By R M Telling, North East London Polytechnic and B K Menzies and N E Simons, University of Surrey
This technical paper was first published in GE’s January 1978 issue
This article is primarily a digest of published material on cut-off wall effectiveness.
The role of the cut-off in controlling underseepage is stated. The main types of cut-off used in civil engineering practice are considered and classified according to the distribution of imperfection. Cut-off effectiveness is defined in terms of flow and head efficieny. A review of previous work in assessing cutoff efliciency is undertaken. Additional analytical methods are developed and a solution for the case of anisotropy is given.
A number of case histories which provide or make reference to piezometric data on installed cut-offs are presented and performance appraisals are made. On the basis of data collated from the various sources some broad proposals are made regarding cut-off design.