Similarity modeling on instability and failure of rock bedding slope with weak interlayer caused by underground mining

Taking the rock bedding slope landslide in Jiwei Mountain located in Wulong,Chongqing,China as an ex- ample,the similarity modeling are conducted based on the similar principle. The bedding slope similarity model experi- ment device with the adjustable slide surface in Chongqing University is adopted. The deformation and fracture respon- ses under the influence of different mining goafs formed by downslope mining,upslope mining and leaving in the upper and lower boundary pillars are shown in the experiments. The results indicates that: Where the subsidence value on slide surface in the rock bedding slope reaches maximum,the deformation and failure are large and fractures are devel- oped obviously. Under the same geological environments and mining conditions,the goaf shaped by upslope mining leads to the worst influence on slope deformation and failure. It is easy to induce instability and failure,followed by downslope mining. The effect on the slope deformation and failure of leaving upper and lower boundary pillars is rela- tively small. Different rock properties and normal distances to the slide surface result in different deformation response characteristics. However,the sliding along the slide surface towards the free face exists generally. Under the influence of underground mining goaf,the deformation mechanism of gently inclined bedding slope with weak interlayer is bend- fracture,extrusion-slipping-tension crack.