矩形巷道顶板围岩塑性区分析与支护设计

Plastic zone analysis and support design of surrounding rock of rectangular roadway roof

煤矿采掘大量采用矩形巷道,传统巷道支护设计一般依据圆形巷道塑性区范围确定,而对于矩形巷道塑性区的确定普遍采用数值模拟的方法。为确定矩形巷道顶板围岩塑性区范围,建立巷道顶板梁模型并考虑围岩抗拉压强度不等的特点,对模型进行弹塑性分析,得出巷道顶板最大塑性区高度理论计算式,并据此提出锚杆支护设计方法。为验证理论计算式的适用性,对柠条塔煤矿S1231掘进工作面胶运顺槽巷道顶板围岩最大塑性区高度进行现场监测。研究结果表明,依据理论计算出的巷道顶板围岩最大塑性区高度与现场监测结果基本一致;同时,对柠条塔煤矿S1231掘进工作面胶运顺槽巷道顶板围岩进行支护设计,并对顶板围岩的稳定性进行评价,进一步验证了理论的合理性。

Rectangular roadway is widely used in coal mining, traditional roadway support design is generally determined according to the plastic zone range of circular roadway, and numerical simulation is generally used to determine the plastic zone of rectangular roadway.In order to determine the plastic zone of surrounding rock in rectangular roadway roof, the beam model of roadway roof was established and elastic-plastic analysis was carried out on the model considering the characteristics of different tensile and compressive strength of surrounding rock, the theoretical calculation formula of maximum plastic zone height of roadway roof is obtained, and the design method of bolt support is proposed accordingly.In order to verify the applicability of the theoretical calculation formula, the maximum plastic zone height of surrounding rock in the belt transport mining roadway roof of S1231 mining face of Ningtiaota Coal Mine was monitored on site.The research results show that the maximum plastic zone height of roadway roof surrounding rock calculated according to the theory is basically consistent with the field monitoring results;At the same time, the support design of the roof surrounding rock of the belt transport mining roadway in the S1231 mining face of Ningtiaota Coal Mine was carried out, and the stability of the roof surrounding rock was evaluated, which further verified the rationality of the theory.