深部开采上覆岩层采动裂隙网络演化的分形特征研究

借助相似模拟材料模型试验,模拟了在深部开采条件下上覆岩层采动岩体裂隙分布状态,运用分形几何理论研究了采动岩体裂隙网络分形维数随开采宽度、采场矿山压力、岩层沉降的动态演化规律,并分析了断层对采动岩体裂隙网络分布演化的影响以及采动岩体裂隙网络在三带的分布特征.结果表明:随开采宽度增加,采动岩体裂隙网络分形维数呈现总体增大趋势,在断层影响下表现出降维特点;分形维数与超前工作面压力和岩层沉降均具有非线性关系;三带采动岩体裂隙网络均具自相似性,冒落带、裂隙带、弯曲带分形维数比为1.082 3:1.139 4:1.

Research on fractal characterization of mined crack network evolution in overburden rock stratum under deep mining

The simulated material models are employed to simulate the spatial distribution of mined crack network in overburden rock stratum under the condition of deep mining. By using the fractal geometry, the evolutional law that the fractal dimension of mined crack network varied with mining width, underground pressure, rock stratum sedimentation is studied. The effect of fault on the evolutional law and the distribution characters for the crack network of rockmass in triple-zone are analyzed. It is shown that the fractal dimension of crack network increases with increasing of mining width in general, decreases under the effect of fault, and has nonlinear relation with advance supporting pressure, rock stratum sedimentation. The crack network of rocks in triple-zone expresses self-similarity, the fractal dimension ratio of crack network of rocks in caving zone, fractured zone and bent zone is 1.0823:1.139 4:1.