cee176-sp09-mt-Pestana-soln

cee176-sp09-mt-Pestana-soln - University ofCalifiJrnia....

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Unformatted text preview: University ofCalifiJrnia. Berkeley fi-I‘Iflel'i-IIE 9 CE176 Ember-mm Germain-tics asc' March 18, 2009 5 - Provide support for your answers. Be organized, concise and neat. Calculations must be clearly presented to obtain partial credit. (100 points) Part A: TRUE! FALSE QUESTIONS (2.5 pt each, total=10 pts) 1. The double layer of a clay particle, t, will decrease with decreasing dielectric constant, with increasing / cation concentration and increasing valence of exchangeable cation. ' (I) F 2. To obtain the lowest hydraulic conductivity for a compacted clay liner you must compact the soil with a water content higher than the optimum water content (wet side of the line of optima) in order to obtain / a “dispersed structure” T F 3. In general, as you decrease the hydraulic conductivity of compacted clay liners, the main mechanism / of contaminant migration changes from advection-dispersion to constrained molecular diffusion @D F 4. A material is considered hazardous when it contains a material listed as hazardous by the USEPA, displays hazardous characteristics (i.e., i gnitability, corrosivity, reactivity or toxicity) andlor causes environmental or health damage F Part B: Respond briefly to the following questions (5 pts each, total = 30 pts) 1. Describe (very briefly) some of th difficulties encountered in determining waste properties such as unit weight. strength and compressibility. ' slum ctr-ants act, to i W VII/1:5 m (N - 402ka be 5&9: 091mg“, nabs/L aquchl enacted bchow RM- \Ous’h'bfis 2. List (at least three) precesses affecting the movem t and change in concentration of a contaminant in groundwater and how would you reduce the risk associated with t se procesSes in a waste containment system .CKWBA ’5'- “ \o Gillan?“ VQWL")R¢ ‘NKvbmA --§ GMWMWW NRLMMb OC' - flb‘awphonw (aims/(2H0!) {/wa \wor ‘m 0W ‘mirumwvmh (Jr W Serum (m. renews: \DWfiU) What 3. Describe briefly what is chemical compatibility testing and what is the main testing difference between low hydraulic conductivity soils (e.g., clays) vs. high hydraulic conductivity soils (e.g., sands). Emmanth CoMQukW‘Mi‘NB SFCS-KM is Wis/Ynme vs avivr-wktr Mn CWm/Ust. tn k9 w (mutanme Qwfidfidflfl W3?sz m 0W \0 WM 35 \.0«’\uJ):-t’.rw\ w mam its W» “WM ksz> ii: MWw 0(- soix (Jimmie; W hm. (truf- (_\(,-...JJ_} lvgb ‘11:, My» 0N“) "LR m KIM/x r guy-(153)9f \s \Qgg, 00 we University of Berkeley Department of Civil and Enfirmnrmta] Engineering 9 C5176 Enfironmmlal Gunteclmits -2- Prof J. M. Pestam-Nascinmm 5. List three key elements of the Sealed Double Ring Infiltrometer used for field testing of hydraulic conductivity for clays. fir Maseru, 10 \W ‘vU\wwL cu- '\\ {B wmma 1‘ Shad“. V i n N WWCU\ dxmdrhn .u h draulic conducti t testin for comacted cla s : dvanta‘e of Laborator Testin 0" VESVV- in) {Bad ghuifixn 6. List one advanta e and one disadvanta - e for l . . Advantae of Laborato Testin Width/*3 awakens Gm Kfiwn Part C: SIMPLE QUESTION Sf MULTIPLE CHOICE: Provide support for your answer (10 points each) 1. A 0.60m thick drainage blanket constructed with gravely sand, k =5 cmfsec was specified in the design phase of your project. This material is not available in sufficient quantities (at reasonable cost) and you suggested to your supervisor to inquire on several onets available in the market. As a result, the following data is given to you to assess the equivalency of these systems for mfle flow reported in the table for manufactured products at a confining pressure of 100 kPa similar to that ex r in field . ' Geonet number Transmissivit mazsec meter 1 Enkanet4015 - Akzo Nobel Geos theticsCo. 0.039 A 03' 2 0.013 .t 0.} 3 TerraNet 200 WEBTEC 0.026 A 03’ A reduction of 30% in the Transmissivity of the geosyn tic product is expected in ' on term. Based on our analysis, the geonets satisfying or exceeding the perfo : r of the original drainage bl - -.\_ a. only #1 b. only # 1 and # 3 - c. all of them A 0ftth Dad) .60 Lasmiw '* “‘""“ A\ “M- Wfs sous W5, — hm \ _ "3.— - 3 W I“? 6} 3w} 90mm WWMM; Us; LbOu-n =5 VON“- M1 University of California. Berkeley Departan ofCivi] and Enviromrlental Eng-harms 9 013176 Envimrunental Geotechnics -3- Prof: J. M. Puma-Nam:th . 2. A field hydraulic conductivity test is performed in a compacted clay liner with a Boutwell permeameter, with dimensions, d: 1 cm, ms. For the initial stage (a), the initial height H was 100 cm, and the h in 10 hr was 5 cm. For the second stage (b), and a factor UD=1 a head drop of S cm was observed in 3 hrs, from an initial cm. Determine the values of vertical and horizontal hydraulic conductivity in cmfsec. x, O\Z\LV" K ., ’M \ I _—-I--' 1 III-Ila III-Ip- Illllaa , Ill-na- I Ilium-all Innalle-l-l .117. 7%”..- VA-Il-II-I-I-I 1 3 5 7 9 11 13 In Boutwell Permeameter: a) first stage, b) second stage. c) kilikl required for the analysis (after Daniel, 1989) 3. A field hydraulic conductivity test on a c inner ring is 30 cms in diameter and a v a depth of 2 cms m' arlcE zer'd'suflion. pacted clay liner is performed using a S _ ble Rin Infiltrometer. The of 50 cm3 is measured tolhave gone into the soil at the time the tensmmeter at e end of exactly 1 day. The elevation of water above ground level inside the ring is 30 cm kely h waulic conductivity of the compacted clay liner is: a) 5): 10'1' cm/s 1 {s 0) 5x10 arm’s d) too pervious for a compacted clay liner. "‘50 cm u a. * ' .L “Vb? rmionum I Tubing ” . I ‘ p——-- Inner m3 V 1.. quW‘3 A‘ A» '1 . L"? A-\' i“ {1 50pm ¥ MW ‘- ur ~. 1cm "Mm H :‘Ulww K - W3 us I I “a. . in“. r' .. '.<‘l'.n’ . g‘h’I-.r’ . a't'uli_ .-I .- ;-‘..L- .' I .'-;P.o'.'.i -.-..l..a',' I suite? ‘ -.t , d.f,i'.,'. L4 Bonus Question: Identify the following geOSynthetic specimen, its primary function in a waste containment system a c ' ' ‘ 'es (do not list all an rties, but the 1- most relevant 2 - Geos nthetic T ‘_ Potential Functions University of California. Berkeley Departure-rt of Civil and Enfirmnmtal Engineaing 9 CE! 76 Envirmmmtal (looted-mics -4- Prof J. M. Pestam—Nascimmto Table for The Equation for 1-D transport with Advection, Diffusion/Dispersion & Retardation is given by: sacral—amen was) rel-“Mmz‘ivfil! 0.00 I .00000 0.05 0.94363 0.10 0.88754 0.] 5 0.83200 0.20 0.77730 025 0.7236? 0.30 0.67137 0.35 0.62062 0.40 0.57161 0.45 0.52452 0.50 0.47950 For the case of no seepage velocity (VIi = 0). the previous equation simplifies to: _c_ = d4 _R.z_ ] C0 ZfDRIt 4. A clay liner m (—- 3ft) thick with a h dra ' onductivit of 104"cmfs and an effective sit of 0.333 is constructed at the base of a landfill- Assuming that the maxrmum elevation of the leaclhgttg—atythe lop of the liner would be only Mn—lft) and the pore pressure below the liner is assumed atmospheric, the time required for the leachate to appear at the bottom of the liner considefingonly advection would'be most likely: . a- " 7 years b. ~ 14 years aw 00‘s 0130 0125790 u" 5 *th0. 3:33 33:23: was m 0.95 0.17911 Ah 115mm mgr—,0 1.00 0.15730 1.05 0.13756 1.10 0.1 1979 1.15 0.10333 1.20 0.08969 125 0.07710 1.30 0.06599 1.35 0.05624 1.40 0.04772 1.45 0.04031 1.50 0.03390 1.55 0.02333 1.60 0.023155 1.155 0.01962 1.70 0.0162] 1.75 0.01333 1.30 0.01091 1.35 0.00339 1.90 0.00721 1.95 0.00532 2.00 0.00468 2.05 0.00374 0.00293 $700039; Mflsd V75 v 5 345 5. The concentration of a particular chemical in the Ieachate of a landfill islmppb (parts per billion). The constrained molecular diffu 'on for this chemical is *= 5 x 10‘ cmzr'sec. Assume for this part of the - problem that the contami at is not adsorbed into the liner = . initial backgron concentration is Suits 11] from molecular diffusion, the concentration of this chemical at the bottom as ~ 90 cms) at the en 0 is approximately: b. 200~250 ppb ' c. 2-5 ppb d. ~1000ppb ‘ * Ruum m‘ "n i \UUO UR, K “ :SK'NH“ k ’94. C1. (,0 an; a 1 ' I D 1 i W ’1 13k\“ (Wu. \ ' U‘wu 97A _ _ [0°06 _ a; 010m, - 1090 arkUrbo's) 414110.030“: :W 7: 2.7.05 6. While discussing with your colleagues the suitability of this liner you suggest mixing “Zeolites” with your clay material before compacting the liner. You know that the contaminant will be adsorbed into the zeolite particles as it travels through the liner and preliminary tests suggest a retardation factor of 2 [3:21. All the other Earameters remain the same. It is presumed that the addition of Zeolites will not change the hydraulic conductivity, the constrained molecular diffusion or the dispersivity. The longitudinal dispersivity for this liner is 1 cm. With this new design the concentration of the above chemical (is... C“: 1000 ppb) at the bottom of a clay liner (@ch at the end of M, based on advection, dispersion and diffusion is approximately: a. same as before 0. 200-250 ppb _. c. 2060 ppb 1:]. l-2 ppb . 0.00010 9")" CAN" % -_ 10““ “M’s Eotmmum: 3.3? $332 Cay-RV“ '2 o 33B 610..“ 0.00004 "" ~-’ "H. - 0.00003 4 "" h ‘1 001(0)“ 0 v, 511071-wa /5 k \m “L 5.1Mer t}; n w ) “I 29534 \ \J E— ” 3200:9011.) ‘ x _ I. " " I —-""‘- ’ - ’ g. I b‘ ClJ'fluEJM'J!‘ I _ ‘ " 1 " 1) 1/ V3}; '/ l 44: u \UW Cooum’mn due, \9 orymw ' _ , H7“ ...
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This note was uploaded on 12/01/2011 for the course CE 13972 taught by Professor Chow during the Spring '09 term at University of California, Berkeley.

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cee176-sp09-mt-Pestana-soln - University ofCalifiJrnia....

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