Design of a Rigid Cutoff Wall

Abstract

A sheet pile cutoff wall simply called cutoff wall is used in almost all types of water retaining structures to reduce the exit gradient at the downstream toe and prevent the chances of sand boiling and piping. In 1954, Terzaghi has suggested a simplified approach for the design of cutoff walls considering average seepage force. In Terzaghi’s approach, the unbalanced water pressure around the cutoff wall is coupled with the active earth pressure and the resultant thrust is determined by subtracting the passive thrust from the combined active thrust. The value of passive earth pressure coefficient has been assumed to correspond with a downstream failure wedge having an angle of