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Published in J. Russell Boulding, Epa Environmental Engineering Sourcebook, 2019
While site-specific geophysical and engineering studies (e.g., compatibility testing of ground water and backfill materials) are needed to determine the appropriate materials and construction specifications, this technology can effectively isolate wastes and contain migration of hazardous constituents. Slurry walls also may be implemented rather quickly in conjunction with other remedial actions. Long-term monitoring is needed to evaluate the effectiveness of the slurry wall.
Salinity Evaluation, Control, and Management
Published in S. F. Atkinson, G. D. Miller, D. S. Curry, S. B. Lee, Salt Water Intrusion, 2018
S. F. Atkinson, G. D. Miller, D. S. Curry, S. B. Lee
Subsurface barriers are physical barriers to sea water intrusion, as opposed to the hydraulic barriers in the control methods mentioned above. The subsurface barrier is an impermeable, vertical wall which is placed inland to restrict the movement of sea water. Barriers usually take one of three different forms: slurry walls, grout cutoffs, or steel sheet piles. A study undertaken to evaluate the effectiveness of subsurface barriers (Knox, 1983) provided descriptions of the three different forms. Slurry wall construction involves pumping a slurry made of water and bentonite clay into a trench while excavation of the trench is proceeding. The slurry maintains wall stability through hydrostatic pressure, thus decreasing the required width of excavation. As excavation proceeds, backfilling with a soil-bentonite or cement-bentonite mixture follows. The backfill combines with the slurry to form an impermeable membrane. The advantages and disadvantages are listed in Table 5 (Knox, 1983).
Investigation of three-dimensional active earth pressure and load transfer according to aspect ratio
Published in Marine Georesources & Geotechnology, 2019
Byung-Suk Park, Jintae Lee, Su Choel Kim, Sang Duk Lee
Earth pressure distribution on a retaining wall needs to be clearly investigated for the design of structures subjected to earth pressures since the unbalanced stress of earth pressure may cause a dangerous situation. The earth pressure distribution is mostly related to various rigid wall structures including marine geo-structures. It can be applied to not only retaining walls but also slurry wall trenches, well foundations, and vertical shafts analyses. Many researchers have suggested various earth pressure theories but most of them considered only the earth pressure in the vertical direction under the two-dimensional plane strain condition (Saglamer 1975; Walz and Prager 1978; Karstedt 1982; Washbourne 1984; Simpson 1992; Fuji et al. 1994; Tsai and Chang 1996; Hagiwara et al. 1998). In most cases, however, active earth pressure is noticeably lower while passive earth pressure is remarkably higher in the three-dimensional condition than in the two-dimensional condition due to arching effect. Especially the active earth pressures of slurry walls in a limited length or those of walls at a limited width showed three-dimensional movement (Potts and Fourie 1986; Ng and Yan 1999; Hettler and Abdel-Rahman 2000; Gourvenec, Powrie, and De Moor 2002; Florian and Martin 2013). They were influenced by the width and depth of the retaining wall and the ground conditions. Most of the previous studies on the three-dimensional active earth pressure have been conducted usually by focusing on the stability of active wall, only few studies are on the three-dimensional load transfer to the adjacent ground (Loh 2003; Tom Wörden 2010; Florian and Martin 2013). For more accurate prediction of the three-dimensional active earth pressure, it is required to study not only the three-dimensional earth pressure distribution but also the three-dimensional load transfer to the adjacent ground.