特厚煤层矸石充填控制岩层变形特性研究

Study on control characteristics of rock deformation by gangue filling in extra-thick coal seam

为研究特厚煤层在矸石充填下岩层变形特性,以某矿矸石为充填材料,采用侧限压缩试验研究其在压应力下的变形特征,并采用FLAC 3D建立数值模型,将侧限压缩试验中压实8 MPa的矸石的弹性模量应用至数值模型中,对比分析充填和未充填两种开采模式下的岩层的受力及变形。研究结果表明,矸石充填体变形特征表现为随着载荷的持续增加应变量逐渐增加,且两者呈现对数函数关系,应变量前期变化明显,后期逐渐减小;矸石充填开采后,对比未充填时岩层的位移量明显减小,且应力在岩层中分布更加均匀。试验和模拟结果均表明,矸石的压密致使充填体的变形趋于稳定,从而可以承担上部压力。

To study the deformation characteristics of rock strata under gangue filling in the extra-thick coal seam,the confined compression test was used to study the deformation characteristics under compressive stress by taking gangue as filling material,and the numerical model was established by FLAC 3D to compare and analyze the force and deformation of rock strata under the two mining modes of filling and unfilling.The elastic modulus of gangue compacted with 8 MPa under lateral compression test is applied to the numerical model.The research results indicate that the deformation characteristics of gangue filling body show that the strain variable increases gradually with the continuous increase of load,and the two show a logarithmic function relationship.The strain variable changes obviously in the early stage,and gradually decreases in the later stage because the gangue-filling material is compacted.After gangue filling mining,the displacement of rock formation is reduced compared with that without filling,and the distribution of stress in a rock formation is more uniform.Both the test and simulation results show that the compaction of gangue makes the deformation of the filling body stable,so that it can bear compressive stress.