基于保护层开采覆岩移动破坏特征,分析了远程下保护层开采煤岩卸压的可行性,采用FLAC2D数值模拟软件对被保护煤层的应力分布特征、煤厚变形规律、水平位移规律、卸压范围及卸压角进行了研究。结果表明:下保护层开采时,断裂带高度已发育到被保护层,煤层产生膨胀变形,生成大量的次生裂隙,使被保护煤层产生不同程度的卸压,同时水平位移的产生也有利于煤层透气性增加。在走向方向上,被保护层向保护层采空区方向内错约30 m,煤层进入稳定膨胀变形区,走向有效卸压角的大小为66°左右。研究结果应用于工程实践后,淮南某矿13-1煤层瓦斯压力由原来的4.4 MPa变为卸压后的0.7 MPa,煤层透气性系数增大了1 061倍,表明该方法是较好的区域性防突措施。

Based on the overburden strata movement and failure features of the protected seam mining, the paper had an analysis on the feasibility of the coal and rock pressure releasing in the protected seam mining under long distance. The FLAC2D numerical simulation software was applied to the study on the stress distribution features of the protected seam, seam thickness variation law, the horizontal displacement law, the pressure releasing scope and the pressure releasing angle.The result s showed that during the underneath protective seam mining, the height of the crack zone was developed to the protected seam, swelling deformations were occurred i n the seam, great secondary cracks were occurred and thus different pressure releasing were occurred in the protected seam.Meanwhile, the horizontal displacement 0 ccurred would be favorable to improve the permeability of the seam.On the strike direction, the protected seam was moved about 30 m to the direction of the goaf of the protective seam.The protected seam was in the stable swelling deformation zone and the effective pressure releasing angle in the strike was about 66° .After the study「 esults applied to the practical projects, the gas pressure of No.13-1 seam in a mine of Huainan was reduced from previous 4.4 MPa to 0.7 MPa after the seam pressure release, the permeability coefficient of the seam was increased by 1 061 times.Thus the method would be a good regional outburst prevention measure.

教育部新世纪优秀人才支持计划资助项目(NCET-08-0819)；教育部科学技术研究重点资助项目(210096)；国家自然科学基金资助项目(50804003)；霍英东青年教师基金基础性研究课题(121050)；中国矿业大学煤炭资源与安全开采国家重点实验室开放研究基金资助项目(10KF03)；