On sites with rather large areas, it is usually proposed to construct cut-off walls to divide the site into two (or more) partitions to allow for dewatering / excavation works in one (or more) zone of the site, while other activities continue in the remaining zone(s).
   
Drilling method is identical to the method utilized for Diaphragm walls except for that the drilling fluid will not be exchanged. Filling material (a special mix of bentonite slurry and cement) is usually mixed by means of truck mixers, then poured by a tremmie pipe same as the one used for concrete pouring for Diaphragm walls.   
 

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