采动过程中下被保护层煤体变形渗流规律研究

为得到采动过程中被保护层煤体的变形、渗流规律,进行了煤样在加卸载应力作用下的变形与渗流实验研究。以红阳三矿上保护层开采为工程背景,采用数值模拟得到保护层采动过程中下被保护层煤体的加卸载路径,依据该加卸载路径对被保护层煤体试样进行加卸载,得到应力—应变及应力—渗透率关系曲线。研究结果表明:加卸载过程中,轴向应变随加卸载表现为线性向非线性转变,且卸载过程中轴向应变未能恢复至初始值;环向应变随加卸载表现为非线性变化。相同应力值对应的加卸载渗透性变化规律为:一次卸载阶段渗透率小于一次加载阶段渗透率小于二次加载阶段渗透率。

Protected Coalseam Deformation and Seepage LawResearch in the Process of Mining

In order to get the deformation and seepage law of protected coal seam in the process of mining, the thesis has carried deformation and seepage experimental research of coal sample under the effect of stress. Taking Hongyang Third Mine protection layer mining as engineering background,load-unload path of lower protected coal seam is got in the process of protective coal seam mining by numerical simulation. On the basis of this load-unload path, protected coal sample load-unload experiment is carried out. Finally, the stress-strain curve and the stress-permeability curve are obtained. The research results show that during the loading and unloading process, the axial deformation varies fromlinearity to nonlinearity, and the unloading process to strain failed to return tothe initial value; Hoop strain changes with added unloading performance for nonlinear. The same stress value corresponding to permeability change rule is as follows: first unloading phase permeability is lower than first loading phase permeability. First loading phase permeability is lower than secondary loading phasepermeability.