Barrier Technologies for Environmental Management Summary of a Workshop (1997) / Chapter Skim
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Sealable Joint Steel Sheet Piling for Ground-Water Pollution Control
Sealable Joint Steel Sheet Piling for Ground-Water Pollution Control
Pages 162-170
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From page 162... ...
The interlocking joints of adjacent sheet piles have been modified to incorporate a cavity that can be flushed and filled with a sealant subsequent to installation of the sheet piles in the ground. Field hydraulic tests indicate that bulk hydraulic conductivity values of the barrier wall system of less than 10-8 cm/s can be achieved using a variety of sealant materials.
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From page 163... ...
As shown in Figure 1 for the DNAPL case, source zone isolation may be provided by containment within a low-permeability cutoff wall or barrier, long-term hydraulic control using an active pump-and-treat system, or ~n-situ treatment of contaminants emanahng from the source zone using permeable reaction curtains and funnel-and-gate systems. Each of the approaches will have their merits and limitations for different contaminant problems in different hydrogeological settings; however, in many circumstances, there may be good opportunities for using vertical barriers for contaminant source zone isolation.
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From page 164... ...
Conventional construction techniques include compacted clay barriers and slurry trenches, which typically incorporate soil bentonite, soil attapulgite, and cement-bentonite mixtures in the battier. New and developing technologies for barrier construction include vibrated beam cutoff walls, deep soil mixing or auger cast walls, jet grouted walls, geomembrane barriers, and sealable joint steel sheet piling.
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From page 165... ...
The search for methods to improve the seal between adjacent sheet piles ultimately led to the development of a sealable cavity at the joints. Although the initial version involved the modification of conventional sheet piling with an angle-welded sealable cavity at each joint, the capability to produce a special coldrolled sheet pile with the sealable cavity joint incorporated directly in the production process was developed In cooperation with Canadian Metal Rolling Mills of Cambndge, Ontario, by 1991.
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From page 166... ...
The types of issues that may be considered in the sealant selection process may include sealant/contaminant compatibility, the presence of unusual ground-water chemistry conditions such as high salt content, the ability of the sealant to withstand the anticipated differences In hydraulic head across the baITier, the amenity of the sealant to removal of the balTier system following a specified period, permeability characteristics, pumpability characteristics, thermal expansion characteristics of the sealant, design life of the system' and cost. The types of sealants available include cIay-based grouts such as bentonite and attapulgite, cement-based grouts (modified with expanding agents)
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From page 167... ...
; enclosures around contaminant source zones at industrial facilities In Toronto, Ontario, and in the Seattle area; a battier system used in conjunction with a methane gas collection system at a municipal landfall in Kitchener, Ontario; and barrier walls used in conjunction with pump-and-treat systems nt an industrial facility in Vermont and a military facility in Colorado. The size of the barrier systems have ranged from approximately 5,500 m2 (60,000 ft2)
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From page 168... ...
Based on the joint inspection and sealing activities, and hydraulic testing on enclosures where such testing has been feasible, statements regarding the expected hydraulic performance and integrity of the barrier system can be made with some confidence. Like all engineered controls, installation of an effective barrier system using the Waterloo BarTierTM may not be the most appropriate selection of barrier system for all applications.
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From page 169... ...
Although all construction may disrupt normal activities in the vicinity, the installation of sheet piling generates loud noises, and the level of vibration induced by pile driving may not be acceptable in some urban environments. The installation of sheet piling may result in some compaction and subsidence of adjacent soils, which also can be a concern.
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From page 170... ...
1992. A new type of steel sheet piling with sealed joints for gro~ndwater pollution control.
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