鸡尾山特大型岩质滑坡的物理模型试验

Physical modeling of Jiweishan Landslide from massive rock slope failure

鸡尾山滑坡的失稳模式为斜倾厚层岩质滑坡视向滑动。为了研究这种独特的特大型岩质斜坡失稳模式,利用土工离心机,对1个包含4组结构面的地质力学模型进行物理模型试验。研究结果表明:随着离心机加速度的不断增大,后部块体首先失稳并推挤前缘关键块体,粘贴在滑块与基座之间的裂缝监测应变片从斜坡后缘到前缘相继发生破坏;当离心加速度达到80g(1g=9.8 m/s2)时,斜坡前缘关键块体发生位移突变,产生瞬时视向滑动破坏,引起整体滑坡;软弱夹层抗剪强度的降低和关键块体瞬时失稳是鸡尾山滑坡发生的主要原因,斜倾厚层岩质滑坡视向滑动具有"后部块体驱动前缘关键块体失稳"的特征,斜坡的初始变形破坏是一个从稳定到失稳渐进发展的过程。

Jiweishan landslide illustrates a failure pattern of apparent dip slide from oblique inclined layered rock slope failure.Physical modeling test through geotechnical centrifuge was conducted on model consisting of four sets of joints to investigate this remarkable mechanism for landslide initiation from massive rock slope failure.Centrifuge modeling tests shows that the crack strain gauges are damaged successively from back to front as centrifuge acceleration ascends.During the process,the driving blocks in the rear lose stability and crush on the key block in the front.When acceleration reached 80g,instantaneous apparent slip failure happened to key block in the front,which led to sudden displacement rise and triggered the entire landslide.The initial failure is a progressive failure process from being the rear to the front of the slope and from stable to instable.Apparent dip slide from oblique inclined thick layered rock slope failure has a characteristic that the key block destabilized instantaneously with blocks in the rear driving and the initiation is a progressive failure process from stable to unstable.