Experiments on Progressive Failure and Scale Effect using Model Tests

Trap-door probiems with dry sand (I)

Abstract

The progressive failure and scale effect of trap-door problems were investigated by measuring the load-displacement relationships and observing shear band developments. Trap-door tests were performed in passive and active mode using two kinds of apparatuses. The trap-door width of the smaller apparatus was 5 cm and the larger one was 10 cm. The load of the smaller apparatus was measured using circular soil stress measurement cells and the larger measured using 11 separate rectangular cells embedded in the face of the trap-door. The shear band developments were observed using thin horizontal colored sand layers placed in the sand bodies. The progressive shear band development was recognized both in the passive and active mode but the scale effect was only recognized in the passive mode. The progressive failure in the passive mode tests was also indentified by the load-displacement relationships obtained by 11 separate rectangular stress measurement cells.