循环载荷下煤样不同方向渗透特性试验研究

针对循环采动过程中煤层不同方向渗透特征的演化规律问题，以平顶山十二矿己15煤层煤样为研究对象，利用自行研制的应力-渗流-解吸煤体变形试验装置，开展了循环围压加载下煤样不同方向渗透试验。研究结果表明:在相同的轴压、围压和平均孔隙压力下，试样平行层理面方向的渗透率大于垂直层理，平行层理面内的渗透率相差不大。在围压恒定的情况下，通过试样的流量随着渗透压差的增大而增大，且二者之间的关系可以用二次函数描述；围压增加，导致裂隙闭合，渗透率减小，当循环围压大于煤屈服强度和抗压强度时，裂隙扩展，渗透率增加；循环围压加载可以改变煤样原有不同方向渗透率大小顺序，渗透率与原初始渗透率比值随循环加载次数的增加而增大。

Experimental study on permeability of coal samples under cyclic lcoding in different directions

Aiming at the problem of coal seam permeability in different directions during cyclic mining process, taking coal samples of 15 coal seam the sixth of twelve mine in Pingdingshan as research object, using self developed stress seepage desorption coal deformation test device, the permeability experiments of coal samples under different cyclic load were carried out. The results showed that, under the same axial pressure, confining pressure and average pore pressure, the coal permeability in the direction of parallel bedding plane is greater than that in the direction of vertical bedding, and the permeabilig in the parallel bedcling plane is not much different. In the case of constant confining pressure, the flow through the coal sample incrases with the increase of the osmotic pressure, and the relationship could be represented by quadratic function. With the increase of confining pressure, the fracture closes and the permeability decreases. When the cyclic confining pressure is greater than the coal yield strength and compressive strength, the fracture expands and the permeability increases. Cyclic confining pressure loading can change the original permeability order in different directions, and the ratio of permeability to original initial permeability increases with the increase of loading times.