采矿引起的构造应力场变动与地表开裂的关系

Relations between changes of constitution stress field due to mining process and earth surface cracks

青藏高原的持续隆起,从西南方向挤压中国大陆板块,决定了金川矿区的地应力水平和分布特征,所以构造应力和断层分布,以及采矿扰动,是影响金川矿区稳定性的关键因素。在考虑水平最大构造主应力作用的基础上,建立了平面应变弹塑性有限元模型,用于模拟研究金川二矿区一号矿体在采矿过程中地表附近岩体应力状态的变化过程。模型半定量地给出了地表开裂的力学原因,并对地表裂缝的进一步发展作了预测。模拟得到的地表开裂时间和地表裂缝分布的范围均与实际情况相符。基于此模型,进一步研究了回采1150水平矿柱对矿体稳定性的影响。

The cwss extrusion to the continent of China from southwest due to the continual growth and rise of the Tibetan plateau controls the level and distribution of the constitution stress in Jinchuan, so the constitution stress, faults and mining are the key factors that influence the stabilization of the ore district of Jinchuan. Based on the elastic-plastic plane strain theory, we set up FEM model including the influence of the constitution stress to simulate the mining process, and use the results of simulation to probe the formation reason and development process of the earth surface cracks in Jinchuan＇s ore district, and to forecast the further development of these cracks. We find that the theory conclusions about the spacial distribution and appearance time of the cracks are consistent with the locale observations. At last, through simulating the exploitation of the 1150 horizontal jamb in the model, we evaluate the influence extent on the whole stabilization in the ore district.