地下采空诱发含软弱夹层顺层岩质斜坡变形破裂的相似模拟

以重庆武隆鸡尾山顺层岩质滑坡为例,依据相似原理,利用重庆大学变滑面顺层斜坡相似模拟试验装置,进行地下顺坡开采、逆坡开采、留设上下边界矿柱形成不同采空区影响下顺层岩质斜坡变形破裂响应相似模拟试验。试验结果表明:1顺层岩质斜坡在滑动面下沉量变化最大位置,坡体变形破坏剧烈,裂隙发育明显。2同样地质环境和采矿条件下,逆坡开采后形成的采空区对斜坡变形破裂影响最严重,更易诱发坡体破坏失稳,其次是顺坡开采,留设上下边界矿柱开采相对影响斜坡变形破裂较小。斜坡下逆坡开采采空区范围较小,越易造成坡脚岩体发生断裂破坏崩滑。3不同的岩层性质及距滑动面法向距离,其形变移动响应特征不同,但坡体均出现沿滑动面向临空面的滑移。4地下采空区影响下含软弱夹层缓倾斜顺层斜坡的变形机制为弯曲-断裂、挤压-滑移-拉裂。

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 example,the similarity modeling are conducted based on the similar principle.The bedding slope similarity model experiment device with the adjustable slide surface in Chongqing University is adopted.The deformation and fracture responses 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 developed 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 relatively 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.