Stability of weak sublayers in a slurry supported trench

This paper proposes an analytical method to evaluate the stability of weak sublayers against lateral extrusion in a slurry supported trench. This proposed method is developed by modifying existing theoretical solutions, which are based on plasticity theory. The arching effect due to a finite length of trench is taken into account in the computation of vertical pressure distribution in the weak sublayers. A factor of stability is defined as a measurement that describes the effectiveness of slurry pressure for preventing weak sublayers from lateral extrusion. This factor is represented as a ratio of net slurry pressure to lateral earth pressure at the level of the weak sublayer. The validity of the proposed method is examined using a field experiment.