The Institution of Civil Engineers' Specification for the construction of slurry trench cut-off walls is published by Thomas Telford this month.
The specification relates to the use of slurry trench cut-off walls for the control and migration of groundwater, leachate, chemical contaminants and gases. It covers cut-off walls, often including low permeability geomembranes, excavated under the support of self-hardening cementitious slurry as a single-phase process. Cut-off walls constructed by driven methods, two phase processes, or using soil-bentonite are not covered.
Circulation of the draft document has already had a major impact on the slurry trench cut-off wall industry, for example use of strain at failure criteria have been removed largely from practice. The final version of the specification provides a standard and consistent approach to the design, construction, testing and monitoring of cut-off walls plus guidance on the appropriateness of this technique and current best practice.
The specification, said publisher Thomas Telford, is an authoritative and unifying statement of good practice and was commissioned by the Ground Board of the ICE in conjunction with the Building Research Establishment and the Construction Industry Research & Information Association. It was prepared by Graham Doe of Amec Piling & Foundations and Dr Stephan Jefferis of Golder Associates.