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HomeMy WebLinkAbout3537; Vista/Carlsbad Interceptor Sewer; North Agua Hedionda Interceptor Access Road Shoreline; 2003-07-23PRELIMINARY GEOTECHNICAL INVESTIGATION PREFERRED WALL ALTERNATIVE NORTH AGUA HEDIONDA INTERCEPTOR ACCESS ROAD & SHORELINE PROTECTION CARLSBAD, CALIFORNIA Prepared for DUDEK & ASSOCIATES Encinitas, California Prepared by TERRACOSTA CONSULTING GROGP, INC. San Diego, California Project No. 2181 July 23, 2003 Consulting Group Geotechnical Engineering Geology Hydrogeology Coastal Engineering Hydrology Hydraulics Project No. 2181 July 23, 2003 Mr. Edward I. Matthews, P.E. Senior Engineer DODEK& ASSOCIATES 605 Third Street Encinitas, California 92024 PRELIMINARY QEOTECHN1CAL INVESTIGATION PREFERRED WALL ALTERNATIVE NORTH AQUA HEDIONDA INTERCEPTOR ACCESS ROAD & SHORELINE PROTECTION ALTERNATIVE CARLSBAD, CALIFORNIA C Dear Mr. Matthews: TerraCosta Consulting Group, Inc. (TCG) has performed a geotechnical investigation of the proposed preferred alternative for the sewer access roadway and shoreline protection of the North Agua Hedionda Interceptor Sewer-Western Segment. The project alignment is located adjacent to the northerly shores of Agua Hedionda Lagoon, southerly of Adams Street and extending easterly from Hoover Street a distance of 1,800 feet in the City of Carlsbad. The preferred wall alternative is intended to provide support and protection for an existing sewer pipeline and a proposed access roadway. The accompanying report presents the results of our field investigation, geologic mapping, and analyses, and provides geotechnical input and recommendations for the design and construction of the preferred alternative wall system. We appreciate the opportunity to work with you on this project and trust this information meets your needs. If you have any questions or require additional information, please give us a call. Very truly yours, TERRACOSTA CONSULTING , INC. Matthew W. Eckert, Ph R.C.E 45171, R.G.E. MWE/GAS/jg Attachments (6) Addressee leering 4455 Murphy Canyon Road, Suite 100 A San Diego, California 92123-4379 A (858) 573-6900 voice A (858) 573-8900 fax DUDEK & ASSOCIATES July 23, 2003 Project Mo. 2181 TABLE OF CONTENTS 1 INTRODUCTION 1 2 PURPOSE AND SCOPE OF INVESTIGATION 2 3 FIELD INVESTIGATION AND LABORATORY TESTING 3 4 SITE CONDITIONS AND GEOLOGY 4 4.1 Subsurface Soils 4 4.2 Surface Water and Qroundwater Conditions 5 4.3 Faulting and Seismicity 5 4.4 Geologic Hazards 6 4.4.1 Seismicity 6 4.4.2 Landslides 6 5 DISCUSSION 7 5.1 Project Goals 7 5.2 Potential Project Constraints 8 5.2.1 Geologic and Geotechnical Constraints 8 5.2.2 Constraints Related to the Shoreline 14 5.2.3 Environmental Constraints 15 5.2.4 General Design and Construction Constraints 16 5.3 Potential Project Alternatives 17 5.3.1 Gabion/Terramesh® Wall 18 5.3.2 Conventional Wall with Carved Concrete Facade 19 5.3.3 Sheet Pile Wall with Carved Concrete Faqade 21 5.3.4 Cast-in-Place Drilled (CIDH) Pier Wall with Carved Facing 23 5.3.5 Preferred Alternative 24 5.4 Specific Design and Construction Considerations for the Preferred Alternative 24 5.5 Other Project Design Concerns 26 6 PRELIMINARY RECOMMENDATIONS 27 6.1 Earthwork Operations and Site Preparation 27 6.2 CIDH PIER SUPPORTED WALL RECOMMENDATIONS 29 6.3 Access Road 30 7 LIMITATIONS 30 REFERENCES FIGURE 1 VICINITY MAP RGURE 2a SITE PLAN FIGURE 2b SITE PLAN (Continued) FIGURE 2c SITE PLAN (Continued) \\TCa_SERVER\networiAPn4ecM21\2181\2181 R01 QeoUch Inv.doc DUDEK& ASSOCIATES Project No. 2181 July 23, 2003 FIGURE 3a FIGURE 3b FIGURE 4 FIGURES FIGURE 6 RGURE 7 RGURE8 RGURE9 TABLE OF CONTENTS (Continued) PRORLE PRORLE (Continued) SECTION 1 SECTION 2 SECTION 3 SECTION 4 SECTION 5 SECTION 6 APPENDIX A LOGS OF EXPLORATORY EXCAVATIONS APPENDIX B LABORATORY TEST RESULTS APPENDIX C LIST OF FAULTS WITH DISTANCE FROM THE SITE AND ESTIMATED PEAK SITE ACCELERATION \\TCa_SERVERnctvKxMProjtctf\21\2181\2181 R01 Geotech Inv.doc DUDEK& ASSOCIATES Project No. 2181 July 23, 2003 Pagel PRELIMINARY GEOTECHNICAL INVESTIGATION PREFERRED WALL ALTERNATIVE NORTH AGUA HEDIONDA INTERCEPTOR ACCESS ROAD & SHORELINE PROTECTION CARLSBAD, CALIFORNIA 1 INTRODUCTION The North Agua Hedionda Interceptor sewer line parallels the northern shoreline of Aqua Hedionda Lagoon between Hoover Street and Cove Drive in Carlsbad, California. We understand that the project study area begins near the end of Hoover Street, at the north, and extends approximately 1,800 feet southerly and easterly along the northern shore of the Agua Hedionda Lagoon (see Figure 1). As we understand, wave-induced erosion has seriously impacted portions of the northern shoreline of the lagoon. This erosion has exposed portions of the existing 24- inch North Agua Hedionda Interceptor sewer line and has eliminated land access to the sewer line itself. In order to assess the implications of the erosion and to evaluate potential mitigation alternatives, the City of Carlsbad retained the services of Dudek & Associates (DC1DEK). In turn, DUDEK has retained the services of TerraCosta Consulting Group, Inc. (TCG) to provide geotechnical services for this project. DCIDEK's project manager for this project is Mr. Edward Matthews. Based on the results of several DUDEK studies, we understand that the City of Carlsbad wishes to stabilize approximately 1,800 linear feet of shoreline and small bluffs using a wall system to mitigate the erosion problem and prevent a failure of the sewer line. We understand that the preferred wall alternative consists of a pier-supported wall with a vertical free-form colored concrete facing that is sculpted to look like the surrounding natural bluff. \\TCXl_SERVERVwtirork\PrajwM21\2t81\21B1 R01 Qmtoch kw.doc DUDEK & ASSOCIATES July 23, 2003 Project No. 2181 Page 2 2 PURPOSE AMD SCOPE OF INVESTIGATION Based on our understanding of the project, and from discussions with Mr. Edward Matthews, Senior Engineer with DCJDEK, we performed a limited subsurface investigation and geologic reconnaissance of the subject portion of the sewer alignment. The purposes of our investigation are to evaluate the geologic and geotechnical site conditions, discuss site constraints that may affect the design and construction of the preferred alternative, and comment on the pros and cons of other wall alternatives. Specifically, our investigation is designed to: Collect data for the design of the wall's foundation system; • Assess general site and subsurface conditions along the alignment of the sewer and access road; Assess geologic hazards; Evaluate site constraints as they relate to constructability issues, such as excavation characteristics, groundwater conditions, potential trench instability, suitability of excavated materials for backfill, etc; and Assess preliminary wall design criteria. Our scope of work included the following: Reviewing available geologic literature and maps, geotechnical data, and aerial photographs along the alignment and adjacent areas; • Performing a geologic reconnaissance of the pipeline alignment and adjacent areas; • Excavating, sampling, and logging six exploratory borings along, or adjacent to, the alignment of the proposed improvements and sewer pipeline. \\TCa_SERVER\network\Projectj\21\2l8l\2l81 R01 Oeotech Inv.doc DCJDEK& ASSOCIATES Project No. 2181 July 23, 2003 Page 3 Conducting limited laboratory testing to augment our visual characterization of site conditions; Developing potential wall alternatives; Assessing site constraints related to environment, design, and construction concerns; Evaluating the pros and cons of the potential wall alternatives in terms of the identified site constraints; Developing preliminary design parameters for the preferred wall alternative; and Preparing a report summarizing our findings. 3 FIELD INVESTIGATION AND LABORATORY TESTING Our field investigation, conducted February 18 and 19, 2003, included performing a reconnaissance of the alignment and adjacent properties, and drilling, sampling, and logging six exploratory borings ranging from 10.5 to 37 feet in depth. The locations of the borings, and the results of our geologic mapping, are shown on Figures 2a, 2b, 2c, 3a, and 3b. Borings were logged and visually classified in the field, and samples collected for laboratory evaluation of geotechnical characteristics. Drilling operations were managed and overseen by a Registered Geologist from our office. A Key to Excavation Logs is presented in Appendix A as Figure A-l. Final logs of the borings are presented as Figures A-2 through A-7. The descriptions on the logs are based on our field logs and notes, and on subsequent sample inspections and laboratory testing. Representative samples of the soils obtained during our field explorations were tested in the laboratory for the purposes of aiding field classification and characterizing engineering properties of the soils. The laboratory tests performed included liquid and plastic limits, moisture content, and grain size analyses. A summary of laboratory tests results is presented in Appendix B of this report. \\TCQ_SEWBftnc<wo(MProjKt421\2181\2181 HOI Qeotoch Inv.doc DUDEK& ASSOCIATES Project No. 2181 July 23, 2003 Page 4 4 SITE CONDITIONS AND GEOLOGY The existing North Agua Hedionda sewer interceptor alignment is located along the northerly shoreline of Agua Hedionda Lagoon. Elevations along the project alignment range from approximately 0 to 10 feet, Mean Sea Level (MSL) datum. The existing 1,800 lineal feet of subject sewer easement traverses a low coastal bluff and undeveloped hillside. The general site topography along the project alignment is shown on Rgures 2a, 2b, and 2c. Likewise, a general geologic profile, drawn along the southern boundary of the project's right-of-way, is presented on Figures 3a and 3b. Lastly, generalized geologic cross sections at selected pipeline stations are shown in Rgures 4 through 9. 4.1 Subsurface Soils The existing sewer alignment and easement are underlain by artificial fill soils, geologically recent alluvial and colluvial soils, and Quaternary Bay Deposits and Tertiary sedimentary deposits. The specific soil units, in order of increasing age, are described below, along with comments on geotechnical characteristics pertinent to construction. Fill Soils - Locally derived fill soils cover much of the alignment. These soils are relatively shallow and appear to have been generated from grading during construction of the original sewer line. Alluvium/Colluvium - Alluvial and colluvial soils are present along the entire alignment. These soils generally consist of clayey sand and sandy clay, with thin lenses of gravel and cobble. It should be noted that when wetted, such as by perched groundwater or high tides, these soils may become locally unstable in trenches or steep-walled excavations. Bay Deposits - Bay deposits underlie the alignment north of approximate Station 5+00 and between approximate Stations 8+00 and 15+00. These deposits consist primarily of loose, interbedded, silty sands and silty to sandy clays. It should be expected that these deposits will require some type of stabilization or shoring to prevent caving and raveling of excavations during construction. \\TCQ_SEIWER\netwoe1APrcjecW21\2181\2181 R01 Oeotech Inv.doc DUDEK& ASSOCIATES Project No. 2181 July 23, 2003 PageS Santiago Formation - The Santiago Formation consists of a very dense, gray- brown, interbedded, well-indurated, silty to clayey sand. It should be expected that, during excavation through the Santiago Formation, highly cemented zones will be encountered, which may require heavy ripping and breaking. 4.2 Surface Water and Groundwater Conditions During our reconnaissance of the alignment, a number of groundwater seeps, or areas where phreatic vegetation was growing, were observed. The most prolific areas were between approximately Stations 5 and 6 and Stations 15 and 16. It should be noted that surface, as well as subsurface, flows may be encountered along much of the alignment, depending upon the time of year that construction occurs. Groundwater elevations will also fluctuate, depending on tides within the lagoon. 4.3 Faulting and Seismicity The site is located in a moderately active seismic region of Southern California that is subject to significant hazards from moderate to large earthquakes. A search using the computer program, EQFAULT 3.0, was made for locating known active faults within a 62-mile radius from the site. A total of eighteen major active and potentially active fault zones were identified within the search radius. A listing of these faults, along with their distance from the site, and estimated mean peak site acceleration corresponding to an occurrence of a characteristic earthquake on each fault is presented in Appendix C. In addition to the fault search described above, we conducted a geologic reconnaissance of the site that included review of published geologic maps and aerial photographs. No obvious active or potentially active faults were noted along or across the project alignment. However, we did note that a small fault segment has been mapped approximately 0.3 miles northerly of the alignment, the projection of which crosses the project alignment between Stations 14+00 and 15+00. However, this fault segment, as well as the other fault segments in the area, are considered to be secondary in nature, related to development of the offshore zone of deformation, and not considered to be currently or potentially active. \\TCQ_SERVEK\networtiSProJectftfl\2181\2181 ROI Geotech Im.doc DUDEK& ASSOCIATES Project No. 2181 July 23, 2003 Page6 4.4 Geologic Hazards 4.4.1 Seismicity General geologic hazards associated with faulting and site seismicity include ground shaking, ground lurching, ground rupture, tsunamis, liquefaction, seiches, lateral spreading, and seismic-induced slope instability. Liquefaction potential often exists where loose to medium dense, sandy soil is saturated. Lateral spreading is the lateral movement of soils toward free slope faces due to earthquake shaking and/or liquefaction. Typically, lateral spreading occurs along coastlines, seaward edges of lagoons, basins, harbors, and along riverbanks. From our review of the site conditions at and around the site, there are no known active faults that cross the project limits. Based on these observations, it is our opinion that the risk associated with ground lurching and/or ground rupture is negligible to low. Likewise, it is our opinion that the risk associated seismic-induced slope instability is low to negligible. However, in our opinion, the risks associated with ground shaking, liquefaction, lateral spreading, ground shaking, seiches, and tsunamis are moderate to high. Discussions concerning the ground shaking, liquefaction, and lateral spreading are presented in Section 6.0 of this report. An assessment of effects of tsunamis and seiches on the proposed project was not part of our scope of work. 4.4.2 Landslides Our review of the aerial photographs and our geologic reconnaissance of the project site did not reveal evidence of the potential for deep-seated landsliding. However, a review of 1953 aerial photographs revealed the presence of a debris flow in the area of Stations 7+50 and 10+00. A review of historical rainfall data for the County of San Diego revealed a season total rainfall of 21.8 inches at Rainfall Station 3540, in Vista, for the 1951-1952 season. It is our conjecture that this overall rainfall likely contributed to this debris flow. As the topographic conditions and the possibility of extreme rainfalls at the site have not significantly changed since then, it is our opinion that debris flows should be expected \\TCQ_SERVERVwtworiAPrcjKti\21\2181\2181 R01 Ocotech lm.doc DCJDEK& ASSOCIATES Project No. 2181 July 23. 2003 Page? to occur periodically on the adjacent hillsides. As such, maintaining access along the sewer alignment may require the periodic removal of debris flow and surficial slump deposits. 5 DISCUSSION 5.1 Project Goals Agua Hedionda Lagoon is one of the few remaining lagoons along the San Diego County coastline. In addition, a portion of the North Agua Hedionda Interceptor sewer line, a vital link in the area's wastewater control and treatment system, is located landward of the lagoon's northern shoreline (see Figure 1). As such, Agua Hedionda Lagoon is not only a very important public resource, it is also a very important natural and environmentally sensitive resource and habitat. Thus, any public improvement project associated with the North Aqua Hedionda Interceptor sewer line must consider and guard against permanent detrimental impacts to the lagoon. The primary goals of this proposed project, as we understand them, are to provide access to the sewer line, to protect the resources of the lagoon, and to blend the project aesthetically into the surrounding environment. The adopted engineering solution consists of constructing a retaining structure that will support an access road, limit right-of-way requirements for the access road, stabilize the lagoon's shoreline, and be aesthetically blended into the adjacent scenery. Specific elements of the retaining structure include: • Foundation support; Lateral load support; • Mitigation and accommodation of shoreline erosion; Constructability; \\TXXI_SERVER\network\Prcj.cti\21\2181\2181 R01 OeoUch kiv.doc DUDEK& ASSOCIATES Project No. 2181 July 23, 2003 Page8 • Ability to accommodate the necessary aesthetic features; and • Overall environmental impact. In order to develop, assess, and implement the proposed project, one needs to understand the many, and potentially conflicting, constraints associated with the project. Selection of the appropriate project alternative will require balancing project goals and project constraints with long-term benefits to the community and the environment. As this study pertains to the geotechnical and geologic characteristics of the project, potential project constraints and alternatives are presented and discussed primarily from that prospective. 5.2 Potential Project Constraints 5.2.1 Geologic and Geotechnical Constraints Geologic and geotechnical site conditions that may potentially impact the project generally fall within the following categories: Foundation support; Lateral support; • Design; and Construction. 5.2.1.1 Geologic and Geotechnical Foundation Constraints The primary geologic and geotechnical foundation constraints for the project are the variability in foundation soil type and the variability of static and seismic behavior of the soils. For example, formational materials (bedrock) are relatively strong and qualitatively incompressible, both statically and seismically. However, near-surface soils \\TCa_SERVERwtwodAProjocti\21\2181\2181 R01 Ocattdi kw.doc DUDEK & ASSOCIATES Project No. 2181 July 23, 2003 Page 9 and colluvial/slopewash deposits are stable and compressible under static conditions, but are unstable under seismic conditions. A more detailed illustration of the anticipated foundation conditions along the project alignment is presented in Figures 3a and 3b. When examining Figures 3a and 3b, it is important to keep in mind that the idealized geologic cross section is presented along southerly right-of-way limits of the access roadway. This is important to keep in mind when considering points of interest along the project alignment because the formational contact along the alignment is steeply sloped downward towards the lagoon (see Figures 4 through 9). Thus, the depth to the estimated formational contact may vary significantly from one location to another. The reason this is important is that the formational contact along the alignment descends steeply downward towards the lagoon. For example, the depth to formation along the centerline of the sewer line is higher than the depth shown on Figures 3a and 3b, which present a cross section along the southerly limit of the access roadway. As one considers the selection of a foundation system for the project, one must consider the implications associated with the foundation system of the structure as it relates to the variable subsurface conditions. Regardless of the type of retaining structure selected, the foundation system must be able to accommodate the variability in foundation support capacity and foundation settlement likely to be encountered along the alignment. The potential impacts to the retaining wall foundation system, due to variable site conditions, are further tested when one considers seismic activity. Potential seismic impacts that influence foundation performance and design include ground shaking, liquefaction, and lateral spreading. For those portions of the project primarily supported by bedrock, ground shaking is the predominant impact, whereas ground shaking, liquefaction and lateral spreading will be the major concerns for those portions not supported on bedrock. The principal design impact caused by ground shaking alone is increased lateral loading. The impacts associated with liquefaction include possible loss in foundation support, surface damage due to sand boils, increased lateral loads, and seismic- \\TCQ_SERVERSrwtwocWrojectt\21\2181\2181 R01 Oeotecti kw.doc DUDEK& ASSOCIATES Project No. 2181 July 23, 2003 Page 10 induced settlement. Lastly, potential design impacts associated with lateral spreading include liquefaction and the increased potential for lateral displacement of the retaining system. Variable site conditions potentially impact the performance of the existing sewer, as well as the performance and design of the retaining system for the access roadway. Examination of the geologic and geotechnical site model developed for this project suggests that the majority of the sewer line is founded within formational materials. However, this model also suggests that two portions of the sewer line between roadway Stations 10+60 to 12+50 and Stations 13+70 to 15+30 are likely supported by unconsolidated soils, which are potentially liquefiable and susceptible. We estimate that the magnitude of potential ground settlement beneath the pipe in these segments to be on the order of l/2 inch and 1 to 2 inches, respectively. Likewise, estimated surface settlements are expected to be on the order of 1 to 3 inches. 5.2.1.2 Geologic and Geotechnical Impacts Related to Lateral Support The primary geotechnical impacts related to lateral support are the earth loads required for design. In general, these loads will be comprised of a static component and a dynamic component. From a static condition, the earth load component is directly related to the retained soil type, its strength, and any surcharge loads associated with the roadway. The proposed retaining system will likely retain fill and collluvial soils that primarily consist of silty to clayey sands. The dynamic component of the earth load is a function of the retained soil, site ground shaking, and the stability of the underlying soils. As discussed above, portions of the alignment will be founded both on stable formational soils and on colluvial/slopewash soils that are susceptible to liquefaction and lateral spreading. Retaining walls founded on soils susceptible to liquefaction and lateral spreading will be subjected to higher dynamic earth pressure components than for those portions founded on stable ground. \\TCQ_SEWEftncbrark\PrciKti\21\2181\2181 R01 Oeotoch Inv.doc DCJDEK & ASSOCIATES July 23. 2003 Project No. 2181 Page 11 5.2.1.3 Geologic and Geotechnical Constraints Related to Construction The primary geologic and geotechnical constraints related to construction include: • Limitations related to excavations; Excavation stability; Stability of cut and fill slopes; • Impacts associated with groundwater and dewatering; and • Suitability of on-site materials for use as construction materials. 5.2.1.3.1 Issues Related to Excavations Issues associated with the proposed project include: • Excavatability of material; Stability of excavations; Dewatering; and • Required work area and potential encroachments. On-site materials anticipated to be encountered during excavations for the proposed project consist of fill soils, colluvial and slopewash deposits, beach and bay deposits, and competent formational soils. In general, the fill soils, colluvial and slopewash deposits, and beach and bay deposits are comprised of loose to medium dense sands, silty sands, and clayey sands. These soils may typically be excavated using conventional construction equipment, such as backhoes and excavators. In general, these unconsolidated soils should be considered unstable below the water table. Soils above the groundwater table classify as Type C soils per OSHA's guidelines. \\TCQ_SEOTER\netwoiWProjecW21\2181\2181 R01 Ootech bw.doc DCJDEK& ASSOCIATES Project No. 2181 July 23, 2003 Page 12 In general, the formational soils are comprised of very dense and cemented sandstones and hard claystones. We anticipate that these materials can be excavated using construction equipment, such as large excavators and backhoes. In addition, it is possible that cemented zones may be encountered that may require the use of heavy ripping and possibly rock-breaking equipment, such as jackhammers. However, we anticipate that these zones will be limited. Classically, excavations are typically stabilized by either shoring, the use of trench shields, or by sloping the sides of the excavation. Due to the environmental constraints associated with this project, we anticipate that the majority of excavations may require shoring in order to limit encroachments into environmentally sensitive areas. Due to a relatively shallow groundwater table, excavations will require dewatering to maintain stability, due to seepage into the excavation and/or coordination of work efforts with tidal fluctuations. In our opinion, the soils likely to be dewatered are generally highly permeable fine to very fine sands. As such, loss of material due to piping and migration of fines should be considered in the design of any dewatering system. Depending upon depths of excavations, it may be prudent to use sheet pile cut-off walls to help facilitate dewatering efforts for the project. Such a sheet pile cut-off wall system would also help to control potential encroachments into environmentally sensitive areas. 5.2.1.3.2 Cut and Fill Slope Stability In general, cut and fill slopes above the water table are stable at inclinations of 2 to 1 (horizontal to vertical) or flatter. However, the main constraint to cut and fill slopes is the project right-of-way. As such, slope inclinations may locally be able to be increased depending upon slope height and soil composition. However, these conditions require a case-by-case evaluation. Such an evaluation is beyond the scope of this report. 5.2.1.3.3 Groundwater In general, groundwater at the site is directly related to the elevation of water in the lagoon. As such, we anticipate that most, if not all, of the project excavations will \\TCa_SERVEK\netwofttPrafectri21\2181\2iai R01 Qtotech Iro.doc DUDEK& ASSOCIATES Project No. 2181 July 23, 2003 Page 13 encounter groundwater. However, we anticipate that the groundwater levels will generally rise and fall with the lagoon tides. Several potential methods that could be employed to mitigate groundwater impacts include: • Limitation of the depth of excavations; Use of sheet pile cut-off walls; • Use of cofferdams; Shoring systems with gravel stabilization bottoms and sump drains; • Dewatering systems, such as well point systems; and/or • Coordination of work with tides. Lastly, we anticipate that any excavation dewatering will require special permitting. 5.2.1.3.4 Suitability of On-Site Material for Use in Construction On the basis of our review of on-site soils, it is our opinion that most soils encountered on site may be used for fill and general backfill. However, soils contaminated with deleterious or biodegradable materials will not be suitable for use as a fill or general backfill material. Likewise, soils that have excess moisture will not be suitable for use as general fill or backfill purposes; however, they could be used provided that they are processed to remove their excess moisture. In addition, oversize materials that may be encountered during excavation, such as shore protection rock or cemented lenses obtained from excavations within formational areas, will be restricted in their use as construction fill or backfill. Typically, these restrictions pertain to maximum size of individual pieces and the quantity of oversize pieces. Specific recommendations for the use of oversize materials are presented in the Recommendations Section (Section 6.0) of this report. \\TCQ_SattERnctvrorttPn4wrt21\2181\2181 HOI Qcolcch kw.doc DCJDEK & ASSOCIATES Project No. 2181 July 23, 2003 Page 14 5.2.2 Constraints Related to the Shoreline The proposed project alignment is located along the shoreline of Agua Hedionda Lagoon. Currently, ongoing shoreline erosion and shoreline retreat is occurring, which has impacted several portions of the project alignment. While the shoreline erosion and shoreline retreat do not currently impact all portions of the project alignment, eventually all portions of the alignment will be impacted unless measures are taken to stabilize the shoreline. Crude comparisons between 1965 and 1998 topography maps of the site generally suggest overall shoreline retreat (movement of elevation +5 feet [MSL] contour). However, the observed retreat is uneven, and may have been altered due to possible maintenance activities during this period. The rate of shoreline retreat is most consistent up-station of Station 12+00, where estimated rates suggest an average shoreline retreat of approximately 0.4 feet per year, plus or minus 50 percent. A shoreline retreat rate of 0.4 feet per year over a 30-year time frame translates into a horizontal retreat of 12 feet, and for a beach with an 8-degree slope, a correspond vertical loss of 1.7 feet. Current project objectives call for the use of a naturalized, exposed, vertical wall face to stabilizing the lagoon's shoreline. This wall face is to be constructed with a free-form shotcrete surface that is sculpted to simulate a relatively low-profile natural bluff. Coloring of the concrete will likely be accomplished using pigmented concrete. To help mitigate and/or accommodate beach erosion, the vertical wall face will require a cut-off wall or toe protection. The depth and location of the proposed free-form concrete vertical wall will likely impact construction excavation requirements. These impacts may require additional encroachment into environmental areas beyond those anticipated in the selection of the project's right-of-way. As mentioned above, a vertical wall will stabilize the lagoon's shoreline by inhibiting lateral shoreline retreat. The vertical loss of material in front of the wall could continue depending on the overall sediment transport regime in the lagoon, as well as scour at the wall face due to wave action. The loss of material due to the sediment transport \\TCQ_SERVER\rMtwaiMPrajecti\21\2iai\2181 R01 Ocotech kw.doc DUDEK& ASSOCIATES Project No. 2181 July 23, 2003 Page 15 regime in the lagoon is unknown. Scour in front of the wall due to wind-generated waves is estimated to be on the order of the wave height or approximately 1 foot. Vertical loss of material in front of the wall may be mitigated with the use of shoreline protection, such as riprap and/or erosion mats. 5.2.3 Environmental Constraints The alignment of this proposed project is located within and adjacent to highly sensitive environmental areas. Specific environmental habitats located along and adjacent to the project alignment include: • Intertidal mudflats; • Intertidal rocky beach; Open water; • Coastal salt marshes; and • Coastal sage scrub areas. In addition, a California gnatcatcher habitat area has been identified just north of the project alignment between Stations 12+85 to 14+70. We understand that the area of work within the sensitive environmental habitat areas is to be limited as much as possible. As such, excavations that would normally be sloped to provide access for work will likely now have to be shored. In addition, dewatering of project excavations may be restricted or even prohibited, due to discharge requirements within, and adjacent to, habitat areas. For this project, we anticipate that encroachment restrictions will necessitate excavation shoring, and the utilization of specialized equipment so as to enable work within limited and restricted areas. \\TCG_SERVERnetworiAPn4ecM21\2iei\2181 R01 Oeotedi kw.doc DCJDEK& ASSOCIATES Project No. 2181 July 23, 2003 Page 16 Another likely environmental concern or constraint for the project is the control and/or isolation of potential contamination, due to construction. As such, the use of isolation berms or other mitigating structures, as well as restrictions on operating construction equipment, may be imposed or required for this project. 5.2.4 General Design and Construction Constraints • General project design and construction constraints include the following: • Limit the amount of encroachment associated with the temporary construction right-of-way, including encroachment into environmental areas; Maintain access to the sewer; • Limit the amount of required permanent right-of-way; • Maintain and stabilize the shoreline; and • Provide a naturalized, exposed, vertical wall face constructed with a free-form shotcrete surface that is sculpted and colored to simulate a natural bluff adjacent to the lagoon edge. The coloring of the concrete would likely be accomplished with the use of pigmented concrete. Currently, we understand that the project has a temporary construction corridor that is 20 feet wide and a permanent 14-foot-wide right-of-way corridor. In addition, we understand that the permanent 14-foot-wide right-of-way corridor is further subdivided into a 12-foot-wide roadway and a 2-foot-wide structural area that is located along the lagoon side of the roadway. The type of retaining structure selected for the project influences the impact that these construction and design constraints may have on the project. As such, the majority of discussion related to construction and project design is presented in the general discussion for each proposed retaining system alternative. However, one common constraint that impacts the project construction and potential design is the depth of embedment required for the vertical free-form concrete face. \\TCQ DUDEK& ASSOCIATES Project Mo. 2181 July 23, 2003 Page 17 Current project concepts suggest that the free-form colored vertical concrete face should be embedded a minimum of 2 feet below the current beach surface. This would suggest an embedment elevation of approximately 1 + foot (MSL). This, in and of itself, does not pose a problem for those portions of the project alignment where the lagoon edge of the alignment is at, or near, the current toe of the wave-cut bluff face where the anticipated excavation depths are only on the order of a few feet. However, there are also significant portions of the alignment where the lagoon side of the alignment is +10 feet away from the wave-cut bluff face. At these locations, the top-of-bluff is several feet above the toe of the bluff. For these locations, the excavation depths will be on the order of +5 feet and will likely require a width of excavation of +5 feet to permit carving the concrete face. Such excavation dimensions will require significant removal and replacement of soils within the existing wave-cut bluff. To limit the potential impact associated with excavation dimensions, the free-form and carved concrete face could be replaced with a precast panel that is free-formed over a limited exposed area. However, such an approach would require that if, and when, the existing bluff eroded to the concrete wall and fully exposed the vertical concrete face, the free-form face would be reapplied and extended over the exposed wall face. 5.3 Potential Project Alternatives One of the key components for this project is the selection of an earth retaining system for this project. During preliminary project discussions, a preliminary screening of potential retaining structures and systems was made. From this preliminary screening process, the following potential retaining system alternatives were selected for additional study: • Gabion/Terramesh® wall system; Conventional retaining wall with carved concrete facade; • Sheet pile wall with carved concrete facade; and • Cast-in-drilled-hole (CIDH) pier wall with carved concrete facade. ortAPrei«t*ai\2181\218l R01 Ctoctach kw.doc DUDEK & ASSOCIATES Project No. 2181 July 23, 2003 Page 18 Each of these retaining systems is discussed below. 5.3.1 Gabion/Terramesh® Wall Gabion/Terramesh® retaining wall systems consist of cobble, rock, and gravel-filled wire mesh baskets that are generally stacked and connected together. The primary difference between a gabion retaining wall and the Terramesh® retaining system is that, while both systems are gravity retaining systems, the Terramesh® system uses soil reinforcement to construct the gravity mass instead of interconnecting gabion baskets. Both systems are flexible and can accommodate variable settlements that would otherwise damage more conventional rigid gravity wall systems. However, as both systems are gravity structures by nature, both systems require a minimum width-to- height ratio to prevent failure of the retaining system. Generally, this width-to-height ratio varies between 0.7 and 1. Thus, a 10-foot-high wall would require a width of 7 to 10 feet. Both systems tend to ultimately blend into the surrounding areas as vegetation establishes itself within the retaining systems themselves. The Terramesh® system can be designed with a plantable face, whereas the Gabion system generally relies on the establishment of vegetation within the void spaces of the gabion basket. The advantages of a gabion/Terramesh® retaining system include the following: The gabion/Terramesh® system will provide shoreline stabilization. • The proposed system is a flexible wall system that can readily accommodate immediate and future differential settlements. • The retaining system may be aesthetically blend into the surrounding area. However, the common means of blending is through vegetation. The use of structural facades is not common and would require special structural connections to attach any structural element to the wire mesh baskets of the gabion/Terramesh® structure. \\TCQ_SERVERneNnrMPK4tcM21\2181\2181 R01 Oeotochlnv.doc DCJDEK & ASSOCIATES July 23. 2003 Project No. 2181 Page 19 • The retaining system can readily accommodate erosion protection elements, such as enclosed riprap mats and cut-off walls. Several disadvantages of a gabion/Terramesh® retaining system include: Preliminary layouts of the retaining system, based on typical wall height-to-width ratios, suggest that portions of the retaining system foundation will extend over and beyond the centerline of the sewer. Such a condition would require that portions of the retaining wall foundation would need to be demolished and repaired when access to the sewer pipe was needed. To mitigate this impact, the proposed wall alignment could be realigned so as to eliminate the encroachment of the wall foundation over the sewer line. Incorporation of erosion protection for the gabion/Terramesh® system will likely require additional encroachment into environmental habitat areas beyond the proposed construction and permanent project right-of-ways. Use of erosion mats will require additional permanent encroachments, whereas use of a cut-off wall will likely require additional construction encroachments to accommodate construction excavations. Minimum widths of construction excavations located in front of the retaining system are estimated to range between 3 and 5 feet. The incorporation of a free-form vertical concrete facade on the gabion/Terramesh® system face poses two issues. The first issue is the compatibility of a rigid facade attached to a flexible system that might settle over time. We anticipate that future settlements of the retaining system will result in cracking of the concrete facade. This cracking will likely degrade the aesthetic appeal of the facade. The second issue is associated with the potential need to use a specialized connecting system to attach the facade to the gabion/Terramesh® wire mesh baskets. 5.3.2 Conventional Wall with Cawed Concrete Facade The conventional retaining wall with carved concrete facade is a gravity mass retaining system. As with the gabion/Terramesh® systems, the conventional retaining wall \\TCQ_SERVERVMtwofWic4KM21\2181\2181 R01 Ototocti Inv.doc DUDEK & ASSOCIATES Project Mo. 2181 July 23, 2003 Page 20 requires a minimum width-to-height ratio to ensure system stability. In general, gravity mass retaining systems require a width-to-height ratio between 0.75 to 1 to be stable. Two primary differences between a conventional wall system and the gabion/Terramesh® systems are the aesthetics of the finished wall face and structural flexibility, as it relates to accommodating differential settlements and weak foundation support. In general, the conventional wall system can be aesthetically blended into the surrounding areas by using a carved and colored wall facing to simulate nature bluff faces and/or rock exposures. In order to accommodate weak foundation conditions and differential settlement, the wall system needs to be designed with variable footing widths and structurally isolated segments that would be free to adjust with local settlements. Such an articulated wall system may behave in a manner that could possibly compromise and degrade the aesthetic features of the wall system. The advantages of a conventional concrete wall with carved concrete facade include: A system that will provide shoreline stabilization; and • An outer wall face that was constructed of a free-form surface that could simulate adjacent bluff faces. Several disadvantages of the conventional retaining system include: Preliminary layouts of the retaining system, based on typical height-to-width ratios, suggest that portions of the retaining system will extend beyond the centerline of the sewer. Such a condition would require that portions of the retaining wall foundation would need to be demolished and repaired when access to the sewer pipe was needed. To mitigate this impact, the proposed wall alignment could be realigned so as to eliminate the encroachment of the wall foundation over the sewer line. The proposed retaining system is a rigid system that would require specific segmenting and articulation in order to accommodate the variability of foundation soils and anticipated immediate and future differential settlements. \\TCa_SERVER\mtworiAPx4ccuN21\2181\2iai R01 Ocotoch kw.doc DUDEK& ASSOCIATES Project No. 2181 July 23, 2003 Page 21 Incorporation of erosion protection for the conventional wall system will likely require additional encroachment into environmental habitat areas beyond the proposed construction and permanent project right-of-ways. Use of erosion mats will require additional permanent encroachments, whereas use of a cut-off wall will likely require additional construction encroachments to accommodate construction excavations. Minimum widths of construction excavations located in front of the retaining system are estimated to range between 3 and 5 feet. The incorporation of a free-form carved concrete facade on the conventional wall system poses an important issue associated with the accommodation of wall settlement with continuous rigid facade. We anticipate that future settlements of the retaining system will result in cracking of a continuous concrete facade. This cracking will likely degrade the aesthetic appeal of the facade. One mitigation measure would be to articulate the vertical facade with expansion joints in order to help accommodate differential settlements between separate system elements. However, the details of these joints may be fairly complicated and expensive to construct. 5.3.3 Sheet Pile Wall with Carved Concrete Facade The cantilevered sheet pile wall with carved concrete facade is a retaining system that derives its stability from structural embedment instead of a gravity mass. Sheet pile wall systems general do not require a minimum width-to-height ratio to maintain stability. The stability of sheet pile systems is generally achieved with a sheet pile embedment approximately two times the retained height of the sheet pile. In addition, sheet pile systems generally do not require the same level of construction excavation to install said system. However, installing sheet pile systems may require a large work area in order to accommodate the construction equipment. When work area is limited, use of specialized equipment and/or increased adjustments to equipment siting is required to install the sheet pile wall. As sheet pile walls require embedment for stability, the ability to drive the structural elements of the sheet pile wall to the required tip depths is oftentimes a controlling \\TCa_SEWERnttworWK4KM21\2181\2181 R01 Geotoch Inv.doc DUDEK & ASSOCIATES July 23, 2003 Project No. 2181 Page 22 feature in the applicability of the system. Thus, sites with highly variable bedrock depths pose construction and installation issues that may eliminate the sheet pile system as a viable economic option. The advantages of a cantilevered sheet pile wall with carved concrete facade include: • A sheet pile wall system will provide shoreline stabilization; The sheet pile wall system will not inhibit repair and maintenance access to the sewer line; The outer face of the proposed sheet pile system could be constructed with a free-form carved concrete surface that would be integral with the pile system; and • There would be no need for additional erosion protection other than the free- form carved concrete facade. Several disadvantages of the sheet pile wall system include: The inability to install the sheet pile wall system into the underlying bedrock. As such, some portions of the project alignment would require an alternative retaining system in order to provide shoreline protection along the entire length of the project. If a steel sheet pile wall system were used, the wall system would require corrosion protection to maintain and extend the design life of the system. The use of vinyl sheet pile sections could offset this issue. However, the use of vinyl sheets would further restrict their use, due to driveability issues, hence requiring increased use of a supplemental wall system. Construction of the free-form carved concrete facade will require construction access to the front of the sheet pile. A construction excavation will likely provide this access. In order to limit potential encroachments into environmental habitat areas, this excavation will likely have to be shored. In addition, the \\TCX2_SatVEftnttwariAPrajcctt21\2181\2181 ROKteaUchlnv.doc DUDEK& ASSOCIATES Project No. 2181 July 23, 2003 Page 23 excavation may require dewatering. Minimum widths of construction excavations located in front of the retaining system are estimated to range between 3 and 5 feet. 5.3.4 Cast-in-Place Drilled (CIDH) Pier Wall with Cawed Facing A cantilevered CIDH pier wall with carved concrete facade is, like the sheet pile wall, a retaining system that derives its stability by structural embedment instead of gravity mass. As stated above, such systems generally do not require a minimum width-to- height ratio to maintain stability, but instead achieve their stability with an embedment that is on the order of two times the retained height. Likewise, the installation of a CIDH pier generally does not require extensive construction excavations, but does require sufficient workspace for construction equipment. When workspace is limited, the use of specialized equipment and/or increased adjustments to equipment siting is required to install the CIDH pier. The advantages of a CIDH pier wall with carved concrete facade include: • The CIDH pier may be installed at sites with variable foundation conditions; The CIDH pier may be installed into formational materials; • The CIDH pier wall may be installed anywhere along the alignment of the project; • The free-form concrete facade is integral with the pier wall system; The CIDH pier wall system can be installed and constructed to provide repair and maintenance of the sewer without significant modification to the proposed project right-of-ways; • The performance of the system is independent of the long-term performance of the proposed roadway. Hence, future settlements of the roadway should not significantly impact the performance of the CIDH pier system; \\TCQ_SERVEIfrMtworiAPraiKtrfei\2181\2181 R01 OtoUch kw.doc DUDEK& ASSOCIATES Project No. 2181 July 23. 2003 Page 24 The proposed CIDH wall system will stabilize the lateral location of the shoreline; and The free-form concrete facade can be designed to serve as a cut-off wall; Several disadvantages of a CIDH pier wall system include: Incorporation of free-form concrete facade and pier wall will likely require additional encroachment into environmental habitat areas beyond the proposed construction right-of-way. Minimum widths of construction excavations located in front of the retaining system are estimated to range between 3 to 5 feet. Variable formational material composition, such as cemented zones, may require the use of variable drilling techniques that could impact project schedules. 5.3.5 Preferred Alternative As demonstrated above, the CIDH pier wall with carved facade clearly accommodates project objectives better and with fewer impacts. Thus, on the basis of our evaluation of the potential project alternatives as describe above, we conclude that the CIDH pier wall with carved concrete facade is the preferred retaining system alternative. 5.4 Specific Design and Construction Considerations for the Preferred Alternative With respect to the design of the preferred alternative (i.e., the CIDH pier-supported wall), there are various issues that require further clarification before the specific design may proceed. These considerations are as follows: What level of seismic risk should the project be designed? Cinder seismic loading, there will be differential lateral wall movements that may result in cracking of the vertical wall facacde. As such, is damage to the carved and naturalized wall facing acceptable? \\TCQ_S£RVER\n«worWr^ect»\2l\218l\218l R01 Oeotech Im.doc DCJDEK & ASSOCIATES Project No. 2181 July 23, 2003 Page 25 Is encroachment into the environmental habitat areas beyond the current construction easement or right-of-way permissible during construction? What type of vehicular loading does the proposed roadway need to support? • Will periodic maintenance of the exposed vertical facade be allowed in order to maintain the aesthetic appearance of the wall? Also, is it likely that such maintenance will need to be included in budgetary planning by the owner? What is the minimum clear edge distance that may be maintained between the outside edge of the CIDH piers and the outside edge of the existing sewer trench? If a 1- to 2-foot distance is appropriate, adjustments to the proposed wall alignment may be required between Stations 11+00 and 13+00. Construction of the preferred alternative will likely follow the following general sequence: 1. Clear and grub alignment of roadway. Grade roadway to create access for the installation of the CIDH piers. 2. Depending upon the encroachment restrictions of the project, a temporary sheet pile wall may be needed to maintain and support excavations required for the construction of the vertical wall and CIDH shafts. 3. Drill and construct CIDH piers. These operations will require that work begin on one end of the project and will proceed to the other end. The operations will likely involve a drill rig that works in conjunction with a crane. Casing through the upper alluvial/colluvial and bay deposits will likely be required to stabilize the drilled shafts and to mitigate discharge of spoil, drilling fluid, and water from the drilled shafts. Drilling fluids will likely be required to stabilize the pier shafts below the water table. The fluids will require the use of large (Baker) mixing/settling tanks during drilling and construction of the CIDH shafts. Once a CIDH pier shaft has been drilled, the steel reinforcing cage will need to be lifted and placed in the shaft by a crane. Once the reinforcing cage has been place, concrete will be pumped by tremie into the drilled shaft from the bottom up. The drilling fluid will be displaced from the drilled pier shaft by the \\TCQ_SEWERnetirofMPn4ectt21\2181\2181 R01 Gwtech Inv.doc DCJDEK& ASSOCIATES Project No. 2181 July 23, 2003 Page 26 concrete. This fluid will need to be collected in tanks and processed for reuse on the site. 4. After the CIDH piers have been constructed, excavations for the construction of the vertical concrete wall will be made. Once the depth required for the vertical wall has been achieved, the wall will be constructed and attached to the CIDH piers. Encroachment restrictions will dictate the method of wall construction. Likely, construction techniques may include, cast-in-placed, shotcrete-in-place, or placement of precast panels. 5. Following construction of the wall, the roadway will be constructed to planned grades. 6. The free-form carved and colored wall facade will be constructed, during Step 4 or 5, depending upon the encroachment restrictions in front of the proposed wall. The specific type of construction equipment will depend for the most part on the environmental and encroachment constraints of the project. Construction of the vertical concrete wall will likely require excavations that will be within the tidal zone. As such, the contractor will either have to time his construction with the tides in order to place steel and to form and shotcrete the wall, or he will need to dewater his excavations. Likely dewatering methods may include the use of driven sheet piles or construction of coffer dams that will separate the excavation from the lagoon waters. In addition, sump pumps within the excavation will likely be needed to keep the interior of the excavations dry for construction activity. Waters pumped from the excavations will likely need special discharge permits for handling the discharge of the water off site. 5.5 Other Project Design Concerns One other project design concern pertains to the seismic response of the existing sewer line. As stated above, two portions of the sewer line between roadway Stations 10+60 \\TCXl_SERVERVMtworiAPn4Kli\21\2181\2181 R01 Gwtoch Inv.doc DUDEK& ASSOCIATES Project No. 2181 July 23, 2003 Page 27 to 12+50 and Stations 13+70 to 15+30 are likely supported by unconsolidated soils, which are potentially liquefiable and susceptible to settlement. We estimate that the magnitude of potential ground settlement beneath the pipe in these segments to be on the order of !£ inch and 1 to 2 inches, respectively. Likewise, estimated surface settlements are expected to be on the order of 1 to 3 inches. If the existing sewer cannot accommodate these settlements and if the consequences associated with potential failure of the sewer are a concern, then it would seem reasonable to assume that some level of mitigation is in order. From a geotechnical perspective, liquefaction-prone soils are generally mitigated by densification. Several in-situ soil densification methods include vibro-replacement and compaction grouting. Vibro-replacement consists in advancing a vibrating device into the soil. This device has the capability of delivering material into the soil mass as the soil is densified. Usually, gravel or stone is used to replace the loss of ground created by the vibrating probe. Compaction grouting consists in physically displacing soil by the injection of grout into the ground. Either method results in soil being displaced. This displacement could damage the sewer line. As such, an alternative mitigation method may be in-situ densification/solidification by cementing the soil around the sewer by chemical or cementitious grout injection. However, if the sewer can accommodate the anticipated settlements, then no mitigation would be indicated. 6 PRELIMINARY RECOMMENDATIONS 6.1 Earthwork Operations and Site Preparation All grading and site preparation should be performed under the observation of the geotechnical engineer and in accordance with the City of Carlsbad's Grading Ordinance, the 1997 Edition of the Standard Specifications for Public Works Construction (SSPWC), and the 1997 Regional Supplement Amendments. \\TCQ_SERVER\rwtwocWrojKts\2l\2l8l\218l R01 Ootedi lm.doc DUDEK& ASSOCIATES Project Mo. 2181 July 23, 2003 Page 28 All vegetation, debris, and other deleterious material should be removed from areas to receive fill prior to site regrading. We recommend that all areas be excavated to competent colluvial and/or formational soils and benched as required by the City Grading Ordinance. All structural fill soils should be compacted to a minimum 90 percent of the maximum dry density as determined by ASTM Test Method D 1557-91. Moisture content in the fill should be maintained between the optimum moisture content and 3 percent over optimum. We recommend that the geotechnical engineer review the project plans to evaluate whether the intent of the design recommendations presented herein has been properly interpreted and incorporated into the contract documents. We recommend that all fill slopes be graded at a maximum inclination of 2:1, and that cut slopes be designed and constructed to a maximum inclination of 2:1. If steeper inclinations are required due to project constraints, the slopes should be evaluated on a case-by-case basis, and additional recommendations provided to mitigate anticipated surficial instability. In areas above the water table, we recommend that all temporary construction slopes have a maximum inclination of Vr.l or flatter. In our opinion, such a slope will be grossly stable for temporary construction, although minor ravelling may occur. We recommend that an engineering geologist inspect all temporary construction slopes during grading. Should evidence of locally unstable conditions be observed, mitigation measures should be taken immediately. In areas receiving pavement or foundations, we recommend that the upper 1 foot of subgrade soils be compacted to 90 percent of the maximum dry density, as determined by ASTM D 1557-91. We recommend that all trenching operations for the proposed project comply with OSHA and CALOSHA requirements. As such, trench excavations will generally need to be either shored or sloped back. Trench shields may be used in lieu of shoring or sloping the excavations, provided CALOSHA and OSHA regulations are followed. The \\TCa_SERVEnnetwxk\PK4Kt421\2181\2181 R01 (bated) Inv.doc DUDEK& ASSOCIATES Project No. 2181 July 23, 2003 Page 29 stability and safety of all construction excavations is the responsibility of the contractor and his "competent person." We recommend that excavation conditions be verified in the field, and that modifications be made to any trench excavation support systems, as needed, based upon the actual exposed conditions in the field. We recommend that the designated "competent person" determine the need for, and method for, trench stabilization as stated in the OSHA and CALOSHA requirements. 6.2 CIDH PIER SUPPORTED WALL RECOMMENDATIONS Once a detailed layout of the proposed project has been selected and reviewed, we can provide specific recommendations for the design and construction of the CIDH pier- supported wall. In order to assist in the selection of the final layout for the wall, we recommend the following preliminary guidelines: Vertical concrete wall should extend down to a toe elevation less than or equal to+lfoot(MSL); • Assume a 5-foot-wide excavation to construct the vertical concrete wall; Assume that CIDH piers are spaced 6 feet on centers and have a minimum diameter of 2 feet; • The outside edge of the CIDH piers should be kept a minimum of 2 feet away from the outside edge of the existing sewer trench wall. Assume that the sewer trench wall is located approximately 6 inches beyond the outside diameter of the sewer; • Assume that the vertical concrete wall is a minimum of 19 inches wide, exclusive of a 4-inch carved concrete face; • Assume that the elevation of the bedrock contact beneath the CIDH piers varies in the following manner: \\TCa.SERVERVMtwoi1APn4wM21\2181\2181 R01 OoUsch kw.doc DUDEK & ASSOCIATES July 23, 2003 Project No. 2181 Page 30 • At Station 3+00, the bedrock contact is at elevation -28 feet (MSL); • From Station 3+00 to Station 5+25, the elevation of the bedrock contact varies linearly from elevation -28 feet (MSL) to elevation +5 feet (MSL); • From Station 5+25 to Station 7+50, assume that the elevation of bedrock is constant at elevation +5 feet (MSL); From Station 7+50 to Station 8+50, assume that the elevation of the bedrock contact varies from elevation +5 feet (MSL) to elevation -10 feet (MSL); From Station 8+50 to Station 15+00, assume that the minimum bedrock contact is at elevation -10 feet (MSL) (in reality, the bedrock contact varies between elevation -5 and -10 feet [MSL]); and From Station 15+00 to Station 19+00, assume that the bedrock contact is at elevation 0 feet (MSL). Assume the minimum depth of embedment into the bedrock is 20 feet. 6.3 Access Road We recommend that the access road be designed in accordance with the County of San Diego's Standards for Private Roads. 7 LIMITATIONS Geotechnical engineering and the earth sciences are characterized by uncertainty. Professional judgements presented herein are based partly on our evaluation of the technical information gathered, partly on our understanding of the proposed construction, and partly on our general experience. Our engineering work and judgments rendered meet the current professional standards. We do not guarantee the performance of the project in any respect. \\TCQ_SERVERNnttwrMPri4ecrt21\218l\2181 R01 Ceotech Inv.doc DUDEK & ASSOCIATES July 23, 2003 Project No. 2181 Page 31 We have investigated only a small portion of the pertinent soil, rock, and groundwater conditions of the subject site. The opinions and conclusions made herein were based on the assumption that those rock and soil conditions do not deviate appreciably from those encountered during our field investigation. We recommend that a soil engineer from our office observe construction to assist in identifying soil conditions that may be significantly different from those encountered in our borings. Additional recommendations may be required at that time. \\TCQ SERVER\rvrtworWroj«ct.\21\218t\2181 R01 Oeotech lnv.doc DUDEK & ASSOCIATES July 23, 2003 Project No. 2181 REFERENCES Blake, T.F., 2000, EQFAULT, a computer program for deterministic prediction of peak horizontal acceleration, Computer Services and Software. California Division of Mines and Geology, 1996, Geologic Maps of the Northwestern Part of San Diego County, California, Plate 1, Geologic Maps of the Oceanside, San Luis Rey, and San Marcos 7.5' Quadrangles, DMG Open-File Report 96-02. Aerial Photographs County of San Diego, flown 07-1989, WAL-89CA, 3-7. County of San Diego, flown 10-9-1970, Photos 2-2 and 3-5. CI..S. Army, flown 1928, Photos 30E1, 30E2, and 30E3. U.S. Department of Agricultural, flown 4-11-1953, Photograph Nos. AXN-8M-101 and 102. \\TCQ_SERVEftnetwoffc\PKfecb\21\21B1\2181 R01 Owtoch kw.doc v •ptcjir S s V.. ~~4--' 4 V \ BASE MAP1CONSISTS W THE FOLLOWING U.S.G.S ACCOMPANYING INDEX HAP: B - BONSALL, 1968 0 - OCEANSIDE, 1968 (PHOTOREVISED, 1975); (PHOTOREVISED, 1975); SM - SAN MARCOS (196 REFERENCE: GEOLOGIC MAP OF NORTH-CENTRAL COASTAL AREA OF SAN DIEGO COUNTY, CALIFORNIA, 1982, BY F. HAROLD WEBER, JR. LEGEND: DO I 01 ' 'Lagoon*! deposits: Fine, sllty, wcsfiy deposits sojso ' i ?ni£i 'ii8"™!^" 1Sdon""" T*^?1"*81 ^itlsgo fotrotion (miaeie-uuxr o*n t?J): Ihe iwei (•rt consists Drincl[»ll» of wsslvely bKWed pale clayey rocfcs ningr. Tb* t«wr put contaim B L3H1 - Upper part. Bnwilsfi to qrsy SBthe ronwtion Is eiposed at e lub-unit « sow localities. 1000 clsyitone! l . reBeep-seated landslides «re WOOH) I •n •Odltlonal, Urge Imcttllot-like graOed slopes in DTK iiea In I960. 3000 5000 7000 (FEET) 117°21.000' W 117C20.000' W WGS84 117°1B.OOO' W 117°21.000' W 117°20.000' W Q 117° 19.000' W 1MIIE WGSB4 117° 18.000' W 1000 FEET 0 500 HXn METERS Printed from TOPO! ©2000 National Geographic Holding (www.topo.com) TERRACOSTA CONSULTING GROUP ENGINEERS AND GEOLOGISTS 4455 MURPHY CANYON ROAD, SUITE 100 SAN DIEGO. CA 92123 (868) 673-8900 PROJECT NAME NORTH AQUA HEDIONDA INTERCEPTOR FIGURE NUMBER PROJECT NUMBER 2181 GEOLOGY AND VICINITY MAPS LEGENDI r B-J Approximate Boring Location (TCG) B-f^^ Approximate Agua Hedionda Boring 10 T Location (AMEC) Approximate Manhole Location High Water Line (per 1965 City As-8uilts) TERRACOSTA CONSULTING GROUP ENGINEERS AND GEOLOGISTS 4455 MURPHY CANYON ROAD. SUITE 100 SAN DIEGO. CA 92123 (858) 573-6900 PROJECT NAME NORTH AGUA HEDIONDA INTERCEPTOR FIGURE NUMBER 2A PROJECT NUMBER 2181 SITE PLAN rr rTT B-4 Qk Approximate Boring Location (TCG) Approximate Agua Hedionda Boring Location (AMEC) Approximate Manhole Location High Water Line (per 1965 City As-Builts) 13 TERRACOSTA CONSULTING GROUP ENGINEERS AND GEOLOGISTS 4455 MURPHY CANYON ROAD, SUITE 100 SAN DIEGO. CA 92123 (858) 573-6900 PROJECT NAME NORTH AGUA HEDIONDA INTERCEPTOR FIGURE NUMBER 2B PROJECT NUMBER 2181 SITE PLAN r r LEGEND 6-5 T T M_ '4 17 Approximate Boring Location (TCG) Approximate Agua Hedionda Boring Location (AMEC) Approximate Manhole Location High Water Line (per 1965 City As-Builts) TERRACOSTA CONSULTING GROUP ENGINEERS AND GEOLOGISTS 4455 MURPHY CANYON ROAD, SUITE 100 SAN DIEGO. CA 92123 (858) 973-6900 PROJECT NAME NORTH AQUA HEDIONDA INTERCEPTOR FIGURE NUMBER 2C PROJECT NUMBER 2181 SITE PLAN s r i n B 1 -20- B-4(P) e-r(p)B-2(P)—PROPOSED FINISHED GRADE 8-3(P) r [—EXISTING GROUND M_l_-MJ^LLL—-UNc~^ I 4+OO 5+OO 6+00 I 7+OO 8+00 9+00 I 10+00 I11+00 I 12+00 Uj I I 13+OO ft M k j LEGEND Qaf PHI Qb Beach Sand Qcol/ Qsw Terrace Deposits / Slopewash Qbay Bay Deposits Tsa Santiago Formation Ground Surface Geologic Contacts s-r(p) I Boring (P=PrpJected) GEOLOGIC PROFILE ALONG SOUTHERN LIMITS OF EXISTING RIGHT-OF-WAY SCALE: I"=IOO' (HORIZ.) I"-IO' (VERT.) TERRACOSTA CONSULTING GROUP ENGINEERS AND GEOLOGISTS 4495 MURPHY CANYON ROAD. SUITE 100 SAN DIEGO. CA 92123 I858I 573-6900 PROJECT NAME NORTH AQUA HEDIONDA INTERCEPTOR FIGURE NUMBER 3A PROJECT NUMBER 2181 PROFILE tu —PROPOSED FINISHED GKADE ^EXISTING GROUND B-5 B-6 I 13+OO Tsa ILHJ n 14+OO 15+OO I 16+OO I 17+OO I 18+OO 19+OO 2O+OO 21+OO 22+00 -o I 5! --20 --30 LEGEND Qaf Fin Qb Beach Sand Qcol/ Qsw Terrace Deposits / Slopewash Qbay Bay Deposits Tsa Santiago Formation Ground Surface Geologic Contacts Boring (P=Projected)i GEOLOGIC PROFILE ALONG SOUTHERN LIMITS OF EXISTING RIGHT-OF-WAY SCALE: I"=IOO' (HORIZ.) I"-IO' (VERT.) TERRACOSTA CONSULTING GROUP ENGINEERS AND GEOLOGISTS 4455 MURPHY CANYON ROAD. SUITE 100 SAN DIEGO. CA 92123 I858I 573-6900 PROJECT NAME NORTH AGUAHEDIONDA INTERCEPTOR FIGURE NUMBER 3B PROJECT NUMBER 2181 PROFILE o— -10 — B -20 — 51 -30 — -4O —J B-f(P) Qbay 3O 4O SO DISTANCE, FEET 60 7O SO 9O /OO LEGEND Qb Beach Sand Qcol/ Qsw Terrace Deposits / Slopewash Qbay Bay Deposits Tsa Santiago Formation Ground Surface Geologic Contacts B-f(P) i Boring (P=Projected) TERRACOSTA CONSULTING GROUP ENGINEERS AND GEOLOGISTS 4455 MURPHY CANYON ROAD. SUITE 100 SAN DIEGO. CA 92123 (858) 573-6900 PROJECT NAME NORTH AGUA HEDIONDA INTERCEPTOR FIGURE NUMBER PROJECT NUMBER 2181 SECTION 1 o— K I -10 — -20 —' S-2(P) fO 20 3O 40 50 DISTANCE, FEET 60 70 8O 9O LEGEND Qbay Tsa B-2(P) i Bay Deposits Santiago Formation Ground Surface Geologic Contacts (Queried where unknown) Boring (P=Projected) TERRACOSTA CONSULTING GROUP ENGINEERS AND GEOLOGISTS 445S MURPHY CANYON ROAD, SUITE 100 SAN DIEGO. CA 92123 (8581 573-6900 PROJECT NAME NORTH AGUA HEDIONDA INTERCEPTOR FIGURE NUMBER PROJECT NUMBER 2181 SECTION 2 8I +20—( +10 -10 -\ -20 H -30 4O 50 6O 7O 80 90 1OO DISTANCE, FEET LEGEND Qaf FHI Qcol/ Qsw Terrace Deposits / Slopewash Qbay Bay Deposits Tsa Santiago Formation Ground Surface 7 Geologic Contacts B-3(P) 1 Boring (P=Projected) TERRACOSTA CONSULTING GROUP ENGINEERS AND GEOLOGISTS 4455 MURPHY CANYON ROAD. SUITE 100 SAN DIEGO, CA 92123 IB58I 573-6900 PROJECT NAME NORTH AGUA HEDIONDA INTERCEPTOR FIGURE NUMBER PROJECT NUMBER 2181 SECTION 3 I I I +20 — +JO — o— -10 — -20 — -3O —' e-4(p) LEGEMD Qaf Fin Qcol/ Qsw Terrace Deposits / Slopewash Qbay Bay Deposits Tsa Santiago Formation Ground Surface 7 Geologic Contacts *Boring (P=ProJected) 0 to 2O 3O 40 5O DISTANCE, FEET 6O 70 8O 9O 100 TERRACOSTA CONSULTING GROUP ENGINEERS AND GEOLOGISTS 4455 MURPHY CANYON ROAD. SUITE 100 SAN DIEGO, CA 92123 1858) 573-8900 PROJECT NAME NORTH AQUA HEDtONDA INTERCEPTOR FIGURE NUMBER PROJECT NUMBER 2181 SECTION 4 ri r* n +2O—[ r * i , I I +10 — ff li w M f| i *t w -to —J w 20 3O 4O 5O DISTANCE, FEET 60 70 8O 9O t j ij LEGEND Qb Beach Sand Qcol/ Qsw Terrace Deposits / Slopewash Tsa Santiago Formation Ground Surface f Geologic Contacts TERRACOSTA CONSULTING GROUP ENGINEERS AND GEOLOGISTS 4455 MURPHY CANYON ROAD. SUITE 100 SAN DIEGO. CA 92123 [658! 573-6900 PROJECT NAME NORTH AQUA HEDIONDA INTERCEPTOR FIGURE NUMBER 8 PROJECT NUMBER 2181 SECTION 5 +3O—< +20 — I I it! +10 — o— -w — -20 —' w 20 3O 4O 50 6O 70 SO DISTANCE, FEET LEGEND Qcol/ Qsw Terrace Deposits / Slopewash Tsa Santiago Formation Ground Surface Geologic Contacts B-6I Boring TERRACOSTA CONSULTING GROUP ENGINEERS AND GEOLOGISTS 4455 MURPHY CANYON ROAD, SUITE 100 SAN DIEGO. CA 92123 (858] 573-6900 PROJECT NAME NORTH AGUA HEDIONDA INTERCEPTOR FIGURE NUMBER PROJECT NUMBER 2181 SECTION 6 APPENDIX A LOGS OF EXPLORATORY EXCAVATIONS TCG METRIC LOG<3) 2181.GPJ GDCLOGMT.GOT 7/23/03LOG OF TEST BORING PROJECT NAME Morth Agua Hedionda Interceptor SITE LOCATION Carlsbad, California DRILLING COMPANY DRILLING EQUIPMENT SAMPLING METHOD DEPTH (ft)-5 10 -15 -20 ELEVATION (ft)SAMPLE TYPE^SAMPLE NO.1 PENETRATIONRESISTANCE(BLOWS/ft)DRY DENSITY(pcf)MOISTURE(%)DRILLING METHOD BORING DIA. (In) NOTES OTHERTESTSGRAPHICLOG1 aTerraCosta Consulting Group, Inc. 4455 Murphy Canyon Road, Suite 100 San Diego, California 92123 PROJECT NUMBER BORING 2181 LEGEND START FINISH SHEET NO. 1 Of 1 LOGGED BY CHECKED BY TOTAL DEPTH (ft) GROUND ELEV (ft) DEPTH/ELEV. GROUND WATER (ft) 21 I n/a DESCRIPTION AND CLASSIFICATION KEY TO EXCAVATION LOGS '- WATER TABLE MEASURED AT TIME OF DRILLING OTHER TESTS GS Grain Size Analysis PI Plasticity Index SA Sieve Analysis PENETRATION RESISTANCE (BLOWS/ftl Number of blows required to advance the sampler 1 foot. SAMPLE TYPE S ("SPT") - a.k.a. Standard Penetration Test, an 18-inch-long, 2-inch O.D., 1-3/8-inch I.D. drive sampler. NOTES ON FIELD INVESTIGATION Borings were advanced using a track-mounted drill rig with a 6-inch hollow-stem auger, and a limited access tripod rig. Standard Penetration Tests (SPT). Samplers were used to obtain soil samples. The SPT Samplers were driven into the soil at the bottom of the borings with a 140-pound hammer falling 30 inches. When the samplers were withdrawn from the boring, the samples were removed, visually classified, sealed in plastic bags, and taken to the laboratory for detailed inspection. Free groundwater was encountered in the borings as shown on the logs. Classifications are based upon the Unified Soil Classification System and include color, moisture, and consistency. Field descriptions have been modified to reflect results of laboratory inspection where deemed appropriate. THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF DRILLING.SUBSURFACE CONDITIONS MAY DIFFER AT OTHER _.«. loc A . LOCATIONS AND MAY CHANGE AT THIS LOCATION FIGURE A-l WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. TCG METRC LOGO) 2181.GPJ GDCLOGMT.GDT 7/23/03LOG OF TEST BORING PROJECT NAME PROJECT NUMBER BORING North Agua Hedionda Interceptor 2181 B-1 SITE LOCATION Carlsbad, California DRILLING COMPANY Pacific Drillina DRILLING EQUIPMENT Mole Rig SAMPLING METHOD 140-lb hammer/ 30-inch drop & m 0 - - 5 10 15 -20 £ O 5 ai -5 - -0 —5 —10 i — • — » — > — . • • I 1 2 3 4 5 git 7 2 2 1/18" 15 DRY DENSITY(pcf)MOISTURE(%)START FINISH SHEET NO. 2/19/2003 2/19/2003 1 of 2 DRILLING METHOD LOGGED BY CHECKED BY Hollow Stem Auaer D. Nevius BORING DIA (In) 6 NOTES OTHERTESTSGRAPHICLOG' f aTerraCosta Consulting Group, Inc. 4455 Murphy Canyon Road, Suite 100 San Diego, California 92123 TOTAL DEPTH (ft) GROUND ELEV (ft) DEPTH/ELEV. GROUND WATER (ft) 36.5 6 * 4.5/15 DESCRIPTION AND CLASSIFICATION BEACH DEPOSITS Silty SAND (SM), loose to medium dense, yellow to gray, moist, with occasional day stringers - Becomes gray in color f BAY DEPOSITS Fat CLAY (CH), very soft, gray, moist to wet - Pocket Penetrometer < 0.25 tsf Silty SAND (SM), very loose, gray, moist to wet Sandy CLAY (CL), very soft, gray, moist to wet, with shell fragments - Pocket Penetrometer < 0.25 tsf - Encountered some gravel at 18 feet Silty SAND (SM). medium dense, light brown to brown-gray, moist to wet THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER _.«. ._,._ A o „ LOCATIONS AND MAY CHANGE AT THIS LOCATION FICjUKt A-^ 3 WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. LOG OF TEST BORING PROJECT NAME PROJECT Nl North Agua Hedionda Interceptor 2181 SITE LOCATION Carlsbad, California DRILLING COMPANY Pacific Drilling DRILLING EQUIPMENT Mole Rig SAMPLING METHOD 140-lb hammer/ 30-inch drop g UJO -25 30 35 -40 g O5 UJ —20 - —25 —30 —35 UJ E UJ g j— ^ — « — • — % O a0. 6 7 8 HiuJw2 ZVB 24 15 50 DRY DENSITY(pcf)MOISTURE(%)START FINISt 2/19/2003 2/1 DRILLING METHOD LOGGED 81 Hollow Stem Auger D. Nevii BORING D1A. (In) 6 NOTES OTHERTESTSGRAPHICLOG"FT" k\ Vs |jjp™g TerraCosta Consulting Group, Inc. ! ^^S 4455 Murphy Canyon Road, Suite 100 ••SB! San Diego, California 92123 TOTAL DEPTH (ft) GROUND ELEV (ft) 36.5 6 JMBER BORING B-1 4 SHEET NO. 9/2003 2 Of 2 ( CHECKED BY IS DEPTH/HLEV. GROUND WATER (ft) * 4.5/1.5 DESCRIPTION AND CLASSIFICATION Poorly Graded SAND (SP), medium dense, light brown, wet Silty SAND (SM), medium dense, light brown to gray, moist to wet - Harder drilling at 28 feet WEATHERED SANTIAGO FORMATION CLAY (CL/CH), stiff, gray, moist, interbedded with Silty SAND (SM), medium dense, mottled brown / yellow Boring terminated at depth of 36.5 feet. Groundwater encountered at 4.5 feet at time of excavation. THIS SUMMARY APPLIES ONLY AT THE LOCATIO OF THIS BORING AND AT THE TIME OF DRILLING SUBSURFACE CONDITIONS MAY DIFFER AT OTH LOCATIONS AND MAY CHANGE AT THIS LOCATIC WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUV CONDITIONS ENCOUNTERED. N IN* FIGURE A-2 b u. j i flO _J ! LOG OF TEST BORING PROJECT NAME North Agua Hedionda Interceptor SITE LOCATION Carlsbad, California DRILLING COMPANY Pacific Drilling DRILLING EQUIPMENT Little Beaver SAMPLING METHOD 140-lb hammer/ 30-inch drop DEPTH (ft)-5 10 -15 -20 LEVATION (ft)UJ 0 .5 —10 —15 AMPLE TYPE(/} -i <— ; I 1 2 ENETRATIONRESISTANCE(BLOWS/ft)u. 76/10" 50/6"RY DENSITY(pcf)Q MOISTURE(%)DRILLING METHOD Rotary Wash BORING DIA. (In) 4 NOTES OTHERTESTSGRAPHICLOG*<ffi vss \4 aTerraCosta Consulting Group, Inc. 4455 Murphy Canyon Road, Suite 100 San Diego, California 92123 START 2/19/2003 TOTAL DEPTH (ft) 10.5 PROJECT NUMBEf 2181 FINISH 2/19/20C LOGGED BY G. Soaulding GROUND ELEV (ft) DEPTt 5 In/ I BORING B-2 SHEET NO. 3 1 of 1 CHECKED BY VELEV. GROUND WATER (ft) a DESCRIPTION AND CLASSIFICATION SANTIAGO FORMATION Silty to Clayey SAND (SM/SC), very dense, gray-brown, moist to wet. interbedded, well indurated Boring terminated at depth of 10.5 feet. No free groundwater encountered at time of excavation. THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND MAY CHANGE AT THIS LOCATION WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. FIGURE A-3 LOG OF TEST BORING PROJECT NAME North Agua Hedionda Interceptor PROJECT NUMBER 2181 BORING B-3 SITE LOCATION Carlsbad. California START 2/19/2003 FINISH 2/19/2003 SHEET NO. 1 of 2DRILLING COMPANY Pacific Drilling >RILUNG EQUIPMENT DRILLING METHOD Solid Flight Auger LOGGED BY G. Spaylding CHECKED BY DRILLING I Little Beaver BORING DIA. (In) 6 TOTAL DEPTH (ft) 32.5 GROUND ELEV (ft) 7 DEPTH/ELEV. GROUND WATER (ft) 8.3 / -1.3 SAMPLING METHOD 140-lb hammer / 30-Inch drop NOTES LU O V)2'o. LU IW o DESCRIPTION AMD CLASSIFICATION -5 -10 -15 -5 12 -0 —5 —10 -20 - I £!U= Silty to Clayey SAND (SM/SC), medium dense, gray-brown, damp, with occasional gravels I COLLUVIUM Silty to Clayey SAND (SM/SC), medium dense, red-brown, damp - Becomes moist BAY DEPOSITS Clayey SAND to Silty SAND (SC/SM), loose, gray-to gray-brown, wet, fine-grained sand, interbedded, micaceous, occasional gravels and cobbles - No recovery TerraCosta Consulting Group, Inc. 4455 Murphy Canyon Road, Suite 100 San Diego, California 92123 THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND MAY CHANGE AT THIS LOCATION WITH THE PASSAGE Of TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. FIGURE A-4 a TCG_METRIC_LOG(3) 2181 .GPJ GDCLOGMT.GDT 7/23/03LOG OF TEST BORING PROJECT NAME PROJECT MUM North Agua Hedionda Interceptor 2181 SITE LOCATION START FINISH Carlsbad, California 2/19/2003 2/1 9/ DRILLING COMPANY Pacific Drillina DRILLING EQUIPMENT Little Beaver SAMPLING METHOD 140-lb hammer / 30-inch drop g Ulo -25 30 -35 -40 E 1 -15 _- 20 -25 —30 aD- , i i 4 ZLJ |l 28 DRY DENSITY(jxrf)MOISTURE(%)DRILLING METHOD LOGGED BY Solid Pliant Auaer G. Spauld BORING DIA (In) TOTAL DEPTH (ft) GROUND ELEV (ft) DE 6 32.5 7 I NOTES OTHERTESTSGRAPHICLOG^/H//?// aTerraCosta Consulting Group, Inc. 4455 Murphy Canyon Road, Suite 100 San Diego, California 92123 BER BORING B-3 SHEET NO. 2003 2 of 2 CHECKED BY ina FTHIELEV. GROUND WATER (ft) 8.3 1-1.3 DESCRIPTION AND CLASSIFICATION WEATHERED SANTIAGO FORMATION Sandy CLAY to Clayey SAND (SC/CL), medium dense, mottled olive-gray / light gray, moist SANTIAGO FORMATION ~A Clayey SAND (SC), medium dense to dense, mottled olive-gray / light r~ \arav. moist / Boring terminated at depth of 32.5 feet Groundwater encountered at 8.25 feet at time of excavation. THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHEF LOCATIONS AND MAY CHANGE AT THIS LOCATION WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. 1 FIGURE A-4 b .«• I o § 00 „ s 1 LOG OF TEST BORING PROJECT NAME North Agua Hedionda Interceptor SITE LOCATION Carlsbad, California DRILLING COMPANY Pacific Drilling DRILLING EQUIPMENT Mole Rig SAMPLING METHOD 140-lb hammer/ 30-inch drop § £ Q . - 5 10 -15 20 § §< GJ UJ — 5 — 0 —5 —10 LU Q. "\n 1CO (— - • — ' ^ d LU P- < 1 2 3 ZLU KtOfi[M 73* ^ Luca °~ 2 14 16 CO 3SOS r7Q 8! Hgew *— 'o DRILLING METHOD START 2/19/2003 Hollow Stem Auaer BORING DIA (In) 6 NOTES £co H* UJ0 O SFo?ot& ~^o i mrnmammPySi TerraCosta Consulting Group, Inc. | ^|g 4455 Murphy Canyon Road, Suite 100 ••MB San Diego, California 92123 TOTAL DEPTH (ft) 37 PROJECT NUMBEf 2181 FINISH 2/19/20C LOGGED BY D. Nevius GROUND ELEV (ft) DEPTI 9 * ie % BORING B-4 SHEET NO. 3 1 of 2 CHECKED BY VELEV. GROUND WATER (n) J.5/-7.5 DESCRIPTION AND CLASSIFICATION FILL Silty SAND (SM), loose to medium dense, light brown, moist - Possible gravel at 2 feet COLLUVIUM Silty SAND (SM), loose, mottled light brown / red-brown, moist BAY DEPOSITS Silty SAND (SM), medium dense, mottled light brown / gray / red-brown, moist to wet, interbedded r THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND MAY CHANGE AT THIS LOCATION WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. FIGURE A-5 a I"-1 i o CO 0* _J1 1 LOG OF TEST BORING PROJECT NAME North Agua Hedionda Interceptor SITE LOCATION Carlsbad, California DRILLING COMPANY Pacific Drilling DRILLING EQUIPMENT Mole Rig SAMPLING METHOD 140-lb hammer / 30-inch drop § 8 - -25 30 -35 -40 ELEVATION (ft)—15 —20 —25 —30 SAMPLE TYPE[—} , ^ C — ,SAMPLE NO.4 5 PENETRATIONRESISTANCE(BLOWS/ft)g 11 DRY DENSITY(pcf)MOISTURE(%)START 2/19/2003 DRILLING METHOD Hollow Stem Auaer BORING DIA. (In) 6 NOTES OTHERTESTSGRAPHICLOGw1 aTerraCosta Consulting Group, Inc. 4455 Murphy Canyon Road, Suite 100 San Diego, California 92123 TOTAL DEPTH (ft) 37 PROJECT NUMBEF 2181 FINISH 2/19/200 LOGGED BY D. Nevius GROUND ELEV (ft) DEPTt 9 * ie t BORING B-4 SHEET NO. 3 2 Of 2 CHECKED BY VELEV. GROUND WATER (ft) I.5/-7.5 DESCRIPTION AND CLASSIFICATION - Harder drilling noted at 24 feet - Harder drilling noted at 28 feet Silty SAND (SM), loose, gray, moist to wet SANTIAGO FORMATION Fat CLAY (CH), medium stiff, gray, moist - Hard drilling noted at 34 feet - Pocket Penetrometer = 2.75 tsf Boring terminated at depth of 37 feet. Groundwater encountered at 16.5 feet at time of excavation. THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND MAY CHANGE AT THIS LOCATION WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. FIGURE A-5 b § iss i LOG OF TEST BORING PROJECT NAME North Agua Hedionda Interceptor SITE LOCATION Carlsbad, California DRILLING COMPANY Pacific Drillina DRILLING EQUIPMENT Little Beaver SAMPLING METHOD 140-lb hammer/ 30-inch drop g iUJo - 5 10 -15 -20 ELEVATION (ft)- o .5 —10 —15 UJ 1 S <— ; s SAMPLE NO.1 2 3 PENETRATIONRESISTANCE(BLOWS/ft)55/6"DRY DENSITY(pcf)MOISTURE(%)DRILLING METHOD Rotarv Wash BORING DIA (In) 3 NOTES IP O o ! I 1 aTerraCosta Consulting Group, Inc. 4455 Murphy Canyon Road, Suite 100 San Diego, California 92123 PROJECT NUN 2181 START FINISH 2/18/2003 2/1 8/ TOTAL DEPTH (ft) 19.5 LOGGED BY G. Spauld GROUND ELEV (ft) Di 5 I BER BORING B-5 SHEET NO. 2003 1 of 1 CHECKED BY ina •PTH/ELEV. GROUND WATER (ft) n/a DESCRIPTION AND CLASSIFICATION BEACH DEPOSITS Sllty SAND (SM), medium dense, brown-gray, moist, with gravel and cobble to 50 percent SANTIAGO FORMATION Clayey SAND to Sandy CLAY (SC/CL), medium dense to dense, light olive-gray, moist, interbedded, well indurated - Cemented zone from 8 to 8.75 feet - No recovery Boring terminated at depth of 19.5 feet No free groundwater encountered at time of excavation. THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF DRILLING. SUBSURFACE CONDITIONS MAY OFFER AT OTHEF LOCATIONS AND MAY CHANGE AT THIS LOCATION WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. 1 FIGURE A-6 LOG OF TEST BORING PROJECT NAME North Agua Hedionda Interceptor SITE LOCATION Carlsbad, California DRILLING COMPANY Pacific Drilling DRILLING EQUIPMENT Little Beaver SAMPLING METHOD 140-lb hammer/ 30-inch drop g tit0 -• -10 -15 -20 £ 1 UJ - -0 —5 - —10 —15 SAMPLE TYPE— S s SAMPLE NO.1 2 3 PENETRATIONRESISTANCE(BLOWS/ft)58 50/6" 50/5.5"DRY DENSITY(PCOMOISTURE(%)DRILLING METHOD Rotary Wash BORING DIA (In) 3 NOTES ifc oT GRAPHICLOG$, % % W I '/I '/, // //i // I aTerraCosta Consulting Group, Inc. 4455 Murphy Canyon Road, Suite 100 San Diego, California 92123 PROJECT NUN 2181 START FINISH 2/18/2003 2/1 8/ TOTAL DEPTH (ft) 17.46 LOGGED BY G. Spauld GROUND ELEV (ft) DE 3 I IBER BORING B-6 SHEET NO. 2003 1 of 1 CHECKED BY ing EPTH/ELEV. GROUND WATER (ft) n/a DESCRIPTION AND CLASSIFICATION SANTIAGO FORMATION Clayey SAND to Sandy CLAY (SC/CL), very dense, light olive-gray, moist, interbedded, well Indurated - Soft zone, easy drilling from 10.75 to 1 1.75 feet -Hard drilling at 11. 75 feet - Soft drilling from 13.5 to 15 feet Boring terminated at depth of 1 7.46 feet No free groundwater encountered at time of excavation. THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHEF LOCATIONS AND MAY CHANGE AT THIS LOCATION WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. 1 FIGURE A-7 APPENDIX B LABORATORY TEST RESULTS PHYSICAL PROPERTIES OF SOILS PROJECT: TerraCosta Consulting Group Project #2 181 Agua Hcdionda Sewer LAB NO.: 14156 SAMPLED BY: Spaulding/Eckert SUBMITTED BY: G. Spaulding AUTHORIZED BY: G. Spaulding REVIEWED BY: J. Hutalla PROJECT NO.: 50140.30002.0383 1 DATE: 03/04-0? DATE: 03/Ci/O? ij DATE: 03 '04/0? 1- REPORT DATE: C3/11/0? •: :j Sample l.D. BI-2 Bl-3 Bl-4 B3-1 B3-3 B4-1 B4-2 Depth (ft-) 4 10 15 4.5 19 5 10 Liquid Limit/ Plastic Limit ASTMD4318- 00 87.8/32.1 22.7/20.0 34.5/20.9 * N.P./N.V. * * Expansion Index ASTM D4829- 95 * * * * * * >ii Percent Passing #200 Sieve ASTM Dl 140-00 Dry Moisture Content - Density (%), as received '•• (pcf)' ASTMD22I6 : * ??.! * 37.3 : * -10.2 : * 12.5 :: * 2^ ^ * i ' /, * 253 • i \ . i: I' j . * Indicates test not requested Distribution: TerraCosta/ B. Smillie Submitted By: E. Lowry Shuler, RCE #63789 9T/8T 39Vd 0310VW £9:68 £11 \L- i gai Q. i i 100 60 60 70 60 60 40 30 20 10 0 PARTICLE SIZE DISTRIBUTION TEST REPORT i * s § i « • • « 5 3 s i s i 2 1 - 200 100 % + 3" i i | , - i • . (.... I '. 10 % GRAVEL % SAND 88.0 • -'t T" i , ! ; ""? ; M ... \ ...N j \ , ... . \ \ \ 1 ! 1 • ^-«— i : : | !::; i | i! . . 1 i • -'I ii T T -^ i : 1 0.1 0.01 O.OC' : GRAIN SIZE - mm % SILT 10.7 %CLAY U USCS AASHTO PL . LL 1 j. SIEVE mete*•be ^XT D60 ( DSO ( D-io 0 "^xT CC Cu PERCENT FINER •> GRAIN SIZE ).178 ).109 .0289 COEFFICIENTS 232 6.18 SIEVE nwpbor HZ8 #10 #20 #40 #100 #200 PERCENT FINER o 100.0 99.6 98.9 50.0 12.0 SOIL DESCRIPTION 1 1 REMARKS: '. ) ! i ii : Location: B4-2@IO' LAW ENGINEERING, INC. Client TenaCosta Consulting Group L Project AguaH«diondaSe\ver#2181 Protect No.: 50140.30002.03831 Plate 01/20 3Wd 0310WW £9 : GRAIN SIZE DISTRIBUTION TEST DATA Client: TerraCosta Consulting Group Project: Agua Hedionda Sewer #2181 Project Number: 50140.30002.03831 Sample Data Source: ,„ Sample No. : B4-2 Elev. or Depth: 10' — Location: B4-2S10' Description: **** Liquid Limit: — USCS Classification: Testing Remarks: Sample Length (in./cm.): Plastic Limit: AASHTO Classification: Mechanical Analysis Data Sieve # # # * # 10 20 40 100 200 Size, mm 2 0 0 0 0 .000 .350 .425 .150 .075 Percent 100. 99. 98. 50. 12. finer 0 6 9 0 0 Hydrometer Analysis Data *"" Separation sieve is #10 ^ Percent -#10 based upon complete sample= 100.0 "" Weight of hydrometer sample: 100 •*• Hygroscopic moisture correction: Moist weight & tare - 19.30 Dry weight & tare = 19.10 ,,m Tare =0.00 Hygroscopic moisture^ 1.1 % , Calculated biased weight— 98.96 Table of composite correction values: *" Temp, deg C: 23.3 22.6 18.1 15.8 Comp. corr: -6.0 -6.0 -7.0 -8.0 •*» Meniscus correction only= y Specific gravity of solids= 2.65 '** Specific gravity correction factor= 1.000 — Hydrometer type: 152H Effective depth L= 16.294964 - 0.164 x Rm Elapsed time, 1. 2. 5. 15. 30. 60. 120. 250. min 00 00 00 00 00 00 00 00 Temp, deg C 68.6 68.6 69.0 69.0 69.9 70.4 69.0 68.8 Actual reading 17.0 14.0 13.0 10.0 8.0 7.0 7.0 7.0 Corrected reading 11.0 8.0 7.0 4.0 2.0 1.0 1.0 1.0 K 0. 0. 0. 0. 0. 0. 0. 0. 0087 0087 0087 0087 0086 0086 0087 0087 Rm 17. 14. 13. 10. 8. 7. 7. 7. 0 0 0 0 0 0 0 0 Eff . depth 13.5 14.0 14.2 14.7 15.0 15.1 15.1 15.1 Diameter mm 0. 0. 0. 0. 0. 0. 0. 0. 0320 0230 0146 0086 0061 0043 0031 0021 Percent finer 11.1 3.1 -^ •« / . J. 4.0 2.0 1440.00 71.0 7.0 1.0 0.0086 7.0 15.1 0.0009 LAW ENGINEERING, INC. <**0I/E0 3=Wd 031DVW 00ES-8/I.2-898 Fractional Components Gravel/Sand based on #4 Sand/Fines based on #200 % + 3" - % GRAVEL - % SAND = 88.0 % SILT =10.7 % CLAY =1.3 (% CLAY COLLOIDS =1.0) D8s= 0.30 DgO55 0.18 DSQ= 0.15 D3Q= 0.11 DIS= 0.08 D10= 0.03 Cc- 2.3199 Cu= 6.1797 — LAW ENGINEERING, INC. £9:60 trLi E h LL g 1a > • 100 eo BO 70 i 60 : soiI i 40 30 20 10 0 PARTICLE SIZE DISTRIBUTION TEST REPORT 5 £ £ § £ i 9 s * S g 1 1 1 1 I 1 j i | 1 i ; j : - """r \ 1 -t * SJ t \l 1\ • :1 i i : f > 1 V j\ Ij ; i i "T* i ' • ' < • - i i .' . j : : : : : 1: : I 1 . ___j '• i : : : — "Sv Ml ; . : 1 j i | : - ^i^ — f • — T m 200 100 10 1 0.1 O.C: C OC1 ~ GRAIN SIZE -mm % + 3"% GRAVEL % SAND % SILT 0.6 78.4 13.7 %CLAY 73 USCS AASHTO i PL i LL ] i i ! ! 1 1 SIEVE Inches size .375 ^X^°60 O^O DID c ^xT cu PERCENT FINER - t 00.0 GRAIN SIZE 0.197 0.102 J.0085 COEFFICIENTS 6.23 23.25 SIEVE PERCENT FINER number size ' ' #4 99.4 #10 97.4 #20 95.1 #40 88.1 #100 47.2 #200 21.0 SOIL DESCRIPTION 1 J 1 REMARKS: t : " Location: B4-l@5' LAW ENGINEERING, INC. Client TerraCosta Consulting Group . Project AguaHediondaSovcr#2181 ; ii Protect No.: 50140 J0002.03831 Plate !' 01/90 3Wd 0310WW 00E9-8i2-898 £9:50 £002/21, '£6 GRAIN SIZE DISTRIBUTION TEST DATA Client: TerraCosta Consulting Group Project: Agua Hedionda Sewer #2181 Project Number: 50140.30002.03831 Sample Data. Soured: Sample No.: B4-1 Elev. or Depth: 5' Location: B4-1Q5' Description: Liquid Limit: USCS Classification: Testing Remarks: Sample Length (in./cm.) Plastic Limit: AASHTO Classification: Mechanical Analysis Data Sieve .375 inch # 4 # 10 # 20 # 40 # 100 # 200 Size, mm 9.525 4.750 2.000 0.850 0.425 0.150 0.075 Percent finer 100.0 99.4 97.4 95.1 88.1 47.2 21.0 Hydrometer Analysis Data ** Separation sieve is m Percent -#10 based upon complete sample= 97.4 Weight of hydrometer sample: 100 » Hygroscopic moisture correction: m Moist weight & tare = 19.20 Dry weight & tare = 19.00 Tare =0.00 Hygroscopic moisture^ 1.1 % •** Calculated biased weight= 101.60 Table of composite correction values: Temp, deg C: 23.3 22.6 18.1 15.8 Comp. corr: -6.0 -6.0 -7.0 -8.0 * Meniscus correction only= y — Specific gravity of solids= 2, 65 Specific gravity correction factor= 1.000 m Hydrometer type: 152H Effective depth L= 16.294964 - 0.164 x Rm Elapsed Temp, Actual Corrected K time, min deg C reading reading Rtn Eff.Diameter Percent: 1.00 2.00 5.00 15.00 30.00 60.00 120.00 68.6 68.7 69.2 69.5 69.3 69.2 68.8 26.0 23.0 20.0 16.0 14.0 13.0 7.0 20.0 17.0 14.0 10.0 8.0 7. 0 1.0 —r~ LAW 0.0087 0.0087 0.0087 0.0086 0.0087 0.0087 0.0087 LAW ENGINEERING, INC. depth mm 26.0 23.0 20.0 16.0 14.0 13,0 7.0 wr 12.0 12.5 13.0 13.7 14.0 14.2 15.1 0.0302 0.0218 0.0140 0.0083 0.0059 0.0042 0.0031 finer 19 16 13 9 7 6 1 ~7 , / .8 .8 Q .9 .0 01/90 031CWW £9=60 £082/21/£ Elapsed time, 250. 1440. min 00 00 loop. deg C 68.8 71.6 Actual reading 7.0 6.0 Corrected K Km reading 1 0 .0 .0 0. 0. 0087 0085 7.0 6.0 Eff . depth 15.1 15.3 Diameter mxn O.C021 0.0009 ?e~cn: fririer J~ • *vx f\ •". fractional Components Gravel/Sand based on #4 Sand/Fines based on #200 % + 3" = % GRAVEL % SILT - 13.7 % CLAY = = 0.6 7.3 % SAND as 78.4 (% CLAY COLLOIDS 0.2) 0.38 D30= 0.10 Cc= 6.2309 Dgo=0.20 050= 0.16 0.02 DIO= 0.01 23.2538 -~ LAW ENGINEERING, INC. 0I//0 03JLOWW 08E9-8Z.3-898 1 il 1- U g UJa 100 90 80 70 eo 60 40 30 20 10 0 PARTICL £ 2 £ ! 5 s s i — ' — r I : 1 ES F i IZI S i E DISTRIBUTION TEST REPORT S 5 2 5 5 « ! 1 Sx . _ ;SV S \Ny \ V\, ^ : : , . | i \'.\ • . •ftU_N: ".. 1 \ : ''• \ ': | : ! 1 ; ; ! i 1 ^ : i : " i• i • • 200 100 10 1 0.1 0.01 •J.CC!-. GRAIN SIZE - mm % + 3"% GRAVEL 0.4 % SAND % SILT 71.0 %CLAY USCS j AASHTO PL LL ; ; ; i1 1 SIEVE inches Size .5 1 .375 ^xC °60 < 030 o D10 ^xcT ce cu PERCENT FINER c.i 00.0 99.6 GRAIN SIZE ).275 .0809 COEFFICIENTS SIEVE PERCENT FINER numbor . size #4 99.6 #10 97.1 #20 87.6 #40 72.6 #100 42.8 #200 28.6 SOIL DESCRIPTION t ; REMAgHS: <.:• ! . • Location: B3-l@4.5' J 1 LAW ENGINEERING, INC. Client TenaCosta Consulting Group Project: AguaHediondaSewer#2181 Protect No.: 50140.30002,03831 Plata 01/80 0310W 00E9-8Z.2-898 =60 GRAIN SIZE DISTRIBUTION TEST DATA Client: TerraCosta Consulting Group •"» Project: Agua Hedionda Sewer #2181 ^ Project NTamber: 50140.30002.03831 Sample Data Source: Sample No.: B3-1 Elev. or Depth: 4.5' Location: B3-104.51 Description: Liquid Limit: USCS Classification: Testing Remarks: Sample Length (in./can.) Plastic Limit: AASHTO Classification: Mechanical Analysis Data Sieve . 5 inch .375 inch # 4 # 10 # 20 # 40 # 100 # 200 Size, mm 12.700 9.525 4.750 2.000 0.850 0.425 0.150 0.075 Percent finer 100.0 99.6 99.6 97.1 87.6 72.6 42.8 28.6 Fractional Components Gravel/Sand based on #4 Sand/Fines based on #200 % + 3" = % GRAVEL % FINES = 28.6 = 0.4 % SAND = 71.0 D85= 0.73 030= 0.08 Deo= 0.27 D50= 0.20 LAW ENGINEERING, INC. 01/60 D31DW 00£S-8iZ-898 APPENDIX C LIST OF FAULTS WITH DISTANCE FROM THE SITE AND ESTIMATED PEAK SITE ACCELERATION EQFAULT Version 3.00 DETERMINISTIC ESTIMATION OF PEAK ACCELERATION FROM DIGITIZED FAULTS JOB NUMBER: 2181 DATE: 03-07-2003 JOB NAME: Agua Hedionda Sewer CALCULATION NAME: Seismic Analysis FAULT-DATA-FILE NAME: CDMGFLTE.DAT SITE COORDINATES: SITE LATITUDE: 33.1480 SITE LONGITUDE: 117.3290 SEARCH RADIUS: 62 mi ATTENUATION RELATION: 11) Bozorgnia Campbell Niazi (1999) Hor.-Pleist. Soil-Cor. UNCERTAINTY (M=Median, S=Sigma) : M Number of Sigmas: 0.0 DISTANCE MEASURE: cdist SCOND: 1 Basement Depth: .00 km Campbell SSR: 0 Campbell SHR: 0 COMPUTE PEAK HORIZONTAL ACCELERATION FAULT-DATA FILE USED: CDMGFLTE.DAT MINIMUM DEPTH VALUE (km): 3.0 EQFAULT SUMMARY DETERMINISTIC SITE PARAMETERS ABBREVIATED FAULT NAME ROSE CANYON NEWPORT-INGLEWOOD (Offshore) CORONADO BANK ELSINORE-TEMECULA ELSINORE-JULIAN ELSINORE-GLEN IVY PALOS VERDES EARTHQUAKE VALLEY SANJACINTO-ANZA NEWPORT-INGLEWOOD (L.A. Basin) SAN JACINTO-SAN JACINTO VALLEY CfflNO-CENTRAL AVE. (Elsinore) WHITTIER SAN JACINTO-COYOTE CREEK COMPTON THRUST ELSINORE-COYOTE MOUNTAIN ELYSIAN PARK THRUST SAN JACINTO-SAN BERNARDINO APPROXIMATE DISTANCE mi (km) 5.3 ( 8.5) 6.1 ( 9.8) 21.2 ( 34.1) 24.1 ( 38.8) 24.2 ( 39.0) 34.3 ( 55.2) 36.5 ( 58.8) 43.4 ( 69.8) 46.7 ( 75.2) 46.9 ( 75.4) 47.3 ( 76.2) 48.5 ( 78.0) 51.9 ( 83.6) 52.1 ( 83.9) 56.5 ( 91.0) 57.4 ( 92.3) 59.4 ( 95.6) 60.2 ( 96.9) ESTIMATED MAX. EARTHQUAKE EVENT MAXIMUM EARTHQUAKE MAG. (Mw) 69 6.9 7.4 6.8 7.1 6.8 7.1 6.5 7.2 6.9 6.9 6.7 6.8 6.8 6.8 6.8 6.7 6.7 PEAK SITE ACCEL, g 0.349 0.320 0.150 0.088 0.107 0.061 0.070 0.039 0.058 0.047 0.047 0.056 0.040 0.039 0.051 0.036 0.046 0.032 EST. SITE INTENSITY MOD. MERC. i ___ DC VIII VII VII VI VI V VI VI VI VI V V VI V VI V -END OF SEARCH-18 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS. THE ROSE CANYON FAULT IS CLOSEST TO THE SITE. IT IS ABOUT 5.3 MILES (8.5 km) AWAY. LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 03490 g LEGEND Abbreviation mi km Mw g Mod. Merc. V VI VII VIII DC Description miles kilometers moment magnitude gravity Modified Mercalli Intensity Scale Felt by nearly everyone, many awakened. Some dishes, windows, etc., broken; a few instances of cracked plaster; unstable objects overturned. Disturbances of trees, poles, and other tall objects sometimes noticed. Pendulum clocks may stop. Felt by all, many frightened and run outdoors. Some heavy furniture moved; a few instances of fallen plaster or damaged chimneys. Damage slight. Everybody runs outdoors. Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures; considerable in poorly built or badly designed structures; some chimneys broken. Noticed by persons driving motor cars. Damage slight in specially designed structures; considerable in ordinary substantial buildings, with partial collapse; great in poorly built structures. Panel walls thrown out of frame structures. Fall of chimneys, factory stacks, columns, monuments, walls. Heavy furniture overturned. Sand and mud ejected in small amounts. Changes in well water. Persons driving motor cars disturbed. Damage considerable in hi specially designed structures; well designed frame structures thrown out of plumb; great in substantial buildings, with partial collapse. Buildings shifted off foundations. Ground cracked conspicuously. Underground pipes broken.