巷道极限跨度研究

Study on limit span of roadway

随着矿山开采强度和规模逐渐增加,确保锡矿矿区大理岩岩体巷道顶板的稳定对矿山安全生产具有重要意义,极限跨度的计算研究为提升巷道稳定性提供了保障。依据矿山现状,结合板梁理论、Mathews图解法与Q系统分级对巷道进行极限跨度分析,并研究抗拉强度折减下极限跨度的变化情况。研究结果表明,采用板梁理论计算巷道顶板极限跨度为4.8 m,Q系统分级下的极限跨度为5.0 m,巷道极限跨度取4.8 m;Mathews图解法得出实际水力半径值2.184 m,大于其理论水力半径值2.000 m,巷道垂直开口跨度9.3 m超过了极限跨度,需对巷道口暴露空间采取处理措施。巷道岩体抗拉强度衰减10%时的极限跨度为4.2 m;抗拉强度衰减20%时的极限跨度为3.8 m;抗拉强度衰减30%时的极限跨度为3.7 m,达到或超过极限跨度应及时对巷道进行系统支护,使采场保持稳定,增强矿山安全生产。

With the increasing mining strength and scale,it is of great significance for safety production to ensure the stability of roadway roof of marble rock mass in tin mining area,and the calculation and study of limit span increase the stability of roadway.According to the current situation of mine,the ultimate span of roadway is analyzed by combining the slab and beam theory,Mathews graphic method and Q system classification,and the change of the ultimate span under the reduction of tensile strength is studied.The results show that the ultimate span of roadway roof is 4.8 m by using the slab and beam theory,and 5.0 m by Q system classification.The ultimate span of roadway is 4.8 m.According to the Mathews graphic method,the actual hydraulic radius value of 2.184 m is greater than the theoretical hydraulic radius value of 2.000 m,and the vertical opening span of roadway is 9.3 m,which exceeds the limit span.Therefore,it is necessary to take treatment measures for the exposed space of roadway opening.The ultimate span of roadway rock mass is 4.2 m when the tensile strength decays by 10%.When the tensile strength decays by 20%,the limit span is 3.8 m.When the tensile strength decays by 30%,the limit span is 3.7 m.When the limit span is reached or exceeded,the roadway should be supported systematically in time to keep the stope stable and enhance the safety of mine production.