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HomeMy WebLinkAbout389; Cannon Road Bridge Over Macario Canyon; Cannon Road Bridge Over Macario Canyon; 1989-01-10Woodward-Clyde Consultants Project No. 8751455R-SI02 GEOTECHNICAL INVESTIGATION CANNON ROAD BRIDGE OVER MACARIO CANYON CARLSBAD, CALIFORNIA Prepared for: The Buie Corporation/Carlsbad Development Company Rancho Del Cerro Joint Venture P & D Technologies 401 West 'A1 Street, Suite 2500 San Diego, California 92101 a/vbl 1550 Hotel Circle North San Diego, California 92108 (619) 294-9400 Fax: (619) 293-7920 Woodward-Clyde Consultants January 10, 1989 Project No 8751455R-SI02 P & D Technologies 401 West 'A' Street, Suite 2500 San Diego, California 92101 Attention: Mr. Lee Vance GEOTECHNICAL INVESTIGATION CANNON ROAD BRIDGE OVER MACARIO CANYON CARLSBAD, CALIFORNIA Gentlemen: Woodward-Clyde Consultants is pleased to provide the accompanying report, which presents the results of our geotechnical investigation for the project. This study was performed in accordance with our proposal dated December 14, 1987, our Agreement for Supplemental Soil Engineering Services, dated September 16, 1988 and authorization by the Buie Corporation/Carlsbad Development Company and Rancho Del Cerro Joint Venture of February 29, 1988, December 15, 1988, and January 5, 1989. This report presents our conclusions and recommendations pertaining to the project, as well as the results of our field explorations and laboratory tests. If you have any questions or if we can be of further service, please give us a call. Very truly yours, WOODWARD-CLYDE CONSULTANTS Vera Berger G.E. 2054 X^E2*^VB/DLS/rig /^irar^;^ f/gfe^ '<:^::\ fa' No. 2054 \s! David L. Schug C.E.G. 1212 i.W CM1 Consulting Engineers. Geologists and Environmental Scientists Offices in Other Principal Cities D Wood ward-Clyde Consultants Project No. 8751455R-SI02 TABLE OF CONTENTS PAGE NO. PURPOSE AND SCOPE OF INVESTIGATION 1 DESCRIPTION OF THE PROJECT 2 FIELD AND LABORATORY INVESTIGATIONS 2 SITE CONDITIONS 3 Geologic Setting 3 Surface Conditions 3 Subsurface Conditions 4 Geologic Structure and Landslides 5 Local and Regional Faults 6 Groundwater 7 DISCUSSIONS, CONCLUSIONS, AND RECOMMENDATIONS 7 Potential Geologic Hazards 7 Groundwater 10 Site Grading and Earthwork 11 East Embankment 11 West Embankment 16 Pile Foundations 17 Lateral Earth Pressures 18 UNCERTAINTY AND LIMITATIONS 19 TABLES 1. Soil Properties Assumed in Slope Stability Analyses 2. Site Treatment Plans Summary 3. Estimated Pile Tip Elevations 4. Ultimate and Allowable Pile Load Capacities FIGURES 1. Location Map 2. Site Plan 3. Generalized Geologic Cross-Section at Centerline Cannon Road 4. Liquefaction Potential Chart 5. Typical Side Berm Sections a/vbl Woodward-Clyde Consultants Project No. 8751455R-SI02 TABLE OF CONTENTS (continued) PAGE NO. APPENDICES A. Field Investigation B. Laboratory Tests ATTACHMENTS 1. Logs of Test Borings Sheet a/vbl 11 Woodward-Clyde Consultants Project No. 8751455R-SI02 GEOTECHNICAL INVESTIGATION CANNON ROAD BRIDGE OVER MACARIO CANYON CARLSBAD, CALIFORNIA PURPOSE AND SCOPE OF INVESTIGATION This report presents the results of our geotechnical investigation at the site of the proposed Cannon Road Bridge over Macario Canyon. The site is located east of Agua Hedionda Lagoon and west of Hidden Valley Road in Carlsbad, California. This report has been prepared exclusively for the Buie Corporation/Carlsbad Development Company, Rancho Del Cerro Joint Venture, P & D Technologies and their consultants for use in evaluating the property and in project design. This report presents our conclusions and/or recommendations regarding: • The geologic setting of the site; Potential geologic hazards; • General subsurface soil conditions; Groundwater conditions within the depths of our subsurface investigation; • Stability of slopes; • Grading and earthwork; • Pile foundations; Allowable and ultimate soil bearing pressures and uplift capacities; • Negative skin friction; • Settlements; Design pressures for retaining walls; and • Geotechnical data for seismic design. a/vbl - 1 - Woodward-Clyde Consultants Project No. 8751455R-SI02 DESCRIPTION OF THE PROJECT For our study, we have discussed the project with Mr. Lee Vance of P&D Technologies and Mr. Mark Ashley of McDaniel Engineering, and we have been provided with a set of drawings entitled "Plans for the improvement of Cannon Road Assessment District", Sheets 1 through 10, prepared by VTN, undated; a bridge drawing entitled "Cannon Road Bridge over Macario Canyon, General Plan," prepared by McDaniel Engineering, stamp- dated December 19, 1988, and a drawing entitled "Plans for the Improvement and Grading of Cannon Road Sta. 64+50 to Sta. 72+61.30" prepared by Crosby, Mead, Benton and Associates, undated. We understand that the proposed project will include construction of a five-span bridge over the western portion of the Macario Canyon, and construction of a road fill up to 40 feet high with slope inclinations of 2 to 1 (horizontal to vertical) in the eastern portion of the canyon. The bridge will be approximately 455 feet long and it will consist of two parallel bridges. The bridge abutments and piers will be supported on piles. The project vicinity map is presented in Figure 1. The location and layout of the bridge are shown on the Site Plan (Figure 2). FIELD AND LABORATORY INVESTIGATIONS Our field investigation included making a visual geologic reconnaissance of the existing surface conditions, making five exploratory borings between April 5 and 12, 1988, and two exploratory borings on September 28, 1988 and obtaining representative soil samples. Two of the borings made with large diameter bucket auger in the west abutment area were downhole logged by a geologist from our firm. The borings were advanced to depths ranging from 40.5 to 120.5 feet. The locations of the borings are shown on the Site Plan (Figure 2). A Key to Logs is presented in Appendix A as Figure A-l. Final logs of the borings are presented in Appendix A as Figures A-2 through A-18 and on a Log of Test Borings Sheet, Attachment 1. The description on the logs are based on field logs, sample inspection, and laboratory test results. Results of laboratory tests are shown at the corresponding sample a/vbl - 2 - Woodward-Clyde Consultants Project No. 8751455R-SI02 locations on the logs and in Appendix B. The field investigation and laboratory testing programs are discussed in Appendices A and B. SITE CONDITIONS Geologic Setting The site is located at the mouth of Macario Canyon, a major southeast - northwest trending tributary canyon, which empties into Agua Hedionda Lagoon in coastal northern San Diego County. The canyon is cut through tertiary sedimentary strata which are underlain at depth by the granitic and metavolcanic bedrock which outcrops to the east. Presently, the canyon is the site of deposition of alluvial soils and accumulation of slopewash soils from the adjacent hillsides with periods of erosion during heavier seasonal rains. Surface Conditions The proposed bridge and road alignment stretches southwest to northeast across the mouth of Macario Canyon. The eroded southwest hillsides of the canyon are the site of the proposed western abutment of the bridge. These steep slopes are vegetated with a dense growth of chaparral and grasses. Several overhead power lines and access roads for the supporting poles and towers are present in the immediate vicinity. The eastern abutment of the proposed bridge will be located near a fill slope to be constructed out from the east edge of the canyon. The area within the proposed road alignment on the east canyon bank presently includes undisturbed chaparral-covered hillsides, fill slopes and a small filled-in basin. The canyon bottom itself is densely vegetated with trees and brush on the eastern half and with low ground cover and isolated trees for most of the western half. Thick reeds are present in the active stream course located in the extreme west side of the canyon. Several transients live within the canyon bottom in the immediate vicinity of the project alignment. Piles of litter and makeshift dwellings are present throughout the canyon area. a/vbl - 3 - Wood ward-Clyde Consultants Project No. 8751455R-SI02 Subsurface Conditions The project site is underlain by Quaternary age overburden soils including: fill, surficial soils, slopewash, and alluvial deposits; and by Eocene age sediments of the Santiago Formation. These soil units are described below. The geologic symbols are given after the names of the units. Approximate stratigraphy for the site is shown on Generalized Geologic Cross Section at Centerline Cannon Road (Figure 3). At least some of the geologic contacts in the northeast portion of the canyon are inferred from the available grading plans. Fill Fill soils were observed in the northeast portion of the canyon. Approximately 10 feet of fill underlain by filter fabric and a layer of crushed rock approximately 2.5 feet thick were encountered in our Boring 7. The fill soils in Boring 7 generally consist of pale brown silty sands and pale gray and clayey sands with some zones of dark brown sandy lean clay. Penetration blow counts of 11 and 7 blows per foot were recorded within the fill soils in Boring 7. Presence of the filter fabric and the crushed rock suggest that the fill was probably placed under the engineering observation. No record of fill placement was available to us at the time of preparing of this report. Surficial Soils Natural surficial soils were observed overlying formational soils on the undisturbed hillsides along the alignment. Based on our observations and experience, these surficial soils generally consist of 0 to 2 feet of silty sand topsoil overlying 0 to 2 feet of residual clay. Slopewash (Qsw) Slopewash soils cover a large portion of the lower hillsides on the southwest side of the canyon. These soils, as encountered in Boring 4, consist of sandy clay and clayey sand, which overlie natural alluvial deposits. Slopewash soils extended to a depth of nearly 5 feet in Boring 4. a/vbl - 4 - Woodward-Clyde Consultants Project No. 8751455R-SI02 Alluvium(Qal) A thick section of erratically interbedded clean, silty and clayey sands and lean clays underlies the bottom of the canyon. Our test borings encountered the deepest alluvium of up to approximately 110 feet thick in Boring 3. Approximately 58 and 41 feet of alluvial soils were found in Boring 6 and Boring 1, respectively. Approximately 11 feet of alluvium was encountered in Boring 4 below the slopewash soil; 22 feet of alluvium were encountered in Boring 7 below the fill. Sands comprise more than half of the alluvial soils encountered in our borings. The alluvial sands are generally in a loose to medium dense condition throughout the entire section. Numerous, relatively thin layers of lean sandy clay and occasional thin layers of fat clay were encountered within alluvial soils in all borings located in the canyon bottom area with the exception of Boring 1. Approximately 28 feet of clayey soils consisting of interbedded lean clays and clayey sands were encountered in the upper portion of Boring 3. Clayey alluvial soils underlying the project site appear to be of soft to firm consistency. Santiago Formation (Ts) Sediments assigned to the Santiago Formation underlie the overburden soils in the general site area. Our test borings indicate that these sediments consist of very dense silty sands with interbeds of very dense silt and hard clay. Clayey portions of the Santiago Formation are generally considered to be prone to landsliding. An upper portion of Santiago Formation, approximately 18 feet thick encountered in Boring 4 appears to be highly weathered. Geologic Structure and Possible Ancient Landslides Bedding attitude measurements taken within the west bridge abutment in our large diameter Borings 2 and 5 indicate that sediments of the Santiago Formation dip at generally 4 to 13 degrees in a west or southwest direction. Some cross bedding dipping at up to 13 degrees to the northeast was observed in Borings 2 and 5. Reviewed geologic literature indicates that bedding on the northeast banks of the Macario Canyon dips at up to 15 degrees in a west to northwest direction. a/vbl - 5 - Wood ward-Clyde Consultants Project No. 8751455R-SI02 Our preliminary review of aerial photographs suggested that the hillside underlying the proposed west bridge abutment may be a portion of a large ancient landslide. Test borings were made in this area to specifically address the possible existence of a landslide. Our downhole observations in these test borings did not reveal slip planes, clay seams, M brecciated zones or anomalous bedding which could indicate that ancient landslides are present. No other landslides were indicated to be on or in the near vicinity of the site during our site studies. Local and Regional Faults Faults or indications of faults were not observed in our site reconnaissance or in our test borings. Our review of geologic literature and our experience in the area indicates that several relatively discontinuous faults are mapped in areas south, north and east of the site. The majority of these faults are mapped as trending between N60W and N20E with dips 1 north or south ranging from 40 degrees to near vertical. The nearest fault is mapped as being approximately 1300 feet south of the west abutment of the proposed bridge. None of the nearby faults is considered active. The dominant local fault system is the Rose Canyon Fault zone projected offshore along the cost approximately 6 miles south-southwest of the site. Although the Rose Canyon Fault zone has been seismically quiescent through most of recorded history, a series of PI earthquakes with events up to Richter magnitude 4.2 were attributed to the Rose Canyon Fault zone in San Diego Bay in mid 1985. Studies on the geologic history and character of D the Rose Canyon Fault zone indicate that it is capable of producing a moderate to large earthquake up to the estimated maximum Magnitude 7. Other known active fault systems where recurring seismic events of Richter magnitude 4.0 or greater have been recorded are within the Elsinore Fault zone and the Coronado Banks Fault zone, located approximately 23 miles northeast and approximately 21 miles southwest (offshore) of the site, respectively. Both of these systems are also considered capable of producing a moderate to large earthquake. The most recent activity on local fault systems included a series of earthquakes registering up to magnitude 5.3 on the Richter Scale which occurred on the nearest portions of the Coronado Banks Fault zone in July of 1986. a/vbl - 6 - Wood ward-Clyde Consultants Project No. 8751455R-SI02 Groundwater f1 Due to the low site elevations and the proximity to the coastline, groundwater is generally present within one foot of the ground surface in most areas of the canyon bottom. The observed groundwater levels correspond to elevations ranging from approximately 13 to 16 feet (Mean Sea Level Datum). Borings made on the adjacent hillsides also encountered groundwater at similar elevations. DISCUSSIONS, CONCLUSION AND RECOMMENDATIONS The discussions, conclusions and recommendations presented in this report are based on the information provided to us, results of our field and laboratory studies, analyses, and professional judgement. We have observed only a very small portion of the pertinent soil and groundwater conditions. The geotechnical recommendations made are based on the assumption that soil conditions do not deviate appreciably from those found during our field investigation. If the plans for site development are changed, or if variations or undesirable geotechnical conditions are encountered during construction, we should be" consulted for further recommendations. Potential Geologic Hazards Faults and Seismicity Our field studies did not indicate the presence of faulting within the project site. Several fault segments mapped in the general site area are not considered active and are typical of other faults observed in the Carlsbad area. It is our opinion that these faults do not represent a significant geologic hazard to site development. However, if on-site faults are discovered during future site studies or site grading their impact on site development should be evaluated by an engineering geologist. As noted previously, known active fault systems exist to the northeast and southwest of the site. Therefore, it is not unreasonable to anticipate that the site as well as the entire North County Coastal area, could experience relatively strong ground shaking due to a nearby or distant earthquake. a/vbl - 7 - Woodward-Clyde Consultants Project No. 8751455R-SI02 U Landslides {~1 Two large diameter test borings were made in the west bridge abutment area within landforms suspected as being possible ancient landslides. Our downhole observation of D the above borings indicated that a landslide is not present in that area. No other landslides are indicated by our studies to be at the project site. Seismic Ground Motion We understand that seismic design of the proposed bridge will be performed in accordance y with current CALTRANS standards, based on ultimate strength concepts and the maximum credible rock acceleration. Based on the California Division of Mines and Geology Map I Sheet 45 "Rock Acceleration from Maximum Credible Earthquakes in California," 1987 by Lalliana Mualchin and Allen Lynn Jones, the maximum credible bedrock acceleration in the [~~j proposed bridge area is approximately 0.38g. The maximum peak accelerations at the ^ ground surface level in the deep alluvium areas may be lower than 0.38g due to damping of D the earthquake waves in unconsolidated soils. Based on the information presented in Seed and Idriss, 1982 we estimate the peak ground acceleration of 0.23g at the ground surface in the bottom of Macario Canyon area.Q Using selected shear wave velocity measurements done by our firm in the San Diego area, D along with general information on the correlation between shear wave velocity and geologic age and type of material, summarized in the Handbook of Engineering Geophysics 1977, it is our conclusion that "rock-like" material, defined as a material having shear wave velocity |j in excess of 2,000 feet per second, is located approximately from 10 to 80 feet from the present ground surface at Abutment 1 and Pier 2 and approximately from 80 to 150 feet from the present ground surface at Piers 3 through 5 and Abutment 6. p. Liquefaction Potential Based on the model developed by Youd and Perkins (1978), the liquefaction susceptibility n of saturated soils can be assessed in a very general way in accordance with the age and type ^ of deposit. According to this model, the alluvial deposits are expected to have moderate to D high susceptibility for liquefaction. The Eocene age Santiago Formation on the other hand, is unlikely to experience seismic induced liquefaction. The liquefaction susceptibility of a/vbl - 8 - Woodward-Clyde Consultants Project No. 8751455R-SI02 soils can vary substantially from one site to another, dependent on the amount of cohesionless sediment and its density in each unit. According to the results of our field investigation, a considerable portion of the alluvial deposits underlying the subject site is composed of clean or slightly silty sands that are known to pose much larger liquefaction hazards than, for instance, fine-grained soils (clays and plastic silts) of the same geologic age and type of deposition. To evaluate the liquefaction potential of the alluvial soils at the project site in more detail, we have utilized the approach based on the correlation of the soil behavior during the past earthquakes with the Standard Penetration Test (SPT) blow counts developed by Seed and Idriss. In accordance with the established correlation procedures, all blow counts taken in sandy soils of the alluvium located below the water table were corrected for the overburden pressure, rod length and silt content. These blow counts are plotted versus depth below the ground surface on the Liquefaction Potential Chart (Figure 4). Two liquefaction potential cut-off lines corresponding to the maximum peak ground accelerations of 0.38g and 0.23g respectively are also shown in Figure 4. The above accelerations correspond to the maximum credible bedrock acceleration and the estimated maximum credible acceleration of the top of deep alluvial deposits in the canyon. All blow counts located to the left of the liquefaction potential cut-off lines represent liquefaction potential at a corresponding location. Figure 4 indicates that most of the blow counts for sandy soils at the subject site plot to the left of both cut-off lines. Based on the results of our analyses, it is our opinion that sandy portions of the alluvial soils underlying the project site may experience liquefaction during the maximum earthquake. It is our opinion that slopewash materials and fill soils at the subject site have low potential for seismic induced liquefaction because they are located predominantly above the groundwater table. There is no potential for liquefaction of soils of the Santiago Formation. Based on the results of our subsurface investigation we estimate that approximately 50 to 60 percent of the alluvial soils at the project site are comprised of granular materials susceptible to liquefaction. We further estimate that the maximum thickness of a continuous layer of such material at a given location is likely to vary from 10 to 20 feet. a/vbl - 9 - Wood ward-Clyde Consultants Project No. 8751455R-SI02 Erratic nature of the alluvial soils at the project site may result in even thicker continuous layers of liquefaction susceptible soils at some locations. It is our opinion that portions of the subsurface profile that undergo liquefaction may experience considerable reduction in soil strength. Recent studies by Seed, 1987 provide correlation between the average corrected blow count, NI, and residual strength of liquefied material. Using this correlation, we estimate that the residual strength of liquefied soil at the project site may range from 400 psf to 800 psf. Based on the time lag between the strongest impact on the structure and liquefaction of the underlying soils observed in several major earthquakes, such as Niigata (1964) and Alaska (1964), and inferred from numerous acceleration-time histories, it is our opinion that a larger portion of the original soil strength than indicated above may be available to resist earthquake loads. Soil liquefaction if it occurs at the project site will most likely manifest itself in sand boils, ground subsidence and differential settlement, as well as permanent lateral deformation in slope areas. Subsidence of the alluvial soils around a pile foundation rigidly supported on underlying formational soils will generate negative skin friction (downdrag force) on the pile surface. Recommendations relative to downdrag forces are presented further in this report under "Pile Foundations." Stability of slopes for seismic and liquefaction condition is discussed under "East Embankment Slope Stability." Whether or not there would be lateral flow of the soils during liquefaction, is unknown. Severe damage over a broad area is to be expected if lateral flow occurs. Damage to the bridge and road embankment in case of lateral flow probably would not be prevented by the f1 design recommendation presented herein. In this regard, in our opinion, the subsurface conditions at the subject site are similar to much of the San Diego County coastal areas. Groundwater The groundwater encountered in the test borings at approximate elevations of 13 to 16 feet (MSL Datum) appears to be the approximate surface of the permanent groundwater table. Based on our experience, we expect that the groundwater surface slopes down slightly toward Agua Hedionda Lagoon and that the groundwater level will vary only slightly due a/vbl -10- Woodward-Clyde Consultants Project No. 8751455R-SI02 to seasonal variations in precipitation and runoff. Our experience indicates that local zones of perched water may be found at higher elevations in formational and overburden soils where permeable granular sediments are underlain by impermeable fine grained soils. Site Grading and Earthwork It is anticipated that site grading and earthwork will consist primarily of constructing of the road embankments east and west of the proposed bridge in the Macario Canyon area. We understand that all grading and earthwork will be done in accordance with applicable portions of the Standard Specifications, State of California Department of Transportation. The grading should be observed by and the compacted fills tested by a firm specializing in soil testing services. We recommend that all surface structures, pavements, vegetation, loose and/or porous topsoils and slopewash materials, and large tree roots not removed by planned demolition or grading, be excavated and removed from the planned fill areas. The exposed ground surface should then be scarified, watered if required and recompacted to the required density prior to placing fill. Debris and perishable material should be removed from the site; topsoil may be stockpiled for future landscaping use, if desired. In addition to the general earthwork recommendations described above, we recommend that special procedures be used for construction of fill in the eastern portion of the Macario Canyon. These procedures are discussed below. East Embankment Construction Options Our subsurface investigation revealed that the east embankment area is underlain by a deep section of alluvial soils consisting of erratically interbedded loose to medium dense sands and soft to firm clays. We estimate that sliding slope failures are likely to occur if the proposed embankment fill of up to 40 feet high is placed directly over the existing alluvial soils. Soft clay materials with low shear strength, such as those found in Borings 3, 6 and 7, are especially prone to sliding failure. Mitigation of the slope stability failure in the east embankment area can be done using one of the options described below. a/vbl -11- Woodward-Clyde Consultants Project No. 8751455R-SI02 Option 1 - Construction of Embankment with Temporary Berms. This option requires construction of temporary side berms around the proposed road embankment in the area I underlain by alluvial soils (up to approximate Station 71+50). We recommend that 3 to 5 feet of especially compressible surficial alluvial soils be removed and a gravel mat wrapped in filter fabric be placed over the embankment and the berms area prior to placement of the earth fill. The gravel mat should have the minimum thickness of 3 feet and it may consist of 3/4-inch or 1-inch crushed rock or of Caltrans Class II permeable material. The filter fabric should be Mirafi 600X or equivalent. The gravel mat will facilitate placement of fill below or in close proximity to the groundwater table, provide a relatively stable working area, and it will also speed up consolidation of underlying alluvial soils. We estimate that berms of approximately 20 feet high and 130 feet wide are required for an embankment fill of 40 feet to prevent a sliding slope failure during or immediately after the roadway construction. In our analysis we used a safety factor of 1.2 for sliding slope failure at the time of embankment placement. We estimate that safety factor will reach a value of 1.5 approximately one month later due to consolidation of soil with time under embankment load. A typical section showing the embankment configuration for Option 1 is presented in Figure 5. The side berms shown in Figure 5 should be kept in place until underlying alluvial soils attain strength needed to support the road embankment without a sliding failure. We estimate that approximately 6 months will be required before the berms can be removed. We recommend that settlement monitoring records be evaluated prior to berm removal. Recommendations on settlement monitoring are presented further in the report under "Settlement Monitoring." Option 2 - Stage Construction. Stage construction option includes placement of the embankment fill in two or more stages with waiting periods in between. The schedule of stage construction is controlled by the strength of the underlying soils in their natural condition and by the rate of soil strength increase under each increment of embankment load. Results of our analyses for an example of a two-stage construction scheme indicate that the alluvial soils in the east embankment area can support approximately 20 feet of embankment fill if no side berms are constructed. In our calculations, we have assumed that upper 3 to 5 feet of surficial material is removed and substituted with gravel and a/vbl -12- Woodward-Clyde Consultants Project No. 8751455R-SI02 compacted fill as discussed above. We estimate that approximately 6 months will be required until the alluvial soils attain strength sufficient to withstand a load from the remaining 20 feet of embankment. Option 3 - Stone Columns. This option includes reinforcement of alluvial soils within the proposed east embankment area with stone columns extending down to competent formational soil. Based on the subsurface profile in Figure 3, the depth of the stone columns may reach over 100 feet in the toe of the slope area. Typical stone columns are 3 to 4 feet in diameter and are constructed at 6 to 8 feet on center. Our experience indicates that installation of stone columns may be considerably more expensive than other comparable site treatment alternatives. We recommend that the stone column option be considered if project constraints preclude use of Options 1 and 2. Estimated Settlement We estimate that the total settlement of the east embankment due to consolidation of compressible alluvial soils subjected to an embankment load may range from 24 to 36 inches. We estimate that it may take from 2 to 3 years for this settlement to achieve 80 to 90 percent of the above total values. The remaining estimated 2.5 to 7 inches of settlement will, in our opinion, occur gradually over a relatively long period of time. The above values assume a 40-foot high embankment placed in one stage. More time will be required to achieve 80 to 90 percent of consolidation if a two-stage construction is selected. Additional settlement may develop due to consolidation of compacted fill during its lifetime II if the fill material increase in moisture. We estimate that such settlement may be up to 0.5 percent of the total fill height. Our experience indicates that fills with substantial amounts of clayey soils are generally more settlement prone than fills composed of granular material. Time and rate of this settlement (if it occurs) is unknown. It is our opinion, that settlement due to compacted fill consolidation is a minor factor compared to settlement generated within alluvial soils. Procedures to Accelerate Settlement Acceleration of the rate of settlement at the project site can be generally achieved by installation of a vertical drain system and/or surcharging the site. Our experience indicates a/vbl - 13 - Woodward-Clyde Consultants Project No. 8751455R-SI02 that wick drains are usually less expensive and they can be installed faster than other vertical drain systems. A typical wick drain is a prefabricated strip with a core of flexible polypropylene surrounded by a non-woven geotextile with high permeability. The drains are inserted in the ground on a mandrel by a crawler-type crane or a backhoe. Usually, a gravel or a sand blanket are laid over the site prior to drain installation to facilitate drainage and construction operations. A wick drain system can be used in combination with either Option 1 (Side Berms) or Option 2 (Stage Construction) described above to accelerate consolidation of alluvial soils and embankment settlement. Further settlement acceleration can be achieved by surcharging the site. Surcharge can be also used without wick drains. Thickness of surcharge fill and time of its placement is controlled by the time rate of consolidation of the alluvial soils. Settlements Monitoring We recommend that settlement monuments be placed in the areas that have potential for consolidation settlement prior to placing any fill, and the settlements be recorded by a licensed surveyor on a weekly basis during grading and for the first month upon completion of grading; readings may be made monthly thereafter. The location of the settlement monuments will be determined in the field at the time of grading. We recommend that settlement readings be forwarded to Woodward-Clyde Consultants for periodic evaluation so that a time of surcharge removal can be established from the data. Stability of Slopes Stability of the east embankment slopes during the construction period was evaluated as a part of our studies of construction options described above. Construction period is defined in this report as a period of time required for the alluvial soils to reach 80 to 90 percent consolidation. For the post-construction period we estimate that the east embankment with slopes 40 feet high and inclination of 2 to 1 (horizontal to vertical) have a safety factor for static conditions of 1.5 or greater. During earthquake ground shaking, transient lateral seismic loads and the potential for soil liquefaction may affect stability of the east embankment slopes. To evaluate seismic a/vbl - 14 - Wood ward-Clyde Consultants Project No. 8751455R-SI02 stability of those slopes, we used the simplified seismic stability and deformation analysis approach presented by Makdisi and Seed (1977). A set of pseudo-static slope stability analyses was first performed for the subject slope using Bishop method of slices modified for use with composite failure surfaces. Computer program PC-SLOPE developed by Geo-Slope Programming Ltd. (May 1985) was used in our computations; total stress analysis method was used for all cases. Soil strength parameters utilized in the slope stability analyses are summarized in Table 1. The undrained residual shear strength of liquified sand was evaluated from a relationship with SPT NI value (Seed, 1987). This relationship is based on parametric studies performed for actual liquefaction induced slides. A conservative, 30th percentile blow count value (Ni = 12) was used with this correlation which resulted in the undrained residual shear strength of liquefied sand of 600 psf. Results of the pseudo-static slope stability analyses were then used to evaluate permanent displacement of the embankment in accordance with the above-mentioned Makdisi and Seed procedures. Peak ground accelerations and earthquake magnitudes associated with the maximum credible earthquake described above were used in our analysis. Results of our analyses indicate that a permanent lateral deformation of up to 3 inches may develop within the east embankment during the maximum credible earthquake if sandy soils of alluvial deposits experience seismic-induced liquefaction. Stability analyses require using parameters selected from a range of possible values. Mathematical procedures used in slope stability analyses are based on several simplifying assumptions. Therefore, there is a finite possibility that slopes having calculated factors of safety as indicated above may become unstable and that permanent deformation larger than those given above may develop during an earthquake. In our opinion, the probability of slopes becoming unstable is low, and it is our professional opinion that the slopes can be constructed as indicated above. Protection From Slope Erosion Fill slopes with 2:1 inclinations are susceptible to erosion and shallow sloughing in periods of rainfall, heavy irrigation, and/or upslope surface runoff. Periodic slope maintenance a/vbl - 15 - Woodward-Clyde Consultants Project No. 8751455R-SI02 may be required, including rebuilding the outer 1-1/2 to 4 feet of the slope. Erosion and sloughing can be reduced by using inclinations flatter than 2:1, by overbuilding at least 3 feet and cutting back to the desired slope or by proper landscaping. To a lesser extent, erosion and sloughing can be reduced by backrolling slopes at frequent intervals. As a minimum, we recommend that fill slopes be backrolled at maximum 4-foot fill height intervals. Additionally, we recommend that all fill slopes be trackwalked so that a dozer track covers all surfaces at least twice. Summary Table 2 shows several examples of possible site treatment plans that may be used for the east embankment area. For each of the plans, the table specifies one of the two construction options: side berms or stage construction, and additional settlement acceleration measures such as wick drains or surcharge. Total estimated waiting period required to reach 80 to 90 percent consolidation is also presented in the table for each plan. Information shown in Table 2 is intended as a guide for selection of a conceptual site treatment plan. Combinations of site treatment measures other than those shown in Table 2 are possible. We will provide evaluation of feasibility and settlement estimates for other plans of treatment if requested to do so. West Embankment Estimated Settlement We anticipate that west embankment fills in the area of the west bridge abutment will be placed over dense to very dense sands, silts and hard clays of the Santiago Formation. It is our opinion that settlement of the foundation of those fills will be mostly instantaneous in nature, and they will be essentially complete as the embankment is brought to specified grades. We do not recommend a settlement waiting period for the west embankment. We estimate that total post-embankment construction settlement will range from approximately 1 to 2 inches. It may take several years for this settlement to occur. a/vbl - 16 - Woodward-Clyde Consultants Project No. 8751455R-SI02 Slope Stability It is our opinion that west abutment slopes composed of compacted fill placed over soils of Santiago Formation in accordance with the above grading recommendations and having inclinations of 2:1 (horizontal to vertical) should have a calculated factor of safety for deep- seated failure in excess of 1.5 for static conditions. This safety factor assumes that all loose and/or compressible overburden soils are removed from the embankment as recommended above under "Grading and Earthwork" and that no adverse geologic condition exist in the slope area. We recommend that an engineering geologist examine slope areas undercut for placement of compacted fill for possible adverse geologic conditions such as out-of-slope bedding or water seeps during grading. Pile Foundations It is our opinion that steel H-sections and concrete-filled, steel-cased piles are more appropriate than prestressed, precast concrete piles for highly seismic areas, especially where there is a potential for soil liquefaction. Potential for steel corrosion may be evaluated using local soil and water corrosivity data and results of our soil corrosivity test presented in Appendix B. It is our opinion that all piles supporting the subject bridge should be embedded in soil by a minimum of 20 feet and they should be embedded at least 10 feet into unweathered soils of the Santiago Formation. Estimated pile tip elevations based on the above recommendations for each abutment and pier location are summarized in Table 3. The above elevations are applicable to the current bridge layout available to us at this time. The pile tip elevations should be adjusted if location of bridge supports is changed. The actual pile tip elevations may vary at each pile group location and provisions should be made to allow cut off or adding on to piles. We recommend that ultimate and allowable pile load capacities be calculated using unit end bearing and skin friction resistance values summarized in Table 4. The above values are applicable to unweathered soils of the Santiago Formation. Both, end bearing and skin friction resistance within the Santiago Formation can be used to calculate the downward pile load capacities. Only friction resistance is available to withstand uplift loads. a/vbl - 17 - Project No. 8751455R-SI02 We further recommend that negative skin friction (downdrag force) associated with potential for soil liquefaction be applied to each pile at Piers 3, 4, 5 and Abutment 6 for seismic conditions. We estimate a downdrag force of 50 tons for a 12xl2-inch square pile. The downdrag force can be prorated for other pile sizes proportionate to the pile surface area. We recommend that actual pile capacities be verified in the field by a suitable pile driving formula at the time of driving. No reduction for group action is required if piles have a minimum center to center spacing of at least three times the butt width. We recommend that abutment piles not be driven until the abutment fills have stabilized and settlement is essentially complete. It is estimated that long-term settlement due to pile loads will be less than 1 inch. Local experience indicates that predrilling or jetting may be required to advance displacement piles through the dense soils underlying the bridge site. We recommend that all piles be driven a minimum of 5 feet below the deepest point of jetting or predrilling. Lateral Earth Pressures It is recommended that retaining structures with level backfills, or with sloping backfills of up to an inclination of 3:1 (horizontal to vertical), be designed for an earth pressure equal to an equivalent fluid pressure of 36 pcf; retaining structures with sloping backfills with inclinations from 3:1 to a maximum of 2:1 should be designed for an earth pressure equal to an equivalent fluid pressure of 45 pcf. The above values are for backfill composed of nonexpansive granular soil. All walls should be provided with backfill drainage to relieve hydrostatic pressures. It is recommended that a friction value between soil and concrete equal to 0.35 be used to resist lateral pressures. If additional resistance is needed, it is recommended that a passive pressure equal to an equivalent fluid pressure of 300 pcf be used for design. This pressure assumes that the ground in front of the wall is level for a minimum distance of 10 feet or twice the depth of the footing or key, whichever is greater. The upper 1 foot of material should be neglected unless it is protected by paving. The above friction coefficient and the passive equivalent fluid pressure incorporate a safety factor of 1.5 a/vbl - 18 - Woodward-Clyde Consultants Project No. 8751455R-SI02 UNCERTAINTY AND LIMITATIONS We have observed only a very small portion of the pertinent soil and groundwater conditions. The recommendations made herein are based on the assumption that soil conditions do not deviate appreciably from those found during our field investigation. We recommend that Woodward-Clyde Consultants review the foundation and grading plans to verify that the intent of the recommendations presented herein has been properly interpreted and incorporated into the contract documents. We further recommend that Woodward- Clyde Consultants observe the site grading, subgrade preparation under concrete slabs and paved areas, and foundation excavations to verify that site conditions are as anticipated or to provide revised recommendations if necessary. If the plans for site development are changed, or if variations or undesirable geotechnical conditions are encountered during construction, we should be consulted for further recommendations. M This report is intended for design purposes only and may not be sufficient to prepare an accurate bid. California, including San Diego, is an area of high seismic risk. It is generally considered economically unfeasible to build a totally earthquake-resistant project; it is, therefore, possible that a large or nearby earthquake could cause damage at the site. Geotechnical engineering and the geologic sciences are characterized by uncertainty. Professional judgements presented herein are based partly on our understanding of the proposed construction, and partly on our general experience. Our engineering work and judgements rendered meet current professional standards; we do not guarantee the performance of the project in any respect. Inspection services allow the testing of only a small percentage of the fill placed at the site. Contractual arrangements with the grading contractor should contain the provision that he is [J responsible for excavating, placing, and compacting fill in accordance with project specifications. Inspection by the geotechnical engineer during grading should not relieve the grading contractor of his primary responsibility to perform all work in accordance with the specifications. a/vbl - 19 - Woodward-Clyde Consultants Project No. 8751455R-SI02 This firm does not practice or consult in the field of safety engineering. We do not direct the contractor's operations, and we can not be responsible for the safety of personnel other than our own on the site; the safety of others is the responsibility of the contractor. The contractor should notify the owner if he considers any of the recommended actions presented herein to be unsafe. a/vbl - 20 - Project No. 8751455R-SI02 TABLE 1 Soil Properties Assumed in Slope Stability Analyses Soil Unit <{) (degrees) c'(psf) y(pcf) Compacted Fill 34 100 125 Alluvium 10 1,000 125 Alluvial Sand, Liquefied 0 600 125 Santiago Formation 35 300 125 a/vbl &Cr*j 3 CO CN v> fJ J >-J OHCQ ~g s a £ 4—1 c^ 4-*CJ •/-™**bo 5 C .S o ° -2 ««'is "•-•' *5 'cS "£ t>- "O ^"O C || ol E oo ^ c.2+-• o flj Q on_C (-, C Q'u g -^ Q,*^ .^ CO 0) V2 bo g co H 4—* ^4—i (^ N c/5 t^o r§ ^ CN « S S s 1| IS ^^ f— (Dbo 4_( CO § 6E Z vo O O\ CO CO VO CO OOo o o o o *-"*-» 4-* 4-1 4-* ^ OO >O VO f»CN ^H CN D D ai 0 C vo C vo X— H X— t (^! I S | - | t^o « C co a - 1^ oc ^ o o CJ D DS CN CN CN „ C C•a 83 o o 0 c8 Z Z S CO co ^ O O O D 4) CO CO CO C C •— I T-H T-H O Oz ^ O O O £? c? 0 0CN CN O O O O O•* "t ^f CN (N < CQ U < pq •~ ' •— ' r- ' CN CN c/5 JD -oC SSrt ^ -' S (U t) <UW) bJ3 ^3 • 2 2 *"* Soo c^ b ^ <4_i VH V3 t3JO C^ C^3 r^ oj ^ j2 c co C c R •£o o c -5:g g vo ? VO CO "g "g fl_i fli ^ ^" u la, "&, .— « t_^ ^5 y^ Qj O • i-H • ^H on t/j <U D• rH -^H &J) b-0 <N CN £ fe (U D XI X!bo fcO JJ o SI co do co co 2 Project No. 8751455R-SI02 TABLE 3 Estimated Pile Tip Elevations Estimated Tip Elevation, feet Bridge Support (MSL Datum) Abutment 1 +40 Pier 2 +3 Pier 3 -67 Pier 4 -112 Pier 5 -102 Abutment 6 -72 TABLE 4 Ultimate and Allowable Pile Load Capacities Unit Capacities, tsf Ultimate Allowable End Bearing 140 70 Skin Friction 2 1 a/vbl OJECT^TE CONTOUR INTERVAL 20 FEET LOCATION MAP MACARIO CANYON BRIDGE CHECKED BY: l/^ [ PROJECT NO: 8751455R-SI01J PATE: 9~7~88 | FIGURE NO: 1 WOODWARD-CLYDE CONSULTANTS -t-><D r®C*-l 0)Oa tMS-t en T3C3O & 0)r-* -(-> (^;~? Ot-t JZ-t-> 0! Q DRAWN N1 , blows per foot 10 20 30 40 50 0 III.. 10 _ 20 . 30 _ 40 . 50 - 60 _ 70- 80 _ 90- 100- 110- 120- 0 o •1 • 1 • o / • /. o /A _. /• O | //• / • / /- •/ ° // . // / • / // /./ /• / / A • 1 \\ 1 I II ' 1• \ LEGEND : o Blow counts from Boring- 1 • Blow counts from Boring 6 • Blow counts from Boring 3 A Blow counts from Boring 7 Liquefaction Potential Cut-off Lines: for amax = 0.38g- for amax = 0.23g- Note: Blow counts, M^ shown for soil classifications SP, S.M , SC (due ;to mixed soils presence of ML and CL in soriie samples can no be precluded) LIQUEFACTION POTENTIAL CHART MACARIO CANYON BRIDGE BY: Cb CHECKED BY: l//^ I PROJECT NO:8751455R-SI01 DATE:9-7-88 1 FIGURE NO: 4 WOODWARD-CLYDE CONSULTANTS i-zUJ CQ LU Q < Oo: Q UJt/>OQ. Oo:o. i/)to u zo H U UJto a: I-D Oi UJ toOa. °UJ Oi UJ H 1- < UJ CQ toto UJ Qia Ou u LLI D_toLU i± LU Q. Q. si uj LU I-o to Is u-LU Qi tO CQ S Zcs: oUJ >. CQ z S3 to O _I QL < < U U ^ i ooi DATEROJECT NO:8751U55R-SI 02a Oui Uui U CQ DRAWN Wood ward-Clyde Consultants Project No. 8751455R-SI02 APPENDIX A FIELD INVESTIGATION Seven exploratory borings were advanced at the approximate locations shown on the Site Plan (Figure 2). The drilling was performed between April 5 and 12, 1988 and on LJ September 28, 1988 under the direction of a geologist from our firm. Borings 1, 3 and 4 were done using 8-inch diameter hollow-stem auger, Borings 2 and 5 were done using 30- inch diameter bucket auger and Borings 6 and 7 were done using rotary-wash technique and a 4-7/8-inch bit. Samples of the subsurface materials were obtained from the borings using a modified California drive sampler (2-inch diameter and 2.5-inch outside diameter) with thin brass liners, or a Standard Penetration sampler (1 3/8-inch diameter and 2-inch outside diameter). The sampler was generally driven 18 inches into the material at the bottom of the hole by a 140-pound hammer falling 30 inches; thin metal liner tubes containing the sample were removed from the sampler, sealed to preserve the natural moisture content of the sample, and returned to the laboratory for examination and testing. The location of each boring and the elevation of the.ground surface at each location were estimated by available grading plan. a/vbl A-l Project: MACARIO CANYON BRIDGE KEY TO LOGS Date Drilled: Type of Boring: Q 8a. to CO Blows/ftWater Depth: Measured: Type of Drill Rig: Hammer: Material Description |f o £* <n "oQ § a-Q h_ • s| Surface Elevation: °- 5- 10- 15- 20- - - 25- 30^ /. I I -^ -— - / ,/ •,N \-\/ s DISTURBED SAMPLE LOCATION Sample obtained by collecting auger cuttings in a plastic bag. LOCATION OF DRIVE SAMPLE OBTAINED WITH MODIFIED CALIFORNIA SAMPLER Sample with recorded blows per foot was obtained with a Modified California drive sampler (2" inside diameter, 2.5" outside diameter) lined with sample tubes. The sampler was driven into the soil at the bottom of the hole with a 1 40 pound hammer falling 30 inches. LOCATION OF DRIVE SAMPLE OBTAINED WITH STANDARD PENETRATION SAMPLER Sample with recorded blows per foot was obtained with a standard split spoon sampler (1.375" Inside diameter, 2" outside diameter). The sampler was driven into the soil at the bottom of the hole with a 140 pound hammer falling 30 inches and the sample placed in a plastic bag. Fill Sand Clay Silt Sand/Clay GS - Grain Size Distribution Analysis PI - Plasticity Index LL - Liquid Limit SDS - Slow Direct Shear Test DCS - Unconfined Compression Test CT - Consolidation Test Project NO: 8751 455R-SI02 Woodward-Clyde Consultants^ - •« Figure: A-1 Project: MACARIO CANYON BRIDGE Date Drilled: 4-5-88 Water Depth: 7" Type of Boring: 8" HSA Type of Drill Rig: CME 550 * see Key to Logs, Fig. A-1 j£H.i:<D 0 in<D 0. (0to Blows/ftLog of Boring No: 1 Measured: At time of drilling Hammer: 140 Ibs. at 30" drop Material Description MoistureContent,%^£*'<o "o Q g °- Q 5 *<"•B «6,2 Surface Elevation: Approximately 17' 0 - 5- 10- 15- 20- 25- 30^ 1-1 1-2 1-3 1-4 1-5 1-6 X II I I I I Push 18" 2 7 7 22* 19 22 Loose, moist to wet, light brown to light gray, silty medium to fine sand (SM) ALLUVIUM Loose, wet, very dark gray, very silty medium to fine sand with some clay (SM) ALLUVIUM Loose, wet, pale olive, clayey medium sand (SC) to silty sand (SM) ALLUVIUM "On rock Medium dense, wet, light gray, silty medium to fine sand (SM) ALLUVIUM Project NO: 8751 455R-SI02 Woodward-Clyde Consultants^ - - — — — . — - 31 20 22 87 109 106 GS GS GS GS Figure: A-2 Project: MACARIO CANYON BRIDGE '5-i: Q 30" 35- - 40- - 45- 50- 55- 60- 65^ 00CD Q. CO 1-8 1-9 1-10 1-11 1-12 1-13 1 I \/\ * s n Blows/ft21 20 22 837 5" 507 3" 100 Log of Boring No: 1 (Cont'd) Material Description (Continued) medium dense, wet, light gray, silty medium to fine sand (SM) ALLUVIUM Very dense, moist, pale olive, siity medium sand (SM) SANTIAGO FORMATION 'Bottom of Boring at 56 feet Project NO: 8751 455R-SI02 Woodward-Clyde Consultants^ - - - - - - 2 +s 22 17 &* U> 15"""^ C Q, 0)Q 104 114 -c to SDS Figure: A-3 Project: MACARIO CANYON BRIDGE Log of Boring No: 2 Date Drilled: 4-12-88 Water Depth: 42' Measured: At time of drilling Type of Boring: 30" bucket auger Type of Drill Rig: ED-45L Hammer: -- * see Key to Logs, Fig. A-1 Q o Q. 03 Blows/ftMaterial Description MoistureContent,%£•"</> t3 Q t__ « <D W-C (/) Surface Elevation: Approximately 56' 0 - 5- - 10- _ - 15- - 20- 25- 30^ 2-1 2-2 2-3 2-4 2-5 2-6 ^ z / 1_ 2 Very dense, moist, pale olive, very silty fine sand (SM) SANTIAGO FORMATION Contact attitude N21'W 10'S at 5.5' U Hard, olive, fat clay (CH) Contact attitude N25'W 6'S on a 5" layer of silt at 9' Contact attitude N25'W 4'S on a 5" layer of silt at 13.5' Very dense, moist, pale gray brown with light reddish brown mottles, silty fine sand (SM) SANTIAGO FORMATION Project NO: 8751 455R-SI02 Woodward-Clyde Consultants ^ - — - — _ - - " - — — - Figure: A-4 Project: MACARIO CANYON BRIDGE Log of Boring No: 2 (Cont'd) <B "*~ 30^ - 35- - 40- 45- - 50- 55- r r\ .bU 65^ CO CD "Q. co CO 2-7 2-8 2-9 2-10 2-11 2-12 2-13 2-14 2 7_ I 7 I I 7_ /Blows/ftMaterial Description \ \ '//, (Continued) very dense, moist, pale gray brown with light reddish brown mottles, silty fine sand (SM) SANTIAGO FORMATION Contact attitude N25'W 5'S on a irregular 6" layer of silt at 32.5' Very dense, moist, gray brown, silty fine sand (SM) with some discontinuous thin lenses of hard, dark brown, silty lean clay and very dense, fine sandy silt (ML) SANTIAGO FORMATION Contact attitude N25'W 6'S at 50' Very hard, moist, brown with olive brown mottles, silty lean clay (CL) SANTIAGO FORMATION Very dense, moist, gray brown, fine sandy silt (ML) SANTIAGO FORMATION Very hard, moist, olive brown, fat clay (CH) SANTIAGO FORMATION h very hard, moist, olive brown, silty lean clay (CL) " SANTIAGO FORMATION Bottom of Boring at 65 feet Project NO: 8751 455R-SI02 Woodward-Clyde Consultants^ - - — - — — - - - ;MoistureContent,%&* (rt O*™\ c o1~1 CD O CD »> Figure: A-5 Project: MACARIO CANYON BRIDGE Log of Boring No: 3 Date Drilled: 4-6-88 Water Depth: 8" Measured: At time of drilling Type of Boring: 8" HSA Type of Drill Rig: CME550 Hammer: 140 Ibs. at 30" drop * see Key to Logs, Fig. A-1 . CD "~ $ O. COCO *;01 0 CD Material Description 2 —•" '5 o °2 O s; Q c Q.CD Q w_ * CD £ 6 H Surface Elevation: Approximately 16' 0 _ - 5- w 10- - - _ 15- _ 20- " 25- _ 30^ 3-1 3-2 3-3 3-4 3-5 3-6 3-7 y_j ilLJ . ; i y ^ 1 1 I push 18" 1/18" 9 9 9 9 18 \ \s sX Xf SX Xy sX X^ sX Xf /X X X Xf Sx xf S s / Vxf SX X/ s s sx xy /X Xf f s sX X x xf SX X X Xf / X Xf Sx x x xf S X Xf /X Xf Sx xf Sx x f SX X^ sX X X X X X^ sX X^ sX X Vxf / X Xf SX Xf SX X/ /X X X Xf SX Xf SX X f SX Xf SX X/ sX Xf /X X/ s X Xj' SX Xy /X Xy sX X/ /X X^ /X X ^x x X X X X x x X X X X x x x x X XsX X jTx x X Xf /X Xf SX X f SX X/ sX X Loose, wet, gray brown, silty medium sand (SM) ""x^ ALLUVIUM ^ Loose, wet, gray, clayey fine to medium sand (SC) and sandy lean clay (CL) ALLUVIUM Firm, wet, dark gray, sandy lean clay (CL) and loose, wet, dark gray, very clayey fine sand (SC) ALLUVIUM Firm, wet, gray, sandy lean clay (CL) and loose, wet, gray, very clayey fine sand (SC) with some interlayers of gray. silty medium to fine sand (SM) ALLUVIUM Interbedded, loose, wet, light brown, poorly graded sand (SP) and medium dense, wet, mottled, light brown and light gray, clayey medium to fine sand (SC) and sandy clay (CL) ALLUVIUM Project NO: 8751 455R-SI02 Woodward-Clyde Consultants^ _ - — ~ — - - _ — _ — - ~" __ - «. 24 27 101 97 GS, LL=35 Pl=16 GS, LL=36 Pl=20 LL=35 Pl=19 CT Figure: A-6 Project: MACARIO CANYON BRIDGE _,_- Q 30" _ 35- ™ _ 40- 45- <H 50- - 55- 60- - - - 65^ to<D Q. ro CO 3-8 3-9 3-10 3-11 3-12 3-13 3-14 I - y ~ - I_ I I I , 7* o CD 10 13 35 18 16 6** Log of Boring No: 3 (Cont'd) Material Description x xS fX Xf fX Xf fX Xf fX Xf SX XfX X X X X XsX XsX XsX X x x X XsX X X X X X X X X X X X X X X XfX X X X X X X XsX X X X X X X Xy (Continued) interbedded, loose, wet, light brown, poorly graded sand (SP) and medium dense, wet, mottled, light brown and light gray, clayey medium to fine sand ALLUVIUM (SC) and sandy clay (CL) Medium dense, wet, light brown, silty medium sand (SM) and poorly graded sand (SP) ALLUVIUM _ With interbeds of mottled light brown and gray and light gray, silty fine sand (SM) and clayey sand (SC) \ F "Sand in sample liquified /Interbedded, medium dense, wet, dark / (SW) containing particles of dark gray gray, well graded sand \ claystone and siltstone, \ and dark gray, silty fine sand (SM), with layers of firm, wet, very dark gray, fat clay (CH) or dark gray, fine sandy lean clay (CL) ALLUVIUM Project NO: 8751455R-SI02 Woodward-Clyde Consultants^ - — - _ — — — ~ <D *J ^ §*- UJ rt .<£. c 3s O o20 19 si £•"</> t3Q C Q. Q 108 . • <D » -C to5,2 GS GS Figure: A-7 Project: MACARIO CANYON BRIDGE Log of Boring No: 3 (Cont'd) . <D *~Q 65^ - 70- 75- 80- 85- 90- 95- 100^ in "5. roCO 3-15 3-16 3-17 3-18 3-19 3-20 3-21 K I , V I I I £c/> 0 CD 18 16 19 13 13 20 24 Material Description x \f SX Xf SX Xf S X Xf SX Xf SX X\\s sX Xf SX Xf SX Xf SX Xf SX X^ s / sX Xf SX Xf SX Xf SX V^ sX Xf SX X^ sX X^ sX X^ sX X^ sX Xf S X X^ sX X f SX Xf S s s X X^ s s s s s s sX X/ s s sX Xf S / s s s s s s sX Xf /X X^ sX \f SX X^ sX X/ ss \^ sX Xf /, X X/ s s / s s, X X/ s (Continued) interbedded medium dense, wet, dark gray, well graded sand (SW) with layers of lean clay (CL) and fat clay (CH) ALLUVIUM ^ — Sample predominantly clayey ^ — Sample predominantly sandy Medium dense, wet, gray, silty medium sand (SM) with firm, gray, lean sandy clay (CL) ALLUVIUM Project NO: 8751 455R-SI02 Woodward-Clyde Consultants^ - - J - - - - ~- CD «_r ^ c 5 8 28 si 0>Q 99 o> <2-c to K LL=32 Pl=16 GS Figure: A-8 Project: MACARIO CANYON BRIDGE Log of Boring No: 3 (Cont'd) 0- ~0) 0 100 _ 105- 110- 115- 120- 125- 130- 135^ ina> a. nsCO 3-22 3-23 3-24 3-25 X I I F.Blows/ft17 17 99 SO/ 1.5" Material Description x x' fX X' fX X' fX X' fX Xf fX Xf SX X X X X Xf SX Xf f X X X Xf SX X X X \ X X X X Xf fX Xf S (Continued) medium dense, wet, gray, silty medium sand (SM) with firm, gray, lean sandy clay (CL) ALLUVIUM Dense, moist, gray to dark gray, clayey fine sand (SC) with many small dark gray, siltstone particles SANTIAGO FORMATDN Very dense, moist, olive gray, fine sandy silt (ML) SANTIAGO FORMATION Very dense, moist, pale olive gray, silty medium to fine sand (SM) SANTIAGO FORMATION Bottom of Boring at 120.5 feet Project NO: 8751 455R-SI02 Woodward-Clyde Consultants ^ - — -MoistureContent,%Q i_ * -C UJ GS Figure: A-9 Project: MACARIO CANYON BRIDGE Log of Boring No: 4 Date Drilled: 4-5-88 Water Depth: 4' Measured: At time of drilling Type of Boring: 8" HSA Type of Drill Rig: CME 550 Hammer: 1 40 Ibs. at 30" drop * see Key to Logs, Fig. A-1 _£-- Q CD CL CO vt 0m Material Description = 1to -j± S^is >,^- Q 5 ^2 5,2 Surface Elevation: Approximately 18' 0 ™ 5- 10- 15- ™ - 20- - 25- - _ 30^ 4-1 4-2 4-3 4-4 4-S*T \J 4-6 4-7 y ^L_ VA jyf\ i n V /\l I u I 10 10 10 8 181 O 30 54 //// V y/ //// s sX Xs sX Xs sX \s sX Xs sX Xs sX Xs sX Xs sX Xs sX X X X/• sX Xs sX Xs sX Xs sX Xs sX X X Xs sX Xs sX X/ sX X / s // V ty // V, V/Ay/y/ s. Moist, gray brown, clayey fine sand > ^X^. CM 1 S^*<^ FILL / Stiff, moist, dark gray brown, fine sandy lean clay (CL) porous SLOPEWASH Loose to medium dense, moist, gray brown, very clayey fine sand to sandy clay (SC/CL) ALLUVIUM Medium dense, moist, pale brown, very silty fine sand (SM) ALLUVIUM Stiff, wet, olive brown, fat clay (CH) highly brecciated WEATHERED SANTIAGO FORMATION Dense, moist, pale olive, very silty fine sand (SM) WEATHERED SANTIAGO FORMATION Hard, moist, pale olive to olive gray, lean to fat clay (CL-CH) WEATHERED SANTIAGO FORMATION Very dense, moist, olive , fine sandy silt (ML) WEATHERED SANTIAGO FORMATION Very hard, moist, olive brown, lean clay (CL) WEATHRED SANTIAGO FORMATION Very dense, moist, pale olive, silty medium sand (SM) with some reddish brown mottles and interbeds of olive, fine sandy silt (ML) SANTIAGO FORMATION Project NO: 8751455R-SI02 Woodward-Clyde Consultants 4r — 31 92 GS LL=41 Pl=26 GS LL=63 Pl=33 UCS= 1170PSF Figure: A-10 Project: MACARIO CANYON BRIDGE Log of Boring No: 4 (Cont'd) -C~a.~o> Q 30^ - 35- 40- 45- 50- 55- 60- 65^ CO CD Q. roCO 4-8 4-9 4-10 )( I X Blows/ft77 50/4" 50/3" Material Description (Continued) very dense, moist, pale olive, silty medium sand (SM) with some reddish brown mottles and interbeds of olive, fine sandy silt (ML) SANTIAGO FORMATION Bottom of Boring at 41 feet Project NO: 8751 455R-SI02 Woodward-Clyde Consultants^ - - — — -MoistureContent,%3^£" « t5 Q § °- Q k^ *<D co -C t)6^5 Fgure: A-11 Project: MACARIO CANYON BRIDGE Log of Boring No: 5 Date Drilled: 4-12-88 Water Depth: 45' Measured: At time of drilling Type of Boring: 30" bucket auger Type of Drill Rig: ED 45L Hammer: * see Key to Logs, Fig. A-1 0.— CD Q enCO Q. EroV) „ 5o CD Material Description CO »-" l|aR O O2 O - E^'tn t3 Q 5 ^>jC (/) 6£ Surface Elevation: Approximately 58' Q"" _ - _ - 5- 10- 15- 20- 25- 30^ 5-1 5-2 5-3 5-4 5-5 5-6 5-7 7 I ~L 7 1~ —,/ // % '// // Dense, moist, pale olive, silty fine sand (SM) with some clasts of dark olive claystoneSANTIAGO FORMATION Very hard, moist, olive, lean clay (CL) brecciated with some lime infilling SANTIAGO FORMATION Very dense, moist, pale olive gray, silty medium to fine sand (SM) SANTIAGO FORMATION Very dense, moist, olive brown, fine sandy silt (ML) SANTIAGO FORMATION Contact attitude N21 'W 5'S at 9.5' Very dense, moist, pale olive, silty medium to fine sand (SM) SANTIAGO FORMATION Contact attitude N45'W 9'S at 19' Firm to stiff, moist, olive brown, lean to fat clay (CL/CH) . SANTIAGO FORMATION Very hard, moist, olive brown with dusky red mottles, lean clay (CL) SANTIAGO FORMATION Very dense, moist, gray brown with dusky red mottles, very silty fine sand (SM) SANTIAGO FORMATION Project NO: 8751 455R-SI02 Woodward-Clyde Consultants^ _ - _ - — - LL=76 PI 40 Figure: A-1 2 Project: MACARIO CANYON BRIDGE <D "~ Q 30" — 35- - 40- 45- 50- 55- * 60- M •• 65^ 0> Q. (0co 5-8 5-9 2 7_ To 0m Log of Boring No: 5 (Cont'd) Material Description // (Continued) very dense, moist, gray brown with dusky red mottles, very silty fine sand (SM) SANTIAGO FORMATION Contact attitude N29KW 13'S at 64' Very hard, moist, olive brown, lean to fat clay (CL/CH) SANTIAGO FORMATION Project No: 8751455R-SI02 Woodward-Clyde Consultants ^ - — — - — —MoistureContent,%£*'tn "o^ C Q,<B Q >» * Figure: A-13 Project: MACARIO CANYON BRIDGE Log of Boring No: 5 (Cont'd) _cf 0) **~ Q 65^ 70- 75- 80- 85- 90- 95- 100^ ino> Q. (0 CO 5-9A 5-10 2 2 Blows/ftMaterial Description ' // l (Continued) very hard, moist, olive brown, lean to fat clay (CL/CH), NS^ SANTIAGO FORMATION / Very hard, moist, brown with olive brown mottles, lean clay (CL) SANTIAGO FORMATION Bottom of Boring at 72 feet Project NO: 8751 455R-SI02 Woodward-Clyde Consultants^ - — - — — -MoistureContent,%e~\ c. Q.<DQ <D £> 6° Figure: A-^H Project: MACARIO CANYON BRIDGE Log of Boring No: 6 Date Drilled: 4-28-88 Water Depth: 4' Measured: At time of drilling Type of Boring: 4.875" Rotary Type of Drill Rig: Mayhew 1 000 Hammer: 1 40 Ibs. at 30" drop * see Key to Logs, Fig. A-1 j£ CD "~ Q COCD Q. EcoC/3 0 5- - - 10- - 1 KI O 20- 30^" 6-1 6-2 6-3 6-4 6-5 6-6 6-7 6-8 6-9 6-10 Blows/ftMaterial Description MoistureContent,%Q 5 .2 f^ (/) Surface Elevation: Approximately 18' 3 9 5 8 4 L ' 11 9 10 21 7 - X X X X X X X X Moist, pale gray brown, clayey fine sand FILL Loose, moist, pale brown, poorly graded sand (SP) with some thin layers (up to 2") of gray, fine sandy lean clay (CL) ALLUVIUM Loose, wet, mottled dark gray brown, very clayey medium to fine sand (SC) and light brown, silty medium to fine sand (SM) with occasional layers of lean clay (CL) ALLUVIUM Fat clay (CH) 10.5' to 11. 5' Loose, wet, gray with some dark green mottles, clayey medium to fine sand (SC) ALLUVIUM Loose, wet, gray, silty medium and fine silty sand (SM) ALLUVIUM Loose to medium dense, wet, light brown, poorly graded sand . and silty medium to fine sand (SC-SM) . \ ALLUVIUM / Loose, wet, gray to gray brown, slightly to very clayey medium to fine sand (SC) and sandy lean clay (CL) ALLUVIUM Project NO: 8751 455R-SI02 Woodward-Clyde Consultants^ - - - - — - 6 26 39 10 31 99 82 GS GS, LL=25 Pl=7 LL=30 Pl=18 GS GS, LL=35 Pl=19 UCS= 865 psf Fgure: A-15" D Project: MACARIO CANYON BRIDGE Log of Boring No: 6 (Cont'd) . a. ~<DQ 30"- ~ 35- - - 40- - 50- 55- c noO p cDO v tnCD "5. Ero 6-11 6-12 6-13 6-14 6-15 6-16 6-17 6-18 6-19 6-20 6-21 6-22 5CO o m 10 19 14 24 16 14 22 38 21 55/3 62/ 3.5" 75/6 Material Description X Xt sX XsX XsX XsX XsX X f SX X^ sX Xf SX Xf S y\ X Xf SX Xf S X Xf SX Xf SX Xf SX X '// /// //• ^ (Continued) loose, wet, gray to gray brown, slightly to very clayey medium to fine sand (SC) and sandy lean clay (CL) ALLUVIUM Medium dense, wet, gray brown with some dark reddish brown mottles, clayey medium to fine sand (SC) ALLUVIUM Medium dense, wet, brown, slightly silty to poorly graded sand (SM/SP) with some very clayey medium to fine sand (SC) ALLUVIUM Medium dense to firm, wet, gray brown to gray, very clayey medium to fine sand (SC) and sandy lean clay (CL) with interbeds (up to 8") of brown, silty to poorly graded sand (SM/SP) ALLUVIUM Medium dense, wet, light gray with some light yellowish brown mottles, silty medium to fine sand (SM) ALLUVIUM Stiff, wet, gray to olive gray, fine sandy to silty lean to fat clay (CL/CH) with some zones of clayey sand (SC) ALLUVIUM Very dense, moist, olive gray, very fine sandy silt (ML) SANTIAGO FORMATION Very dense, wet, pale olive gray, silty fine sand (SM) SANTIAGO FORMATION Bottom or Bormq at 64.5 feet Project NO: 8751 455R-SI02 Woodward-Clyde Consultants^ - ~ — - - — - - D «-." 5 o2 O 23 21 si ^ <n "o 0) Q 103 106 <D CO -C «6£ GS, LL=24 Pl=7 GS GS LL=42 Pl=25 Figure: A-16 D Project: MACARIO CANYON BRIDGE Log of Boring No: 7 Date Drilled: 9-28-88 Water Depth: 7' Measured: At time of drilling Type of Boring: 4.875" Rotary Type of Drill Rig: Mayhew 1000 Hammer: 1 40 Ibs. at 30" drop * see Key to Logs, Fig. A-1 CO0> Q.e 03CO ^^ ^CO o m Material Description 0) ~ii* O o2 0 . £•"« "o Q OJ W -C CO H Surface Elevation: Approximately 20' o" 5- - 10- 15- 20- 25- o r\30^ 7-1 7-2 7-3 7-4 7-5 7-6 7-7 7-8 7-9 K K I I J •^T IJ_ i) r ^_ y/> 11 7 10 14 18 14 13 10 12 iX X X X X Xf SX XX / s /X Xjf S / /X X^ /XX /X XX XXf SxX /X XX XX^ s s s X^ s\.s s\.s /\s sXf SX^ s s s s s s s X^ sXf S\.s sx^ sXf SX/ fX/ s\. Moist, pale gray, silty sand with some zones of fine sandy clay FILL Moist, pale brown, silty sand and pale gray, clayey sand with some zones of dark brown, sandy lean clay FILL Wet, dark gray, poorly graded gravel (crushed rock) FILL Filter fabric at contact Soft to firm, wet, dark gray, silty to fine sandy lean to fat clay (CL/CH) ALLUVIUM Medium dense, wet, gray to dark gray with brown mottles, clayey medium to fine sand (SC) and lean sandy clay (CL) ALLUVIUM Medium dense, wet, light brown, silty sand (SM) and poorly graded sand (SP) ALLUVIUM Project NO: 8751 455R-SI02 Woodward-Clyde Consultants^ - - - - - 24 20 108 LL=32 Pl=19 GS Figure: A-1 7 Project: MACARIO CANYON BRIDGE Log of Boring No: 7 (Cont'd) <D "~Q 30" - 35- 40- 45- - 50- 55- 60- 65X in<D"5. ra CO 7-10 7-11 7-12 7-13 7-14 Blows/ft29 50/6" 55/2" 55/3" 85/6 Material Description (Continued) medium dense, wet, light brown, silty sand (SM) and poorly graded sand (SP) ^^ ALLUVIUM ^ Medium dense, wet, gray brown with reddish brown zones, clayey sand (SC) and silty sand (SM) \ ALLUVIUM ^^ Very dense, wet, pale gray, silty fine sand (SM) SANTIAGO FORMATION Bottom of Boring at 55.5 feet Project NO: 8751 455R-SI02 Woodward-Clyde Consultants^ - — — — - <s _- ^ C 5 o2 O ^ C O<DQ J__ * -C (/) Fgure: A-1 8 Woodward-Clyde Consultants Project No. 8751455R-SI02 APPENDIX B LABORATORY TESTS The materials observed in the borings were visually classified and evaluated with respect to strength, swelling, and compressibility characteristics; dry density; and moisture content. The classifications were substantiated by performing grain size analyses and evaluating plasticity characteristics of representative samples of the soils. The strength of the soils was evaluated by performing unconfined compression tests and a direct shear test on selected samples, and by considering the density and moisture content of the samples and the penetration resistance of the sampler. Compressibility characteristics were evaluated by performing consolidation tests. Soil corrosivity was evaluated by a pH and resistivity tests. The results of the moisture content and the dry density tests on drive samples, are shown with the penetration resistance of the sampler at the corresponding sample location on the logs, Figure A-2 through A-19. The grain size distribution curves and plasticity index test results are shown in Figure B-l through B-4 and B-7 through B-9. The results of the direct shear test are presented in Figure B-5. The ,-, results of the consolidation tests are reported in Figure B-6 and in Figures B-10 and B-l 1. Results of the corrosivity test as submitted to us by Clarkson Laboratory and Supply, Inc. L-' are shown in Figure B-12. a/vbl B-l UNIFIED SOIL CLASSIFICATION COBBLES GRAVEL COARSE FINE U.3. tUKVK SIZE IN INCHES SAND COARSE] MEDIUM FINE U.3. STANDARD SEVE No. SILT OR CLAY HYDROMETER 100 3/4 3/8 4 10 20 40 80 14O 200 0 20 O fe CJ 5 CO%o< woPC:wPL, ffi woKW 20 100 GRAIN SIZE IN MILLIMETER SYMBOL BORING O 1-2 n 1-3-4 A 1-4 0 1-6-4 Remark : DEPTH(ft) (SBJ DESCRIPTION SILTY FINE SAND (SM) SILTY FINE SAND (SM) SILTY FINE SAND (SM) SILTY FINE SAND (SM) 87551455R S101 MACAR10 CANYON BRIDGE Woodward Clyde Consultants San Diego, CA GRAIN SIZE DISTRIBUTION Figure NO. B i c UNIFIED SOIL CLASSIFICATION COBBLES GRAVEL COARSE 1 FINE U.S. SIEVE SIZE IN INCHES SAND CtMRSEJ MEDIUM FINE U.3. STANDARD SffiVE No. S/£7* Q/J CLAr HYDBOHETBR 100 20 40 60 14O 200 10s 10 10 1 1(T GRAIN SIZE IN MILLIMETER SYMBOL BORING O 3-2-4 D 3-4-4 A 3-8-4 0 3-11-4 Remark : DEPTH (ft) J*J 35 36 fc) DESCRIPTION 16 FINE SANDY CLAY (CL) 20 CLAYEY FINE SAND (SC) SILFY FINE SAND (SM) SIL7Y FINE SAND (SM) 0 8751455R SI01 MACARIO CANYON BRIDGE Woodward Clyde Consultants San Diego, CA GRAIN SIZE DISTRIBUTION AND PLASTICITY INDEX Figure No. B-2 UNIFIED SOIL CLASSIFIC COBBLES GRAVEL COARSE | FINE U.S. ausYK SIZE IN INCHES SAND CtMRSEJ MEDIUM FINE U.3. STANDARD SEVE No. S/£r 072 CL4r HYDBOMETER 100 3/4 3/8 4 10 80 40 80 140 200 80 « 60 CO 40 o 20 0 103 SYMBOL BORING O 3-19-4 D 3-22-4 5-6 10'10 1 KT1 GRAIN SIZE IN MILLIMETER 3-15-3 4-6-3 DEPTH(ft) (*J 76 35 32 63 DESCRIPTION SILTY FINE SAND (SM) SILTY FINE SAND (SM) 40 19 16 33 Remark : ICT £ W CU 100 875U55R SI01 MACAR10 CANYON BRIDGE Woodirard Clyde Consultants San Diego, CA GRAINSIZE DISTRIBUTION AND PLASTICITY INDEX Figure No. B-3 UNIFIED SOIL CLASSIFICATION COBBLES GRAVEL COARSE | FINE U.S. SIEVE SIZE IN INCHES SAND COWSEJ MEDIUM FINE U.S. STANDARD SIEVE No. SILT OR CLAY HYDROMETER 100 O CO<! DH gwo«w(X, 3/4 3/8 4 10 20 40 60 140 200 T^t GHTD BYRETPERCEM>ooGRAIN SIZE IN MILLIMETER SYMBOL BORING O 4-2-4 D 4-4 DESCRIPTION 41 26 FINE SANDY LEAN CLAY (CL) SILT WFTH FINE SAND (ML) Remark ; 87551455R SI01 MACARIO CANYON BRIDGE Woodward Clyde Consultants San Diego, CA GRAIN SIZE DISTRIBUTION Figure No. B-4 r r 5 CO gK 62 28 10.0 5.0 .0 5.0 10.0 15.0 NORMAL STRESS IN KSF 20.0 25.0 10.0 (72 CO 5.0 4fi r-i H o oc .00 .06 .12 .18 .24 HORIZONTAL DEFORMATION IN INCH .30 DEPTH (ft)BORING/SAMPLE : 1-12-4 DESCRIPTION : SUY SAND (SM) STRENGTH INTERCEPT (C) : 1.411 KSF FRICTION ANGLE (PHI) : 47.8 DEC f oTOFK,rTHN (PEAK STRENGTH^ SYMBOL O D MOISTURE CONTENT (s) 14.9 15.2 DRY DENSITY VOID (pet) RATIO 118.4 .396 118.1 .400 NORMAL PEAK STRESS (leaf) SHEAR (kef) 2.00 4.00 3.62 5.82 RESIDUAL SHEAR (kal) 1.93 4.15 Remark : 8751455R SI01 MARCARIO CANYON BRIDGE Woodward Clyde Consultants San Diego, CA DIRECT SHEAE TEST Figure NO. B 5 CONSOLIDAIOrURAPH X axis:Log of Pressure,tsf; Y axis:Uoid Ratio, e (.35. S.2& S.17. S.07. 5.93. s.8* 5.7* 5.70. 5.60. 5.51. 5.32. -S.32 — ' - 1 - 1 - 1 - 1 - 1 - 1 - 1-5.2S -3. €7 -2.01 -0.11 1 - 1 - 1 - 1 - 1 - 1 - 1.22 2.85 1.18 f.ll 10,-1 Sample 3-5-4 INITIAL DRY DENSITY, pcf INITIAL WATER CONTENT, % INITIAL SATURATION, % FINAL DRY DENSITY, pcf FINAL WATER CONTENT, % FINAL SATURATION, % 102 24 97 109 21 100+ SPECIFIC GRAVITY OF SOLIDS INITIAL VOID RATIO, 60 COMPRESSION INDEX. Cr SWELL INDEX, C,. EFFECTIVE OVERBURDEN PRESS, P'0, tsf MAX. PAST PRESSURE, Pc, tsf 2.69 0.6-5 0.14 0.5 CONSOLIDATION TEST MACARIO CANYON BRIDGE DRAWN BY: cfa | CHECKED BY: | PROJECT NO: 8751455R-SI01 | PATE: 9-7-83 j FIGURE NO: B-6 WOODWARD-CLYDE CONSULTANTS UNIFIED SOIL CLASSIFICATION COBBLES GRAVEL COARSE FINE U.S. SIEVE SEE IN INCHES SAND COARSE MEDIUM FINE U.S. STANDARD SIEVE No. SILT OR CLAY HYDROMETER 100 3/4 3/8 4 10 30 40 60 14O 200 0 1CP GRAIN SIZE IN MILLIMETER SYMBOL BORING O D A 6-2-3 6-2-4 6-3 6-7 25 DESCRIPTION SILTY FINE SAND (SM) POORLY GRADED FINE SAND WITH SILT (SP-SM) 7 CLAYEY FINE SAND (SC) CLAYEY FINE SAND (SC) Remark : 8751455R SI02 MACARIO CANYON BRIDGE Woodward Clyde Consultants San Diego, CA GKAIN SIZE DISTRIBUTION Figure NO.B-7 UNIFIED SOIL CLASSIFICATION COBBLES GRAVEL COARSE | FINE U.S. SIEVE SEE IN INCHES COARSE U.S. SAND MEDIUM | FINE STANDARD SIEVE No. SILT OR CLAY HYDROMETER 100 3/4 3/8 4 10 20 40 60 140 200 « 60 to<3P-, uKwPL, 20 0 10' SYMBOL BORING O 6-8-3 D 6-12-2 A 6-14-4 0 6-16-3 Remark : 10 10 1 10"1 GRAIN SIZE IN MILLIMETER LL PI fit) 60 DESCRIPTION 35 19 CLAYEY FINE SAND (SC) 24- 7 SILJY CLAYEY FINE SAND (SC-SM) SILTY.CLAYEY RNE SAND (SC-SM) CLAYEY FINE SAND (SC) 0 E-a QW Z I WoKW PH 100 icr3 8751455R SI02 MACARIO CANYON BRIDGE Woodward Clyde Consultants San Diego, CA GRAIN SIZE DISTRIBUTION Figure NO. B-a UNIFIED SOIL CLASSIFICATION 100 80 t-£0t— 1 « 60 »•— 4CO S30. £ 40 o04 PL, 20 0 1 SYMBC O Rem rnaar pc1 GRAVEL COARSE FINE U.3. SIEVE SIZE IN INCHES 3 3/4 3/8 4 o* 10 )L BORING 7-9-4 ark : 2 D SAND COARSE MEDIUM FINE U.S. STANDARD SIEVE No. 10 2O 40 60 14O 2x-\ ^t Y\ \ \1 \(i S/X7* 07? CLAY HYDROMETER 00 >V\,^-e-H* QD O) *^ N OO O O O OOPERCENT RETAINED BY WEIGHT10 i icr' I'CT^ icr3 GRAIN SIZE IN MILLIMETER EPTH LL PI(ft) OO (*) DESCRIPTION CLAYEY FINE SAND <SC) \ 8751455R SI02 Woodward Clyde Consultants San Diego, CA MACAR10 CANYON BRIDGE GRAIN SIZE DISTRIBUTION Figure NO. B-9 10 4 E- ffi W ffi 5 8w 0 E- O 20 Comp Spec Reir COMPRESSIVE STRESS 1 \ > \\ \V \ IN ^\ KSF 10 ( ^\ BORING : 6-4-4 DESCRIPTION DEPTH (ft) : LIQUID LIMIT SPEC. GRAVITY : 2.80 PLASTIC LIMIT MOISTURE DRY DENSITY CONTENT («) (pcf) INITIAL 38.7 81.6 FINAL 28.7 97.0 ression Index, Cc = 0.39 ific Gravity of Solids = 2.75 iark : 8751455R SI02 WOODWARD-CLYDE CONSULTANTS SAN DIEGO \\\\ : FAT CLAY (CH) PERCENT SATURATION 95 100 10 2 1 I 1.146 . 1.060 . _ .976 O 1 Q1— «0 . . .889 > - .803 .717 VOID RATIO 1.146 .806 MACARIO CANYON BRIDGE CONSOLIDATION TEST Figure NO. B-IO COMPRESSIVE STRESS IN KSF CHANGE IN HEIGHT*». to oi-*^ 6 o wa, 8 10 •c-I o^•- ."-•N. > ^s 1 t \ \ 10 1 \ ^V\,\\\\\v\> 10 2 _i_J .590 BORING : 7-7-4 DESCRIPTION : CLAYEY SAND (SC) .558 .528 O 1 0 O .494 > .462 .431 DEPTH (ft) : UQUID LIMIT : 32 SPEC. GRAVITY : 2.75 PLASTIC LIMIT : 13 MOISTURE DRY DENSITY PERCENT VOID INITIAL CONTENT (*) 20.0 (pcf) 108.0 SATURATION 94 RATIO .590 FINAL 16.8 117.4 100 .463 Compression Index, Cc = 0.19 Specific Gravity of Solids = 2.67 Remark : 87514585R SI02 WOODWARD-CLYDE CONSULTANTS SAN DIEGO MACAR10 CANYON BRIDGE CONSOLIDATION TEST Figure NO. B-II LABORATORY REPORT Telephone (619) 425-1993 Established 1928 CLARKSON LABORATORY AND SUPPLY INC. 350 Trousdale Dr. Chula Vista, Ca. 92010 ANALYTICAL AND CONSULTING CHEMISTS Date: 10-10-88 Purchase Order Number: Job Number 8751455R SI02 Account Nuirber: WOOX To: Woodward Clyde 1550 Hotel Circle North, Suite 200 San Diego, CA. 92108 Laboratory Number: S02045 Customers Phone No: 224-2911 Sample Designation:* * One soil sample from Macoria Canyon Bridge Job Number 8751455R SI02 mix of boring 7. ANALYSIS: By Test Method No. Calif. 643-C October 2, 1972 State of California Department of Public Works Division of Highways Materials and Research Department Method for Estimating the Service Life of Metal Culverts. SAMPLE pH 7.8 Water Added (ml) Resistivity (ohm-cm) 100 12640 50 8530 50 2720 50 1200 50 850 50 820 50 920 50 1010 The above results indicate 28 years to perforation for a 16 gauge metal culvert, and 51 years to perforation for a 12 gauge. Water Soluble Sulfate 0.02 % Figure B-12 Wood ward-Clyde Consultants Project No. 8751455R-SI02 ATTACHMENT 1 LOGS OF TEST BORINGS SHEET a/vbl