silt soils, elastic silts Inorganic clays of high plasticity, fat clays Organic clays of medium to high plasticity, or anic silt cla s, or anic silts Pt Peat and other highly organic soils PLASTICITY CHART 70 60 / / .,v / CH / V / v' / CL / MH&OH .I / / / I r CL-L ., ML&OL 0 f I 0 'l} 20 30 40 SO 60 70 80 90 'DO UQ UID LIMIT (LL}, % U.S.C.S. METHOD OF SOIL CLASSIFICATION Updated Nov. 2004 en w ...J a. U:-::1ii ~ (.) z ,;;::;, <C I-e:, 0 G) en 0 ~ ;:: . ~ 0 ~ ...J w 0 <C Cl) u.. a:: co (.) . :c ~ ::, en -U ::1ii u.. . t I-z -Cl) en w >-en . w ~ c; 0 5 0 en Cl)::, 0 -%! ...J ::i ~-.::: co ::1ii >-0 a:: (.) 0 SM SM 5 50/6" 7.3 109.8 50/3" 10 15 DATE DRILLED 3/28/08 BORING NO . B-l ------------------ GROUND ELEVATION 30' ± (MSL) ----'---"-------SHEET OF --- METHOD OF DRILLING 8" Hollow-Stem Auger (Scott's Drilling CME 55) DRIVE WEIGHT 140 lbs. (Auto-Trip Hammer) DROP 30" -------- SAMPLED BY CAT LOGGED BY CAT REVIEWED BY JG ---------DES CR IP TIO N /INTERPRET AT 1O N FILL: Brown, damp, loose, silty, clayey fine to coarse SAND. Reddish brown; scattered gravel up to 1/2 inch in diameter; scattered chunks of asphalt. ALLUVIUM: Grayish brown, damp, loose, silty fine to coarse SAND; scattered gravel up to 1/2 inch in diameter. Dark brown; silty fine sand. SANTIAGO FORMATION: Grayish brown, damp, weakly cemented, silty, gravelly, fine-to coarse-grained SANDSTONE; trace clay; gravel up to 2 inches in diameter. GrayTshorown,aamp, inoaeratelycemerrtecr,-sifty-;-sandy graveT CONGLOMERATE; - trace clay. Difficult drilling. Tota Dept = 8.3 eet Re sal to No groundwater encountered. Backfilled with approximately 3 cubic feet of bentonite grout immediately after drilling o 3/28/08. Groundwater, though not encountered at the time of drilling, may rise to a higher level due to seasonal variations in precipitation and several other factors as discussed in the report. PROJECT NO. 106289001 BORING LOG BUENA VISTA LIFT STATION FORCE MAIN CARLSBAD, CALIFORNIA DATE 4/08 FIGURE A-I (/) w ..J c.. U::-:E e (.) z ~ <( f-e:. 0 (/) 0 ~ Cl) ~ 0 ~ ..J w 0 LL 0:: (.) . :c ~ :::) 1i:i cc -0 :E LL • f-f-z -(/) c.. C: (/) w >-(/) . w ~ g? 5 0 (/) (/) :::) 0 ...J ::s ~-;;:: cc :E >-0 0:: (.) 0 SM SM 5 IO 3.5 110.8 10 10 7 15 7 DATE DRILLED 3/28/08 BORING NO. B-2 GROUND ELEVATION 20'±(MSL) SHEET OF METHOD OF DRILLING 8" Hollow-Stem Auger (Scott's Drilling -CME 55) DRIVE WEIGHT 140 lbs. (Auto-Trip Hammer) DROP 30" SAMPLED BY CAT LOGGED BY CAT REVIEWED BY JG DESCRIPTION/INTERPRETATION fine to coarse SAND. Reddish brown. Difficult drilling. Fine sand; trace of coarse sand. Tota Dep 16.5 eet. Groundwater encountered at approximately 9 feet at time of drilling. Backfilled with approximately 6 cubic feet ofbentonite grout immediately after drilling o 3/28/08. Note: Groundwater may rise to a level higher than that measured in the borehole due to seasonal variations in precipitation and several other factors as discussed in the report. PROJECT NO. 106289001 BORING LOG BUENA VISTA L!Ff STATION FORCE MAIN CARLSBAD, CALIFORNIA DATE 4/08 FIGURE A-2 (/) w ...J a. U::-:E ~ (.) z ,if <( I-~ e:, 0 (/) 0 !:!-~ Cl.) ~ --0 w ~ ...J LI.. 0:: 0 (.) . :r: i :::, ci:i ID _(.) :E LI.. . I-I-z -(/) a. C: (/) w >-(/) . w :l!: ~ 5 0 (/) (/) :::, 0 ...J ::s ~-;:: co :E >-0 0::: (.) 0 DATE DRILLED 3/28/08 GROUND ELEVATION _15_' ±_(M.,__S_L)'------- BORING NO. --------- SHEET I OF ------- METHOD OF DRILLING 8" Hollow-Stem Auger (Scott's Drilling -CME 55) DRIVE WEIGHT ___ 14_0_l_bs_ . .,_(A_u_to_-T_r_.ip_H_am_m_e .... r)'--- SAMPLED BY CAT LOGGED BY CAT REVIEWED BY DROP B-3 30" JG ---------DES CR IP TIO N /INTERPRET AT 1O N u 111111 ML FILL: i-----1---t---tt't'!'tt-----1,\LJP..rown, damp, loose, gravelly, sandy SILT; pea gravel. - 5-t- 27 mi SANTIAGO FORMATION: :!!! Light grayish brown, damp to moist, weakly cemented, fine-to medium-grained !iii SANDSTONE; scattered reddish brown mottling. :::: 1m 13.1 111.6 m~ :::: :::: : : : : :::: :::: : : : : Moist; scattered gravel. Silty; scattered fine gravel. ---Brownish gray,n:ioist, mocterately""Inaurated;clayey SI:CTST""ONE-:-- ------~--!Iii --Dark-gray, moist, weakly cementecl, clayey nne-' to meaium.:grainedSANDSTONE:--- 13 - - ----- 15-- 3 -- I--- ?0 :::: :::: :::: :::: :::: : : : : :::: :::: 1111 : : : : ! ! ! ! : : : : :::: iiii :::: 1111 :::: ! ! ! 5 :::: :::: :::: : : : : Light gray. Light tan; silty; trace clay. Clayey. -----~-------GrayTsnbrown,saTurateo, weakfy cementeo,silfy nne-graTneo SANDSiONE; micaceous; cohesionless. 1111 ----Gray, saturafed-;-wealay7ndurated-;sfrty CLAYSTONE; mTcaceous. -------- Total Depth = 16.5 teet. Groundwater encountered at approximately 9 feet at time of drilling; measured at approximately 8 feet after drilling. Backfilled with approximately 6 cubic feet ofbentonite grout immediately after drilling on 3/28/08. Note: Groundwater may rise to a level higher than that measured in the borehole due to seasonal variations in precipitation and several other factors as discussed in the report. f---P-R-OJ-E-c=1-N=o-. __ l_c_ARL __ s:-'::=1=~-cAL_IF_o_RNIA_,---~F~,G~u=R=E-----u . 106289001 4/08 A-3 Buena Vista Lift Station Force Main (VC-4) April 21, 2008 Carlsbad, California Project No. 106289001 106289001 R.doc 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. Soil classifications are indicated on the logs of the exploratory excavations in Appendix A. In-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. The test results are presented on the logs of the exploratory excavations in Appendix A. Gradation Analysis Gradation analysis tests were performed on selected representative soil samples in general accor- dance with ASTM D 422 and ASTM D 1140. Grain-size distribution curves are shown on Figures B-1 and B-2. The test results were utilized in evaluating the soil classification in accor- dance with the Unified Soil Classification System. 200 Wash An evaluation of the percentage of particles finer than the No. 200 sieve in a selected soil sample was performed in general accordance with ASTM D 1140. The results of the test are presented on Figure B-3. 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. The test re- sults were utilized to evaluate the soil classification in accordance with the Unified Soil Classification System (USCS). The test results and classification are shown on Figure B-4. Direct Shear Tests A direct shear test was performed on undisturbed samples in general accordance with ASTM D 3080 to evaluate the shear strength characteristics of the selected material. The sample was inundated dur- ing shearing to represent adverse field conditions. The results are shown on Figure B-3. Soil Corrosivity Tests Soil pH, and resistivity tests were performed on a representative sample in general accordance with California Test (CT) 643. The chloride content of the selected sample was evaluated in gen- eral accordance with CT 422. The sulfate content of the selected sample was evaluated in general accordance with CT 417. The test results are presented on Figure B-6. I GRAVEL SAND FINES I I Coarse Fine Coarse Medium I Fine SILT CLAY I U.S. STANDARD SIEVE NUMBERS HYDROMETER 3" Z 1½" !" .iAt ½" ¾" 4 8 16 30 50 100 200 100.0 I I I T T ,...~ I I 90.0 I I I I I I I I I I I I I I I I I I I ~ I I 80.0 I I I I I I I I I I I I I I I I I I I I I I-70.0 J: Cl I I I I ' I w I I I I I I I I I I I ~ 60.0 >-I I I I \ I co I I I I I I I I I I I 0:: 50.0 LL! I I II I I I z u:: I I I I I I I I I \ I I I-40.0 I I II I I \ I z LL! I I I I I I I I I I I () 0:: 30.0 I I '{ LL! I I a. 20.0 I I I I I I I I I I I I I I I I I I I I ~ ~ 10.0 I I I I I I I I I I I I I I I I I I I I I I 0.0 I I I I I 100 10 1 0.1 0.01 0.001 0.0001 GRAIN SIZE IN MILLIMETERS Sample Depth Liquid Plastic Plasticity D10 030 D50 Cu Co Passing Symbol Location (ft) Limit Limit Index No.200 uses (%) • B-2 2.0-5.0 --------------16 SM PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 422-63 (02) JYln90&/(tOO-re GRADATION TEST RESULTS FIGURE PROJECT NO. DATE 8-1 BUENA VISTA LIFT STATION FORCE MAIN 106289001 4/08 CARSLBAD, CALIFORNIA 106289001 SIEVE B-2 @ 2.0.5.0.xls GRAVEL SAND I FINES I Coarse Fine Coarse Medium Fine I SILT CLAY I U.S. STANDARD SIEVE NUMBERS HYDROMETER 3" 2' 1½" 1'' ¾" ½"¾" 4 8 16 30 50 100 200 100.0 I I I I I I I-r,-N I I 90.0 I I I I I I I I ~~ I I I I I I I I I I I 80.0 I I I I ' I I I I I ' I I I I I I I I I I I\ I I I-70.0 :c I I I I \ I C) jjj I I I I I I I I I \ I I s: 60.0 >-I I I I \ I Ill I I I I I I I I I [\ I I 0:: 50.0 w I I I I ~ z u::: I I I I I I I I I I I-40.0 I I I I I z w I I I I I I I I I I I (.) 0:: 30.0 w I I I I I ll. 20.0 I I I I I I I I I I I I I I I I I I I I I I 10.0 I I I I I I I I I I I I I I I I I I I I I I 0.0 I I I I I 100 10 1 0.1 0.01 0.001 0.0001 GRAIN SIZE IN MILLIMETERS Sample Depth Liquid Plastic Plasticity D10 D30 Dso Cu Cc Passing Equivalen Symbol Location (ft) Limit Limit Index No. 200 uses (%) • B-3 1.0-4.0 ----------------37 SM PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 422-63 (02) 1(ln90&1(\0o~e GRADATION TEST RES UL TS FIGURE PROJECT NO. DATE 8-2 BUENA VISTA LIFT STATION FORCE MAIN 106289001 4/08 CARSLBAD, CALIFORNIA 106289001 SIEVE B-3@ 1.0-4.0.xls SAMPLE PERCENT PERCENT SAMPLE DEPTH DESCRIPTION PASSING PASSING LOCATION (FT) NO.4 NO. 200 B-1 5.0-7.0 Silty, Gravelly SAND 61 14 (Derived from the Santiago Formation) PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 1140-00 PROJECT NO. 106289001 106289001·200 WASH B-1@ 5.0-7.0.xls DATE 4/08 NO. 200 SIEVE ANALYSIS BUENA VISTA LIFT STATION FORCE MAIN CARLSBAD, CALIFORNIA uses {TOTAL SAMPLE) SM FIGURE B-3 uses SYMBOL LOCATION DEPTH LIQUID PLASTIC PLASTICITY CLASSIFICATION {FT) LIMIT, LL LIMIT, PL INDEX, Pl {Fraction Finer Than No. 40 Sieve) • B-1 5.0-7.0 25 21 4 CL-ML NP-INDICATES NON-PLASTIC 60----/--~/- 50+----+---+------l---+----.i~--+---+---+--711'"1----I 0:: / CHorOH /v >< 40+----+---+------1---#--.........,1-----1---+-.,....-+--+----I ! I/ /' t-30+----+---+-----,f"----+--.........,1-----:l,ill"---+---+--+----I ~ V ~/ i 20 / CLor0~----1/-......-i;.a---1----1-MHorOH--+----11 10---/'------✓---------------------11 /~~C~L--~M~L+--,,..r MLorOL o / -I 0 10 20 30 40 50 60 LIQUID LIMIT, LL 70 80 PERFORMED IN GENERAL ACCORDANCE WlTH ASTM D 4318-05 90 100 Equivalent uses {Entire Sample) SM ATTERBERG LIMITS TEST RESULTS FIGURE PROJECT NO. 106289001 106289001 ATTERBERCl Page 1.xls DATE 4/08 BUENA VISTA LIFT STATION FORCE MAIN CARLSBAD, CALIFORNIA B-4 3000 I i .--. 2000 ~v LL / . (/) / V a.. .._, V ., , (/) / (/) w G / a::: ,.A I-(/) I V ,,_ ~ a::: I i I/ u5 i.,' ' ' J~~ I (/) 1000 VI"' l 'w:/ / I i~ ... , ! I I /;"' ! ; J.. .... i ~ ,J' ' I 0 V1 i 0 1000 2000 3000 NORMAL STRESS (PSF) Description Symbol Sample Depth Shear Cohesion, c Friction Angle, ~ Soil Type Location (ft) Strength (psf) (degrees) Silty SAND -B-2 5.0-6.5 Peak 50 35 SM Silty SAND .... -x -. B-2 5.0-6.5 Ultimate 40 33 SM PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 3080-04 l(ln90 & }(tllUT'e DIRECT SHEAR TEST RESULTS FIGURE PROJECT NO. DATE B-5 BUENA VISTA LIFT STATION FORCE MAIN 106289001 4/08 CARLSBAD, CALIFORNIA 106289001 SHEAR 8-2@ 5.0-6.5.xls SAMPLE LOCATION B-3 SAMPLE DEPTH (FT) 1.0-4.0 6.1 RESISTIVITY 1 (Ohm-cm) 370 SULFATE CONTENT 2 (ppm) (%) 350 0.035 1 PERFORMED IN GENERAL ACCORDANCE WITH CALIFORNIA TEST METHOD 643 2 PERFORMED IN GENERAL ACCORDANCE WITH CALIFORNIA TEST METHOD 417 3 PERFORMED IN GENERAL ACCORDANCE WITH CALIFORNIA TEST METHOD 422 PROJECT NO. 106289001 106289001 CORROSIVITY Page 1.xls DATE 4/08 CORROSIVITY TEST RESULTS BUENA VISTA LIFT STATION FORCE MAIN CARLSBAD, CALIFORNIA CHLORIDE CONTENT 3 (ppm) 940 FIGURE 8-6 Buena Vista Lift Station Force Main (VC-4) Appendix C Carlsbad, California Project No. 106289001 106289001 TEG.doc APPENDIX C TYPICAL EARTHWORK GUIDELINES Buena Vista Lift Station Force Main (VC-4) Appendix C Carlsbad, California Project No. 106289001 106289001 TEG.doc Rev. 12/05 i 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 Buena Vista Lift Station Force Main (VC-4) Appendix C Carlsbad, California Project No. 106289001 106289001 TEG.doc Rev. 12/05 1 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 construction may result in new recommendations which could supersede these specifications and/or the recommendations 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. Buena Vista Lift Station Force Main (VC-4) Appendix C Carlsbad, California Project No. 106289001 106289001 TEG.doc Rev. 12/05 2 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. Buena Vista Lift Station Force Main (VC-4) Appendix C Carlsbad, California Project No. 106289001 106289001 TEG.doc Rev. 12/05 3 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 relative compaction as evaluated by ASTM D 1557. Backfill soils shall be placed in loose lifts 8 inches thick or thinner, moisture conditioned, and com- pacted in accordance with the recommendations of the geotechnical report and of these guidelines. The backfill shall be tested by the geotechnical consultant at vertical inter- vals 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- Buena Vista Lift Station Force Main (VC-4) Appendix C Carlsbad, California Project No. 106289001 106289001 TEG.doc Rev. 12/05 4 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 as evaluated by ASTM D 1557. 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 as evaluated by ASTM D 1557. For minor interior trenches, density testing may be omitted or spot testing may be performed, as deemed appropri- ate 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 in 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- Buena Vista Lift Station Force Main (VC-4) Appendix C Carlsbad, California Project No. 106289001 106289001 TEG.doc Rev. 12/05 5 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 appropriate 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. Buena Vista Lift Station Force Main (VC-4) Appendix C Carlsbad, California Project No. 106289001 106289001 TEG.doc Rev. 12/05 6 6. DEFINITIONS OF TERMS ALLUVIUM: 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. AS-GRADED (AS-BUILT): The site conditions upon completion of grading. BEDROCK: Relatively undisturbed in-place rock, either at the surface or beneath surficial deposits of soil. BORROW (IMPORT): Any fill material hauled to the project site from off-site areas. CIVIL ENGINEER: The Registered Civil Engineer or consulting firm responsible for preparation of the grading plans and surveying, and evaluating as-graded topographic conditions. CLIENT: 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. COLLUVIUM: 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). COMPACTION: The densification of a fill by mechanical means. CONTRACTOR: A person or company under contract or otherwise retained by the client to perform, excavation, pipeline installation, and other site improvements. DEBRIS: 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. ENGINEERED FILL: 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. Buena Vista Lift Station Force Main (VC-4) Appendix C Carlsbad, California Project No. 106289001 106289001 TEG.doc Rev. 12/05 7 ENGINEERING GEOLOGIST: 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. EROSION: The wearing away of the ground surface as a result of the movement of wind, water, and/or ice. EXCAVATION: The mechanical removal of earth materials. EXISTING GRADE: The ground surface configuration prior to grading; original grade. FILL: Any deposit of soil, rock, soil-rock blends, or other similar materials placed by man. FINISH GRADE: The as-graded ground surface elevation that conforms to the grading plan. GEOFABRIC: An engineering textile utilized in geotechnical applications such as subgrade stabilization and filtering. GEOTECHNICAL CONSULTANT: 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. GEOTECHNICAL ENGINEER: 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. GRADING: Any operation consisting of excavation, filling, or combina- tions thereof and associated operations. LANDSLIDE DEPOSITS: Material, often porous and of low density, produced from instability of natural or manmade slopes. Buena Vista Lift Station Force Main (VC-4) Appendix C Carlsbad, California Project No. 106289001 106289001 TEG.doc Rev. 12/05 8 OPTIMUM MOISTURE: The moisture content that is considered optimum relative to compaction operations. RELATIVE COMPACTION: The degree of compaction (expressed as a percentage) of a material as compared to the dry density obtained from ASTM test method D 1557. SITE: The particular parcel of land where earthwork is being per- formed. SLOPE WASH: 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). SLOUGH: Loose, uncompacted fill material generated during grading operations. SOIL: Naturally occurring deposits of sand, silt, clay, etc., or com- binations thereof.