Vertical Earth Pressure Behavior and Shear Band Propagation on Cyclic Loading Mode in Trap-door

Abstract

Vertical earth pressure behavior and shear band propagation on cyclic loading mode in a trap door part were compared with experimental results obtained for monotonic loading mode. For the taper loading mode, the peak minimum value and residual value in the active side were larger than the values of monotonic loading mode, and the peak maximum value in the passive side was equal to that of value of monotonic loading mode and the residual value was smaller than the value of monotonic loading mode. For cyclic loading mode in constant displacement, the gradient in a loop shape of vertical earth pressure ratio (σ_v/σ_v(0)) became small as constant displacement became large and σ_v/σ_v(0) tended to be the maximum value around constant displacement ±0.7 mm. Also, the shear band inside the extensive arch-shape in an active state and that outside the extensive fan-shape in a passive state on cyclic loading mode developed upper direction alternately resembling a deer horn.