陡倾煤层开采条件下上覆山体变形破坏物理模型试验研究

大型岩质滑坡是中国西南岩溶矿区的主要地质灾害类型，其破坏和成灾过程具有复合性。以我国重庆武隆鸡冠岭滑坡为例，通过离心物理模型试验研究了地下开采条件下陡倾灰岩斜坡的变形失稳机制。试验时随着煤层模型板被拔出，上覆岩层在拟重力作用下开始出现位移与层间错动，当煤层模型被拔出150 mm时，模型山体发生显著破坏。试验结果表明:陡倾灰岩斜坡在长期重力作用下，会出现弯曲倾倒的变形，随着地下煤层逐渐采空，上覆陡倾层状岩体失去支撑，岩层层面分离并产生拉张裂缝，岩体变形加剧发生倾倒破坏，并对煤层下部的稳定岩体形成挤压，下伏稳定岩体发生剪切破坏，最终导致鸡冠岭以倾倒-滑移的复合模式整体失稳。这一研究对中国西南山区大型岩质滑坡的早期识别与失稳机制分析具有指导意义。 

PHYSICAL MODEL EXPERIMENTAL STUDY ON DEFORMATION AND FAILURE OF OVERLYING ROCK SLOPE UNDER THE CONDITION OF STEEP COAL SEAM MINING

Major rockslide is the main type of geological hazards in the mining mountainous areas of southwestern China. The failure modes and behaviors of this kind of rockslides are complex. Taking the Jiguanling landslide as an example, centrifuge modelling was taken to analyze the failure mechanism of a steep-dip carbonate slope which was induced by goaf in this study. With the model plate of coal seam was pulling out, the overlying strata began to move and dislocate under centrifugal acceleration. The model rock slope failed completely when the model plate was pulled out about 150mm.The experimental results show that the deformation tendency of bending and toppling appeared in steep-dip and layered limestone slopes by gravity. With the underground mining of coal seams, overlying steep-dip and layered rock slope lost its support, then strata got separated and tension fissures were generated. These rock strata were toppled due to severe deformation. The underlying stable rock mass was squeezed by the toppled overlying strata, and shear failure occurred. In the end, the Jiguangling rock slope was failed with the composite mode of toppling-sliding. This study could be a guide of early identification and failure mechanism analysis for major rockslides in mountainous area of southwestern China.