油页岩原位开采对岩体结构影响分析

Effects of In-Situ Mining of Oil Shale on Rock Mass Structure

对吉林省扶余县油页岩及围岩进行了物理力学参数的测定,在此基础上,获取了容重、弹性模量、泊松比、内摩擦角及黏聚力等参数.并利用SIGMA/W模块,采用弹-塑性模型进行有限元计算,得到了原位开采区内任一点应力、应变、位移的详细信息.结果显示,采区的最大下沉位移为1.05 m,位于开采中心处;同时,根据这些信息分析了采区岩体的应力分布,受拉区与剪应力极值分布较大区一致,都位于油页岩的上覆地层泥岩层中,从而确定了岩体的破坏过程:首先是受拉,产生大量裂隙;然后再沿着剪应力极值所在的截面发生滑动.

Physical and mechanical parameters of the oil shale and its wall rock from Fuyu County in Jilin Province were measured, on the basis of which, unit weight, elasticitymodulus, Poisson＇s ratio, internal frictional angle, cohesion and other parameters were obtained. And the SIGMA/W module was used to calculate elastic-plastic finite element model, thus, the stress, stain and displacement of any point within in-situ mining area were gained. The results show that the maximum subsidence displacement is 1.05 m, which is located at the center of mining. Meanwhile, according to these information, the stress distribution of rock mass is analyzed. Tension zone is consistent with larger shear stress extreme distribution area, both are located in shale which is the overlying strata of oil shale, thus the failure process of rock mass is determined. First, rock mass is stretched, producing a large number of cracks, and then occurs sliding along the cross-section where the shear stress extreme.