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HomeMy WebLinkAbout3873; Sewer Pipeline Replacement,2359 Carlsbad Blvd.; Sewer Pipeline Replacement,2359 Carlsbad Blvd.; 2009-03-05Geotechnical and Environmental Sciences Consultants GEOTECHNICAL EVALUATION HOME PLANT LIFT STATION SEWER PIPELINE REPLACEMENT CARLSBAD, CALIFORNIA ft&JtfCT Ha PREPARED FOR: Boyle Engineering 7807 Convoy Court, Suite 200 San Diego, California 92111 PREPARED BY: Ninyo & Moore Geotechnical and Environmental Sciences Consultants 5710RuffmRoad San Diego, California 92123 March 5, 2008 (Revised December 8, 2008) Project No. 106275001 5710 Ruffin Road • San Diego, California 921 23 • Phone [858) 576-1 000 • Fax (858) 576-9600 San Diego • Irvine • Rancho Cucamonga • Los Angeles • Oakland • Las Vegas • Phoenix • Denver • El Paso • Tucson Geotechnical and Environmental Sciences Consultants March 5, 2008 (Revised December 8, 2008) Project No. 106275001 Mr. Roman Obzejta Boyle Engineering 7807 Convoy Court, Suite 200 San Diego, California 92111 Subject: Geotechnical Evaluation Home Plant Lift Station Sewer Pipeline Replacement Carlsbad, California Dear Mr. Obzejta: In accordance with your authorization, we have performed a geotechnical evaluation for the Home Plant Lift Station Sewer Pipeline Replacement project located in the city of Carlsbad, California. This report presents our geotechnical findings, conclusions, and recommendations regarding the proposed project. Our report was prepared in accordance with our proposal dated October 24, 2007. We appreciate the opportunity to be of service on this project. Sincerely, «NYO & MOORE Ronald D. Hallum, C.E.G. Senior Geologist Gregory T. Farrand, C.E.G. Principal Geologist MJB/RDH/ABS/GTF/ek Distribution: (5) Addressee Andres Bernal, G.E. Senior Project Engineer 57 1 0 Ruffin Road • San Diego, California 92 1 23 • Phone (858) 576-1 000 • Fax (858) 576-9600 San Diego • Irvine • Rancho Cucamonga • Los Angeles • Oakland • Las Vegas • Phoenix • Denver • El Paso • Tucson Sewer Pipeline Replacement Revised December 8, 2008 Carlsbad, California Project No. 106275001 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(Qaf) 4 5.2.2. Topsoil/Colluvium (Col) 4 5.2.3. Terrace Deposits (Qt) 4 5.3. Groundwater 5 5.4. Landsliding 5 6. FAULTING AND SEISMICITY 5 6.1. Ground Rupture 6 6.2. Ground Shaking 6 6.3. Liquefaction 6 7. CONCLUSIONS 7 8. RECOMMENDATIONS 7 8.1. Excavation Characteristics 8 8.2. Shoring 8 8.3. Excavation Bottom Stability 9 8.4. Construction Dewatering 10 8.5. Microtunneling and Pipe Jacking 10 8.6. Lateral Pressures for Thrust Blocks 11 8.7. Modulus of Soil Reaction 11 8.8. Pipe Bedding 12 8.9. Trench Backfill 12 8.10. Fill Placement and Compaction 13 8.11. Corrosion 14 8.12. Concrete 14 8.13. Pre-Construction Conference 15 8.14. Construction Observation 15 9. LIMITATIONS 15 10. REFERENCES 17 106275001 R Boyle Home Plant Rev doc • •^••••mMmJ& Sewer Pipeline Replacement Revised December 8,2008 Carlsbad, California Project No. 106275001 Figures Figure 1 - Site Location Map Figure 2 - Boring Location Map Figure 3 - Fault Location Map Figure 4 - Lateral Earth Pressures for Braced Excavation Figure 5 - Thrust Block Lateral Earth Pressure Diagram Appendices Appendix A - Boring Logs Appendix B - Laboratory Testing Appendix C - Typical Earthwork Guidelines l0627500IRBoyleHomePlantRev.doc •*****m~mj Sewer Pipeline Replacement Revised December 8,2008 Carlsbad, California Project No. 106275001 1. INTRODUCTION In accordance with your request and our proposal dated October 24, 2007, we have performed a geotechnical evaluation for the Home Plant Lift Station Sewer Pipeline Replacement project lo- cated in Carlsbad, California (Figure 1). The purpose of this study was to evaluate the geotechnical conditions at the site and provide geotechnical design and construction recommen- dations for the proposed improvements. This report presents our geotechnical findings, conclusions, and recommendations regarding the proposed projects. 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. 2. SCOPE OF SERVICES The scope of services for this study included the following: • Reviewing background information including available geotechnical reports, geologic maps, and topographic maps. • Performing a geologic reconnaissance of the site. • Visiting the site to mark the boring locations and coordinating with Underground Service Alert for utility clearance. • Coordinating with the North County Transit District (NCTD) to obtain encroachment per- mits and access to their property for subsurface exploration. • Drilling, logging, and sampling of two exploratory borings with a truck-mounted drilling rig equipped with 8-inch diameter hollow-stem augers. Borings were advanced to depths of up to approximately 19J/2 feet below the existing ground surface. • Collecting bulk and relatively undisturbed samples of the soils encountered during the per- formance of the exploratory borings. Samples were then transported to our in-house geotechnical laboratory for testing. • Performing geotechnical laboratory testing on selected samples. Laboratory testing included in-situ moisture content and dry density, grain-size analysis, percentage of particles passing 106275001 R Boyle Home Plant Rev doc Sewer Pipeline Replacement Revised December 8, 2008 Carlsbad, California Project No. 106275001 the No. 200 sieve, Atterberg limits, shear strength, and soil corrosivity (pH, resistivity, chlo- ride content, and sulfate content). • Compiling and analyzing the data obtained. • Preparing this geotechnical report for preliminary design of the proposed improvements. 3. PROJECT AND SITE DESCRIPTION We understand the Home Plant Lift Station Sewer project will consist of replacement of an ap- proximately 175 foot long section of an existing 15-inch ductile iron pipe. We understand the existing pipeline is distressed, with significant deposits, sagging, and an observed break (Krieger & Stewart, 2007). The new sewer will be constructed, largely utilizing trenchless con- struction methods (e.g., jack-and-bore, microtunneling, etc.), parallel to the existing 15-inch sewer. The proposed pipeline will extend from a new manhole to be located southwest of the pump station, beneath the roadway to a new manhole on the east side of Carlsbad Boulevard. We understand the existing sewer invert is less than 20 feet in depth, with approximate invert eleva- tions between 13 and 17 feet above mean sea level (MSL). The project site is located adjacent to and south of the existing Home Plant Lift Station in north- ern Carlsbad. The existing lift station is located at 2359 Carlsbad Boulevard, on the western side of Carlsbad Boulevard and north of the NCTD railroad tracks. Carlsbad Boulevard in this area is located atop a fill embankment north of an overpass for the NCTD tracks. The area of the new manhole east of Carlsbad Boulevard, at the base of the 8 to 15 foot high road embankment, is relatively level and is currently occupied by a cul-de-sac off of State Street, and a storage and maintenance yard owned by NCTD. Surface elevations along the project alignment range from approximately 25 to 40 feet above MSL. 4. SUBSURFACE EXPLORATION AND LABORATORY TESTING Our subsurface exploration was conducted on January 24, 2008 and consisted of the excavation, logging, and sampling of two exploratory borings. The borings were drilled with a truck-mounted drill rig with an 8-inch diameter continuous-flight, hollow-stem auger. The l& 106275001 R Boyle Home Plant Rev doc ~ Sewer Pipeline Replacement Revised December 8, 2008 Carlsbad, California Project No. 106275001 borings were drilled to depths of up to approximately 19!^ feet below the existing ground sur- face. The purpose of the exploratory borings was to observe and sample the 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 corresponding logs are presented in Appendix A. Borings were backfilled with bentonite and capped with soil. Laboratory testing of samples obtained during our subsurface exploration included an evaluation of in-situ moisture content and dry density, grain-size analysis, percentage passing the No. 200 sieve, Atterberg limits, shear strength, and soil corrosivity (pH, resistivity, chloride con- tent, and sulfate content). The laboratory tests were performed at our in-house geotechm'cal laboratory. The results of the in-situ moisture content and dry density tests are shown at the cor- responding 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, including faulting and seismicity, landslides, ex- cavatability, and groundwater conditions at the subject site are provided in the following sections. 5.1. Regional Geologic Setting The project area is situated in the coastal foothill section of the Peninsular Ranges Geomor- phic 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 approxi- mately 30 to 100 miles. In general, the province consists of rugged mountains underlain by Jurassic metavolcanic and metasedimentary rocks, and Cretaceous igneous rocks of the southern California batholith. 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 Elsinore, San Jacinto and San Andreas faults are active fault systems located northeast of the 10627500] R Boyle Home Plant Rev doc Sewer Pipeline Replacement Revised December 8, 2008 Carlsbad, California Project No. 106275001 project area and the Agua Blanca-Coronado Bank, San Clemente, Newport-Inglewood, 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 primar- ily 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 Geologic units encountered during our subsurface evaluation include fill materials, top- soil/colluvium and terrace deposits. Generalized descriptions of the earth units encountered during our subsurface exploration are provided in the subsequent sections. More detailed de- scriptions are provided on the boring logs in Appendix A. 5.2.1. Fill (Qaf) Fill material was encountered in exploratory borings B-l and B-2 to depths of approxi- mately 414 feet and 7 feet below the existing ground surface (bgs), respectively. As encountered, the fill material generally consisted of dark brown to gray brown, damp to moist, soft, sandy clay and medium dense, clayey and silty sand with trace (less than 5 percent) gravel, cobbles, and small (less than 2 inches in diameter) pieces of asphalt. 5.2.2. Topsoil/Colluvium (Col) Topsoil/colluvium was encountered in exploratory borings B-l and B-2 underlying the fill materials to depths of approximately 11 feet and 9 feet bgs, respectively. As encountered, this material generally consisted of dark brown, damp to moist, very stiff to hard, sandy clay. 5.2.3. Terrace Deposits (Qt) Quaternary-aged terrace deposits (Tan and Kennedy, 1996) were encountered in ex- ploratory borings B-l and B-2 underlying topsoil/colluvium and extending to the total depths explored. Recently these deposits have been remapped as Old Paralic Deposits (Kennedy and Tan, 2005). As encountered, the deposits generally consisted of light gray 106275001 R Boyle Home Plant Rev doc Sewer Pipeline Replacement Revised December 8, 2008 Carlsbad, California Project No. 106275001 brown and light reddish brown, damp to moist, dense to very dense, silty fine to me- dium sand, with trace (less than 5 percent) coarse sand and clay. 5.3. Groundwater Groundwater was not encountered in our exploratory borings. Groundwater levels may fluc- tuate due to seasonal variations, irrigation, and other factors or be present as perched groundwater or seepage in some areas. Due to these potential factors, groundwater may be encountered during construction. 5.4. Landsliding Based on our review of the original geotechnical evaluation for the site, other published geo- logic literature, and aerial photographs and our subsurface evaluation, no landslides or related features underlie or are adjacent to the subject site. 6. FAULTING AND SEISMICITY Based on our review of referenced geologic maps and stereoscopic aerial photographs, 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) have not been mapped in the site vicinity. The closest known active fault is the offshore portion of the Rose Canyon fault zone, which is capa- ble of generating an earthquake of magnitude of 7.2 (United States Geological Survey [USGSJ/California Geological Survey [CGS], 2002), located approximately 4 miles west of the site (Treiman, 1993). The principal seismic hazard considerations at the site are surface ground rupture, ground shak- ing and seismically induced liquefaction. A brief description of the hazards and the potential for their occurrence on site is presented below. 106275001 R Boyle Home Plant Rev doc Sewer Pipeline Replacement Revised December 8, 2008 Carlsbad, California Project No. 106275001 6.1. Ground Rupture The probability of damage from surface ground rupture is low due to the lack of known ac- tive faults underlying the subject site or its vicinity. Surface ground cracking related to shaking from distant events is not considered a significant hazard, although it is a possibility. 6.2. Ground Shaking Based on a Probabilistic Seismic Hazard Assessment for the Western United States, issued by the USGS/CGS (2002), the project site is located in a zone where the horizontal peak ground acceleration having a 10 percent probability of exceedance in 50 years is 0.30g (30 percent of the acceleration of gravity) with an estimated vertical peak ground accelera- tion of 0.20g. The requirements of the governing jurisdictions and the 2007 California Building Code (CBC) should be considered in the project design. 6.3. Liquefaction Liquefaction is the phenomenon in which loosely deposited, saturated granular soils (located below the water table) with clay contents (particles less than 0.005 mm) of less than 15 percent, liquid limit of less than 35 percent, and natural moisture content greater than 90 percent of the liquid limit undergo rapid loss of shear strength due to development of ex- cess pore pressure during strong earthquake-induced ground shaking. Ground shaking of sufficient duration results in the loss of grain-to-grain contact due to rapid rise in pore water pressure, and it eventually causes the soil to behave as a fluid for a short period of time. Liquefaction is known generally to occur in saturated or near-saturated cohesionless soils at depths shallower than 50 feet bgs. Factors known to influence liquefaction potential include composition and thickness of soil layers, grain size, relative density, groundwater level, de- gree of saturation, and both intensity and duration of ground shaking. Based on the lack of encountered groundwater to the depths explored (approximately 19V2 feet) and the density of the fill, topsoil/colluvium, and terrace deposits underlying the 106275001 R Boyle Home Plant Rev doc -——mj Sewer Pipeline Replacement Revised December 8, 2008 Carlsbad, California Project No. 106275001 site, it is our opinion that the potential for liquefaction and consequent dynamic settlement to occur at this site is not a design consideration. 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 excavatable with conventional heavy-duty earth- moving equipment in good working condition. • Although groundwater was not encountered in our exploratory borings, groundwater may be encountered during construction. • No active faults are reported underlying or adjacent to the site. The active Rose Canyon fault zone has been mapped approximately 4 miles west of the site. • Clayey topsoil/colluvial soils were encountered in both borings. These soils are not consid- ered suitable for usage as trench zone (intermediate) backfill. The contractor should be prepared to import soil to the site. Terrace deposits may be reused as trench zone backfill. • Based on the anticipated invert elevation of the proposed pipeline, it is considered likely that the jack-and-bore or microtunneling activities will be performed through terrace deposits. • The project site would be considered corrosive based upon Caltrans criteria. • Based on the lack of encountered groundwater to the depths explored and the consistency of the fill, topsoil/colluvium, and terrace deposits underlying the site, it is our opinion that the potential for liquefaction and consequent dynamic settlement to occur at this site is not a de- sign consideration. 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- 106275001 R Boyle Home Plant Rev doc - m-mm**mmMmJ & Sewer Pipeline Replacement Revised December 8, 2008 Carlsbad, California Project No. 106275001 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. Excavation Characteristics For temporary open excavations, such as open trench areas or access pits, we recommend that the following Occupational Safety and Health Administration (OSHA) soil classifica- tions be used: Fill, Topsoil/Colluvium, Terrace Deposits Type C Upon making the excavations, the soil classifications and excavation performance should be evaluated in the field by the geotechnical consultant in accordance with OSHA. Temporary excavations should be constructed in accordance with OSHA recommendations. For trench excavations, OSHA requirements regarding personnel safety should be met using appropri- ate shoring (including trench boxes) or by laying back the slopes to no steeper than 1.5:1 (horizontal to vertical). Temporary excavations that encounter seepage may be shored or stabilized by placing sand- bags or gravel along the base of the seepage zone. Excavations close to or below the groundwater (before or after dewatering) may encounter wet and loose or soft ground condi- tions. Wet soils may be subject to pumping under heavy equipment loads. On-site safety of personnel is the responsibility of the contractor. 8.2. Shoring It is anticipated that the sewer pipeline will be installed with trenchless methods. We antici- pate that shoring systems with bracings will be installed for the jacking and receiving pits as well as for trenches over 4 feet deep. Shoring systems will be constructed through fill, top- soil/colluvium, and terrace deposit materials. The shoring system should be designed using 106275001 R Boyle Home Plant Rev doc Sewer Pipeline Replacement Revised December 8, 2008 Carlsbad, California Project No. 106275001 the lateral earth pressures shown on Figure 4. The recommended design pressures are based on the assumptions that the shoring system is constructed without raising the ground surface elevation behind the sheet piles, that there are no surcharge loads, such as soil stockpiles and construction materials, and that no loads act above a 1:1 (horizontal to vertical) plane ex- tending up and back from the base of the sheet pile system. The contractor should include the effect of any surcharge loads on the lateral pressures against the sheet pile wall. Shoring systems should be watertight, especially if a slurry microtunneling method is selected. We anticipate that settlement of the ground surface will occur behind the shoring wall during excavation. The amount of settlement depends heavily on the type of shoring system, the shoring contractor's workmanship, and soil conditions. We recommend that struc- tures/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 l/2 inch or less. Possible causes of settlement that should be addressed include settlement during shoring installation, excavations, con- struction vibrations, dewatering, and removal of the support system. It is not the intent of this report to provide a detailed shoring plan. Based on the method of installation, the contractor should retain a qualified and experienced engineer to design the shoring system, 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. OSHA requirements per- taining to worker safety should be observed. 8.3. 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. Excavations that are close to or below the water table (if encountered) may be unstable. In general, unstable bottom conditions may be mitigated by overexcavating the excavation bottom to suitable depths and replacing with 106275001 R Boyle Home Plant Rev doc Q j\jlllUO & Sewer Pipeline Replacement Revised December 8, 2008 Carlsbad, California Project No. 106275001 compacted fill. Recommendations for stabilizing excavation bottoms should be based on evaluation in the field by the geotechnical consultant at the time of construction. 8.4. Construction Dewatering Groundwater was not encountered in our exploratory borings. However, significant fluctua- tions in the groundwater level may occur. Dewatering measures during excavation operations (if necessary) should be prepared by the contractor's engineer and reviewed by the district design engineer. Considerations for construction dewatering should include an- ticipated drawdown, volume of pumping, potential for settlement, and groundwater discharge. Disposal of groundwater should be performed in accordance with guidelines of the Regional Water Quality Control Board. 8.5. Microtunneling and Pipe Jacking We understand microtunneling or jack-and-bore methods may be used for the pipeline sec- tion beneath Carlsbad Boulevard. We anticipate that the potential micro tunnel or jack-and- bore pipeline segment located beneath Carlsbad Boulevard will be approximately 120 lineal feet in length. The invert elevation of the pipeline is not known at this time, but is anticipated to be at approximate elevations varying between 13 and 17 feet above MSL. Dense to very sand is expected to be encountered at the anticipated elevations of the pro- posed micro tunnel or jack-and-bore segment of the pipeline. The contractor should take appropriate measures to reduce the loss of material at the drilling or casing head. Pipe fric- tion can be reduced by over drilling, excavating a slightly larger diameter than the pipe size, and by using drilling mud or other lubricants. We recommend that an experienced specialty contractor be used for the micro tunnel or jack-and-bore operations. The terrace deposit materials that will be encountered during the construction are expected to have unconfined compressive strengths varying from zero pounds per square inch (psi) to approximately 20 psi. These estimates are for the sand layers that make up the majority of 106275001 R Boyle Home Plant Rev doc IA Sewer Pipeline Replacement Revised December 8, 2008 Carlsbad, California Project No. 106275001 the unit. However, resistant cobbles and gravel may be encountered which may result in dif- ficult drilling or jacking conditions. Due to the depth of the proposed pipeline, settlement is not anticipated to impact surface improvements and underground utilities, provided an experienced contractor performs the work. However, we recommend that settlement monuments be placed on the street section and other improvements in the vicinity of the pipeline. Settlement monuments should be monitored during construction and for one month after completion. In order to evaluate the load factors on the proposed pipeline, the loading presented in the fol- lowing table should be used. This load includes the embankment fill for Carlsbad Boulevard. Table 1 - Loading on Trenchless Segment of Pipeline Approximate Depth from Existing Ground Surface to Top of Pipeline (feet) 5 10 15 20 25 Load on Pipeline (pounds/lineal foot of pipe) 775 1,275 1,600 1,800 1,900 Notes: Linear interpolation may be used to obtain loading between the depths shown. Loading assumes 36-inch sleeve diameter of the trenchless section. Loading may need to be modified for different sleeve sizes. 8.6. 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 5. Thrust blocks should be backfilled with granular backfill material, and compacted in accordance with recommendations presented in this report. 8.7. 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 pipelines for 106275001 R Boyle Home Plant Rev doc 1 1 Sewer Pipeline Replacement Revised December 8, 2008 Carlsbad, California Project No. 106275001 the purpose of evaluating deflection caused by the weight of the backfill above the pipe. For pipelines constructed in granular fill, topsoil/colluvium, and terrace deposit materials, we rec- ommend that a modulus of soil reaction of 1,000 psi be used for design, provided that granular bedding material is placed adjacent to the pipe, as recommended in this report. 8.8. Pipe Bedding We recommend that pipes in open excavations be supported on 6 inches or more of granular bedding material such as sand with a Sand Equivalent 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 accor- dance with the most recent edition of the Standard Specifications for Public Works Construction ("Greenbook"). We do not recommend the use of crushed rock as bedding mate- rial. 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 develop 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 to prevent 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 Section 8.9. 8.9. Trench Backfill Fill material, including trench backfill and structure backfill, should consist of granular soil with low expansion potential that conforms to the latest edition of the Standard Specifica- tions for Public Works Construction ("Greenbook") for structure backfill. The clayey topsoil/colluvial materials are not considered suitable for usage as trench zone (intermediate) backfill. The contractor should be prepared to import soil to the site. The sandy terrace de- posit materials are considered suitable for re-use as structural fill material. Fill material should be comprised of low-expansion-potential granular soil and should be free of trash, 106275001 R Boyle Home Plant Rev doc 1 9 Sewer Pipeline Replacement Revised December 8, 2008 Carlsbad, California Project No. 106275001 debris, roots, vegetation, or deleterious materials. Fill should generally be free of rocks or hard lumps of material in excess of 4 inches in diameter. Rocks or hard lumps larger than about 4 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. 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 bedding material or structural fill 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 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 material 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. 8.10. Fill Placement and Compaction Fill, structure backfill, and trench backfill should be compacted in horizontal lifts to a rela- tive 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 pavement 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 com- pacting trench backfill above the pipe. 106275001 R Boyle Home Plant Rev doc ] -j ***m*mmM*J Sewer Pipeline Replacement Revised December 8,2008 Carlsbad, California Project No. 106275001 8.11. 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 CT417 and CT 422, respectively. These laboratory test results are presented in Appendix B. The results of the corrosivity testing indicated an electrical resistivity of 220 ohm-cm, a soil pH of 7.6, a chloride content of 1,725 parts per million (ppm), and a sulfate content of 0.060 percent (i.e., 600 ppm). Based on the Caltrans corrosion (2003) criteria, the on-site soils would be classified as corrosive, which is defined as soils with more than 500 ppm chlorides, more than 0.2 percent sulfates, or a pH less than 5.5. Due to the potential variability of soils, we recommend that corrosion protection for im- provements in contact with site soils be designed by a corrosion engineer. The water-soluble sulfate content test results are addressed in the following section of this report. 8.12. Concrete Concrete in contact with soil or water that contains high concentrations of water-soluble sul- fates can be subject to premature chemical and/or physical deterioration. The soil sample tested in this evaluation indicated a water-soluble sulfate content of 0.060 percent by weight (i.e., about 600 ppm). According to the American Concrete Institute 318-05 building code, the potential for sulfate attack is negligible for water-soluble sulfate contents in soils ranging from about 0.00 to 0.10 percent by weight (0 to 1,000 ppm). Therefore, the site soils may be considered to have a negligible potential for sulfate attack. However, due to the potential variability of site soils, 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 con- crete and a 28-day compressive strength of 4,500 psi or more for the project. 106275001 R Boyle Home Plant Rev doc ]4 ***mmmm*mj& Sewer Pipeline Replacement Revised December 8, 2008 Carlsbad, California Project No. 106275001 8.13. 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. 8.14. 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. The recommendations provided in this report are based on the assumption that Ninyo & Moore will provide geotechnical observation and testing services during construc- tion. 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 recommen- dations, 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 subcontractors 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 J&106275001 R Boyle Home Plant Rev doc i c -— ..—«^ Sewer Pipeline Replacement Revised December 8, 2008 Carlsbad, California Project No. 106275001 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 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 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. 106275001 R Boyle Home Plant Rev doc 1 /: Sewer Pipeline Replacement Revised December 8, 2008 Carlsbad, California Project No. 106275001 10. REFERENCES American Concrete Institute (ACI), 2005, ACI 318-05 Building Code Requirements for Struc- tural Concrete and Commentary. California Building Standards Commission, 2007, California Building Code, Title 24, Part 2, Volumes 1 and 2. California Geological Survey (COS), 1998, Maps of Known Active Fault Near-Source Zones in Cali- fornia and Adjacent Portions of Nevada: International Conference of Building Officials. California Geological Survey, 1999, Seismic Shaking Hazards Maps of California: Map Sheet 48. Caltrans, 2003, Corrosion Guidelines: dated September. International Code Council, Inc. (ICCI), 2006, International Building Code. Kennedy, M.P., and Tan, S.S., 2005, Geologic Map of the San Diego 30' x 60' Quadrangle, California, Scale 1:100,000. Krieger & Stewart, Incorporated, 2007, Draft City of Carlsbad Preliminary Design Report for the CIP Sewer Projects, Evaluation of Rehabilitating Existing Sewers (Project Nos. 1 through 12), dated October. Ninyo & Moore, In-house proprietary information. 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 Construction. Tan, S.S. and Kennedy, M.P., 1996, Geologic Maps of the Northwestern Part of San Diego County, California; California Geological Survey, Open File Report 96-02. Treiman, J.A., 1993, The Rose Canyon Fault Zone, Southern California: California Geological Sur- vey, Open-File Report 93-02. United States Department of the Interior, Bureau of Reclamation, 1998, Engineering Geology Field Manual. United States Geological Survey (USGS), 1968 (Photorevised 1975), San Luis Rey Quadrangle, 7.5 Minute Series Topographic Map, San Diego County, California: scale 1:24,000. United States Geological Survey/California Geological Survey (USGS/CGS), 2002 (Revised April 2003), Probabilistic Seismic Hazards Assessment (PSHA) Model, World Wide Web, http://www.consrv.ca.gov/CGS/rghm/pshamap/pshaniain.html. Source USDA AERIAL PHOTOGRAPHS Date Flight Numbers 5/2/1953 AXN-14M 19&20 Scale 1:20,000 106275001 R Boyle Home Plant Rev doc | y ^^^^^^ \frta^ 4 '&*&M;/tfc* ~j^ttyj®&/^*:': il'.•,?>'} 1&ftf%T]a •. ^aC'^w -9-s^. .. ' kv'' 3£ 3»S^I_W?-S-«—H "*\ A\&K>> ' :«?P«te^Ca3u'^r &if3SJs^te_S^ya» S'^'B^fAVfcfs, AI , ,#. ^-^ sff^7w VUKCU«» IMIWAVI* KM 1C (lAKfetA11 awutc*12 VIA OUITA \ >••'_•"•"* ,(Tt^B \ i •%« V^^^X - lm%*° f—*^"'-^-^—_ii_» , j*\ »i \y\ V^B50^<v ¥®^ '•* JA^ ^^• •*^iB.V\- j._x v TF-.'YB, ,\ ••XTX-^ • -L1^^ V*;'• «^. ^3%* w^- ^k'lV ** \<m w^C H?9&oE<Afi&<&u&\ i^^\Mc \. m««V^^.* -xv^ CUUMC WK^lDs«i*i i^ - Vi «IB8»3»iv\A\* Vr-^YfeVviiS \. REFERENCE: 2005 THOMAS GUIDE FOR SAN DIEGO COUNTY, STREET GUIDE AND DIRECTORY, 2400 4800 APPROXIMATE SCALE IN FEET NOTE: ALL DIMENSIONS. DIRECTIONS AND LOCATIONS ARE APPROXIMATE. Map SI Rand McNally. R.L 07-S-129 PROJECT NO. 106275001 DATE 3/08 SITE LOCATION MAP HOME PLANT LIFT STATION SEWER REPLACEMENT PROJECT CARLSBAD, CALIFORNIA FIGURE 1 I I I I I I I I I I I I I I I I I I I LEGEND -0-B-2 APPROXIMATE LOCATION OF EXPLORATORY TD=19.5 BORING TD=TOTAL DEPTH IN FEET (g> APPROXIMATE LOCATION OF MANHOLE —.._ APPROXIMATE LOCATION OF PROPOSED ALIGNMENT NOTE: ALL DIMENSIONS. DIRECTIONS AND LOCATIONS ARE APPROXIMATE. NOT TO SCALE REFERENCE: GOOGLE EARTH MAPS, 2008 tyinyo PROJECT NO. 106275001 DATE 3/08 BORING LOCATION MAP HOME PLANT LIFT STATION SEWER REPLACEMENT PROJECT CARLSBAD, CALIFORNIA FIGURE LOS ANGELES CO. VICTORVILLE WRIGHTWOOD LAKE ARROWHEAD • THOUSAND OAKS COAST POMONA SAN BERNARDINO SAN BERNARDINO C RIVERSIDE CO RIVERSIDE CO. IMPERIAL'CO. SITE ESCONDIDO SAN CLEMENTE \ V;A °< 0 30 60 MILES NOTE: Aa DIMENSIONS. DIRECTIONS AND LOCATIONS ARE APPROXIMATE FAULT LOCATION MAP HOME PLANT LIFT STATION SEWER REPLACEMENT PROJECT CARLSBAD, CALIFORNIA GROUND SURFACE fl c H/4 I + 12 INCHES OR MORE 1 w 12 INCHES OR MORE D ] ] NO 7 TO NOTES: APPARENT LATERAL EARTH PRESSURE, Pa Pa = 47h,+ 23 h2 psf CONSTRUCTION TRAFFIC INDUCED SURCHARGE PRESSURE, R. Ps = 120 psf WATER PRESSURE, Pw Pw= 62.4 h 2 psf PASSIVE LATERAL EARTH PRESSURE, Pp Pp = 400 + 57 d psf SURCHARGES FROM EXCAVATED SOIL OR CONSTRUCTION MATERIALS ARE NOT INCLUDED ^- GROUNDWATER TABLE h, ,h2, H AND D ARE IN FEET 1 ty//y0*Mpvr& [PROJECT NO. 106275001 DATE 3/08 LATERAL EARTH PRESSURES FOR BRACED EXCAVATION HOME PLANT LIFT STATION SEWER REPLACEMENT PROJECT CARLSBAD, CALIFORNIA FIGURE 4 GROUND SURFACE- THRUST BLOCK Up hi D (VARIES) Kp[h,7t NOTES: GROUNDWATER BELOW BLOCK Pp = (1/2)Kp 7, P = 180 (D2-d2) Ib/ft 2. GROUNDWATER ABOVE BLOCK Pp= ;! (^[(0-^,71+ P-d 3. 7, =7,- 62.4 pcf;USE7f= 120 pcf 4. Kp = 3.0 5. ASSUMES BACKFILL IS GRANULAR MATERIAL 6. ASSUMES THRUST BLOCK IS ADJACENT TO COMPETENT MATERIAL 7. ? GROUNDWATER TABLE 8. hi , d AND D ARE IN FEET NOT TO SCALE PROJECT NO. 106275001 DATE 3/08 THRUST BLOCK LATERAL EARTH PRESSURE DIAGRAM HOME PLANT LIFT STATION SEWER REPLACEMENT PROJECT CARLSBAD, CALIFORNIA FIGURE APPENDIX A Sewer Pipeline Replacement Revised December 8, 2008 Carlsbad, California Project No. 106275001 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 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. 10627500] R Boyle Home Plant Rev doc DEPTH (feet)0 5- 70 SAMPLES |ll 1° f ;iii \\ r BLOWS/FOOTXX/XX MOISTURE (%)9 Sr DRY DENSITY (PCF)SYMBOL |1 CLASSIFICATIONU.S.C.S.SM tyinyo flfp 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. DashedTine denotes material change. 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 boring. bottom of the BORING LOG |%,P^i~"lB| EXPLANATION OF BORING LOG SYMBOLS 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 F- (More than 1/2 of coarse 1 « fraction p '11 '> No. 4 sieve size) |_.,n mm llilljl."•* •• »»»•,'i •> i • ^*}&/*sy/s SANDS iiliilHKiffi (More than 1/2 of coarse fraction I <No. 4 sieve size) •jj||jiTI SILTS & CLAYS ^ Liquid Limit <50 ^ SILTS & CLAYS ^ Liquid Limit >50 X/ :: w • 1 H HIGHLY ORGANIC SOILS GW GP GM GC SW SP SM SC ML CL OL MH CH OH 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. 1 0 No. 1 0 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 0.075 4 76 to 2. 00 2.00 to 0.420 0.420 to 0.075 Below 0.075 PLASTICITY CHART £ fc, B" * TO. ^^^/ / CL- W / I. _/ / CL ^ s^ ML / / iOL / / / CH /I X ' MH J / OH / 0 10 20 30 40 50 60 70 80 BO 100 LIQUID LEVITT (IX), % U.S.C.S. METHOD OF SOIL CLASSIFICATION USCS Soil Classification Updated Nov 2004 0) X Q.LUQ 0 5- 10- 15- </u n «: < <J .* - I 1 - 1 1 C0)>Q 1 — [ •1 1 j 0OQ_ O CO 36 42 82/11" 100/8" 1 50/6" m mSv/F g 01a:ID w O*> 15.2 13.1 28.6 11.4 fl/iU OQ^ tv> LJJ Q >- ITQ 104.8 109.5 93.1 109.6 ro 0m ^>-w ({HKif*!»fwJ*rrwwM?*yfyw Ii1iV,i ki zo1- .< w2 ou. ^ W _;w 3 5o SC CH SP-SM • ^MuF DATE DRILLED 1/24/08 BORING NO. B-l GROUND ELEVATION 33'±(MSL) SHEET 1 OF 2 METHOD OF DRILLING 8" Diameter Hollow Stem Auger DRIVE WEIGHT 1 40 Ibs. (Cathead) DROP 30" SAMPLED BY MJB/RDH LOGGED BY MJB/RDH REVIEWED BY JG DESCRIPTION/INTERPRETATION FILL: Dark brown (mottled), moist, medium dense, clayey SAND; scattered (less than 5 %) gravel; small (less than 2" in diameter) pieces of asphalt. TOPSOIL/COLLUVIUM: Dark brown, damp to moist, hard, sandy CLAY; flecks of calcium carbonate. TERRACE DEPOSITS: Light gray brown, damp, dense, fine SAND; silty; friable. Very dense. Total Depth = 19. 5 feet. BORING LOG VmW* ^^ HOME PLANT LIFT STATION SEWER REPLACEMENT PROJECT I^JV %5 CARLSBAD, CALIFORNIA PROJECT NO. DATE FIGURE 106275001 12/08 A-l J? X Q_ LU Q 20 z5 -*U uu f\ ^<£/ "5LU 1 J 1 O j OOLJ_ 0§CD M * Jv/F g LU CC3 W O ^ 7£u 0Q^ f W LUQ >-ceQ f0< oCO? w fci Oi— .< w^d H- (yj ^o m mvv°F DATE DRILLED 1/24/08 BORING NO. B-l GROUND ELEVATION 33'±(MSL) SHEET 2 OF 2 METHOD OF DRILLING 8" Diameter Hollow Stem Auger DRIVE WEIGHT 1 40 Ibs. (Cathead) DROP 30" SAMPLED BY MJB/RDH LOGGED BY MJB/RDH REVIEWED BY JG DESCRIPTION/INTERPRETATION Groundwater not encountered during drilling. Backfilled shortly after drilling with bentonite chips on 1/24/08. Note: 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. BORING LOG Vm^B ^m HOME PLANT LIFT STATION SEWER REPLACEMENT PROJECT I^Bfl VS CARLSBAD, CALIFORNIA PROJECT NO. DATE FIGURE 106275001 12/08 A-2 a>.2 I CLLU Q 0 5- 10- 15- 0u r <0 | 1 1 ' 9 LIJ » 5 C0) Q J j I'- LL CD 39 45 50/6" 50/4.5" 61/6" m mSMLf g UJcc13 W 0 6.8 10.2 13.5 10.2 WU O — c g $ Q V// 't I 104.1 y / / / // 109.0 : 101.9 i 109.2 : fff& O ) < (/)3 (_) * » : ^ W 3 W ^ 0 ^ CL % I SM ^ CH/ / / /, SM j^Af]^ DATE DRILLED 1/24/08 BORING NO. B-2 GROUND ELEVATION 30'±(MSL) SHEET 1 OF 2 METHOD OF DRILLING 8" Diameter Hollow Stem Auger DRIVE WEIGHT 1 40 Ibs. (Cathead) DROP 30" SAMPLED BY MJB/RDH LOGGED BY MJB/RDH REVIEWED BY JG DESCRIPTION/INTERPRETATION FILL: Dark brown, moist, soft, sandy CLAY. Gray brown, damp, medium dense, sllty SAND. @ 2'- 3': Few (less than 10 %) gravel and cobbles. Dark brown. TOPSOIL/COLLUVIUM: Dark brown, damp, very stiff, sandy CLAY. TERRACE DEPOSITS: Light reddish brown, moist, very dense, silty fine SAND. Light gray brown. Fine to coarse sand. Total Depth = 19.5 feet. BORING LOG VmHM ^m HOME PLANT LIFT STATION SEWER REPLACEMENT PROJECT !%•• «5 CARLSBAD, CALIFORNIA PROJECT NO. DATE FIGURE 106275001 12/08 A-3 0>•S X 0.UJ Q 20 c/u n• <0 "5LU 5 j 3 1 Q J SO1§ CO M *JMBF g LUa:ID co 0 me«/ oQ^ £w LU Q >-a:Q r/7 oCO?>-w ^j •z.o1- .< w^6"- coCO _; 3O ^ «iViaF DATE DRILLED 1/24/08 BORING NO. B-2 GROUND ELEVATION 30'±(MSL) SHEET 2 OF 2 METHOD OF DRILLING 8" Diameter Hollow Stem Auger DRIVE WEIGHT 140 Ibs. (Cathead) DROP 30" SAMPLED BY MJB/RDH LOGGED BY MJB/RDH REVIEWED BY JG DESCRIPTION/INTERPRETATION Groundwater not encountered during drilling. Backfilled shortly after drilling with bentonite chips on 1/24/08. Note: 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. BORING LOG VmMfc fk HOME PLANT LIFT STATION SEWER REPLACEMENT PROJECT Iml • ^S CARLSBAD, CALIFORNIA PROJECT NO. DATE FIGURE 106275001 12/08 A-4 KEY TO SYMBOLS I [ [ Symbol Description Strata symbols clayey sand (Qal) High plasticity clay Poorly graded sand with silt Low plasticity clay Silty sand (Qaf, Qal) Soil Samplers • California sampler APPENDIX B Sewer Pipeline Replacement Revised December 12,2008 Carlsbad, California Project No. 106275001 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. A grain-size distribution curve is shown on Figure B-l. The test results were utilized in evaluating the soil classification in accordance with the Uni- fied Soil Classification System. 200 Wash An evaluation of the percentage of particles finer than the No. 200 sieve in selected soil samples was performed in general accordance with ASTM D 1140. The results of the tests are presented on Figure B-2. Atterberg Limits Tests were 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. These test re- sults were utilized to evaluate the soil classification in accordance with the USCS. The test results and classification are shown on Figure B-3. Direct Shear Tests Direct shear tests were performed on undisturbed samples in genera] accordance with ASTM D 3080 to evaluate the shear strength characteristics of the selected material. The samples were inundated during shearing to represent adverse field conditions. The results are shown on Figures B-4 and B-5. Soil Corrosivity Tests Soil pH and resistivity tests were performed on a representative sample in general accordance with CT643. The chloride content of the selected sample was evaluated in general 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. 106275001 R Boyle Home Plant Rcv.doc GRAVEL Coarse Fine SAND Coarse Medium I U.S. STANDARD SIEVE NUMBERS 1000 3" 2' r/'" TV VV " J 16 30 50 CD UJ CO fy- z UJ O UJ 0- I I I I I I I I •«-• \ \ \ \ fine FINES SILT CLAY HYDROMETER 100 200 \ \ V i II" 100 10 1 0.1 0.01 0.001 0.0001 GRAIN SIZE IN MILLIMETERS .Symbol • Sample Location B-2 Depth (ft) 5.0-6.5 Liquid Limit - Plastic Limit - Plasticity Index - ' D10 -- c. - c. - Passing No. 200 46 uses SM PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 422-63 (02) M/nyo&Mfixyr& PROJECT NO. 106275001 DATE 12/08 GRADATION TEST RESULTS HOME PLANT LIFT STATION SEWER REPLACEMENT PROJECT CARLSBAD, CALIFORNIA FIGURE B-1 106275001 SIEVE B-2 ® 5.0-6.5 xls SAMPLE LOCATION B-1 B-2 SAMPLE DEPTH (FT) 15.0-16.2 10.0-11.0 DESCRIPTION SAND with Silt Silty SAND PERCENT PASSING NO. 4 98 100 PERCENT PASSING NO. 200 8 15 uses (TOTAL SAMPLE) SP-SM SM PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 1140-00 PROJECT NO. 106275001 DATE 12/08 NO. 200 SIEVE ANALYSIS HOME PLANT LIFT STATION SEWER REPLACEMENT PROJECT CARLSBAD, CALIFORNIA FIGURE B-2 106275001-200 WASH Page1.xls SYMBOL • LOCATION B-1 DEPTH (FT) 5.0-6.5 LIQUID LIMIT, LL 52 PLASTIC LIMIT, PL 22 PLASTICITY INDEX, PI 30 uses CLASSIFICATION (Fraction Finer Than No. 40 Sieve) CH uses (Entire Sample) CH NP - INDICATES NON-PLASTIC 0. x~inQz CO 60 50 40 30 20 10 CL-ML -CLorOL- ML or OL CH or OH -MHorOH- 0 10 20 30 40 50 60 70 80 90 100 LIQUID LIMIT, LL PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4318-05 PROJECT NO. 106275001 DATE 12/08 ATTERBERG LIMITS TEST RESULTS HOME PLANT LIFT STATION SEWER REPLACEMENT PROJECT CARLSBAD, CALIFORNIA FIGURE B-3 106275001 ATTERBERG Page1.xls 3000 2000 CO COCO LU OL COa: Iw 1000 1000 2000 NORMAL STRESS (PSF) 3000 Description SAND with Silt SAND with Silt Symbol - -X - - Sample Location B-1 B-1 Depth (ft) 15.0-16.2 15.0-16.2 Shear Strength Peak Ultimate Cohesion, c (psf) 280 100 Friction Angle, <j> (degrees) 37 31 Soil Type SP-SM SP-SM PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 3080-04 PROJECT NO. 106275001 DATE 12/08 DIRECT SHEAR TEST RESULTS HOME PLANT LIFT STATION SEWER REPLACEMENT PROJECT CARLSBAD, CALIFORNIA FIGURE B-4 106275001 SHEAR B-1 @ 15.0-16.0.xls 3000 1000 2000 NORMAL STRESS (PSF) 3000 Description Silty SAND Silty SAND Symbol - -X - - Sample Location B-2 B-2 Depth (ft) 5.0-6.5 5.0-6.5 Shear Strength Peak Ultimate Cohesion, c (psf) 260 160 Friction Angle, <j> (degrees) 26 26 Soil Type SM SM PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 3080-04 PROJECT NO. 106275001 DATE 12/08 DIRECT SHEAR TEST RESULTS HOME PLANT LIFT STATION SEWER REPLACEMENT PROJECT CARLSBAD, CALIFORNIA FIGURE B-5 106275001 SHEAR B-2 @ 5.0-6.5.xls SAMPLE LOCATION B-1 SAMPLE DEPTH (FT) 5.0-10.0 PH1 7.6 RESISTIVITY 1 (Ohm-cm) 220 SULFATE CONTENT 2 (ppm) 600 (%) 0.060 CHLORIDE CONTENT 3 (ppm) 1725 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. 106275001 DATE 12/08 CORROSIVITY TEST RESULTS HOME PLANT LIFT STATION SEWER REPLACEMENT PROJECT CARLSBAD, CALIFORNIA FIGURE B-6 106275001 CORROSIVITY PageLxls APPENDIX C Home Plant Lift Station Sewer Replacement Appendix C Carlsbad, California Project No. 106275001 APPENDIX C TYPICAL EARTHWORK GUIDELINES 106275001 Earthwork doc Home Plant Lift Station Sewer Replacement Appendix C Carlsbad, California Project No. 106275001 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 10627500] Earthwork doc Home Plant Lift Station Sewer Replacement Appendix C Carlsbad, California Project No. 106275001 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. 106275001 Earthwork.doc Home Plant Lift Station Sewer Replacement Appendix C Carlsbad, California Project No. 106275001 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. 106275001 Earthwork doc -> Rev 12/05 Home Plant Lift Station Sewer Replacement Appendix C Carlsbad, California Project No. 106275001 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- 106275001 Earthwork doc Home Plant Lift Station Sewer Replacement Appendix C Carlsbad, California Project No. 106275001 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- 106275001 Earthwork doc Home Plant Lift Station Sewer Replacement Appendix C Carlsbad, California Project No. 106275001 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. 106275001 Earthwork doc Home Plant Lift Station Sewer Replacement Carlsbad, California Appendix C Project No. 106275001 6. DEFINITIONS OF TERMS ALLUVIUM: AS-GRADED (AS-BUILT): BEDROCK: BORROW (IMPORT): CIVIL ENGINEER: CLIENT: COLLUVIUM: COMPACTION: CONTRACTOR: DEBRIS: ENGINEERED FILL: 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. 106275001 Earthwork doc Home Plant Lift Station Sewer Replacement Carlsbad, California Appendix C Project No. 106275001 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. 10627500! Earthwork doc Home Plant Lift Station Sewer Replacement Carlsbad, California Appendix C Project No. 106275001 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. 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. 106275001 Earthwork doc