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Home My WebLink About3190; Rancho Santa Fe Bridge Crossing/ San Marcos Ck; Rancho Santa Fe Bridge Crossing/ San Marcos Ck; 1990-09-01BRIDGE FOUNDATION INVESTIGATION FOR RANCHO SAOTA FE ROAD REALIGNMENT RANCHO SANTA FE BRIDGE CROSSING AT SAN MARCOS CREEK CARLSBAD, CALIFORNIA PREPARED FOR THE HELDSTONE COMPANY SAN DIEGO, CALIFORNIA PREPARED BY GEOCON INCORPORATED SAN DIEGO, CALIFORNIA SEPTEMBER 1990 GEOCON INCORPORATED ^ Geotechnical Engineers and Engineering Geologists File No. 04367-05-03 September 13, 1990 The Fieldstone Company 5465 Morehouse Drive, Suite 250 San Diego, California 92121 Attention: Mr. John Barone Subject: RANCHO SANTA FE ROAD REALIGNMENT RANCHO SANTA FE BRIDGE CROSSING AT SAN MARCOS CREEK CARLSBAD, CALIFORNIA BRIDGE FOUNDATION INVESTIGATION Gentlemen: In accordance with your request, we are pleased to submit the accompanying report which presents the results of our foundation investigation for the proposed Rancho Santa Fe Road bridge crossing at San Marcos Creek in Carlsbad, California. It is understood this study will be used to facilitate the design and analysis for the proposed bridge. This report presents our conclusions and recommendations pertaining to the geotechnical aspects ofthe proposed bridge construction, as well as a review of the field data upon which they are based. If you have any questions, or if we may be of further service, please contact the undersigned at your convenience. Very truly yours, GEOCON INCORPORATED Weslej^Spang Georg^ C. CopenhaveijQ/^ Steve J. Greenfield RCE 38789 CEG 86 Staff Engineer SJG:GCC:WS:dmc (2) addressee (2) McDaniel Engineering Attention: Mr. Mark Creveling (5) Project Design Consultants Attention: Ms. Karen Kossup 6960 Flanders Drive San Diego, CA 92121-2974 619 558-6900 FAX 619 558-6159. TABLE OF CONTENTS PURPOSE AND SCOPE 1 SITE AND PROJECT DESCRIPTION 2 Proposed Development 3 SOIL AND GEOLOGIC CONDITIONS 3 General '^ Description of Geologic Units 4 Alluvium (Qal) 4 Bonsall Tonalite (Kgr) 4 Groundwater ^ Faulting and Seismicity 5 Liquefaction Potential 6 Landsliding g Rippability 'y CONCLUSIONS AND RECOMMENDATIONS 8 General ' ' g Grading 8 Slope Stability // JQ Soil and Excavation Characteristics n Foundations n Abutn^ent Walls and Lateral Loads 13 Seismicity Analysis Parameters 14 Site Drainage and Moisture Protection Yr 14 Grading and Foundation Plan Review 15 LIMITATIONS AND UNIFORMITY OF CONDITIONS LIST OF MAPS AND ILLUSTRATIONS Figure 1, Vicinity Map Figure 2, Geologic Map (Map Pocket) APPENDIX A FIELD INVESTIGATION Figures A-1 - A-5, Logs of Test Borings Figures A-6 - A-9, Logs of Previous Test Borings (File No. D-4367-402) Figures A-10 - A-11, Logs of Test Trenches Figures A-12 - A-19, Logs of Air Track Borings APPENDIX B PREVIOUS LABORATORY TESTING Table B-I, Summary of Laboratory Compaction Test Results Table B-II, Summary of In-PIace Moisture-Density and Direct Shear Test Results Figure B-1, Consolidation Curve APPENDIX C RECOMMENDED GRADING SPECIFICATIONS File No. 04367-05-03 September 13, 1990 BRIDGE FOUNDATION INVESTIGATION PURPOSE AND SCOPE The purpose of this foundation investigation is to provide geotechnical information and design criteria for the proposed development of the Rancho Santa Fe Road Bridge crossing at San Marcos Creek in Carlsbad, California (see Vicinity Map, Figure 1) The results of our study are presented herein along with a discussion of the potential geotechnical constraints and preliminary recommendations regarding the geotechnical aspects of project design. The scope of our services consisted of a site reconnaissance by an engineering geologist to define the geologic features within the property and a review of geotechnical reports and information relative to the site, including the following: o Supplemental Soil and Geologic Investigation for Rancho Santa Fe Road Realignment, prepared by Geocon Incorporated, dated January 8, 1990. o Unpublished reports, aerial photographs and maps on file with our firm. The field work consisted of a site reconnaissance as discussed above, excavation of 2 exploratory trenches, 5 small-diameter borings and 8 air track borings. Additionally, data obtained from the excavation of 4 small-diameter borings excavated in the vicinity of the bridge during the Supplemental Soil and Geologic Investigation for Rancho Santa Fe Road Realignment were reviewed and incorporated within this report. Laboratory tests were performed previously on samples from the above referenced supplemental report to assess pertinent physical characteristics of subsurface soil and rock conditions encountered. The current field exploration program was limited to certain portions of the site due to the - 1 - File No. 04367-05-03 September 13, 1990 BRIDGE FOUNDATION INVESTIGATION PURPOSE AND SCOPE The purpose of this foundation investigation is to provide geotechnical information and design criteria for the proposed development of the Rancho Santa Fe Road Bridge crossing at San Marcos Creek in Carlsbad, Califomia (see Vicinity Map, Figure 1) The results of our study are presented herein along with a discussion of the potential geotechnical constraints and preliminary recommendations regarding the geotechnical aspects of project design. The scope of our services consisted of a site reconnaissance by an engineering geologist to define the geologic features within the property and a review of geotechnical reports and information relative to the site, including the following: o Supplemental Soil and Geologic Investigation for Rancho Santa Fe Road Realignment, prepared by Geocon Incorporated, dated January 8, 1990. o Unpublished reports, aerial photographs and maps on file with our firm. The field work consisted of a site reconnaissance as discussed above, excavation of 2 exploratory trenches, 5 small-diameter borings and 8 air track borings. Additionally, data obtained from the excavation of 4 small-diameter borings excavated in the vicinity of the bridge during the Supplemental Soil and Geologic Investigation for Rancho Santa Fe Road Realignment were reviewed and incorporated within this report. Laboratory tests were performed previously on samples from the above referenced supplemental report to assess pertinent physical characteristics of subsurface soil and rock conditions encountered. The current field exploration program was limited to certain portions of the site due to the File No. 04367-05-03 September 13, 1990 presence of a protected riparian habitat. The assessment of the geologic conditions of the site and the conclusions in this report are based upon this limited accessibility and subsequent investigation. It is possible that site conditions encountered during construction within areas inaccessible for investigation may differ significantly than those outlined in this report. Details of the field exploration and laboratory testing programs are presented in Appendixes A and B, respectively. SITE AND PROJECT DESCRIPTION The proposed bridge will be located at the northem terminus of the Rancho Santa Fe Road Realignment project, immediately south of La Costa Meadows Drive in Carlsbad, California. A review of preliminary project plans prepared by Project Design Consultants, dated June 18,1990, and by McDaniel Engineering, undated, indicates that Rancho Santa Fe Road will pass over San Marcos Creek and be supported by abutments at the northern and southem approach embankments and by two bridge bents located between the abutments. The bridge will initially accommodate six lanes of traffic with an ultimate capacity of eight lanes of traffic. Discussions with the project structural engineer indicate that the maximum bent column loads will be approximately 800 kips with abutment loads of approxi- mately 3,200 kips. It is anticipated that the southern abutment and the bridge bents will be supported on spread or continuous footings and that the northem abutment will be supported on driven piling. The proposed bridge is located within the San Marcos Creek channel and the adjacent channel embankments. The channel is a heavily vegetated, marshy, riparian habitat. The existing riparian habitat limited access to the site, particularly within the southern portion File No. 04367-05-03 September 13, 1990 of San Marcos Creek. A granitic knob is located to the southwest of the bridge site, the southem bridge abutment will be located on the northeast flank of this knob. Elevations at the site range from approximately 360 feet Mean Sea Level (MSL) at the southern abutment location to approximately 325 feet MSL in the bottom of the creek channel. The existing elevation of the proposed location of the northern abutment is approximately 330 feet MSL. Proposed Development It is our understanding that proposed development will consist of cuts and fills at the channel embankments with cut and fill slopes inclined at 2:1 (horizontahvertical). The southem bridge embankment will require a cut into formational soils to achieve design grade with a 2:1 cut slope to be excavated to the southwest of the bridge. The two center bents of the bridge will consist of four concrete columns spaced approximately 30 feet apart center to center. The bents are skewed relative to the axis of the bridge alignment and are thus aligned with the San Marcos Creek channel at the crossing location. The bridge will consist of CIP/PS Box Girder construction. The northern bridge approach embankment will consist of the placement of 15 feet of fill soils above existing grade. SOIL AND GEOLOGIC CONDITIONS General One geologic formation and one surficial soil type were encountered during the foundation investigation. The geologic formation consists of Cretaceous-aged Bonsall Tonalite. The surficial soil deposit consists of aUuvium. Each of these units is discussed below in order of increasing age and is depicted on Figure 2, Geologic Map (map pocket). File No. 04367-05-03 September 13, 1990 Description of Geologic Units AUuvium (Qal). Alluvial soils were encountered at the surface within the majority of the low-lying portions of the site including the northern channel embankment and within the San Marcos Creek channel. The alluvial soils are characterized by loose to moderately dense, moist to saturated, dark brown silty and clayey sands with some gravel and cobble. The thickness of the alluvium encountered within the current and previous exploratory excavations ranged from approximately 4 to 10 feet. All of the exploratory borings excavated with the hand-held power auger encountered refusal on gravels and cobbles within the alluvium. No borings were excavated within the vicinity of Bent No. 2, due to the riparian habitat. Bonsall Tonalite (Kgr). Cretaceous-aged granitic rock correlated to the Bonsall Tonalite of the Southem Califomia Batholith comprises the bedrock material underlying the site. The weathered granitic rock is characterized by a dense to very dense, light brown, weathered to highly weathered Bonsall Tonalite that excavates to a fine- to coarse-grained sand with gravel and cobble size fragments. The granitic rock is exposed at the proposed southem bridge abutment location. In the river channel, the depth to the weathered granitic rock is 5 to 10 feet from the existing ground surface. It is not uncommon for granitic rock to weather to an uneven erosional surface resulting in "pinnacles" and "knobs" being located at shallow depths below the ground surface. Hence, the depth to granitic rock should be anticipated to vary throughout the site. Proposed cut slopes within granitic rock are planned with heights on the order of 20 feet. The stability of cut slopes within granitic rock are controlled by the direction and spacing FHe No. 04367-05-03 September 13, 1990 of joints and fractures. However, no adverse major joint or fracture pattems adversely oriented with respect to the stability of the proposed cut slope on the southwest end ofthe bridge were observed. Based on previous experience with similar conditions, it is anticipated that the decomposed granitic bedrock has moderate- to high-shear strength and "low" ex- pansive potential. Rippability, as interpreted from the results of the air track borings, will be presented in a following section. Groundwater Groundwater was present at a depth of approximately 2 feet below the ground surface in the San Marcos Creek channel. It is anticipated that footing elevations for Bent Nos. 2 and 3 could be as deep as 12 feet or more below the ground surface. Dewatering during construction wiU likely be necessary to facilitate the foundation excavations and permit the foundations to be constructed in a dry environment. Well points or other dewatering methods should be installed by the contractor to insure that all of the excavations remain free of standing water throughout construction. Faulting and Seismicity It is our opinion, based on the site reconnaissance, evidence obtained in the exploratory excavations and a review of published geologic maps and reports, that the site is not located on any known active fault trace. Ancient faults described in preceding reports were encountered entirely within Jurassic-aged formations, so the potential for movement of these faults is considered very low to nonexistent. File No. 04367-05-03 September 13, 1990 Recent offshore seismic activity has demonstrated that small magnitude earthquakes can be generated by the offshore faults. The offshore faults and the Elsinore Fault are the closest active faults to the site, being located approximately 20 and 25 miles to the southwest and northeast, respectively. The probability of the Carlsbad area experiencing a locally generated Magnitude 6.5 or greater earthquake would appear to be low based on present knowledge. Earthquakes less than Magnitude 4 have been common to the San Diego region. Additional information regarding site seismicity is presented hereinafter in the Conclusions and Recommendations section. Liquefaction Potential Due to the dense nature of the underlying granitic rock, it is our opinion that the potential for liquefaction within the formational soils is very low. The potential for liquefaction to occur in the saturated alluvial soils is low to moderate. The placement of fill soils for the northern bridge embankment wiU reduce the potential for liquefaction of the alluvial soils beneath this embankment. The remaining bridge foundations will be founded in dense formational soils per the recommendations of this report and should not be affected by the liquefaction of overlying alluvial soils. Landsliding No landslides were identified on or adjacent to the proposed bridge site and it is not likely that any will be encountered during the proposed earthwork construction. - 6 - File No. 04367-05-03 September 13, 1990 Rippability A review of the Rancho Santa Fe Road Mass Grading Diagram, prepared by Project Design Consultants, indicates that portions of the southern bridge abutment will be cut to achieve design grade and that a 2:1 cut slope will be excavated to the southwest of the bridge. Eight hydraulic air track borings were excavated to assess the rippability of and depth to dense formational soils. Two of the air track borings were excavated within the area of the proposed cut slope. The logs of the air track borings are located in Appendix A, Figures A-12 through A-19. The rippability terms used in the following discussions are approximately correlated to a D-9L or D-9N Caterpillar tractor equipped with a single shank ripper. For purposes of this investigation rippable conditions were assumed for air track drilling rates equal or less than 15 seconds/foot, marginally rippable conditions for rates between 15 and 30 seconds/foot and non-rippable conditions for rates greater than 30 seconds/foot. The air track borings in the vicinity of the proposed cut encountered generally rippable conditions with isolated regions of marginally rippable formational soils. It is our opinion, based on previous experience^ that marginally rippable granitic rock materials do not require blasting for their excavation. Isolated depths in the cut areas may require additional effort, however, blasting should not generally be required for the bridge construction. -7- File No. 04367-05-03 September 13, 1990 CONCLUSIONS AND RECOMMENDATIONS General 1. It is our opinion that no geologic hazards or significantly adverse soil conditions were encountered within the general bridge location area that would preclude the construc- tion of the bridge and associated improvements, provided the recommendations of this report are followed. The site is underlain by alluvial soils overlying granitic rock. The granitic rock outcrops south of the southem embankment of the San Marcos Creek. It is recommended that the bridge foundations be founded within granitic rock. 3. It is recommended that a scour depth of 10 feet (estimated maximum thickness of alluvium) be utilized for project design. Grading 4. All grading should be performed in accordance with the attached Recommended Grading Specifications, (Appendix C). Where the recommendations of this section conflict with Appendix C, the recommendations of this section take precedence. All earthwork should be observed and all fills tested for proper compaction by Geocon Incorporated. - 8 - File No. 04367-05-03 September 13, 1990 5. Prior to commencing grading, a preconstruction conference should be held at the site with the Owner or Developer, Grading Contractor, Civil Engineer, and Geotechnical Engineer in attendance. Special soil handling, and/or the grading plans can be discussed at that time. 6. Site preparation should begin with removal of aU deleterious matter and vegetation from the creek embankments. The vegetation in the channel should be removed where the bridge bent footings are to be constructed. 7. The site should then be brought to final subgrade elevations with structural fill compacted in layers. In general, native soils are suitable for reuse as fill if they are relatively free of vegetation, debris and other deleterious matter. Layers of fill should be no thicker than will allow for adequate bonding and compaction. In general, all fill (including backfill and scarified ground surfaces) should be compacted to at least 90 percent of the maximum dry density at optimum moisture content or above, as determined in accordance with ASTM Test Procedure D1557-78. 8. The majority of the southem bridge approach embankment will consist of cut in order to achieve finish grade. However, the northeastern portion of this approach embankment will consist of fill. This fill should be properly benched into the existing formational material and compacted to at least 95 percent of the maximum dry density at optimum moisture content or above to reduce the potential for differential settlement. - 9 - FUe No. 04367-05-03 September 13, 1990 9. The northern bridge approach embankment will be constructed over approxi- mately 10 feet of alluvium. It is recommended that a minimum of two settlement monuments be installed when finish grade is attained to monitor the settlement ofthe approach embankment. The driven piles should not be installed until the settlement monuments indicate the primary settlement ofthe underlying alluvial soil is complete. It is estimated two to three months will be required for the above settlement to occur. Slope Stability 10. Our experience with similar soil conditions in nearby areas indicates that 2:1 (horizontahvertical) cut and fill slopes composed of granitic materials on the order of 20 to 30 feet in height will have factors of safety in excess of 1.5 under static conditions for both deep-seated and shallow sloughing failures. 11. It is recommended that all cut slopes be observed during grading by an engineering geologist to verify that soil and geologic conditions do not differ significantly from those anticipated. 12. The outer 15 feet (or a distance equal to the height of the slope, whichever is less) of fill slopes should be composed of properly compacted granular "soil" fill to reduce the potential for surface sloughing. All fill slopes should be compacted by back-rolling at vertical intervals not exceeding 4 feet and should be track-walked at the completion of each slope such that the fill soils are uniformly compacted to at least 90 percent relative compaction to the face of the completed slope. 10 - File No. 04367-05-03 September 13, 1990 Soil and Excavation Characteristics 13. It is our opinion that the alluvial soil and the granitic rock can generally be excavated with heavy duty grading equipment. As previously discussed, it is estimated that the proposed grading will generally encounter rippable material with isolated areas of marginally rippable rocks to maximum depths of the proposed grading plan. Any oversized rocks that may be generated during grading should be placed in accordance with the Recommended Grading Specifications presented in Appendix C. It should be anticipated that difficult foundation excavation operations will be encountered for the foundations excavated into granitic rock at Abutment No. 1 and Bent Nos. 2 and 3. Foundations 14. It is anticipated that Abutment No. 1 and Bent Nos. 2 and 3 will be constructed within dense, undisturbed formational material and will utilize conventional spread and/or continuous footings. Allowable soil bearing pressures of 10,000 psf will be able to be utilized for foundations having minimum widths of 5 feet and minimum depths of at least 2 feet into dense, undisturbed formational material. The allowable bearing pressure may be increased by 1,000 and 1,500 psf for each additional foot of foundation width and depth, respectively, up to a maximum allowable bearing pressure of 15,000 psf. The northeastern portion of the footing for Abutment No. 1 will need to be extended through the approach embankment fill soils into the underlying granitic rock. 15. Due to the shallow groundwater, the footing excavation locations will need to be dewatered prior to the commencement of the excavation. -11- FHe No. 04367-05-03 September 13, 1990 16. It is recommended that the northern bridge abutment (Abutment No. 4) be supported by driven steel HP, end bearing piling. Both vertical and batter piles will be used to support the abutment structure. It is recommended that 12-inch and 14-inch piles driven to a minimum embedment depth of 3 feet into dense formational material be designed for an allowable axial load of 70 tons and 80 tons, respectively. These allowable loads are for downward vertical and batter piles. 17. The reduction of pile capacity due to negative skin friction may be considered to be negligible for this site, provided the piles are driven after the settlement monitoring program indicates the settlement ofthe northern approach embankment is complete. 18. The results of the exploratory borings indicate dense to very dense formational materials underlie the site at an approximate depth of 8 to 10 feet below the existing grade. Localized areas exist where the depth to formational material is less. Hence, steel piles which encounter refusal at elevations above the design tip elevation should be cut off at the design pile butt elevation. 19. The piles should be provided with a protective tip or "rock point" to reduce the potential for pile damage and to facilitate driving of the pile in the dense granitic rock. 20. It is recommended that a pile hammer capable of developing a driving energy of at least 25,000 foot-pounds be utilized for pile driving operations. A pile hammer system should be selected by the foundation contractor which will preclude over- - 12- File No. 04367-05-03 September 13, 1990 stressing the steel piles during driving. Driving cushions and followers should be capable of imparting a uniform distribution of hammer energy to the piles. 21. It is recommended that the allowable capacity of the driven piles be verified in the field using an appropriate dynamic pUe driving formula such as the ENR (Engineering News Record) or the "So Equation." The pile driving operations should be observed by representatives of Geocon Incorporated. Continuous records of the pile driving operations should be kept and any field changes reviewed by the project structural engineer. Abutment Walls and Lateral Loads 22. It is assumed that the bridge abutment walls will be designed for sufficient movement such that they will act as unrestrained walls. It is recommended that the abutment walls be designed for an earth pressure of 36 pcf. This value assumes a drained and granular backfill condition. A surcharge equivalent to 2 feet of soil should be included in the design for abutments subject to vehicular traffic. 23. The passive earth pressure of the prevailing soil conditions may be assumed to be equivalent to a fluid pressure of 300 pcf unit weight. 24. A coefficient of friction of 0.35 may be assumed for resistance to sliding between concrete and soil. - 13 I I File No. 04367-05-03 September 13, 1990 Seismicity Analysis Parameters 25. We have reviewed the Caltrans Highway Bridges design manual, Article 3.21, dated January 1985, in order to present recommended geotechnical parameters for the seismic analysis of the proposed bridge. A review of California Division of Mines and Geology Map Sheet 23 Maximum Credible Rock Accelerations From Earthquakes in Califomia prepared by Mr. Roger W. Greensfelder, suggests that the subject site be designed for a maximum rock acceleration of 0.26 g. It is recommended that the A.R.S. Spectra graph on Page 3.21.4.3A (0 to 10 feet alluvium) of the above Caltrans manual be used with an acceleration of 0.26 g for the bridge seismic analysis. The maximum credible earthquake definition utilized by Greensfelder is defined as the seismic event having a 2 percent chance of being exceeded in 100 years. Hence, it is our opinion that an acceleration of 0.26 g is highly unlikely within the anticipated lifetime of the proposed structure (100 years). Site Drainage and Moisture Protection 26. Providing and maintaining adequate drainage and moisture protection of supporting soils is an important design consideration. Foundation recommendations presented herein assume proper site drainage will be established and maintained. 27. Under no circumstances should water be allowed to pond adjacent to footings or structures. The site should be graded such that surface drainage flow is directed away - 14 File No. 04367-05-03 September 13, 1990 from structures and into swales or other controlled drainage facilities. In addition, where landscaping is planned adjacent to the pavement, it is recommended that consideration be given to providing a cutoff wall or extend the curb along the edge of the pavement at least 6 inches below the top of the subgrade. Grading and Foundation Plan Review 28. Geocon Incorporated should review the final grading and foundation plans to determine if additional recommendations or analysis are required. - 15 File No. 04367-05-03 September 13, 1990 LIMITATIONS AND UNIFORMITY OF CONDITIONS 1. The recommendations of this report pertain only to the site investigated and are based upon the assumption that the soil conditions do not deviate from those disclosed in the investigation. K any variations or undesirable conditions are encountered during construction, or if the proposed construction will differ from that anticipated herein, Geocon Incorporated should be notified so that supplemental rec- ommendations can be given. 2. This report is issued with the understanding that it is the responsibility of the owner, or of his representative, to ensure that the information and recommendations contained herein are brought to the attention of the architect and engineer for the project and incorporated into the plans, and the necessary steps are taken to see that the contractor and subcontractors carry out such recommendations in the field. 3. The findings of this report are valid as of the present date. However, changes in the conditions of a property can occur with the passage of time, whether they be due to natural processes or the works of man on this or adjacent properties. In addition, changes in applicable or appropriate standards may occur, whether they result from legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and should not be relied upon after a period of three years. File No. 04367-05-03 '^"5 0€_^lAS HU^S I E^^M^M^^^^^BBB ' ' i ^\&:^r^f^fi, REF. MAP : 1990 SAN DIEGO COUNTY THOMAS GUIDE, PG. ao ( E -4 ) THOMAS BROS. MAP CO., IRVINE, CALIF. w NO SCALE VICINITY MAP RANCHO SANTA FE ROAD REALIGNMENT RANCHO SANTA FE BRIDGE CROSSING AT SAN MARCOS CREEK CARLSBAD, CALIFORNIA Figure 1 APPENDIX A File No. 04367-05-03 September 13, 1990 APPENDIX A FIELD INVESTIGATION The current field investigation was performed on August 9, 10 and 14, 1990, and consisted of 2 exploratory trenches, 5 small-diameter hand-held power auger borings and the performance of 8 hydraulic air track borings. Additionally, 4 small-diameter rotary-wash borings were excavated in the vicinity of the bridge site on September 29, 1989. The trenches were advanced to depths ranging from approximately 4.5 to 5 feet using a John Deere 210 rubber tire backhoe with a 24-inch wide bucket. The hand-held power auger borings were excavated to depths ranging from approximately 2 to 5 feet using 4-inch-diameter continuous flight augers. The hydraulic air track borings were advanced to depths ranging from approximately 15 to 35 feet using an Ingersoll-Rand 500 pneumatic percussion, 4-inch-diameter drill with hydraulic pull-down. The rotary-wash borings were excavated to depths of approximately 7 to 16 feet using a Mayhew 1000 drill rig. The approximate location of the excavations are shown on Figure 2. As boring and trenching proceeded, the soils encountered were continuously observed, visually classified and logged. Relatively undisturbed samples were obtained with the Mayhew 1000 by driving a 3-inch, O.D. split-tube sampler into the "undisturbed" soil mass with blows from a 300-pound hammer falling 18 inches. The sampler was equipped with 1-inch by 2-3/8-inch brass sampler rings to facilitate removal and testing. Bulk samples were also obtained throughout the investigation. File No. 04367-05-03 September 13, 1990 APPENDIX A (Continued) Logs of the borings, trenches and air track graphs are included herein. The logs depict the various soil types encountered. The air track graphs depict the rate (in seconds per foot) at which the drill penetrated each foot of depth examined and illustrate the excavation characteristics of the soil and rock encountered approximately correlated with the capabilities of a D-9L or D-9N Caterpillar tractor equipped with a single shank ripper. FILE NO. 04367-05-03 DEPTH IN FEET SAMPLE NO. SOIL CLASS (USCS) BORING B 1 ELEVATION 325 DATE COMPLETED 8/9/90 EQUIPMENT SOLID STEM AUGER (0§ hi =j H tn z UJ • >! Q u UJ ^ 0 2 h 4 MATERIAL DESCRIPTION V ALLUVIUM Loose to moderately dense, moist, to saturated, dark red-brown, Silty, slightly clayey, fine SAND, with gravel and cobble size sub- angular granitic rock, water and caving at 2 feet I I I I I I I BORING TERMINATED AT 5 FEET (REFUSAL ON COBBLES) Figure A-1 Log of Test Boring B 1, page 1 of 1 RSFB SAMPLE SYMBOLS UNSUCCESSFUL B... STANDARD PENETRATION TEST 1 ... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE 0 ... CHUNK SAMPLE I ... WATER TABLE QR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I FILE NO. 04367-05-03 - 4 DEPTH IN FEET 2 - SAMPLE NO. 2 SOIL CLASS (USCS) BORING B 2 ELEVATION 325 DATE COMPLETED 8/9/90 EQUIPMENT SOLID STEM AUGER MATERIAL DESCRIPTION ALLUVIUM Loose to moderately dense, moist to saturated, dark brown, Silty, slightly clayey, fine to medium SAND; with gravel and cobble BORING TERMINATED AT 4 FEET (REFUSAL ON COBBLES) If) (0 " 5 go to i I I I Figure A-2 Log of Test Boring B 2, page 1 of 1 RSFB SAMPLE SYMBOLS • SAMPLING UNSUCCESSFUL ^ ... DISTURBED OR BAG SAMPLE B... STANDARD PENETRATION TEST 0 ... CHUNK SAMPLE DRIVE SAMPLE (UNDISTURBED) WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I FILE NO. 04367-05-03 DEPTH IN FEET SAMPLE NO. V (3 O -I o X SOIL CLASS (USCS) BORING B 3 ELEVATION 325 DATE COMPLETED 8/9/90 EQUIPMENT SOLID STEM AUGER UJ IN OT ° UJ a. S >- UJ >-°- • ^ o u MATERIAL DESCRIPTION •B3^ 2 - - 4 ALLUVIUM Loose to moderately dense, moist to saturated, dark red-brown, Silty, slightly clayey, fine to coarse SAND: with gravel and cobble BORING TERMINATED AT 4 FEET (REFUSAL ON COBBLES) I I I Figure A-3 Log of Test Boring B 3, page 1 of 1 RSFB SAMPLE SYMBOLS • SAMPLING UNSUCCESSFUL B ^ ... DISTURBED OR BAG SAMPLE 0 STANDARD PENETRATION TEST CHUNK SAMPLE DRIVE SAMPLE (UNDISTURBED) WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS ANO TIMES. FILE NO. 04367-05-03 DEPTH IN FEET 0 2 SAMPLE NO. (T > UJ a o <I -1 3 o • I Z 1-D H O -I Q: C3 SOIL CLASS (USCS) BORING B 4 ELEVATION 325 DATE COMPLETED 8/9/90 EQUIPMENT SOLID STEM AUGER MATERIAL DESCRIPTION UJ 3 • >- go UJ S Q: OT UJ o u 2 ALLUVIUM Loose to moderately dense, moist to saturated, dark brown, Silty, Clayey, fine to coarse SAND; with gravel and cobble (sandy clay on tip) BORING TERMINATED AT 4 FEET (REFUSAL ON COBBLES) Figure A-4 Log of Test Boring B 4, page 1 of 1 RSFB SAMPLE SYMBOLS • SAMPLING UNSUCCESSFUL B.. ^ ... DISTURBED OR BAG SAMPLE 0 .. STANDARD PENETRATION TEST CHUNK SAMPLE DRIVE SAMPLE (UNDISTURBED) WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04367-05-03 DEPTH IN FEET SAMPLE NO. >-a o -J o X H H -I SOIL CLASS (USCS) BORING B 5 ELEVATION 325 DATE COMPLETED 8/9/90 EQUIPMENT SOLID STEM AUGER OT OT > ^u! UJ o • UJ PL- OT UJ ^ o o - 0 MATERIAL DESCRIPTION ALLUVIUM Loose, moist to saturated, dark brown, Silty fine to medium SAND: with angular gravel BORING TERMINATED AT 2 FEET (REFUSAL ON COBBLES) Log of Test Boring B 5, page 1 of 1 "igure A-5 RSFB SAMPLE SYMBOLS ° - UNSUCCESSFUL B.. . STANDARD PENETRATION TEST M . .. DRIVE SAMPLE (UNDISTURBED) ^ ... DISTURBED OR BAG SAMPLE 0.. . CHUNK SAMPLE I . .. WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. D-4367-402 DEPTH IN FEET SAMPLE NO. SOIL CLASS (USCS) BORING SB 1 ELEVATION 327 DATE COMPLETED 9/29/89 EQUIPMENT ROTARY WASH DRILLRIG OT H 3 Z«3 ^u! go >i tr. Ul D: 0 2 - 4 - 6 - 8 MATERIAL DESCRIPTION CL ALLUVIUM Loose, damp to very moist, light brown, Silty CLAY, with little sand and gravel GC BONSALL TONALITE Very dense, saturated, light brown. Gravelly Silty CLAY: slightly weathered fractured, GRANITIC BEDROCK 1 foot/4 minute drill rate 32 BORING TERMINATED AT 8 FEET (REFUSAL DUE TO BEDROCK) Figure A-6 Log of Test Boring SB 1, page 1 of 1 LOSE SAMPLE SYMBOLS ^^"'''-"''^ UNSUCCESSFUL B ... STANDARD PENETRATION TEST ^ ... DISTURBED OR BAG SAMPLE • ... CHUNK SAMPLE .. DRIVE SAMPLE (UNDISTURBED) .. WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. I FILE NO. D-4367-402 DEPTH IN FEET SAMPLE NO. >• C9 O -I O I I-H -I SOIL CLASS (USCS) BORING SB 2 ELEVATION_ EQUIPMENT 329 DATE COMPLETED 9/29/89 ROTARY WASH DRILLRIG OT 5)° >- gul UJ,: • UJ ^ CE MATERIAL DESCRIPTION - 2 4 6 - 8 - 10 - 12 SB2-1 SB2-2 I I SB2-3 I SC ALLUVIUM Medium dense, moist, red brown. Clayey SAND, with some silt 15 20 119.4 109.1 7.8 20.1 Gravel encountered at 8 feet GC BONSALL TONALITE Very dense, orange to brown. Gravelly Clayey SAND, moderately weathered GRANITIC BEDROCK BORING TERMINATED AT 12 FEET (REFUSAL DUE TO BEDROCK) TT3T T^ Figure A-7 Log of Test Boring SB 2, page 1 of 1 LOSE SAMPLE SYMBOLS ° ^'^"''^"^'^ UNSUCCESSFUL B ... STANDARD PENETRATION TEST 1... DRIVE SAMPLE (UNDISTURBED) ^ ... DISTURBED OR BAG SAMPLE 0 ... CHUNK SAMPLE % ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. D-4367-402 0 2 - 4 - - 6 - DEPTH IN FEET SAMPLE NO. SB3-1 SB3-2 > o o -I o I I- H -I 2 SOIL CLASS (USCS) SC SM BORING SB 3 ELEVATION 331 DATE COMPLETED 9/29/89 EQUIPMENT ROTARY WASH DRILLRIG MATERIAL DESCRIPTION ALLUVIUM Medium dense, red-brown, damp to moist. Clayey SAND, with some silt and gravels Medium to high frequency of gravels encountered at 2 feet BONSALL TONALITE Very dense, light brown, Gravelly, Silty SAND, moderately weathered GRANITIC BEDROCK BORING TERMINATED AT 7 FEET s tr h-UJ z UJ OT 26 §u: UJ 125.4 wis 10.5 Figure A-8 Log of Test Boring SB 3. page 1 of 1 LCSE SAMPLE SYMBOLS ° - UNSUCCESSFUL B ... STANDARD PENETRATION TEST 1... DRIVE SAMPLE (UNDISTURBED) ^ ... DISTURBED OR BAG SAMPLE 0 ... CHUNK SAMPLE Z ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. D-4367-402 DEPTH IN FEET - 0 2 - 4 - 6 - h 8 - 10 - 12 14 ^ 16 SAMPLE NO. SB4-1 SB4-2 SB4-3 > a o -J o X H H -I SB4-4 SZ SOIL CLASS (USCS) SP GP GM BORING SB 4 ELEVATION 326 DATE COMPLETED 9/29/89 EQUIPMENT ROTARY WASH DRILLRIG MATERIAL DESCRIPTION ALLUVIUM Loose, saturated, dark brown SAND, with some silt Medium dense to dense, saturated, dark gray-brown. Gravelly SAND, with some silt BONSALL TONALITE Very dense, saturated, gray-brown. Gravelly Silty SAND, moderately weathered GRANITIC BEDROCK Drill rate=l foot/5 minute UJ OT UJ : 20 50/10" 50/7" >- OT „• UJ Q 119.0 105.8 T29T UJ ^ O u 16.2 24.5 ITT BORING TERMINATED AT 16 FEET Figure A-9 Log of Test Boring SB 4, page 1 of 1 LCSE SAMPLE SYMBOLS • SAMPLING UNSUCCESSFUL B.. S ... DISTURBED OR BAG SAMPLE 0 .. STANDARD PENETRATION TEST I CHUNK SAMPLE Y. DRIVE SAMPLE (UNDISTURBED) WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04367-05-03 DEPTH IN FEET SAMPLE NO. SOIL CLASS (USCS) TRENCH T 1 ELEVATION 325 EQUIPMENT DATE COMPLETED 8/10/90 JD 210 BACKHOE OT ' UJ : IV ill >- ^u! go a UJ Q: PL- OT UJ - 0 MATERIAL DESCRIPTION 4 - 2 ALLUVIUM Loose to moderately dense, moist to saturated, dark brown, Silty, fine to coarse SAND -Subangular cobble to small boulders at 3 feet TRENCH TERMINATED AT 4.5 FEET (CAVING) Figure A-10, Log of Test Trench T 1 SAMPLE SYMBOLS ^ '" . SAMPLING UNSUCCESSFUL B.. . STANDARD PENETRATION TEST B... DRIVE SAMPLE (UNDISTURBED) . DISTURBED OR BAG SAMPLE 0.. . CHUNK SAMPLE % ... WATER TABLE OR SEEPAGE int Luu w SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04367-05-03 DEPTH IN FEET 0 2 SAMPLE NO. SOIL CLASS (USCS) TRENCH T 2 ELEVATION 325 DATE COMPLETED 8/10/90 EQUIPMENT JD 210 BACKHOE MATERIAL DESCRIPTION OT§ So Ss >- go UJ cc OT i ALLUVIUM Loose to moderately dense, moist to saturated, dark brown, Silty, slightly clayey, fine to coarse SAND -Subangular gravel and cobble at 2 feet -Heavy seepage 2.5 feet GRANITIC ROCK (BONSALL TONALITE) Very dense, wet, light brown, weathered crystalline GRANITIC ROCK (BONSALL TONALITE) excavated to fine to coarse SAND with gravel and cobble size fragments TRENCH TERMINATED AT 5 FEET Figure A-11, Log of Test Trench T 2 RSFB SAMPLE SYMBOLS ° ••• UNSUCCESSFUL S... DISTURBED OR BAG SAMPLE B.. 0.. . STANDARD PENETRATION TEST DRIVE SAMPLE (UNDISTURBED) . CHUNK SAMPLE 1 ... WATER TABLE OR SEEPAGE ...u ouDou.^r«i.c uuNuiiiuNs snuwN MtKtUN AHKLitb UNLT AI IHE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. 0 0 >+- \ (/) "D c 0 u 0 w '— h- < _l _J CL a 60 50 30 20 10 AIR TRACK BORING LOG HT-1 Rancho Santa Fe Bridge: 4357-05-03 0 0 10 15 20 25 30 35 40 Rippable DEPTH (feet) Marginal Y//A Non-rippable o 0 4- \ OT T5 C 0 u (U OT -—' u H < 60 50 - 40 - 30 - 20 - 10 AIR TRACK BORING LOG HT-2 Rancho Santa Fe Bridge: 4367-05-03 Rippable DEPTH (feet) Marginal 2) Non-rippable 0 0 \ OT c 0 u 0) OT LJ H < 01 Q 60 50 40 - 30 - 20 10 0 AIR TRACK BORING LOG HT-3 Rancho Santa Fe Bridge: 4367-05-03 40 Rippable DEPTH (feet) Marginal Non-rippable o o \ OT x> c o u 0) OT u h- < Ol cm Q 60 50 - 40 30 20 10 0 AIR TRACK BORING LOG HT-4 Rancho Santa Fe Bridge: 4367-05-03 Rippable DEPTH (feet) Marginal Non-rippable o 0 4- \ OT XI c 0 u 0) OT u I- < 60 AIR TRACK BORING LOG HT-5 Rancho Santa Fe Bridge: 4367-05-03 50 - 40 - 30 - 20 Rippable DEPTH (feet) Marginal Non-rippable AIR TRACK BORING LOG HT-6 Rancho Santa Fe Bridge: 4367-05-03 o 0 4- \ M X) c 0 <J 0) OT bJ H < _l -J on Q Rippable DEPTH (feet) Marginal 2j Non-rippable AIR TRACK BORING LOG HT-7 Rancho Santa Fe Bridge: 4367-05-03 0 0 4- \ OT "D C o u 0) OT U I-< CH cx Rippable DEPTH (feet) Marginal Non-rippable AIR TRACK BORING LOG HT-8 Rancho Santa Fe Bridge: 4367-05-03 0 0 4- \ OT T5 C 0 u (U OT UJ I- < Od on Rippable DEPTH (feet) Marginal ^ Non-rippable APPENDIX B File No. 04367-05-03 September 13, 1990 APPENDIX B PREVIOUS LABORATORY TESTING Laboratory tests were performed during the geologic investigation for the Supplemental Soil and Geologic Investigation for Rancho Santa Fe Road Realignment, dated January 8, 1990, in substantial conformance with the generally accepted test methods of the American Society for Testing and Materials (ASTM) or other suggested procedures. Selected relatively undisturbed drive samples were tested for their in-place dry density, moisture content, direct shear strength, and consolidation characteristics. The maximum dry density and optimum moisture content of selected bulk samples were determined in accordance with ASTM Test Procedure D1557-78. Portions of the bulk samples were subjected to residual direct shear tests. The results of selected laboratory tests are presented in tabular and graphical forms hereinafter. The in-place density and moisture characteristics are presented on the logs of test trenches and borings. I I I I I I I I I I I I I I I I I I I File No. 04367-05-03 September 13, 1990 TABLE B-I Summary of Laboratory Compaction Test Results ASTM D1557-78 Maximum Optimum Dry Density Moisture Sample No. Description pcf % Dry Wt. SB4-5 Dark brown, Silty SAND (alluvium) 122.8 11.0 TABLE B-II Summary of In-Place Moisture-Density and Direct Shear Test Results Angle of Dry Moisture Unit Shear Sample Density Content Cohesion Resistance No. pcf % psf Degrees SB2-2 109.1 20.1 520 34 FUe No. 04367-05-03 z o f-< Q _l O CO o o H Z UJ o oc UJ CL SAMPLE NO. SB 2- 0.5 1.0 5.0 10.0 APPLIED PRESSURE (ksf) 50.0 100.0 INITIAL DRY DENSITY 106.9 (pcf) INITIAL WATER CONTENT 8.7 (%) INrriAL SATURATION 45.6 (%) SAMPLE SATURATED AT 0.5 (ksf) CONSOLIDATION CURVE RANCHO SANTA FE ROAD REALIGNMENT RANCHO SANTA FE BRIDGE CROSSING AT SAN MARCOS CREEK CARLSBAD, CALIFORNIA Figure B-1 APPENDIX C APPENDIX C RECOMMENDED GRADING RECOMMENDATIONS FOR RANCHO SANTA FE ROAD REALIGNMENT RANCHO SANTA FE BRIDGE CROSSING AT SAN MARCOS CREEK CARLSBAD, CALIFORNIA File No. 04367-05-03 RECOMMENDED GRADING SPECIFICATIONS GENERAL 1.1 These Recommended Grading Specifications shall be used in conjunction with the Geotechnical Report for the project prepared by Geocon Incorporated. The recommendations contained in the text of the Geotechnical Report are a part of the earthwork and grading specifications and shall supersede the provisions contained hereinafter in the case of conflict. 1.2 Prior to the commencement of grading, a geotechnical consultant (Consultant) shall be employed for the purpose of observing earthwork procedures and testing the fills for substantial conformance with the recommendations of the Geotech- nical Report and these specifications. It will be necessary that the Consultant provide adequate testing and observation services so that he may determine that, in his opinion, the work was performed in substantial conformance with these specifications. It shall be the responsibility of the Contractor to assist the Consultant and keep him apprised of work schedules and changes so that personnel may be scheduled accordingly. 1.3 It shall be the sole responsibility of the Contractor to provide adequate equipment and methods to accomplish the work in accordance with applicable grading codes or agency ordinances, these specifications and the approved grading plans. If, in the opinion of the Consultant, unsatisfactory conditions such as questionable soil materials, poor moisture condition, inadequate compaction, adverse weather, and so forth, result in a quality of work not in conformance with these specifications, the Consultant will be empowered to reject the work and recommend to the Owner that construction be stopped until the unacceptable conditions are corrected. DEFINITIONS 2.1 Owner shaU refer to the owner of the property or the entity on whose behalf the grading work is being performed and who has contracted with the Contractor to have grading performed. 2.2 Contractor shaU refer to the Contractor performing the site gradmg work. 2.3 Civil Engineer or Engineer of Work shaU refer to the California licensed CivU Engineer or consultmg firm responsible for preparation of the grading plans, surveying and verifying as-graded topography. 2.4 Consultant shall refer to the soU engineering and engineering geology consulting firm retained to provide geotechnical services for the project. 2.5 Soil Engineer shaU refer to a California licensed CivU Engineer retained by the Owner, who is experienced in the practice of geotechnical engineering. The SoU Engineer shall be responsible for having qualified representatives on-site to observe and test the Contractor's work for conformance with these specifications. 2.6 Engineering (;;eologist shaU refer to a California licensed Engineering Geologist retained by the Owner to provide geologic observations and recommendations during the site grading. 2.7 Geotechnical Report shaU refer to a soU report (including aU addendums) which may include a geologic reconnaissance or geologic investigation that was prepared specificaUy for the development of the project for which these Recommended Grading Specifications are intended to apply. MATERIALS 3.1 Materials for compacted fUl shaU consist of any soU excavated from the cut areas or imported to the site that, in the opinion of the Consultant, is suitable for use in construction of fiUs. In general, fUl materials can be classified as soil fUls, soil-rock fiUs or rock fiUs, as defined below. 3.1.1 Soil fills are defined as fUls containing no rocks or hard lumps greater than 12 inches in maximum dimension and containing at least 40 percent by weight of material smaUer than 3/4 inch in size. 3.1.2 Soil-rock fills are defined as fUls containing no rocks or hard lumps larger than 4 feet in maximum dimension and containing a sufficient matrix of soil fUl to aUow for proper compaction of ^o/7 fUl around the rock fragments or hard lumps as specified in Paragraph 6.2. Oversize rock is defined as material greater than 12 inches. 3.1.3 Rock fills are defined as fiUs containing no rocks or hard lumps larger than 3 feet in maximum dimension and containing little or no fines. Fines are defined as material smaUer than 3/4 inch in maximum dimension. The quantity of fines shaU be less than approximately 20 percent of the rock fUl quantity. 3.2 Material of a perishable, spongy, or otherwise unsuitable nature as determined by the Consultant shaU not be used in fUls. 3.3 Materials used for fiU, either imported or on-site, shaU not contain hazardous materials as defined by the Califomia Code of Regulations, Title 22, Division 4, Chapter 30, Articles 9 and 10; 40CFR; and any other applicable local, state or federal laws. The Consultant shaU not be responsible for the identification or analysis of the potential presence of hazardous materials. However, if observations, odors or soU discoloration cause Consultant to suspect the presence of hazardous materials, the Consultant may request from the Owner the termination of grading operations within the affected area. Prior to resuming grading operations, the Owner shaU provided a written report to the Consultant indicating that the suspected materials are not hazardous as defined by applicable laws and regiUations. 3.4 The outer 15 feet of soil-rock fUl slopes, measured horizontaUy, should be composed of properly compacted soil fUl materials approved by the Consultant. Rock fiU may extend to the slope face, provided that the slope is not steeper than 2:1 (horizontahvertical) and a soU layer no thicker than 12 inches is track-waUced onto the face for landscaping purposes. This procedure may be utilized, provided it is acceptable to the goveming agency, Owner and Consultant. 3.5 Representative samples of soU materials to be used for fUl shaU be tested in the laboratory by the Consultant to determine the maximum density, optimum moisture content, and, where appropriate, shear strength, expansion, and gradation characteristics of the soU. 3.6 During gradmg, soU or groundwater conditions other than those identified in the Geotechnical Report may be encountered by the Contractor. The Consultant shaU be notified immediately to evaluate the significance ofthe unanticipated condition. 4 CLEARING AND PREPARING AREAS TO BE FILLED 4.1 Areas to be excavated and fUled shaU be cleared and grubbed. Clearing shaU consist of complete removal above the ground surface of trees, stumps, brush, vegetation, man-made structures and simUar debris. Grubbing shaU consist of removal of stumps, roots, buried logs and other unsuitable material and shaU be performed in areas to be graded. Roots and other projections exceeding 1-1/2 inches in diameter shaU be removed to a depth of 3 feet below the surface of the ground. Borrow areas shaU be grubbed to the extent necessary to provide suitable fiU materials. 4.2 Any asphalt pavement material removed during clearing operations should be properly disposed at an approved off-site facUity. Concrete fragments which are free of reinforcing steel may be placed in fUls, provided they are placed in accordance with Section 6.2 or 6.3 of this document. 4.3 After clearing and grubbing of organic matter or other unsuitable material, loose or porous soils shaU be removed to the depth recommended in the Geotechnical Report. The depth of removal and compaction shaU be observed and approved by a representative of the Consultant. The exposed surface shaU then be plowed or scarified to a minimum depth of 6 inches and untU the surface is free from uneven features that would tend to prevent uniform compaction by the equipment to be used. 4.4 Where the slope ratio of the original ground is steeper than 6:1 (horizontahvertical), or where recommended by the Consultant, the original ground should be benched in accordance with the foUowmg Ulustration. TYPICAL BENCHING DETAIL FINISH GRADE FINISH SLOPE SURFACE REMOVE AS RECOMMENDED BY SOIL ENGINEER SLOPE TO BE SUCH THiT SLOUGHINO OR SLIDING DOES NOT OCCUR NO SCALE NOTES: (1) Key width "B" should be a minimum of 10 feet wide, or sufficiently wide to permit complete coverage with the compaction equipment used. The base of the key should be graded horizontal, or inclined slightly into the natural slope. (2) The outside of the bottom key should be below the topsoU or unsuitable surficial material and at least 2 feet into dense formational material. Where hard rock is exposed in the bottom of the key, the depth and configuration of the key may be modified as approved by the Consultant. 4.5 After areas to receive fUl have been cleared, plowed or scarified, the surface should be disced or bladed by the Contractor untU it is uniform and free from large clods. The area should then be moisture conditioned to achieve the proper moisture content, and compacted as recommended in Section 6.0 of these specifications. 5 COMPACTION EQUIPMENT 5.1 Compaction of soil or soil-rock fUl shaU be accomplished by sheepsfoot or segmented-steel wheeled roUers, vibratory roUers, multiple-wheel pneumatic-tired roUers, or other types of acceptable compaction equipment. Equipment shaU be of such a design that it wUl be capable of compacting the soil or soil-rock fUl to the specified relative compaction at the specified moisture content. 5.2- Compaction of rock fUls shaU be performed in accordance with Section 6.3. 6 PLACING, SPREADING AND COMPA(mON OF FILL MATERIAL 6.1 Soil fUl, as defmed in Paragraph 3.1.1, shaU be placed by the Contractor in accordance with the foUowing recommendations: 6.1.1 Soil fUl shaU be placed by the Contractor in layers that, when compacted, should generaUy not exceed 8 mches. Each layer shaU be spread evenly and shaU be thoroughly mixed during spreadmg to obtain uniformity of material and moisture in each layer. The entire fUl shaU be constructed as a unit in nearly level hfts. Rock materials greater than 12 inches in maximum dimension shaU be placed in accordance with Section 6.2 or 6.3 of these specifications. 6.1.2 In general, the soil fUl shaU be compacted at a moisture content at or above the optunum moisture content as determined by ASTM D1557-78. 6.1.3 When the moisture content of soil fUl is below that specified by the Consultant, water shaU be added by the Contractor untU the moisture content is in the range specified. 6.1.4 When the moisture content of the soil fUl is above the range specified by the Consultant or too wet to achieve proper compaction, the soil fUl shaU be aerated by the Contractor by blading/mbdng, or other satisfactory methods untU the moisture content is within the range specified. 6.1.5 After each layer has been placed, mixed, and spread evenly, it shaU be thoroughly compacted by the Contractor to a relative compaction of at least 90 percent. Relative compaction is defined as the ratio (expressed in percent) of the in-place dry density of the compacted fUl to the maximum laboratory dry density as determined in accordance with ASTM D1557-78. Compaction shaU be continuous over the entire area, and compaction equipment shaU make sufficient passes so that the specified mmimum density has been achieved throughout the entire fUl. 6.1.6 SoUs having an Expansion Index of greater than 50 may be used in fills if placed at least 3 feet below fmish pad grade and should be compacted at a moisture content generaUy 2 to 4 percent greater than the optunum moisture content for the material. 6.1.7 Properly compacted soil fiU shaU extend to the design surface of fUl slopes. To achieve proper compaction, it is recommended that fiU slopes be over- buUt by at least 3 feet and then cut to the design grade. This procedure is considered preferable to track-waUcing of slopes, as described in the foUowing paragraph. 6.1.8 As an altemative to over-buUdmg of slopes, slope faces may be back-roUed with a heavy-duty loaded sheepsfoot or vibratory roUer at maximum 4-foot fUl height intervals. Upon completion, slopes should then be track-waUced with a D-8 dozer or simUar equipment, such that a dozer track covers aU slope surfaces at least twice. 6.2 Soil-rock fUl, as defined in Paragraph 3.1.2, shaU be placed by the Contractor in accordance with the foUowing recommendations: 6.2.1 Rocks larger than 12 inches but less than 4 feet in maximum dimension may be incorporated mto the compacted soil fiU, but shaU be limited to the area measured 15 feet minimum horizontaUy from the slope face and 5 feet below finish grade or 3 feet below the deepest utUity, whichever is deeper. 6.2.2 Rocks or rock fragments up to 4 feet in maximum dimension may either be individuaUy placed or placed in windrows. Under certain conditions, rocks or rock fragments up to 10 feet m maxmium dunension may be placed using simUar methods. The acceptabUity of placing rock materials greater than 4 feet m maximum dimension shaU be evaluated during grading, as specific cases arise and shaU be approved by the Consultant prior to placement. 6.2.3 For individual placement, sufficient space shaU be provided between rocks to aUow for passage of compaction equipment. 6.2.4 For windrow placement, the rocks should be placed in trenches excavated in properly compacted soil fUl. Trenches should be approximately 5 feet wide and 4 feet deep in maximum dimension. The voids around and beneath rocks should be fUled with approved granular soU having a Sand Equivalent of 30 or greater and should be compacted by flooding. Windrows may also be placed utUizing an "open-face" method in lieu of the trench procedure, however, this method should first be approved by the Consultant. 6.2.5 Windrows should generaUy be paraUel to each other and may be placed either paraUel to or perpendicular to the face of the slope depending on the site geometry. The minimum horizontal spacing for windrows shaU be 12 feet center-to-center with a 5-foot stagger or offset from lower courses to next overlying course. The minimum vertical spacing between windrow courses shaU be 2 feet from the top of a lower windrow to the bottom of the next higher windrow. 6.2.6 AU rock placement, fUl placement and flooding of approved granular soU in the windrows must be continuously observed by the Consultant or his representative. 6.3 Rock fUls, as defined in Section 3.1.3, shaU be placed by the Contractor in accordance with the foUowing recommendations: 6.3.1 The base of the rock fUl shaU be placed on a sloping surface (minimum slope of 2 percent, maximum slope of 5 percent). The surface shaU slope toward suitable subdrainage outlet facUities. The rock fUls shaU be provided with subdrams during construction so that a hydrostatic pressure buUdup does not develop. The subdrains shaU be permanently connected to controUed drainage facUities to control post-construction infUtration of water. 6.3.2 Rock fUls shaU be placed in lifts not exceeding 3 feet. Placement shaU be by rock trucks traversing previously placed lifts and dumping at the edge of the currently placed lift. Spreading of the rock fUl shaU be by dozer to facUitate seating of the rock. The rock fUl shaU be watered heavUy during placement. Watering shaU consist of water trucks traversing in front of the current rock lift face and spraymg water continuously during rock placement. Compaction equipment with compactive energy comparable to or greater than that of a 20-ton steel vibratory roUer or other compaction equipment providing suitable energy to achieve the required compaction or deflection as recommended in Paragraph 6.3.3 shaU be utUized. The number of passes to be made wUl be determined as described in Paragraph 6.3.3. Once a rock fUl lift has been covered with soU fUl, no additional rock fUl lifts wUl be permitted over the soU fiU. 6.3.3 Plate bearing tests, in accordance with ASTM Dl 196-64, may be performed in both the compacted soil fUl and in the rock fUl to aid in determming the number of passes of the compaction equipment to be performed. If performed, a minimum of three plate bearmg tests shaU be performed in the properly compacted soil fUl (minimum relative compaction of 90 percent). Plate bearing tests shaU then be performed on areas of rock fUl having two passes, four passes and six passes of the compaction equipment, respectively. The number of passes required for the rock fUl shaU be determined by comparing the resuUs of the plate bearing tests for the soil fUl and the rock fUl and by evaluating the deflection variation wUh number of passes. The required number of passes of the compaction equipment wUl be performed as necessary untU the plate bearing deflections are equal to or less than that determined for the properly compacted soU fUl. In no case wUl the required number of passes be less than two. 6.3.4 A representative of the Consuhant shaU be present durmg rock fUl operations to verify that the minimum number of "passes" have been obtained, that water is being properly applied and that specified procedures are bemg foUowed. The actual number of plate bearing tests wUl be determined by the Consuhant during grading. In general, at least one test should be performed for each approximately 5,000 to 10,000 cubic yards of rock fiU placed. 6.3.5 Test pits shaU be excavated by the Contractor so that the Consultant can state that, in his opmion, sufficient water is present and that voids between large rocks are properly fUled with smaUer rock material. In-place density testing wUl not be required in the rock fUls. 6.3.6 To reduce the potenfial for "piping" of fines into the rock fUl from overlying soil fUl material, a 2-foot layer of graded fUter material shaU be placed above the uppermost lift of rock fUl. The need to place graded fUter material below the rock should be determined by the Consultant prior to commencing grading. The gradation of the graded fUter material wUl be determined at the time the rock fUl is being excavated. Materials typical of the rock fUl should be submitted to the Consultant in a tknely manner, to aUow design of the graded fUter prior to the commencement of rock fUl placement. 6.3.7 AU rock fiU placement shaU be continuously observed durmg placement by representatives of the Consultant. OBSERVATION AND TESTING 7.1 The Consultant shaU be the Owners representative to observe and perform tests during clearmg, grubbing, fUling and compaction operations. In general, no more than 2 feet in vertical elevation oisoil or soil-rock fUl shaU be placed without at least one field density test being performed within that interval. In addition, a minimum of one field density test shaU be performed for every 2,000 cubic yards of soil or soil-rock fiU placed and compacted. 7.2 The Consuhant shaU perform random field density tests of the compacted soil or soil-rock fUl to provide a basis for expressing an opmion as to whether the fUl material is compacted as specified. Density tests shaU be performed in the compacted materials below any disturbed surface. When these tests indicate that the density of any layer of fUl or portion thereof is below that specified, the particular layer or areas represented by the test shaU be reworked untU the specified density has been achieved. 7.3 During placement of rock fUl, the Consultant shaU verify that the minimum number of passes have been obtained per the criteria discussed in Section 6.3.3. The Consuhant shaU request the excavation of observation pits and may perform plate bearing tests on the placed rock fUls. The observation pits wUl be excavated to provide a basis for expressing an opinion as to whether the rock fUl is properly seated and sufficient moisture has been appHed to the material. If performed. plate bearmg tests wUl be performed randomly on the surface of the most-recently placed lift. Plate bearing tests wUl be performed to provide a basis for expressmg an opinion as to whether the rock fUl is adequately seated. The maximum deflection in the rock fUl determined in Section 6.3.3 shaU be less than the maximum deflection of the properly compacted soil fUl. When any of the above criteria indicate that a layer of rock fUl or any portion thereof is below that specified, the affected layer or area shaU be reworked untU the rock fUl has been adequately seated and sufficient moisture appUed. 7.4 A settlement monitoring program designed by the Consultant may be conducted in areas of rock fiU placement. The specific design of the monitoring program shall be as recommended m the Conclusions and Recommendations section ofthe project Geotechnical Report or in the final report of testing and observation services performed during grading. 7.5 The Consultant shaU observe the placement of subdrains, to verify that the drainage devices have been placed and constructed in substantial conformance with project specifications. 7.6 Testing procedures shaU conform to the foUowmg Standards as appropriate: 7.6.1 Soil and Soil-Rock Fills: 7.6.1.1 Field Density Test, ASTM D1556-82, Density of Soil In-Place By the Sand-Cone Method. 7.6.1.2 Field Density Test, Nuclear Method, ASTM D2922-81, Density of Soil and Soil-Aggregate In-Place by Nuclear Methods (Shallow Depth). 7.6.1.3 Laboratory Compaction Test, ASTM D1557-78, Moistiire-Density Relations of Soils and Soil-Aggregate Mixtures Using 10-Pound Hammer and 18-Inch Drop. 1.6.1 A Expansion Index Test, Uniform BuUding Code Standard 29-2, Expansion Index Test. 7.6.2 Rock Fills: 7.6.2.1 Field Plate Bearing Test, ASTM Dl 196-64 (Reapproved 1977) Standard Method for Nonrepresentative Static Plate Load Tests of Soils and Flexible Pavement Components, For Use in Evaluation and Design of Airport and Highway Pavements. 8 PROTECTION OF WORK 8.1 Durmg construction, the Contractor shaU properly grade aU excavated surfaces to provide positive dramage and prevent ponding of water. Drainage of surface water shaU be controUed to avoid damage to adjoining properties or to fmished work on the site. The Contractor shaU take remedial measures to prevent erosion of freshly graded areas untU such time as permanent drainage and erosion control features have been mstaUed. Areas subjected to erosion or sedimentation shaU be properly prepared m accordance with the Specifications prior to placing additional fiU or structures. 8.2 After completion of grading as observed and tested by the Consultant, no further excavation or fUling shaU be conducted except in conjunction with the services of the Consultant. CERTIFICATIONS AND FINAL REPORTS 9.1 Upon completion of the work, Contractor shaU furnish Owner a certification by the CivU Engmeer statmg that the lots and/or buUdmg pads are graded to within 0.1 foot verticaUy of elevations shown on the grading plan and that aU tops and toes of slopes are withm 0.5 foot horizontaUy of the poshions shown on the grading plans. After mstaUation of a section of subdrain, the project CivU Engineer should survey its location and prepare an as-built plan of the subdram locafion. The project CivU Engineer should verify the proper outlet for the subdrains and the Contractor should ensure that the drain system is free of obstructions. 9.2 The Owner is responsible for furnishing a final as-graded soU and geologic report satisfactory to the appropriate governing or acceptmg agencies. The as-graded report should be prepared and signed by a California Ucensed CivU Engineer experienced in geotechnical engineering and by a California Certified Engineering Geologist, indicating that the geotechnical aspects of the grading were performed in substantial conformance with the Specifications or approved changes to the Specifications. Geocon Incorporated Form, Revision date: 06/04/90