Stability of Self-Standing High Stiffness-Steel Pipe Sheet Pile Walls Embedded in Soft Rocks

抄録

Five centrifuge model tests are reported in this paper, which discusses the overall behaviours of self-standing stiff sheet pile walls embedded in soft rocks. Two different soft rocks, namely sand rock and mud rock were modelled by using sand-cement-clay mixtures at appropriate mixing ratios. In this study, a centrifuge modelling technique has been developed in which the loading process can be simulated from design conditions to the ultimate failure conditions on an embedded wall in soft rock. A series of centrifuge tests has been carried out to investigate the influence of embedment depth on the stability of self-standing steel pipe sheet pile walls. Experimental observations reveal that, the stiff sheet pile walls suffer from rigid body rotations about a pivot point. An equilibrium analysis was performed by switching the active and passive zones based on the observed pivot point at the verge of rotational failure. A similar contribution of increment in embedment depth on the stability of walls can be confirmed from the analysis and experimental outcomes. Also, it can be confirmed that the wall can stand in the design condition with a reasonable safety margin with a relatively small embedment depth compared to current design practices and a small increment in embedment depth e.g., 0.5m, can significantly increase the wall stability and prevent the wall from ultimate collapse.