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Home My WebLink AboutCT 76-17; CANON PARK UNIT 1, 2 AND 3; SOILS REPORT; 1977-01-03J, I ~ ~~:UNNEKOTTER • ENGINEERING GEOLOGY REGISTERED GEOLOGIST CERTIFIED ENGINEERING GEOLOGIST P. O. BOX 575 • ESCONDIDO, CALIF. 92025 746·2793 SUBSURFACE INVESTIGATION LA COSTA CANON PARK UNITS 1,2,& 1 LINES A29 THROJ, 129 JANUARY 3,1977 • GEOPHYSICAL INVE\iTlGATIONS . For Subdivision besi~n Pipelines • Roads . Seismic Rippability S!udies 1 T. FUNNEKOTTER REGISTERED GEOLOGIST CERTIFIED ENGINEERING GEOLOGIST p, 0, BOX 575 -ESCONDIDO, CALIF, 92025 746-2793 PURPOSE: METHOD: DISCUSSION: ENGINEERING GEOLOGY e GEOPHYSICAL INVESTIGATIONS , For Subdivision 'Design pipelirws -Roods Seismic Rippability Sludi(!S 1 To evaluate subsurface cond~tions at select locations in order to provide excavation and design information. Refraction Seismography. Geologic, rC?,cQnraissance. The area of interest is composed princip.~ll¥ ~f , " extrusive igneous flows (andesite·~nd rhyolite). The structural unit is the Black MOl,lnta~n VQJ.can-· ics. Several areas have a cover Of siity~ clay~y sand -most of this appears'to be from, a previous fill operation, though possibly not.al~. Twelve Seismic trave!:'ses were~l,l.n ..... labe·lled lines A29 thru L29 -located .. appr(,)xim~:tely as' shown on the enclpsed maps", SOI1!-e. J~h,e~ wer.~ alter-.. ed in length and position becaus~ 9:( trasll1l.J, . obstr- ""'., uctions and major elevati.on cban~es,.·,. Inl general, two to four'l~yers'e;X:ist"i.e.~, soil ,.' " --; ':' , and al+uvium., and/or fill mat-e~~9.-I, Q.ec9mpo{3e'd and . ,',' ,,-,.', .: fractured volcanics J and pard 'J' i'igid . .'volca-nics • . ". , . ,.' " ~ ' .. ,"! These layers are represented (by ;:the' following vel-. , . ocity ranges; 1100 to '1~OO ftl,$~CJ.2700 to 3$00 ft/sec, and 5500 to $000-ft!$'eq·,·:,: The following remarks in4ica,te :tl1e.II).ore pertin- ent results of each line:' Lines A29 &. B29 -high velocity volcanics from 6 T. FUNNEKOTTER REGISTERED GEOLOGIST CERTIFIED ENGINEERING GEOlOGIST p, 0, BOX 575 -ESCONDIDO, CALIF, 92025 746-2793 DISCUSSION: '\ ' ENGINEERING GEOLOGY e :: ~" GEOPHYSICAL INVESTIGATIONS to 13 feet de,ep. For Subqivision 'Design Pipeline~ -Ro~ds , Seismic Rippability Studins Line C29 -high velocity material at 20 to 26 feet deep. Fairly thick soil-alluvi~ cover. " Line D29 -high veloc ity volcG\nic~, at.· 7 to 11 feet deep. Line E29 -scattered bould!$!rs here' ,-,high' velocity horizon very irregular -1;3 to ,17 feet deep. , . Line F29 -high veloc ity m~terial" a"t ,9 to 23 feet deep. Scattered boulders here' •. Line G29 -13 feet to high, velQc·ity m,a~eri~l,' Line H29 -high velocity v91can~'cs. 9-:1J ,11 _ to. J? feet 0 Line 129 -~~gh veloc i'tyhqrizon' d~PP~,~g ~ou"thwest l' ,: ._~_ ( , ,.1., '. -from 15 to 29 Line J29 .:. high feet deep·~" 'No~e : .. :~'o!i;J,.: ~;bicknes~ 'here.' ~elocity' mate'r.i~~.:::4ipp:~ng ~O~~h - .... j: , , . from 15 to 27 feet -not ~ncount.e·reQ. op,' l,ast ,run from fStation 2.5 to 3.5 to -3; .. ~'~~i(':~~~p,,· . • -. t.," • Line K29 -all runs are o,n ~xisti~e;p~:y;i.$,.but' at different elevations·. No high velocit,y. materi~l " encountered on southea$t end. On ~emain~ng ,:r~ns , ' high velocity material was loc;at~d, at 2,7 to 36 / feet deep_ , '. " .," . --. ;-. .. ' Line L29 -high velocity materi~l a~,29 feet. ";- , ' Lines J29 and K29 f.lre no:t c~ntin~9\l§ b.ec9-use of ~ -,. ~ , ' major elevation changes alongth~ :~~nes~ This is an ,', -'.,.; , interfering factor that can, be m;lnimiz:a.d by. avoiding' T. FUNNEKOTTER REGISTERED GEO'LOGIST CERTIFIED ENGINEERING GEOlOGIST P. O. BOX 575 -ESCONDIDO. CALIF. 92025 746-2793 DISCUSSION: CONCLUSION: ENGINEERING GEOLOGY G£:;OPHYSICAL INVESTIGATIONS For Subdivision Design Pipelines • Roods Seismic RippobiJity Studies 'J runs over these major changes.· Two intermediate velocity layers were encountered on ,these.lines~, These are a 1700 to 1900 ft/sec layer and the 2900 to 3500 ft/sec layer. The 1700· to 1909 ft/se'c layer is a combination of fill material, sQil auo. alluvium • . Virtually all runs encountered high vel.ocity vol-, canics -as shallow as 6 feet .d~ep 't9'over 35 feet deep. The intermediate zone material ;tsinostly in 3000 to 3500 ft/sec range, however ~, l~rge ,area contains an additional intermediate zone .op, top in the 1700 to ,1900 ft/ sec range. TO;).$ ,latter material is in the southeast corner of'the,site' in the area of old, fills (lines J29 and K29)~ In this type of volcanic mate~ial, the high vel- ocity I horizon is often very errat,ic, rising and fal- ling rapidly in short distances~ BlQc~s of nard mat- erial are scattered about, the s';Lte ,e'speci'ally where indicated on the profile. See attached sheets for addi~ional Seismic -Rip- pability information. ., . " T. FUNNEKOTTER REGISTERED GEOLOGIST CERTIFIED ENGINEERING GEOLOGIST ENGINEERING GEOLOGY • '. GEOPHYSICAL INVESTIGATIONS For Subdivision Design Pipelines • Roads Seismic RiRpability Studies P. O. BOX 575 . ESCONDIDO, CAUF. 92025 746·2793 SEIST,HC -RIPPABILITY I~jFOm'~ATION The following points should be considered when evaluating Seismic information: 1. All velocities, depths, and thicknesses are averages and quafified as follows: G -good F -fair P -poor VP -very poor ? -questionable Grades of G,F, and P should be considered reliable; VP find? should be considered as indications only. 2. Each profile 9rovides information in the immediate area of that profile -extra90lation outward from this line must be considered speculative. In other words a velocity cross section is given along a specific line of investigation -10 to 20 feet fr,om this line the conditions could vary. In order to avoid any surprises between the Seismic lines additional Seismic lines would be in order • . 3. As the velocity of material increases, ripping becomes progressively more difficult until at some point it is more economical to drill and shoot the material ~rior to excavation. Rippability .also varies with the type of material; however, in general, D-9 Cat single ripper performance should be as follows: rippable to 5000 ft/sec, marginal from 5000 to 5500 ft/sec, and non-rippable over 5500 ft/sec. The' changeover from a rippine to a blasting operation usually occurs within the marginal zone. . To determine rippability is essentially an economic decision - whether to continue riW9ing at higher velocities or to blast at lower velocities depends on the type of job, type of equipment, . expertise of the operators, amount of excavation, how the rock is to be disposed of, time factor, etc. For example, in fractured rock a trench tYge of operation is more difficult than a hillside job, especially if boulders are 9resent. In a trench manuverability of the heavy equipment is limited and rock disposal is a bigger problem. The degree of fracturing is a factor in determining r1ppability, i.e., more fracturing, lower'velocities, easier ripping. The same velocity could represent either decomposed or fractured rock. 4. Boulders are identified as scattered boulders (SB), many boulders (HB), and large boulders (LB). These notations can also mean hard angular blocks. Large boulders are considered to be over 10 feet in diameter and even possibly to 30 feet J.n diameter •. L~ ____ ~---... . , T. FUNNEKOTTER REGISTERED GEOLOGIST CERTIFIED ENGINEERING GEOLOGIST ENGINEERING GEOLOGY GEOPHYSICAL INVESTIGATIONS For Subdivision Design Pipelines -Roads Seismic Rippability Studies P. O. BOX 575 -ESCONDIDO, CALIF. 92025 746-2793 SEISKIC -RIPPABILITY INFOill'::J~TION 5. For trenching operations, the rippability figure:;> must· be adjusted downward, i.e., velocities as low as 3500 ft/sec may indicate difficult ripping depending on the degree of fracturing of the rock. Fractured rock and even small boulders can be ve~y trouble- some in a narrO'IJIT trench. For example, decomposed grcmite is easier to dig than fractured granite even when the velocities are simj..lar. However, in general, based on a machine comparable to a Kohring 505, most materials with velocities of approximately 3800 ft/sec or less should be rippable, over h300 ft/sec non,.,rippable, and marginal in between. In a narrow trench a condition of ffial1Y boulders Ganbe almost as troublesome as solid rock ~iO the above figures should be used with discretion. .. -'!!!I-"'!""'------------------------------------~- r I \, . , .... .. T. FUNNEKOTTER REGISTERED GEOLOGIST CERTIFIED ENGINEERING GEOLOGIST • ~ ENGINEERING GEOLOGY GEOPHYSICAL INVESTIGATIONS For P. O. BOX 575 • ESCONDIDQ, CALIF. 92025 746·2793 Subdivision Design Pipelines • Roads Seismic RippQbility Studies RIPPABILITY SCHEDULE The following schedules should apply for the type of mate~ial encountered in this report: Based on a D-9 Cat Velocity (ft/sec) o to 2000 2000 to 5000 5000 to 5500 Over 5500 Excavation Method Scraper' Ripper Marginal Drill &, Shoot For trenching, based on a Kohring 505 Velocity (ft/sec) o to 3800 3800 to 4300 Over 4300 Excavation Method Ripper Marginal Drill Be Shoot