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Home My WebLink About; Stagecoach Park Geotechnical Investigation; Stagecoach Park Supplemental Geotechnical Investigation; 1986-04-18SUPPLEMENTAL GEOTECHNICAL INVESTIGATION FOR STAGECOACH PARK CARLSBAD, CALIFORNIA For CITY OF CARLSBAD Carlsbad, California By GEOCON, INCORPORATED San Diego, California April, 1986 INCORPORATED ENGINEERS AND GEOLOGISTS • CONSULTANTS IN THE APPLIED EARTH SCIENCES File No. D-3480-J02 April 18, 1986 City of Carlsbad Engineering Department 1200 Elm Avenue Carlsbad, California 92008 Attention: Subject: Gentlemen: Mr. Donald E. "Gene" Donovan City Engineer STAGECOACH PARK CARLSBAD, CALIFORNIA SUPPLEMENTAL GEOTECHNICAL INVESTIGATION In response to your request, we have performed a supplemental geotechnical investigation for a portion of the Stagecoach Park Site. The accompanying report presents our findings of that study as well as conclusions and recommendations based on those findings. Should you have any questions or if we can be of further service, please contact the undersigned. Very truly yours, GEOCON, INCORPORATED Michael R. Rahilly RCE 28188 AEF:MRR:lm (4) addressee Andrew E. Farkas CEG 1185 9530 DOWDY DRIVE • SAN DIEGO, CALIFORNIA 92126 • PHONE (619) 695-2880 TABLE OF CONTENTS SUPPLEMENTAL GEOTECHNICAL INVESTIGATION Page Purpose and Scope 1 Site and Project Description 2 Soil and Geologic Conditions 2 Santiago Peak Volcanics 3 Delmar Formation 3 Landslides 4 Groundwater 4 CONCLUSIONS AND RECOMMENDATIONS General 5 LIMITATIONS AND UNIFORMITY OF CONDITIONS . . . 7 Figure 1, Site Plan (Map Pocket) Figure 2, Cross-Section APPENDIX A FIELD INVESTIGATION Figures A-l - A-9, Logs of Test Borings GEOCON INCORPORATED D File No. D-3480-J02 April 18, 1986 SUPPLEMENTAL GEOTECHNICAL INVESTIGATION Purpose and Scope This report presents the results of a supplemental geotechnical investiga- tion within the eastern corner of the Stagecoach Park project and within a limited area of the City of Carlsbad Tract No. 75-9 adjacent to the east (see Site Plan, Figure 1). It is our understanding that Eberhard and Stone, Incorporated identified a landslide during excavation of a cut slope easterly of Mision Estancia within Tract No. 75-9. Subsequent test borings by Eberhard and Stone, Incorporated indicated a deep-seated landslide extending from Tract No. 75-9 below Mision Estancia and emerging within the estern portion of Stagecoach Park and the property northerly of the Park. The landslide proposed by Eberhart and Stone, Incorporated has approximate dimensions of 700 feet in length, 600 feet in width and maximum depths in excess of 50 feet. The purpose of our supplemental investigation was to evaluate the presence of the landslide and to provide recommendations for mitigation of the landslide potential, if present. The subsurface exploration consisted of drilling five large-diameter borings. Previous geotechnical studies performed for the project were reviewed. Geologic cross-sections and maps prepared by Eberhart and Stone, Incorporated presenting some of the information gained during their recent subsurface investigation were also reviewed. The enclosed Figures 1 and 2 are copies of the Grading Plan and Geologic Cross-Section provided by -1- GEOCON INCORPORATED File No. D-3480-J02 April 18, 1986 Eberhart and Stone, Incorporated. Stereoscopic aerial photographs dated March, 1953 and topographic maps were also analyzed to aid in the preparation of this report. A more detailed description of the procedures and methods utilized during the field investigation is presented in Appendix A. The conclusions and recommendations that follow are hased on an analysis of the data obtained and our experience with similar soil and geologic conditions. Site and Project Description At the time of this subsurface exploration, grading on the subject Stagecoach Park project site was essentially completed. The grading resulted in creating several large pads and some cut and fill slopes. One of the cut slopes extends down from Mision Estancia to the Park site in the subject investigated area. Mision Estancia, which represents a future four-lane traffic artery, was under construction at the top of the cut slope. Some fill soils found in the test borings were associated with the Mision Estancia Road easement. On the adjacent Carlsbad Tract No. 75-9, grading was in progress during this supplemental subsurface investigation. Soil and Geologic Conditions As indicated by the exploratory borings, the investigated area is underlain by the Jurassic Santiago Peak Volcanics, the Eocene Delmar Formation landslide debris and fill. Each of these is described below. -2- GEOCON INCORPORATED File No. D-3480-J02 April 18, 1986 Santiago Peak Volcanics. Very hard, angular, metavoloanic rock fragments were encountered in Boring Nos. 2 and 3. It is probable that these fragments are not part of a massive Santiago Peak Volcanics occurrence and, more likely, they were incorporated in the Delmar Formation during the deposition of its basal sequence. Due to its depth below finish grades at this location, the Santiago Peak Volcanics appear to be of no significance to the future development. Delmar Formation. The Delmar Formation in the investigated area consists of a sequence of claystones, siltstones and sandstones. As previously indicated, a breccia-like facies also occurs along the contact with the underlying Santiago Peak Volcanics. The claystone beds within the Delmar Formation are typically characterized by low shear strength and a high degree of fracturing. Numerous randomly oriented shear zones are also very common within the clayey portions of the Delmar Formation. Unlike the claystone beds, the siltstone, and particularly the sandstone beds of this geologic unit, exhibit good geotechnical characteristics. Within the upper approximately 30 feet of Boring No. 1, numerous minor random shear planes were encountered, however, no shear zones suggesting the presence of a landslide were observed. Fracturing encountered in Boring Nos. 2 and 3 was less significant. Therefore, it is our opinion that the fracturing and minor random shearing is likely to be related to past tectonic activity in the Southern California region rather than landsliding as suggested by the Eberhart and Stone, Incorporated investigation. -3- GEOCON INCORPORATED File No. D-3480-J02 April 18, 1986 Landslides A relatively shallow landslide was encountered on the adjacent Carlsbad Tract No. 75-9. As revealed by Boring Nos. 4 and 5 and also in exposures of recent cut slopes, this feature may not exceed 20 feet in maximum depth. Although the limits of the landslide were not directly observed, the possible limits are indicated on the Site Plan, Figure 1, based on topographic expression and extrapolation of boring data (see Site Plan, Figure 1 and Geologic Cross-Section, Figure 2). At the time of this investigation, most of the small landslide encountered on Carlsbad Tract No. 75-9 was already removed by grading. In our opinion, in its actual condition this slide does not represent a geotecbnical constraint to the Stagecoach Park. Groundwater Minor random seeps were encountered in Poring Nos. 1 and 3 between the approximate elevations of 212 and 205 feet MSL, respectively. Moderate general seepage was encountered in Boring No. 3 at 196+_ feet MSL elevation. It is possible that this occurrence represents the high level of a permanent groundwater table in the general area. As suggested by the findings from our exploratory borings, the piezometric surface is sloping gently to the south. GEOCON INCORPORATED File No. D-3480-J02 April 18, 1986 CONCLUSIONS AND RECOMMENDATIONS General 1. It is our opinion based on this subsurface exploration tbat a small landslide approximately 20 feet in depth exists on Carlsbad Tract No. 75-9 immediately east of Mision Estancia. The determination of the limits of sliding within Tract 75-9 was beyond the scope of this investigation. This study indicates that the landslide does not extend westerly beyond Mision Estancia and, hence, in our opinion, it does not represent a potential geotechnical constraint to development of Stagecoach Park. 2. Moderate to high fracturing and random minor shearing was encountered within the more clayey portion of the Delmar Formation. It is likely that fractured claystones exist within the approximately 20-foot-high 2.0 to 1.0 cut slope at the Stagecoach Park easternmost corner. However, most of the fracturing and shearing appears to be favorably oriented with respect to the cut slope. It is, therefore, our opinion that the factor-of-safety against both deep-seated and surficial failures should be satisfactory. 3. Several minor seeps were encountered in Boring Nos. 1 and 3. Moderate general seepage was also observed in Boring No. 3 at approximately 196 feet MSL elevation. It is our opinion that at the present levels, the ground- water will have little or no impact on the subject project. 4. In order to improve the surficial stability of the 20-foot-high cut slope at Stagecoach Park easternmost corner, it is recommended that the ^r GEOCON INCORPORATED File No. D-3480-J02 April 18, 1986 slope be planted with deep-rooted, drought-resistant shrubs or trees and native plants and grasses. Large-leafed iceplant should not he used on slopes. Slope watering should be kept to a minimum to just support the vegetative cover. 5. It is understood that a "Third Party" geotechnical consultant will be retained to perform a supplemental investigation of the subject area. It is requested that Geocon, Incorporated be informed of the time of the field investigation and that we be permitted to observed the test borings with the "Third Party" consultant. -6- GEOCON INCORPORATED File No. D-3480-J02 April 18, 1986 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. If any variations or undesirable conditions are encountered during construction, or if the proposed construction will differ from that planned at the present time, Geocon, Incorporated should be notified so that supplemental recom- mendations 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. GEOCON INCORPORATED File No. D-3480-J02 April 18, 1986 APPENDIX A FIELD INVESTIGATION The field investigation was performed on April 1 and April 2, 1986 and consisted of the excavation of five large-diameter exploratory borings to depths ranging from 13 to 71 feet below existing ground surface. The approximate locations of the exploratory excavations are shown on the attached Figure 1, Site Plan. Drilling was accomplished by a truck-mounted caisson-type drill rig equipped with a 30-inch-diameter bucket auger. The soils encountered in the exploratory excavations were continuously examined, visually classified and down-hole logged. The logs of test borings are presented on Figures A-l through A-9 of in Appendix A. The logs depict the depth and description of the various soil types encountered, seepage occurrences and geologic relationships of the units. GEOCON INCORPORATED File No. D-3480-J02 April 18, 1986 x h Q . 0 "* ™ - 2 . - 4 . — _ 6 - - - 10 -"• . J- W ™ •* • - 12 - - 14 - - 16 - " - 18- - 20 - - 22- - 24- - 26- - 28- » — 30 Oz LU Q. •lE ^co HOLOGYf~ — ' i/^ •''•'••• : ''.y^ ^••: ::'x^ X'-! ".'.' - •' .'^/^ pn / / / / . ./ / & n<iVO /> D !%» <%»^V^o~ 7/ / 7£~ //j<W*,av y / /JNDWATER]_j>O ^C C/5 ^0 O " — 'C/D ~=~ BORING 1 ELEVATION 256 DATE DRILLED 4/1/86 EQUIPMENT MATERIAL DESCRIPTION FILL Medium stiff, moist, mottled Sandy CLAY COLLUVIUM Stiff, moist, light brown, Sandy CLAY DELMAR FORMATION Stiff, moist, highly weathered, olive CLAYSTONE with randomly oriented minor shear zones / grades into highly fractured, weathered, J calichefied, mottled olive-brown SILTSTONE / numerous minor fractures, oriented south, / some caliche and iron oxide and manganese staining along fractures Hard, humid, mottled olive-rust brown CLAYSTONE with pebbles and small rip-up clasts / — minor shear zone, attitude N5 °W/30 ° E J Stiff, moist, mottled, olive-purple CLAYSTONE shear zone, attitude N35°W/72°E \ Stiff, moist, mottled purplish-gray T CLAYSTONEI\1 — minor discontinuous shear plane, dips NW30 ETRATIONilSTANCEDWS/FT.^ — jul ^ CD Ql'3" • • • - " „ " m • " - _ - - .DENSITY IP.C.F. I>-crQ fT* i_j" ^~ LU T^t ~z\J 2 ^o Figure A-l, Log of Test Boring 1 Continued next page SAMPLE SYMBOLS U SAMPLING UNSUCCESSFUL 13 — DISTURBED OR BAG SAMPLE C — STANDARD PENETRATION TEST iy_CHUNK SAMPLE 3 — DRIVE SAMPLE (UNDISTURBED) ?• — WATER TABLE OR SEEPAGE GEOCON INCORPORATED File No. D-3480-J02 April 18, 1986 X ,_ - 32 - - - 34- - 36-_ - 38- - 40- -'42- ™* * -44- - 46-T \J - 48- - - 50- - 52- - 54- - - 56- - - 60- - 62 SAMPLE NO.-*:LITHOLOGY/^^ / <** y£*. / ' / ~/ y/^- / / ^ <w £. •^ *" •* *0 s* >• -:3ROUNDWATER|w »-SOIL CLASS 1(U.S.C.S.) Ixv /' BORING 1 CONTINUED ELEVATION DATE DRILLED EQUIPMENT MATERIAL DESCRIPTION ~\ -\ ^ — minor shear zone, attitude N80°E/36°N \ \ ^ — shear zone, attitude N50°W/26°NE numerous randomly oriented minor shelar zones grades into very hard, fractured, humid, mottled dark gray-purplish SILTSTONE, iron oxide staining \ \ easterly dipping minor shear planes •\ \ \ minor seepage on the north wall -\ \ becomes very hard, massive, moist, mottled dark gray-rusty SILTSTONE moderate seepage on the north wall — :— minor shear zone, attitude N25 *>W/20°E Break in log BORING TERMINATED AT 62.0 FEET PENETRATIONRESISTANCEBLOWS/FT.• • • . . - • * • m - - - - • • - - -DRY DENSITY IP.C.F. IMOISTURE 1CONTENT, % IQ Figure A-2, Log of Test Boring 1 Continued OAHI-H coAMrLt - SAMPLING UNSUCCESSFUL — DISTURBED OR BAG SAMPLE [I - STANDARD PENETRATION TEST SU _ CHUNK SAMPLE H - DRIVE SAMPLE (UNDISTURBED) ?• _ WATER TABLE OR SEEPAGE GEOCON INCORPORATED File No. D-3480-J02 April 18, 1986 I ,_ S^~U-Q . 0 ~ "• . 2. 4 _ - . 6 . . 8_ _ 10 . . 12 . 1 4• L H — - - 16- - 18 - - - 20- - 22- - • - . 24- - - 26- - - 28- 30 dz QJ_j Q. < C/5 x / / } £ >/ A s cc c• h / ' '' / / / / / ;/ / K- 3D J 3 - J / / / / / J/ PC / /I / X / X '-'.:' ' / -•» y/ cr LU ^<:Q Z ^^ __J CO ^C CO WD oSw „ _ _ BORING 2 Fl FVATION 256 H DATE DRILLED 4/1/86 FOUIPMFNT MATERIAL DESCRIPTION FILL Loose, humid, yellowish-tan SAND with sandstone fragments DELMAR FORMATION Stiff, highly fractured, moist, olive-gray CLAYSTONE/ SILTSTONE / Very dense, moist, light gray, weakly / cemented, medium-grained SANDSTONE, bedding / attitude N5°W/5°W ! — grades into fractured, moist, light gray, / Clayey SILTSTONE with occasional small ' — grades into very dense, stiff, moist, / mottled, Clayey SILTSTONE/CLAYSTONE with -/ shiny parting surfaces and frequent syngenetic Sandy zones / grades into stiff, massive, fractured, 1 moist, mottled light gray to rust brown, ' Silty CLAYSTONE with shiny parting surfaces • and randomly oriented minor shear planes 1 shear zone, poorly developed bedding plane / fault, apparently discontinuous, dips 1 gently N-NE(15°?) J poorly developed shear zone, dips 35°SE /J / — becomes stiff, mottled, fractured CLAYSTONE UJ ^J f} t" <<c/5 H~ CO ^^ z{2mo_oc * • • " - . . - . - " . - - - - - - £ C/5 ZLL UJQ QCL CC Q 4 C*^2 «K ioo - Figure A-3, Log of Test Boring 2 Continued next page SAMPLE SYMBOLS LJ _ SAMPLING UNSUCCESSFUL EH — DISTURBED On BAG SAMPLE U—STANDARD PENETRATION TEST •J CHUNK SAMPLE Ei — DRIVE SAMPLE (UNDISTURBED) ?• — WATER TABLE OR SEEPAGE ATTHE DATE INDICATED. I GEOCON INCORPORATED File No. D-3480-J02 April 18. 1986 x ,_ . 30 - . 32. . 34. . 36. . 38. " - 40- - - 42. - 44. - 46-_ - 48- - 50- - 52- - 54- - - 56- - 58- 60 SAMPLE NO.LITHOLOGY'A, / * // / / / - / / / /A / ' / ' / / / 7 . / / / A \ ^ (/3ROUNDWATERJV-* C/D OT —^ CO (f$ %~ \\\\\> / / BORING 2 CONTINUED ELEVATION DATE DRILLED EQUIPMENT MATERIAL DESCRIPTION grades into hard, humid, dark gray/olive, Clayey SILTSTONE/CLAYSTONE with numerous limonite nodules purplish, hematite staining grades into very stiff, olive, gray, moist, massive, Silty CLAYSTONE i Hard, humid, mottled gray-rust, dark brown SILTSTONE J PENETRATIONRESISTANCEBLOWS/FT.- . • • " - • • . • • - - - - •DRY DENSITYP.C.F.MOISTURECONTENT, %Figure A-4, Log of Test Boring 2 Continued Continued next page SAMPLE SYMBOLS Ll SAMPLING UNSUCCESSFUL El — DISTURBED OR BAG SAMPLE IJ STANDARD PENETRATION TEST E_CHUNK SAMPLE m __ DRIVE SAMPLE (UNDISTURBED) ?• — WATER TABLE OR SEEPAGE ATTHE DATE INDICATED. IT IS NOTWARRANTEDTO BE REPRESENTATIVEOFSUBSUHFACECONDITIONS AT OTHER LOCATIONS AND TIMES.GEOCON INCORPORATED File No. D-3480-J02 April 18, 1986 x K £<-£ . 60. H « - 62- -64- "™ ™ - 66- - 68- - - 70- - 72- Oz UJ Q. V) >-o0 0j; '. •/.: '• ^'- •j- " • •' '• •j.-/. .T. -•/-''•> ^M S';:^ •7 •/-'/. '. •/. : • v • •^, rrUJ 1u § ?£tf "^ 8~ BORING 2 CONTINUED ELEVATION DATE DRILLED EQUIPMENT MATERIAL DESCRIPTION • thickness of gouge l/16"-l/8", attitude ~\ N15,°W/70°N \ Very dense, moist, olive BRECCIA, angular metavolcanic rock fragments in Sandy/Clayey matrix BORING TERMINATED AT 71.0 FEET ||t t-o 5|m " - • - - t C/Dzu: UJ(j°o; enQ LU# §£• W^ ^8 Figure A-5, Log of Test Boring 2 Continued SAMPLE SYMBOLS U — SAMPLING UNSUCCESSFUL K — DISTURBED OR BAG SAMPLE I] — STANDARD PENETRATION TEST IJ—'CHUNK SAMPLE • — DRIVE SAMPLE (UNDISTURBED) ?• — WATER TABLE OR SEEPAGE ATTHE DATE INDICATED. IT IS NOTWARRANTED TO BE REPRESS NTATIVEOFSUBSURFACECONDITIONS AT OTHER LOCATIONS AND TIMES GEOCON INCORPORATED File No. D-3480-J02 April 18, 1986 X ,_ Q _ ?- - 4- - - 6- - 8- - - 10-_ - 12 • - - 14 ' - . - 16 - • 18 • " - 20 - ' 22- ' 24- IB « " 26- - • 28- dz LU Q. <co / ' ~ / / ' ( \ // / / / ^ / ' // // >-3 _i DQ ZJ i-.'. / / //'*\ / •' / I'.'.'- ' / /_ *"* / ^/ / 'JNDWATER |0o: C_J „ CO CO — oSco \\\\ / / BORING 3 ELEVATION 226 DATE DRILLED 4/2/86 EQUIPMENT MATERIAL DESCRIPTION FILL Soft, wet, light brown-gray, Silty Sandy CLAY \ DELMAR FORMATION Stiff, fractured, moist, olive gray, Clayey SILTSTONE _ minor shear plane, attitude approximately ; E-W/45°N ' J ( purplish iron oxide staining, shiny / parting surfaces .'' J f— — poorly developed, minor shear zone, j attitude N60°E/25°m>f grades into hard to very hard, moist, dark gray SILTSTONE, purplish iron oxide staining light seepage on NW and SW walls / — grades into hard, moist, olive gray 1 SILTSTONE with iron oxide staining J grades into hard, dark olive gray, Sandy / SILTSTONE/ SANDSTONE/ETRATIONDISTANCEDWS/FT.ZUJ_J Q^CC • • - . • - - . • • • • " " - • - • - - -DENSITYP.C.F.Q; Q QH U-T ^— III r^t "7\j *- O Figure A-6, Log of Test Boring 3 Continued next page o.uni rr fWiioSM oSAMPLc oYMbOLta *— ' - SAMPLING UNSUCCESSFUL K — DISTURBED OR BAG SAMPLE I] - STANDARD PENETRATION TEST 3 - DRIVE SAMPLE (UNDISTURBED) m _ CHUNK SAMPLE ^r — WATER TABLE OR SEEPAGE ATTHE DATE INDICATED. ITISNOTWARRANTEDTO BE REPRESENTATIVEOFSUBSURFACECONDITIONSATOTHER LOCATIONS ANDTIMES.GEOCDN INCORPORATED File No. D-3480-J02 April 18, 1986 £Z5}H u.o - 32- - 34- - 36- - 38- - 40- - - 42- _ „ Oz LLJ 0. 3 -IOLOGY;: ^ ^^ AX;.':"J: ''•'•>^'-• •/• .- -. •• . . /\ : ^,; v :' /?' ^fi\V: y:'.::.^ (T JNDWATEOcro coco — SS BORING 3 CONTINUED ELEVATION DATE DRILLED EQUIPMENT MATERIAL DESCRIPTION moderate, general seepage Very dense, saturated, angular metavolcanic fragments in Clayey SAND matrix Santiago Peak Volcanics? Highly fractured , metavolcanic rocks BORING TERMINATED AT 44.0 FEET ||t f^ B • • - - - . . -DENSITYP.C.F.a:a LU# ^8 Figure A-7, Log .of Test Boring 3 Continued SAMPLE SYMBOLS SAMPLING UNSUCCESSFUL — DISTURBED OR BAG SAMPLE IJ — STANDARD PENETRATION TEST |y_CHUNK SAMPLE B — DRIVE SAMPLE (UNDISTURBED) ?• — WATER TABLE OR SEEPAGE GEOCON INCORPORATED File No. D-3480-J02 April 18, 1986 JE Kj . o - - - 2 - - - 4 - - - 6 - . - 8 - _ - 10 - - 12 - - 14 -_ -16 - - - 18 - " ' -20 - 2.2. -SAMPLE NO.LITHOLOGY••/^'- .'•'•' fc*~i~^;? / / / / / '/< - y y/ , , s .' > / i/ / s '•••/• *"". / ' /5ROUNDWATER|"*SOIL CLASS(U.SC.S)^ BORING 4 ELEVATION 270+' DATE DRILLED 4/2/86 EQUIPMENT MATERIAL DESCRIPTION LANDSLIDE DEBRIS Medium stiff, moist, mottled rust-red-gray, Sandy CLAY grades into medium dense, light brown, tan, fine SAND \V — shear zone, attitude N10°W/15°W\ \\1' — basal shear zone, attitude horizontal 1 \ DELMAR FORMATION \ Stiff, moist, fractured, dark olive gray, \ Clayey SILTSTONE -, Very dense, moist, light gray, weakly \ cemented, medium-grained SANDSTONE \\_ V Stiff, moist, fractured, mottled light \ gray-purple, Silty CLAYSTONE }\ \ Very hard, moist, dark gray, Clayey SILTSTONE \ \ \ 1 — Sandy zone A BORING TERMINATED AT 22.0 FEET PENETRATIONRESISTANCEBLOWS/FT. I• • - • • . , • . - - . . - • • " - - -DRY DENSITYP.C.F.MOISTURECONTENT, %Figure A-8, .Log of Test Boring A SAMPLE SYMBOLS U — SAMPLING UNSUCCESSFUL , [I STANDARD PENETRATION TEST £3 — DISTURBED OR BAG SAMPLE SJ — CHUNK SAMPLE Da DRIVE SAMPLE (UNDISTURBED) i WATER TABLE OR SEEPAGE - ATTHE DATE INDICATED. ITISNOTWARRANTEDTO BE REPRESENT ATIVEOFSUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.GEOCON INCOKPORATED File No. D-3480-J02 April 18, 1986 £ J- 0 - - 2 - - - 4 - - - 6 - - - 8 - - 1 0 - * ** - 12 - - 14 - 0 2 ill, _lQ. CO HOLOGYh- • •;_- • . . .1.I-.K s 7 / x\JNDWATER |ocr COco- co — -^-a BORING 5 Fl EVATION 270+ DATE DRILLED 4/2/86 EQUIPMENT MATERIAL DESCRIPTION LANDSLIDE DEBRIS Loose, dry, whitish-tan, fine SAND Basal shear zone, soft, moist, dark olive, / Silty CLAY, numerous gypsum crystals, ' thickness 3"-4", attitude N30 cE/4-cN \ DELMAR FORMATION Hard, fractured, dark olive-gray, Clayey SILTSTONE Very dense, humid, light brown-tan, weakly cemented, medium-grained SANDSTONE A BORING TERMINATED AT 13.0 FEET ETRATIONISTANCEDWS/FT.5£m • - • - - • "* • -DENSITYP.C.F.cr Q UJ# co£ ^ o Figure A-9, Log of Test Boring 5 SAMPLE SYMBOLS U — SAMPLING UNSUCCESSFUL E3 _ DISTURBED OR BAG SAMPLE _ STANDARD PENETRATION TEST l CHUNK SAMPLE DRIVE SAMPLE (UNDISTURBED) WATER TABLE OR SEEPAGE NOTE: ATTHE DATE INDICATED. I GEOCON INCORPORATED