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Home My WebLink About3907; RANCHO SANTA FE ROAD WIDENING; LIMITED GEOTECHNICAL INVESTIGATION; 2005-04-01LIMTEp GEOTECHMCAL INVESTI GATION RANCHO SANTA FEROAD . PROPOSED WETLANDS MITIGATIONAREA SAN MARCOS, CALIFORNIA PREPARED FOR CITY OF CARLSBAD. % HELMING ENGINEERING, INC. SAN MARCOS, CALIFORNIA. APRIL 1, 2005 PROJECT NO. 05870-32-22 Ii GEOCON INCORPORATED GEOTECHNICAL CONSULTANTS (4 4&>) Project No. 05 870-32-22 April 1, 2005 City of Carlsbad % Helming Engineering, Inc. 1650 Linda Vista Drive, Suite 202 San Marcos, California 92078 Attention: Mr. Doug Helming Subject: RANCHO SANTA FE ROAD I PROPOSED WETLANDS MITIGATION AREA SAN MARCOS, CALIFORNIA LIMITED GEOTECI{NICAL INVESTIGATION I Gentlemen: I In accordance with your request and our proposal LG-05 105 dated March 3, 2005, we have performed a limited geotechnical investigation for the proposed Wetlands Mitigation Area located east of Rancho Santa Fe Road in San Marcos, California. Specifically, the site is located northeast of 1 the Melrose Drive bridge crossing over San Marcos Creek (Vicinity Map, Figure 1). This study focused on the proposed grading along the southeast bank of San Marcos Creek that extends I approximately 800 feet northeast of the Melrose Drive bridge. The purpose of this study was to evaluate the excavation characteristics of the deposits within the I area of proposed grading and obtain information regarding the materials expected to be encountered during earthwork. The study also focused on the materials anticipated to be exposed in the proposed I 2:1 (horizontal: vertical) cut slope, including the stability of those materials. This study specifically does not address check dam stability or design. The information presented herein is intended to assist I potential contractors in estimating the cost associated with grading the mitigation area as presently proposed. Recommendations and specifications for site grading are also provided in this report. " / I The project grading plan is entitled Wetlands Mitigation Area Grading Plans for: Rancho Sant'à Fe Rd. (Offsite Mitigation Site-Carlsbad Portion), prepared by O'Day Consultants, undated. The Tbãse map for this study consists of a reproducible copy of a compilation of digital information provided by O'Day Consultants (Geologic Map, Figure 2). The Geologic Map depicts the limited study area, existing topography, mapped geologic contacts, and the approximate locations of the exploratory I french excavations. The locations of exploratory -trenches previously performed for an adjacent study have also been included on the Geologic Map. Figure 3 presents three cross sections through the I. 6960 Flanders Drive • San Diego, California 92121-2974 • Telephone (858) 558-6900 U Fax (858) 558-6159 I I I proposed grading and depicts our interpretation of the underlying geologic conditions. The conclusions and recommendations presented herein are based on an analysis of the data obtained from the field investigation, previous work at the site, and our experience with similar soil and geologic conditions. Based on 'a review of the referenced project plan, the proposed site grading consists of removing the majority of the existing embankment situated along the southeast side of San Marcos Creek to accommodate a wider, sheet-graded channel for wetland growth. The maximum cuts are anticipated to be 25 feet with a maximum slope height of 30 feet. The slopes along this portion of the bank are varied from 2:1 to 3:1 (horizontal: vertical). The base of the channel is designed to flow from northeast to southwest. The scope of our services consisted of performing'exploratory trenches along the southeast bank of San Marcos Creek to evaluate the existing urficial deposits, and to characterize the underlying formational materials for rippability corisiderations. A total of 10 trenches, were advanced' on March 15, 2005. The trenches were excavated to a depth of the proposed grade or to where refusal was encountered. The excavations were performed utilizing a Link Belt 4300 trackhoe equipped with a V-notch bucket. The materials encountered were visually examined, classified, and logged-by a geologist from our firm. The locations of the trenches are shown on the Geologic Map, along with the previous pertinent trenches performed by our firm. Logs of the recent exploratory excavations are presented on Figures A-i through A-10, Appendix A. The exploratory trench information from our previous study has been included in Appendix B. A brief summary of the soil and geologic conditions encountered is presented below. The site geology consists of a three surficial deposits overlying Cretaceous-age granitic rock (referred to as Escondido Creek Granodiorite). The surficial materials consist of a thin veneer of topsoil overlying the granitic .rock and a relatively thick,' undocumented soil/rock embankment that is believed to be associated with a mining operation that preyiously operated within the canyon. Based on results of our previous study, a relatively thin deposit of alluvium occurs with the creek bottom, which is in turn underlain by granitic rock. In general, the fills encountered in Trenches Ti through T4, T6, and T10 can be characterized as loose, matrix-supported sands and gravels with 30 to 50 percent rock and a maximum dimension of 31/2 feet. The fills encountered in the remaining trenches (T5 and T7 through T9), in general, can be described as loose, clast-supported rock fills with 20 to 40 percent fines and a maximum rock dimension of 4 feet. Severe caving was encountered in the trenches where the material was clast supported. The alluvium encountered in the preious investigation ranged in thickness from 11/2 to 2½ feet. With the exception of the proposed check dams and a 6-foot-high, 3:1 cut slope, the alluvium is not anticipated to be encountered during site construction. Project Nq. 05870-32-22 -2 - , April 1, 2005 1 H' The granitic rock encountered during this recent study consisted of highly to slightly weathered, weak to strong granitic rock. The majority of the trenches performed were able to reach the proposed grades, with the exception of T2, T5, and T7. Practical refusal was encountered in T2 at 18 feet, 5 feet above the proposed grade. Severe caving of the undocumented fills overlying the granitic rock prevented a thorough evaluation of the rock rippability in Trenches T5 and T7. CONCLUSIONS AND RECOMMENDATIONS No soil or geologic conditions were encountered which, in our opinion, would preclude the grading of the channel, as presently planned, provided the recommendations of this report are followed. All grading should be performed 'in accordance with the attached Recommended Grading Specifications (Appendix Q. 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. 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 the grading plans can be discussed at that time. Site preparation should begin with the removal of surface deleterious material and vegetation. The depth of removal should be such that material exposed in the cut areas or soils to be used as fill are relatively free of organic matter. Objectionable debris such as plastic or trash exposd in slope excavations should also be removed. Material generated during stripping should be exported from the proposed grading area. In areas to receive fill, the existing ground surface should be scarified, moisture conditioned and compacted. The site should then be brought to final elevations with structural fill compacted in layers. In general, soils native to the site are suitable for re-use as fill if relatively free from vegetati6n, debris, and other deleterious material. Oversized rock fragments should be placed in #as beyond future proposed surface or subsurface improvements, or should be hauled away from the grading area. Compacted fill should be placed in layers no thicker than will allow for adequate bonding and compaction. All fill, including backfill and scarified, ground surfaces, should be compacted to least 90 percent of maximum dry density near optimum moisture, as determined in accordance with ASTM Test Procedure D 1557-91. - ' Project No: 05870-32-22 1 -3- April 1, 2005 In our opinion, the surficial deposits and the majority of the formational material can be excavated with moderate to heavy effort with conventional heavy-duty grading equipment. Oversize materials within the undocumented fill and granitic rock will require special handling and placement in accordance with the recommendations provided in Appendix C. The rippability conditions at the toe of the proposed cut slope, In the vicinity of: Trenches T2, T5, and T7 are unknown. The potential exists that very heavy effort and possibly blasting may be necessary depending on the degree of weathering of the rock. The proposed fill slopes constructed of the existing materials should have calculated factors of safety in excess of 1.5 under static conditions for both deep-seated failure and shallow sloughing conditions. All slopes should be compacted by track walking with a dozer upon completion such that the fill soils are uniformly compacted to at least 90 percent relative compaction to the face of the finished slope. Based on our analysis of the three cross sections (Figure 3), it appears that the majority of the undocumented fill soils will be removed within the proposed cut slopes. Cut slopes that expose granitic rock should possess a factor of safety greater than 1.5 for surficial and deep-seated conditions provided they are free of adverse jointing. Undocumented fill may be exposed within the upper portions of the cut slopes at isolated locations. Where this occurs, these areas will be evaluated during the grading phase of development to determine if they are suitable in-place or if stability fills will be required. With the exception of the mitigation area, all slopes should be landscaped with drought-tolerant vegetation, having variable root depths and requiring minimal landscape irrigation. In addition, all slopes should, be drained and properly maintained to reduce erosion. If you have any questions regarding this report, or if we may be of further service, please contact the undersigned at your convenience. Very truly yours, GEOCON INCORPORATE Troy K(Aeist Michael E. Embick E. David B. Evans Senior Staff Geologist GE 2462 CEG 1860 i2 1. No.2462 TKR:MEE:DBE: anh UJ Exp.9/30105 Nw ) (8) Addressee OFcAl /0NAL DAVE 19 EVANS NO. 1110) CERTIFIED * ENGINEERING * IP GEOtOGIST OPC -I Project No. 05870-32-22 - 4 - April 1, 2005 TA C CAM DR lo a LAS 4 ::° ? - 'DR PAR#DISE GLDWY. / . i (7 \ 20 A DEL SEE 83 Li _- INGLET RD 1 FALLRIVER WY 2 NEW RAVEN RD -9246 rI! LiTT1i MELF f -7 N; I CM LA Pl- F JX .•.., Lwu .t::i - LSBI sA 9+ d) SEE allN ANC 929QU. CR 7 FALLSV1L.RJ/ . . A. 7/4)---:-_i 1--------F---= 1 :... \\ -\ IrIVIA 31 so SOURCE: 2005 THOMAS BROTHERS MAP SAN DIEGO COUNTY, CALIFORNIA REPRODUCED WITH PERMISSION GRANTED BY THOMAS BORTHERS MAPS. THIS MAP IS COPYRIGHT BY THOMAS BROS. MAPS. IT IS UNLAWFUL TO COPY OR REPRODUCE ALL OR ANY PART THEREOF, WHETHER FOR PERSONAL USE OR RESALE, WITHOUT PERMISSION. ./ N NO SCALE CR) GEOTECHNICAL CONSULTANTS 6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121- 2974 PHONE 858 558-6900 - FAX 858 558-6159 TR/MM DSK/GTYPD VICINITY MAP RANCHO SANTA FE ROAD PROPOSED WETLANDS - MITIGATION AREA SAN MARCOS, CALIFORNIA DATE 04-01-2005 PROJECT NO. 05870-32-22 1 FIG.1 APPENDIX LOGS OF TRENCHES FOR RANCHO SANTA FE ROAD PROPOSED WETLANDS MITIGATION AREA SAN MARCOS, CALIFORNIA • PROJECT'NO 05870-3222 PROJECT NO. 05870-32-22 TRENCHT'I• DEPTH SOIL . IN FEET SAMPLE . NO. CLASS . . ELEV. (MSL) 380' DATE COMPLETED 03-15-2005 . . - 0.1 . - • . EQUIPMENT LINK BELT 4300TR.ACKHOE MATERIAL DESCRIPTION - 0 - UNDOCUMENTED FILL - . Loose, dry to damp, brown, Silty SAND, with 30-40% rock up to 36-inches o' , (matrix supported) S -2 ' .1 :'P SM • - ,.• , ' . -. + .+ GRANITIC ROCK - . ,+ Moderately, weathered, tan, moderately strong to strong GRANITIC ROCK ++ • 6 + ++ + S. + - 8 + + , -Difficult trenching below 8 feet ++ - - 10 - - ++ -Very difficult trenching below I0'feet TRENCH TERMINATED AT 11 FEET • .-' -, Figure. A-I, LOgof Trench T I, Page lofl SAMPLE SYMBOLS ... SAMPLING UNSUCCESSFUL . ... STANDARD PENETRATION TEST •.. DRIVE SAMPLE (UNDISTURBED) 99 DISTURBED OR BAG SAMPLE . ... CHUNK SAMPLE , ... WATER TABLE OR SEEPAGE I 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. 1 PROJECT NO. 05870-32-22 TRENCH 2 . LU DEPTH SOIL IN FEET SAMPLE NO. 9 ELEV. (MSL.) 377 DATE COMPLETED 03-15-2005 Lu 0 0 Lums 20 - - EQUIPMENT LINK BELT 4300 TRACKHOE CL 0 . MATERIAL DESCRIPTION 0 - - UNDOCUMENTED FILL - . . . Loose, moist to wet, brown, Silty SAND, with 40-50%rock up to 36-inches .01 (matrix supported) -2- - 4.. SM . 6 .4 . 8 + + GRANITIC ROCK I 12 - Moderately weathered, tan, moderately strong to strong GRANITIC ROCK + + + ++ 14-. + .. + ++ 16- + . .. . • + - -Becomes slightly weathered and strong below 17 feet (difficult trenching) 1 PRACTICAL REFUSAL AT 18 FEET• / / - Figure A-2, 05870-32-22.GPJ Log of Trench T 2, Page lofl SAMPLE SYMBOLS SAMPLING UNSUCCESSFUL ... STANDARD PENETRATION TEST ... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE X ... WATER TABLE OR SEEPAGE U h: [HE 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 I 11 PROJECT NO. 05870-32-22 LU TRENCH T3 . DEPTH SAMPLE SOIL I U) IN FEET NO. ELEV. (MSL.) . 372 DATE COMPLETED .03-15-2005 0 Q . Of EQUIPMENT LINK BELT 4300TRAcKHOE 0 0 0 - - MATERIAL DESCRIPTION . . - 0 - - UNDOCUMENTED FILL - - . . 4). Loose, moist to wet, brown, Silty SAND, with 40-50% rock up to 40-inches - Cl . (matrix supported) -2- .i:l. -6- SM - 1; •, IJ. -8. d - .. - -, l .- * : b - 10 -12 - - . -14- + + GRANITIC ROCK - + Moderately weathered, tan, moderately strong GRANITIC ROCK - ++ 16 ++ + + - 18 - ++ -Difficult trenching below 18 feet -. ± 20 TRENCH TERMINATED AT 20 FEET 1' 05870-32-22.GPJ -SAMPLE SYMBOLS ... SAMPLING UNSUCCESSFUL [... STANDARD PENETRATION TEST ...DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRFI.J-I I I)I.ATIOJ ANn AT TWr flAT fl rr IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. 1 Figu re A-3 Log of Trench T 3, Page I, 1 lofl PROJECT NO. 05870-32-22 TRENCH T4 > WDEPTH QQ1 SAMPLE SOIL Z U) ET FE IN NO. NO. ELEV. (MSL.) 380 DATE COMPLETED 03-15-2005 0 EQUIPMENT LINK BELT 4300 TRACKHOE Q- ______ - MATERIAL DESCRIPTION - 0 - UNDOCUMENTED FILL Loose, moist, brown, Silty SAND, with 10% rock up to 12-inches - SM - 2 '0 - SMJSC TOPSOIL - Loose, moist. Silty/Clavey SAND - 4 + ± GRANITIC ROCK - + Moderately weathered, tan, moderately strong GRANITIC ROCK + + TRENCH TERMINATED AT 5 FEET Figure A-4, Log of Trench T 4, Page 1 of I 1 JOTE: 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 I 05870-32-22.GPJ SAMPLE SYMBOLS SAMPLING UNSUCCESSFUL Li ... STANDARD PENETRATIONTEST .. DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE CHUNK SAMPLE ... WATER TABLE OR SEEPAGE PROJECT NO. 05870-32-22 w TRENHT 5 1— LIJ2 DEPTH IN SAMPLE SOIL CLASS 0 Ui . - . FEET NO. ELEV. (MSL.). 375' DATE COMPLETED 03-15-2005 Ln 0 uJ W 20 EQUIPMENT.. LINK BELT4300TRACKHOE MATERIAL DESCRIPTION 0 UNDOCUMENTED FILL • .. Loose, dry, ROCK FILL, with 20-30% fines; rocks up to 40-inches (cla.st - o l 010101 suppo ed) 2 - 10l . . . GM 0 0 -6- -Heavy caving • . • - 8 do - .091 a IC - 10 - . -evere caving - -_ ___________ _ _ TRENCH TERMINATED AT II FEET DUE TO CAVING I J / Figure A-5, 05870-32-22.GPJ Log of Trench 1 5, Page 1 off SAMPLE SYMBOLS fl ... SAMPLING UNSUCCESSFUL Li STANDARD PENETRATION TEST ... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK-SAMPLE ... WATER TABLE OR SEEPAGE I 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 PROJECT NO. 05870-32-22 TRENCHT 6 z DEPTH > SOIL >- ET FE IN SAMPLE • NO. NO. - ELEV. (MSL.) 376 DATE COMPLETED 03-15-2005 Ul 0 EQUIPMENT LINKBELT4300TRACKHOE 0 MATERIAL DESCRIPTION 0 _____ _____ T1 UNDOCUMENTED FILL I Loose moist, Silty SAND with 30% rock up to 30-i;'ches (matrix supported) 2 • .I.I - -, - .j. SM -Little to no rock present below 5 feet - 6 - -H 10- + + GRANITIC ROCK - + Highly weathered, tan to brown, weak to moderately weak GRANITIC ROCK - +± 12 TRENCH TERMINATED AT 12 FEET U, Figure A-6, Log of Trench T 6, Page lofl I I- I NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BOIING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. 05870-32-22.GPJ r SAMPLE SYMBOLS El SAMPLING UNSUCCESSFUL Ei STANDARD PENETRATION TEST DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE CHUNK SAMPLE WATER TABLE OR SEEPAGE PROJECT NO. 05870-32-22 > TRENCH T. 7. . . . . z LLI Qo- . DEPTH SAMPLEIN SOIL CLASS . - FEET NO. NO. . ELEV. (MSL.) 374' DATE COMPLETED 03-15-2005 0 . ) . . Z LU Co Cr 20 EQUIPMENT . LINK BELT 4300 TRACKHOE °- , 0 - - - . MATERIAL DESCRIPTION 0 ¶.I7 - . UNDOCUMENTED FILL - Loose, dry, ROCK FILL, with 20-30% fines; rocks up to 48-inches (clast - 2 - ;;ii supported) JK. • - 4 .9o.91 - o GM -Moderate caving at 5 feet 6 9.0 9. . - UI '8 90 ol 91 I N ol -Severe caving at 9 feet . . -10 TRENCH TERMINATED AT 10 FEET DUE TO CAVING / -'I / • - -• -".. 4••_ . .- ____ I 'I Figure A-7, - -'' . ' 05870-32-22.GPJ Log of Trench T 7, Page 1 of I I SAMPLE SYMBOLS E SAMPLING UNSUCCESSFUL l.. STANDARD PENETRATION TEST DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE •.. CHUNK SAMPLE . ...WATER.TABLEORSEEPAGE' 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 . . - . . • . • PROJECT NO. 05870-32-22 . >- TRENCH 8. , >-' I Lu - DEPTH SOIL . z I- Z - U) FEET SAMPLE NO. CLASS ELEV. (MSL.) 370' DATE COMPLETED 03-15-2005 . 0 . . IX 20 EQUIPMENT LINK BELT 4300 TRACKHOE iu C]f °- . 0 0 -. - .. MATERIAL DESCRIPTION . S 0 0Tf - UNDOCUMENTED FILL - I Loose, dry to damp, ROCK FILL, with 20-40% fines; rocks up to. 48-inches. - o . (clast supported) ,. . 2 - . o oli - olo 01°0l GM . - - - . - 4 - > I tI - c$o ol . - - - 6- -_ 01 v 01 . j_._____________ -Severe caving-at 6 feet - TRENCH TERMINATED AT 7 FEET / . . DUE TO CAVING I - . ..- S - --------- •1 t. . .4 ' Figure A-8, 05870-32-22.GPJ Log of Trench T 8, Page lofl SAMPLE SYMBOLS LI ... SAMPLING UNSUCCESSFUL ii ... STANDARD PENETRATION TEST •.. DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE .. •.. WATER TABLE OR SEEPAGE I 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. PROJECT NO. 05870-32-22 TRENCH 9 . LU DEPTH SAMPLE SOIL . . FEET NO. CLASS ELEV. (MSL.) 374' . DATE COMPLETED 03-15-2005 . o . wm EQUIPMENT LINK BELT 4300 TRACKHOE CL - MATERIAL DESCRIPTION - 0 - _____ - UNDOCUMENTED FILL Loose, moist, dark brown, Silty SAND (topsoil) -2- : SM - - - - Loose, moist, ROCK FILL~ with 30-40% fines-, rocks up to 48-inches (clast - - supported) - 6 - oI 91 - - - GM 9-0 9-( -8.- 9019.( 10 -Severe caving below 10 feet TRENCH TERMINATED AT 11 FEET DUE TO CAVING . , a • I . / 05870-32-22.GPJ SAMPLE SYMBOLS LI ... SAMPLING UNSUCCESSFUL II ... STANDARD PENETRATION TEST •.. DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... 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. I Figure A-9, Log of Trench T 9, Page l of I PROJECT NO. 05870-32-22 TRENCH TIO F- z LU > DEPTH > 0 SOIL - w. FEET SAMPLE NO. NO. ELEV. (MSL.) 375 DATE COMPLETED 03-15-2005 o S LU Fn z Uj Co LU 20 EQUIPMENT LINK BELT 4300 TRACKHOE CL 0 _____ _____ MATERIAL DESCRIPTION T]T - UNDOCUMENTED FILL - . Loose, dry to damp, Silty SAND, with 20% rock up to 24-inches (matrix - supported) 2 SM - 4 1 .1 SM TOPSOIL 6 - I Loose, damp, dark brown, Silty SAND - - + + GRANITIC ROCK - + Highly weathered, tan, moderately weak GRANITIC ROCK -8- ++ + ' . - +± TRENCH TERMINATED AT 9 FEET .5 . 'F . / 5l Figure A-b, 05870-32-22.GPJ Log of Trench T1O, Page 1of1 SAMPLE SYMBOLS ... SAMPLING UNSUCCESSFUL ... STANDARD PENETRATION TEST ... DRIVE-SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE ... WATER TABLE OR SEEPAGE U 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. APPENDIX B EXPLORATORY TRENCHES PREVIOUSLY PERFORMED BY GEOCON INCORPORATED FOR RANCHOSANTA FE ROAD PROPOSED WETLANDS MITIGATION AREA SAN MARCOS, CALIFORNIA PROJECT NO. 05870-32-22 Figure A-2, Log of Trench T 2 I SAMPLE SYMBOLS ... SAMPLING UNSUCCESSFUL ... STANDARD PENETRATION TEST ... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE ... WATER TABLE OR SEEPAGE UCOMI PROJECT NO. 05870-32-05 TRENCH T 2 DEPTH SAMPLE SOIL NO. ELEV. (MSL.) 371 DATE COMPLETED 9/1/00 FEET ED EQUIPMENT JD 555 TRACKHOE CL C3 U MATERIAL DESCRIPTION - :J4. UNDOCUMENTED FILL 3M/GM Loose, dry, brown to yellow-brown, Silty, fine to - 2 - coarse SAND, with abundant gravel and cobble - - - size angular rock fragments. Very difficult to 1• excavate due to abundant rock fragments - 4 - ••4 -- - - - -Primarily 12 inch to 36 inch+ fragments below 3 1 -r feet, difficult excavating - 6 - 8 rqi 0 0 -10 - p TRENCH TERMINATED AT 10.5 FEET' / / /• "0 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. 1 • - PROJECT NO. 05870-32-05 >- w TRENCH T 4 . -. DEPTH SAMPLE LD <1 V SOIL '0 V V F-, \ cn• LJJ M IN NO. Z CLASS ELEV. (MSL.) 375. DATE COMPLETED 9/1/00 LL w , FEET (USCS) H LD EQUIPMENT JD 555 TRACKHOE MATERIAL DESCRIPTION 0 SM UNDOCUMENTED FILL r ' I- ____ - ____ • Loose, dry, Silty, fine to coarse SAND from 0-6 V ] . \inches --1 2 - .Lp Clast supported with gravel, cobble 'and boulder - -cj - size rock fragments and little to no fines - -Numerous 2 foot+ rock fragments -•i -Occasional 3 foot+ rock fragments V - ______ TRENCH TERMINATED AT 5 FEET PRACTICAL REFUSAL DUE TO OVERSIZE V ROCK I V / V UCOM1 SAMPLING UNSUCCESSFUL [ ... STANDARD PENETRATION TEST ... DRIVE SAMPLE (UNDISTURBED) SAMPLE SYMBOLS V V ... DISTURBED OR BAG SAMPLE ... 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. 1 Figure A-4, Log of Trench T 4 I V -H PROJECT NO. 05870-32-05 TRENCH TS DEPTH SAMPLE = soiL S Z LL NO. CLASS ELEV. (MSL.) 376. DATE COMPLETED 9/1/00 FEET H (USCS) WHO LD EQUIPMENT JD 555 TRACKHOE CL C3 U MATERIAL DESCRIPTION 0 - = SM UNDOCUMENTED FILL .1. - Loose, dry, Silty, fine to coarse SAND from 0-6. 2 - mches --------------------- Clast supported with gravel, cobble and boulder - c size rock fragments and little to no fines - -Numerous foot+ rock fragments with maximum .2 - -I rock size of 4 feet -Very difficult to excavate due to large rock - - 6 - 8 10 TRENCH.TERMINATED AT 10 FEET PRACTICAL REFUSAL DUE TO OVERSIZE ROCK S • SI /5 Figure A-5, Log of Trench T 5 5 . UCOM I NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCAT I O N A N D A T T H E DATE INDICATED. IT IS NOT WARRANTED lOBE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT. OTHER LOCATIONS A N D T I M E S . I • • - - .5. Es AMPLE SYMBOLS - S SAMPLING UNSUCCESSFUL LI ... STANDARD PENETRATION TEST ... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE ... WATER TABLE OR SEEPAGE - 4- - PROJECT NO. 05870-32-05 •-.. .:.',. . - TRENCH T 6 DEPTH SAMPLE 'SOIL FEET NO.IN ELEV. (MSL.) 350 DATE COMPLETED 9/5/00 EQUIPMENT JD 555 TRACKHOE CL C3 U MATERIAL DESCRIPTION ALLUVIUM Loose, dry to damp, dark brown, Clayey., fine to 2 -. . SC/GC coarse SAND with abundant gravel + + \ -Abundant gravel to 3 foot size fragments + \ -Matrix supported 4 - + + \ -Abundant boulders at surface throughout drainage + ESCONDIDO CREEK GRANODIORITE/SANTIAGO PEAK - \ VOLCANICS (UNDIFFERENTIATED) Slightly weathered, orange-brown, strong . \ •GRANITIC ROCK TRENCH TERMINATED AT 5 FEET / 7'. /- - ' • ' $ • .3 .,Figure A-6, Log of Trench T6 - ;. •' I SAMPLE SYMBOLS ... SAMPLING UNSUCCESSFUL . . .STANDARD PENETRATION TEST IM ... DRIVE SAMPLE (UNDISTURBED) . . ... DISTURBED OR. BAG SAMPLE. ... CHUNK SAMPLE Y ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION A N D A T T H E DATE INDICATED. IT IS-NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS A N D T I M E S . -i . . • . .- • PROJECT NO. 05870-32-05 TRENCH T7 DEPTH D T SAMPLE SO IL H NO. LASS (cLJ ELEV. (MSL.) 351 DATE COMPLETED 9/5/00 FEET EQUIPMENT JD 555 TRACKIIOE CL a ci MATERIAL DESCRIPTION - -.4 - M/SM 0 ALLUVIUM - Loose, damp, yellow-brown, Silty, fine to coarse, - 2 - -'\ Sandy GRAVEL with Silty SAND zones _____ - - \ -Abundant boulders up to 4 feet long in drainage ESCONDIDO CREEK GRANODIOR1TE/SANTJAGO PEAK (UNDIFFERENTIATED) Slightly weathered to fresh, yellow-brown, strong to very strong GRANITIC ROCK TRENCH TERMINATED AT 2 FEET REFUSAL - - . 4- I Figure A-7, Log of Trench T 7 UCOM1 I- SAMPLE SYMBOLS DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE ... WATER TABLE OR SEEPAGE SAMPLING UNSUCCESSFUL ... STANDARD PENETRATION TEST ... DRIVE SAMPLE (UNDISTURBED) I - 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 T I M E S . 1. PROJECT NO. 05g70-32-05 TRENCH T 8 W DEPTH D SAMPLE (0 0 .J 0 0 SOIL i- .Z a C LL '-'. • (n\ W IN NO. Z CLASS ELEV. (MSL.) 351 DATE COMPLETED 9/5/00 (USCS) wj z IM FEET H o LD EQUIPMENT JO 555 TRACKIIOE W co Ci MATERIAL DESCRIPTION - 0 - '4/ SC/GC ALLUVIUM - Loose, moist, dark brown, Clayëy SAND and -2 - - GRAVEL f-i- 4.\ -Abundant 2-3 foot+ boulders at surface \ \ throughout drainage. Maximum size approximately \ 4feet ESCONDIDO CREEK GRANODIOR1TE/SANTIAGO PEAK VOLCANICS (UNDIFFERENTIATED) Slightly weathered, yellow-brown, moderately strong GRANITIC ROCK TRENCH TERMINATED AT 3 FEET j A' I Figure A-S. Log of Trench T S LI SAMPLE SYMBOLS Li SAMPLING UNSUCCESSFUL ... STANDARD PENETRATION, TEST •.. DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE 5J ... CHUNK SAMPLE - ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH L O C A T I O N A N D A T T H E DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATI O N S A N D T I M E S . 1 -. .1 I I, 1 1 0• .. 1 . i APPENDIX C RECOMMENDED GRADING SPECIFICATIONS I I FOR I RANCHO SANTA FE ROAD PROPOSED WETLANDS MITIGATION AREA . I SAN MARCOS,.CALIFORNIA I . . .. .. - PROJECT NO 05870-3222 .. . . I I I I RECOMMENDED GRADING SPECIFICATIONS 1. GENERAL 1 1.1. These Recommended Grading Specifications shall be used in conjunction with the Geotechnical Report for, the project prepared by Geocon Incorporated. The I, , 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 reconilnendations of the Geotechnical 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 adeq'uaie equipment ani methods to accomplish the work in accordance with applicable grading codes or agency I ordinances, these specifications and the approved grading plans. If, in .the opinion of the Consultant, unsatisfactory conditions such as, 'questionable soil materials, poor moisture I' '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 I , ,the work and recommend to the Owner that construction be stopped until the unacceptable conditions are corrected. 2. DEFINITIONS 2.1. Owner shall 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 shall refer to the Contractor performing the site grading work. 2.3. Civil Engineer or Engineer of Work shall refer to the California licensed Civil Engineer or consulting firm responsible for preparation of the grading plans, surveying and verifying I ' as-graded topography. '. I GI rev. 07/02' I I 2.4. Consultant shall refer to the soil engineering and engineering geology consulting firm I retained to provide geotechnical services for the project. I .2.5. Soil Engineer shall refer to a California licensed Civil Engineer retained by the Owner, who is experienced in the practice of geotechnical engineering. The Soil Engineer shall be responsible for having qualified representatives on-site to observe and test the Contractor's 1 work for conformance with these specifications. 2.6. Engineering Geologist shall 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 shall refer to a soil report (including all addenda) which may include I a geologic reconnaissance or geologic investigation that was prepared specifically for the development of the project for which these Recommended Grading Specifications are 1 intended to apply. 3 'MATERIALS 3.1. Materials for compacted fill shall consist of any soil excavated from the cut areas or I .imported to the site that, in the opinion of the Consultant, is suitable for use in construction -, of fills. In general,-fill materials can be classified as soil fills, soil-rock fills or rock fills, as defined below. I 3.1.1. Soil fills are defined as fills containing no rocks or hard lumps greater than 12 I inches in maximum dimension and containing at least 40 percent by weight of material smaller than 3/4 inch in size. • , 3.1.2. Soil-rock fills are defined as fills containing no rocks or hard lumps larger than 4 feet in maximum dimension and containing a sufficient matrix of soil fill to allow I for proper compaction of soil fill around the rock fragments or hard lumps as specified in Paàgraph 6.2. Oversize rock is defined as material greater than 12 inches. 1 . 3.1.3. Rock fills are defined as fills containing no rocks or hard lumps larger than 3 feet in maximum dimension and containing little or no fines. Fines are defined as material smaller than 3/4 inch in maximum dimension. The quantity of fines shall I be less than approximately 20 percent of the rock fill quantity. rev. 07/02 I I 3.2. Material of a perishable, spongy, or otherwise unsuitable nature as determined by the Consultant shall not be used in fills. 3.3. Materials used for fill, .either imported or on-site, shall not contain hazardous materials as defined-by the California 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 shall not be responsible for the identification or analysis of the potential presence of hazardous materials. However, if observations, odors 'or soil 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 shall provide, a written report to the Consultant indicating that the suspected materials are not hazardous as defined by applicable laws and regulations. I 3.4. The outer 15 feet of soil-rock fill slopes, measured horizontally, should be composed of. ' properly compacted soil fill materials approved by the Consultant. Rock fill may extend to the slope face, provided that the slope is not steeper than 2:1 (horizontal: vertical) and a soil layer no thicker than 12 inches is track-walked onto the face for landscaping purposes. This procedure may be utilized, provided it is acceptable to the governing agency, Owner and Consultant. 3.5. Representative samples of soil materials to be used for fill shall be tested in the laboratory I by the Consultant to 'determine the maximum density, optimum moisture content, and, where appropriate, shear strength, expansion, and gradation characteristics of the soil. 3.6. During grading, soil or groundwater conditions other than those identified in, the Geotechnical Report may be encountered by the Contractor. The Consultant shall be notified immediately to evaluate the significance of the unanticipated condition I . 4. CLEARING AND PREPARING AREAS TO BE FILLED 4.1. Areas to be excavated and filled shall be cleared and grubbed. Claring shall consist of I complete removal above the ground surface of trees, stump, brush, vegetation, manmade structures, and similar debris. Grubbing shall consist of removal of stumps, roots, buried 1 . . logs and other unsuitable material and shall be performed in areas to be graded. Roots and other projections exceeding 1-1/2 inches in diameter shall be removed to a depth of 3 feet below the surface of the ground. Borrow areas shall be grubbed to the extent necessary to 1 provide suitable fill materials. GI rev. 07/02 '1 . 0 4.2. Any asphalt pavement material removed during clearing operations should be properly disposed at an approved off-site facility. Concrete fragments which are free of reinforcing steel may be placed in fills, 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 shall be removed to the depth recommended in the Geotechnical Report. The depth of removal and compaction shall be observed and approved by a representative of the Consultant. The exposed surface shall then be plowed or scarified to a minimum depth of 6 inches and until 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 (horizontal: vertical), or where recommended by the Consultant, the original ground should be benched in accordance with the following illustration. TYPICAL BENCHING DETAIL Fin Original Ground Finish Slope Surface Remove All Unsuitable Material As Recommended By S oil Engineer Slope To Be Such That . Sloughing Or Sliding Does Not Occur Varies - See Note 1 See Note 2 I _ No Scale :1 DETAIL NOTES: 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 I key should be graded horizontal, or inclined slightly into the natural slope. • The outside of the bottom key should be below the topsoil or unsuitable surficial material and at least 2 feet into dense formational material. Where hard rock is I exposed in the bottom of the key, the depth and configuration of the key may be modified as approved by the Consultant 1: • • - - • GI rev. 07/02 I 4.5. After areas to receive fill have been cleared, plowed or scarified, the surfaceshould be disced or bladed by the Contractor until 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 fill shall be accomplished by sheepsfoot or segmented-steel wheeled rollers, vibratory rollers, multiple-wheel pneumatic-tired rollers, or other types of acceptable compaction equipment. Equipment shall be of such a design that it will be capable of compacting the soil or soil-rock fill to the specified relative compaction at the specified moisture content. 5.2. Compaction of rock fills shall be performed in accordance with Section 6.3. 6. PLACING, SPREADING AND COMPACTION OF FILL MATERIAL 6.1. Soil fill, as defined in Paragraph 3.1.1, shall be placed by the Contractor in accordance with the following recommendations: 6.1.1. Soil fill shall be placed by the Contractor in layers that, when compacted, should generally not exceed 8 inches. Each layer shall be spread evenly and shall be thoroughly mixed during spreading to obtain uniformity of material and moisture in each layer. The entire fill shall be constructed as a unit in nearly level lifts. Rock materials greater than 12 inches in maximum dimension shall be placed in accordance with Section 6.2 or 6.3 of these specifications. 6.1.2. In general, the soil fill shall be compacted at a moisture content at or above the optimum moisture content as determined by ASTM D1557-00. 6.1.3. When the moisture content of soil fill is below that specified by the Consultant, water shall be added by the. Contractor until the moisture content is in the range specified. 6.1.4. When the moisture content of the soil fill is above the range specified by the Consultant or too wet to achieve proper compaction, the soil fill shall be aerated by the Contractor.by blading/mixing, or other satisfactory methods until the moisture content is within the range specified. . . Gi rev. 07/02 I 6.1.5. After each layer has been placed, mixed,. and spread evenly, it shall be thoroughly I . 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 I dry density of the compacted fill to the maximum laboratory dry density as determined in accordance with ASTM D1557-00. Compaction shall be continuous over the entire area, and compaction equipment shall make sufficient passes so that I the specified minimum relative compaction has been achieved throughout the entire fill. ' V 6.1.6. Soils having an Expansion Index of greater than 50 may be used in fills if placed at least 3 feet below finish pad grade and should be compacted at a. moisture content 1' generally '2 to 4 percent greater than the optimum moisture content for the material. I ' 6.1.7. Properly compacted soil fill shall extend to the design surface of fill slopes. To achieve proper compaction, it is recommended that fill slopes be over-built by at least 3 feet and then' cut to the design grade. This procedure is considered' I . preferable to track-walking of slopes, as described in the following paragraph. 6.1.8. As an alternative to over-building of slopes, slope faces may be back-rolled with a heavy-duty loaded sheepsfoot or vibratory roller at maximum 4-foot fill height 'I intervals. Upon completion, slopes should then be track-walked with a D-8 dozer or similar equipment, such that a dozer track covers all slope surfaces at least twice. 6:2. Soil-rock fill, as defined in Paragraph 3.1.2, shall be placed by the Contractor in accordance - with the following recommendations: V V -' 6.2.1. Rocks larger than 12 inches but less than 4 feet in maximum dimension may be 'I V incorporated into the compacted soil fill, but shall be limited to the area measured 15 feet minimum horizontally from the slope face and 5 feet below finish gr4dé or '3 feet below the deepest utility, whichever is deeper. / 6.2.2. Rocks or rock fragments up to 4 feet in maximum dimension may either 1 . . individually placed or placed in windrows. Under certain conditions, rocks or rock fragments up to 10 feet in maximum dimension may be placed using similat I methods. The acceptability of placing rock materials greater than 4 feet in maximum dimension shall be evaluated during grading as Specific cases arise and shall' be approved by the Consultant prior'to placement.' GI rev. 07/02 1. I 6.2.3. For individual placement, sufficient space shall be,provided between rocks to allow for passage of compaction equipment. 6.2.4. For windrow placement, the rocks' should be placed in trenches excavated in properly compacted soil fill. Trenches should be approximately 5 feet wide and 4 feet deep in maximum dimension. The voids around and beneathrocks should be filled with approved granular soil having a Sand Equivalent of 30 or greater and should be "compacted by flooding. Windrows may also be placed utilizing 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 generally be parallel to each other and may be placed either parallel to or perpendicular to the face of the slope depending on the site geometry. The minimum horizontal spacing for windrows shall be 12 feet center-to-center with a 5-foot stagger or offset from lower courses to next overlying course. The minimum vertical spaci1g between windrow courses shall be 2 feet from the top of a lower windrow to the bottom of the next higher windrow. 6.2.6. All rock placement, fill placement and flooding of approved granular soil in the v'indrows must be continuously observed by the Consultant or his representative. 6.3. Rock fills, as defined in Section 3.1.3., shall be placed by the Contractor in accordance with the following recommendations: 6.3.1. The base of the rock fill shall be placed 'on a sloping surface (minimum slope of 2 percent, maximum slope of 5 percent). The surface shall slope toward suitable subdrainage outlet facilities The rock fills shall be provided with subdrains during construction so that a hydrostatic pressure buildup does"not develop. The subdrains shall be permanently connected to controlled drainage facilities to control pOst- construCtion infiltration of water. 6.3.2. Rock fills shall'beplace' in 'lifts not exceeding 3 feet. Placement shall be by rock trucks traversing prevj,d5isly placed lifts and dumping at the edge of the currently placed lift. Spreading of the rock fill shall be by dozer to facilitate seating of the rock. The rock fill shall 'be watered heavily during placement. Watering shall consist of water trucks traversing in front of the current rock lift face and spraying water continuously during, rock placement. Compaction equipment with compactive energy comparable to or greater than that of a 20-ton steel vibratory roller or other compaction equipment providing suitable energy to achieve the required compaction or deflection as recommended in Paragraph 6.3.3 shall be GI rev. 07 I. utilized. The number of passes to be made will be determined as described in I Paragraph 6.3.3. Once a rock fill lift has been covered with soil fill, no additional rock fill lifts will be permitted over the soil fill. 6.3.3. Plate 'bearing in tests, accordance with ASTM Dl 196-93, may be performed in both the compacted soil fill and in the rock fill to aid in determining the number of 1 passes of the compaction equipment to be performed. If performed, a minimum of three plate bearing tests shall be performed in the properly compacted soil fill I (minimum relative compaction of 90 percent). Plate bearing tests shall then be performed on areas of rock fill having two passes, four passes and six passes of the compaction equipment, respectively. The number of passes required for the rock' fill shall be determined by comparing the results of the plate bearing tests for the soil fill and the rock fill and by evaluating the deflection variation with number of I passes. The required number of passes of the compaction equipment will be performed as necessary until the plate bearing deflections are equal to or less than that determined for the properly compacted soil fill. In no case will the required I number of passes be less than two. I 6.3.4. A representative of the Consultant shall be present during rock fill operations to verify that the minimum number of 'passes" have been obtained, that water is being properly applied and that specified procedures are being followed. The actual number of plate bearing tests will be determined by the Consultant during grading. In general, at least one test should be performed for each approximately 5,000 to '1 10,000 cubic yards of rock fill placed. . I 6.3.5. Test pits shall be excavated by the Contractor so that the Consultant can state that, in his opinion, sufficient water is present and that voids between large rocks are properly filled with smaller, rock material. Inplace density testing will not be I required in the rock fills. 6.3.6. To reduce the potential for "piping" of fines into the rock fill from overlying soil fill material, a 2-foot layer of graded filter material shall be placed above the uppermost lift of rock fill. The need to place graded filter material below the rock I ' should be determined by the consultant prior to commencing . grading. The gradation of the graded filter material will be determined at the time the rock fill is ' being excavated. Materials typical of the rock fill should be submitted to the Consultant in a timely manner, to allow design of the graded filter prior to the 11 commencement of rock fill placement. GI rev, 07/02 I I 6.3.7. All rock fill plaèement shall be continuously observed during placement by. representatives of the Consultant. I . . 7. OBSERVATION AND TESTING - 7.1. The Consultant shall be the Owners representative to observe and perform tests during 'I .. clearing, grubbing, and filling and compaction operations. In general, no more than 2 feet• in vertical elevation of soil or soil-rock fill shall be-placed without at least one field density - test being performed within that interval. In addition, a minimum of one field density test 1 shall be performed for every 2,000 cubic yards of soil or soil-rock fill placed and compacted. 7.2. The Consultant shall perform random field density tests of the compacted soil or soil-rock I fill to provide a basis for expressing an opinion as to, whether the fill material is compacted as specified. Density tests shall be performed in the compacted materials below any disturbed surface. When these tests indicate that the density of any layer of fill or portion (. thereof is below that specified, the particular layer or areas represented by the test shall be reworked until the specified density has been achieved. 7.3. During placement of rock fill, the Consultant shall verif' that the minimum number of passes have been obtained per the criteriadiscussed in Section 6.3.3, The Consultant shall request the excavation of observation pits and may perform plate bearing tests on the placed rock fills. The observation pits will be excavated to provide a basis for expressing an opinion as to whether the rock fill is properly seated and sufficient moisture has been applied to the material. If performed, plate bearing tests will be performed randomly on the surface of the most-recently placed lift.' Plate bearing tests will be performed to provide a 1 . basis for expressing an opinion as to whether the rock fill is adequately seated. The maximum deflection in the rock fill determined in Section 6.3.3 'shall be less' than the I maximum deflection of the properly compacted soil fill. When any of the above criteria indicate that a layer of rock fill or any portion thereof is below that specified, the affected layer or area shall be reworked until the rock fill has been ,adëquately seated and sufficient moisture applied. . , 1 7.4. A settlement monitoring program designed by the Consultant may be conducted in areas of rock fill placement. The specific design of the monitoring program shall be as I. recommended in the. Conclusions, and Recommendations section of the project Geotechnical Report or in the final 'report of testing and observation services performed during grading. k GI rev. 07/02 7.5. The Consultant shall observe the placement of subdrains, to verify that the drainage devices I have been placed and constructed in substantial conformance with project specifications. 7.6. Testing procedures shall conform to the following Standards as appropriate: 7.6.1. Soil and Soil-Rock Fills: .1 7.6.1.1. Field Density Test, ASTM D1556-00, Density of Soil In-Place By the Sand-Cone Method. 7.6.1.2. Field Density Test, Nuclear Method, ASTM D2922-96, Density of Soil and I Soil-Aggregate In-Place by Nuclear Methods (Shallow Depth). 7.6.1.3. Laboratory Compaction Test, ASTM D1557-00, Moisture-Density Relations of Soils and Soil-Aggregate Mixtures Using 10-Pound Hammer I and 18-Inch Drop: I t 7.6.1.4. Expansion Index Test, ASTM D4829-95, Expansion Index Test. 7.6.2., Rock Fills 7.6.2.1. Field Plate Bearing Test, ASTM D1196-93 (Reapproved 1997) Standard Method for Nonreparative 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. During construction, the Contractor shall properly grade all excavated surfaces to provide positive drainage and prevent ponding of water. Drainage of surface water shall be controlled to avoid damage to adjoining properties or to finished work on the site. The - Contractor shall take remedial measures to prevent erosion of freshly graded areas until such time as permanent drainage and erosion control features have been installed. Areas subjected to erosion or sedimentation shall be properly prepared in accordance with the Specifications prior to placing additional fill or structures. 8.2. ,After completion of grading as observed and tested by the Consultant, no further excavation or filling shall be conducted except in conjunction with the services of the - Consultant. GI rev. 07/02 9. CERTIFICATIONS AND FINAL REPORTS 9.1. Upon completion of the work, Contractor shall furnish Owner a certification by the Civil Engineer stating that the lots and/or building pads are graded to within 0.1 foot vertically of elevations shown on the grading plan and that all tops and toes of slopes are within 0.5 foot horizontally of the positions shown on the grading plans. After installation of a section of subdrain, the project Civil Engineer should survey its location and prepare an as-built plan of the subdrain location The project Civil 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 soil and geologic report satisfactory to the appropriate governing or accepting agencies. The as-graded report should be prepared and signed by a California licensed Civil 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. • GI rev. 07/02