Bender element test and numerical simulation of sliding zone soil of Huangtupo landslide

The stiffness property of soil at the low level of strain was often encountered in landslide. In order to study the effect of different consolidation pressures, loading–unloading paths, and gravel contents on the shear modulus of small strain of sliding zone soil, a set of consolidation bender element test device was developed. The device consists of three parts: a consolidation system, a deformation measuring system, and a shear wave testing system. The consolidation system is composed of a traditional consolidation instrument and plexiglass cylinder box. The consolidation displacement is measured by a digital display micrometer. Shear wave testing system is a wave velocity measurement system made of piezoelectric ceramic. The experimental results show that the device can control the consolidation pressure and measure the vertical deformation, measure the shear wave velocity of the sliding zone soil in real time, and then study the variation rules of the small strain shear modulus of the sliding zone soil with gravels. The shear modulus of small strain of sliding zone soil increases with an increase of the consolidation pressure. The shear modulus of sliding zone soil under unloading path is larger than that of loading path. The small strain shear modulus of sliding zone soil was significantly affected by soil mass density, consolidation pressure, and gravel content. Through the finite element numerical simulation of the shear wave, it can be seen that the boundary effect is obvious, and the near field effect of the sliding zone soil with gravels is clear.