Harris Dam Slurry Trench: Design and construction

A slurry trench cutoff up to 27 metres in depth through residual granitic soils, has recently been constructed as part of the seepage control measures for the Harris Dam, Western Australia.

The slurry trench had to accommodate foundation settlements of about 500 mm and still remain relatively impermeable.

Extensive laboratory trials were carried out to develop a cement-bentonite slurry mix that satisfied these requirements. Close monitoring during construction confirmed that these design criteria were largely achieved in the finished product.

This paper describes the design and construction of the Harris Dam cutoff. A companion paper (1) describes the investigation and design of the slurry mix used in construction of the trench.