Abstract
Stability mechanism of 2D and 3D slurry trenches, constructed in cohesive soil ground, were investigated by means of a centrifuge test technique which can simulate the process of excavation. Failure pattern of 2D trench was approximated by a straight line. On the other hand, collapse of 3D trench was due to the failure accompanied with the shear-band yielded by the bulge at the center foot of the long side of the trench and propagated with circular lines to the surface of the ground. The crack caused by it progressed with elliptic lines to the short sides of the trench. Using the derived failure shapes and the critical excavation depth, the 3D analysis reasonably explained the experiment results.
