大倾角俯斜开采综放运输和回风巷超前支护技术

Advanced support technology in large-angle gateway of fully-mechanized face with downhill mining

以葛亭矿2325大倾角伪倾斜综放工作面为例,针对俯斜开采运输和回风巷（简称两巷）的受力与变形特点,采用围岩结构探测、数值模拟和理论分析方法,对大倾角两巷在综放面回采期间可能出现的破坏方式与破坏范围、超前支护强度与迎山角度等进行了研究.探测结果表明,两巷上部118 m及下部42 m为稳定性较差的弱顶板结构区域,而中间42 m为较完整顶板结构区域,顶煤厚度平均为4m、破碎直接顶范围为0～4m.数值模拟结果表明,大角度两巷顶底板均存在较大的倾斜位移,存在沿倾斜滑移的可能性;煤壁前方30 ～ 40 m范围内两巷顶板为重点支护区域,而前方3～5 m为底板重点支护范围.根据探测及模拟结果,估算了回采期间两巷顶板载荷及原有顶板支护残余强度,由此给出了超前支护强度及单体支护密度;按力平衡原则及抵消顶底板倾斜位移差等两种方法,估算了超前支护合理迎山角度.按照上述设计参数进行了现场应用试验,取得较好效果,验证了本方法的科学性及可行性.

According to the stress and deformation specialties of the gateway used in downhill mining,taking the large-angle fully-mechanized face of Geting-2325 coal mine as an example,the research has been done on the following aspects such as the mode and range of failure that might appear in the surrounding rock,the advanced support strength and prop-setting angle in the gateway with the methods of the surrounding rock structure survey,as well as the numerical simulation and theoretical analysis.The detecting results indicated that the lower part with the length of 42 m and the upper part with the length of 118 m of the gateway are less stable regions,while the middle 42 m area belongs to a more complete roof structure.The average thickness of top coal is 4m,and the crushing thickness of the immediate roof ranges from 0 to 4 m.The simulation results indicate that the roof and floor of the gateway have a big tilt displacement and the possibility of a tilt slip.The roof of gateway should be well supported in the range from 30 m to 40 m in front of the coal wall,while the range of floor is from 3 m to 5 m.According to the detection and simulation,the roof loading and the residual strength of the original support are estimated.The advanced support strength and monomer support density are given.According to the methods of force balance principles and tilt displacement offset between roof and floor,a logical prop-setting angle is estimated.The field test which was carried out according to the design parameter achieved good effects,and the science and feasibility of the methods are testified.