Study on the strain response of slopes containing cavities under the effect of strong earthquakes

Abstract

AbstractThe weak points in a slope often control its deformation and failure mode. Under the action of earthquakes, the complex influence of seismic waves on slopes with cavities is rarely considered. By studying the strain response of this kind of slope, the triggering mechanism of the slope under a strong earthquake can be further discussed. On the basis of the existing research, a shaking table test of a slope model with a cavity structure is carried out. The following conclusions were made: (1) Under the condition of a strong earthquake, the initial crack of the slope with cavities mainly occurs around the cavities, the top of the slope, and the boundary of the slope. (2) During the vibration process, the peak air pressure in a cavity has a good correlation with the peak strain in the surrounding material. The peak strain appears just after the peak air pressure, indicating that the sudden change in the air pressure in the cavity will lead to significant tensile damage to the cavity wall. Repeated air pressure changes in the cavity cause progressive damage to the slope near the cavity structure, accelerating fracture expansion and leading to the fracture penetrating the slope boundary. (3) The overall failure of the slope is somewhat related to the development of cracks around the cavity structure, but failure does not necessarily occur along the cavity zone. The failure site is closely related to the free surface condition and the upper slope structure.