Abstract
Bentonite cake is usually formed on the excavated trench surface that is supported by the bentonite slurry during construction of slurry cutoff walls. The lower hydraulic conductivity of bentonite cakes formed during construction of slurry cutoff walls in comparison to backfill materials provides an additional benefit. In the present study, the hydraulic conductivities of bentonite cakes made using three different bentonites were estimated using the modified fluid-loss test under various pressures. Both the hydraulic conductivities of bentonite cakes and cutoff-wall backfill are important in evaluating the in situ hydraulic performance of slurry cutoff-wall construction. Three bentonite slurry concentrations of 4, 6, and 8% were used to fabricate bentonite cakes that represent common field conditions. X-ray diffraction, cation exchange capacity, and swell-index data were collected to characterize the bentonites. Two modified methods for analyzing fluid-loss test results were used to estimate bentonite cake hydraulic conductivities. In addition, the viscosity as a function of time was measured to explain the sealing capacities of the bentonite slurries. The bentonite-cake hydraulic conductivities ranged from 2.15×10−11 m/s to 2.88×10−10 m/s, which were 10 to 500 times lower than the cutoff wall backfill design. Experimental results for 4 and 6% bentonite slurries were relatively similar, but the 8% slurries were noticeably different. Calculated bentonite-cake thickness and stress distribution indicated that the local void ratio and hydraulic conductivity may vary across the cake thickness. The considerably lower bentonite-cake hydraulic conductivities compared to the cutoff wall backfill design show its significance in slurry cutoff-wall construction practices.
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Akther, S., Hwang, J.Y., and Lee, H. (2007) Effects of the water quality on the dispersion properties of bentonites used for drilling fluid. Journal of the Mineralogical Society of Korea, 20, 21–33.
Akther, S., Hwang, J.Y., and Lee, H. (2008) Sedimentation characteristics of two commercial bentonites in aqueous suspensions. Clay Minerals, 43, 449–457.
American Petroleum Institute (API) (1990) Standard procedure for field testing drilling fluids. API Specification 13B, American Petroleum Institute.
American Society for Testing and Materials (ASTM) D5891 (2002) Standard test method for fluid loss of clay component of geosynthetic clay liners. American Society for Testing and Materials.
American Society for Testing and Materials (ASTM) D5890 (2006) Standard test method for swell index of clay mineral component of geosynthetic clay liners. American Society for Testing and Materials.
American Society for Testing and Materials (ASTM) C837 (2009) Standard test method for Methylene Blue Index of Clay. American Society for Testing and Materials.
Barvenik, M.J. and Ayres, J.E. (1987) Construction quality control and post-construction performance verification for the Gilson Road hazardous waste site cutoff wall. EPA/600/ 287/065, US EPA, Washington.
Beeson, C.M. and Wright, C.W. (1952) Loss of mud solids to formation pores. Petroleum Engineer, 8, B40–B52.
Britton, J.P. (2001) Soil-bentonite cutoff walls: hydraulic conductivity and contaminant transport. PhD thesis, Virginia Polytechnic Institute & State University, Blacksburg, Virginia, USA.
Britton, J.P., Filz, G.M., and Herring, W.E. (2004) Measuring the hydraulic conductivity of soil-bentonite backfill. Journal of Geotechnical Engineering, ASCE, 130, 1250–1258.
Caenn, R. and Chillingar, G.V. (1996) Drilling fluids: State of the art. Petroleum Science and Engineering, 14, 221–330.
Choi, H. and Daniel, D.E. (2006b) Slug test analysis in vertical cutoff walls. II: Applications. Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 132, 439–447.
Chung, J. (2004) Hydraulic conductivity of GCLs permeated with inorganic chemical solutions. PhD thesis, University of Illinois, Urbana-Champaign, Illinois.
Chung, J. and Daniel, D. (2008) Modified fluid loss test as an improved measure of hydraulic conductivity for bentonite. Geotechnical Testing Journal, ASTM, 31, 1–9.
D’Appolonia, D.J. (1980) Soil-bentonite slurry trench cutoffs. Journal of Geotechnical Engineering, ASCE, 106, 399–417.
Darcy, H.P.G. (1856) The public fountains of the city of Dijon. Victor Dalmont, Paris, France.
Darley, H.C.H. and Gray, G.R. (1988) Composition and Properties of Drilling and Completion Fluids. Gulf Publishing Company, Houston, Texas, USA.
Filz, G.M., Boyer, R.D., and Davidson, R.R. (1997) Bentonitewater slurry rheology and cutoff wall trench stability. Pp. 139–153 in: Proceedings of In Situ Remediation of the Geoenvironment (J.C. Evans, editor). GSP 71, ASCE, Virginia, USA.
Filz, G.M., Henry, L.B., Heslin, G.M., and Davidson, R.R. (2001) Determining hydraulic conductivity of soil-bentonite using the API filter press. Geotechnical Testing Journal, ASTM, 24, 61–71.
Grube, W.E. Jr. (1992) Slurry trench cutoff walls for environmental pollution control. Pp. 69–77 in: Slurry Walls: Design, Construction, and Quality Control (D.B. Paul, R.R. Davidson, and N.J. Cavalli, editors). ASTM, STP 1129, ASTM International, West Conshohocken, Pennsylvania, USA.
Heller, H. and Keren, R. (2002) Anionic polyacrylamide polymers effect on rheological behavior of Na-montmorillonite suspensions. Soil Science Society of America, 66, 19–25.
Henry, L.B., Filz, G.M., and Davidson, R.R. (1998) Formation and properties of bentonite filter cakes. Pp. 69–88 in: Filtration & Drainage in Geotechnical and Geoenvironmental Engineering (L.N. Reddi and M.V.S. Bonala, editors). GSP 78, ASCE, Virginia, USA.
Heslin, G.M., Filz, G.M., Baxter, D.Y., and Davidson, R.R. (1997) An improved method for interpreting hydraulic conductivity tests performed in the API filter press. Pp. 71–77 in: Proceedings of International Containment Technology. US DoE, DuPont Company, and US EPA.
Hutchinson, M.T., Daw, G.P., Shotton, P.G., and James, A.N. (1974) The properties of bentonite slurries used in diaphragm walling and their control. Pp. 33–39 in: Diaphragm Walls and Anchorages (T.J. Darwent, editor). Institution of Civil Engineers, London.
Krueger, R.V. and Vogel, L.C. (1954) Damage to sandstone cores by particles from drilling fluid. Pp. 158–168 in: Drilling and Production Practice. API.
Nash, K.L. (1974) Stability of trenches filled with fluids. Journal of the Construction Division, ASCE, 100(CO4), 533–542.
Nguyen, T.-B., Lee, C., and Choi, H. (2010a) Slug test analysis in vertical cutoff walls with consideration of filter cake. Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 137, 785–797.
Nguyen, T.-B., Lee, C., Kim, S., and Choi, H. (2010b) Modification of the Bouwer and Rice method to a cutoff wall with a filter cake. Ground Water, 48, 898–902.
Olsta, J., Daniel, D., and Chung, J. (2004) Various aspects of sodium bentonite testing. Pp. 3–10 in: Advances in Geosynthetic Clay Liner Technology: 2nd Symposium (R.E. Mackey and K. von Maubeuge, editors). ASTM, STP 1456, ASTM International, West Conshohocken, Pennsylvania, USA.
Rushton, A., Ward, A.S., and Holdich, R.G. (2000) Solid-Liquid Filtration and Separation Technology, 2nd edition. Wiley-VCH Verlag GmbH, Weinheim, Germany.
Ruth, B.F. (1935) Studies in filtration: III. Derivation of general filtration equations. Industrial and Engineering Chemistry, 27, 708–723.
Soroush, A. and Soroush, M. (2005) Parameters affecting the thickness of bentonite cake in cutoff wall construction: case study and physical modeling. Canadian Geotechnical Journal, 42, 646–654.
U.S. Army Corps of Engineers (US ACE). (2010) Guide specification for construction soil-bentonite (S-B) slurry trench. U.S. Army Corps of Engineers, UFGS-02 35 27.
Xanthakos, P.P. (1979) Slurry Walls. McGraw-Hill, New York.
Xanthakos, P.P., Abramson, L.W., and Bruce, D.A. (1994) Ground Control and Improvement. Wiley-Interscience, New York.
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Nguyen, TB., Lee, C., Lim, J. et al. Hydraulic Characteristics of Bentonite Cake Fabricated on Cutoff Walls. Clays Clay Miner. 60, 40–51 (2012). https://doi.org/10.1346/CCMN.2012.0600104
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DOI: https://doi.org/10.1346/CCMN.2012.0600104