深埋巷道的爆破开采活动对邻近巷道稳定性影响研究

以某铁矿出矿巷道为工程背景，针对爆破开采扰动影响下临近巷道易发生片帮、冒顶等安全问题，运用FLAC3D数值软件分别对自重应力作用下和爆破荷载作用下临近巷道围岩的应力、位移和塑性区的变化特征进行数值模拟分析，并且与现场实测振动数据进行了对比分析。结果表明：同自重应力状态相比，爆破荷载影响下临近巷道围岩的最大水平位移、最大拉应力及塑性区体积均有着很大程度的增长，增幅分别达到了68.2%、58.6%及76.5%，临近巷道发生失稳破坏的概率显著增加；爆破开采活动对既有巷道迎爆测直墙中上部围岩稳定性影响最大，拱顶及墙脚处围岩受到的影响次之，而对远离爆源侧围岩影响很小。为避免爆破引发临近既有巷道失稳破坏，需加强对既有巷道的迎爆测直墙中上部等危险部位的监测与支护，并对地质条件薄弱区域及时采取素喷混凝土或锚网喷混凝土等有效的支护措施。

Study on stability of adjacent roadways affected by blasting mining activities of deep buried roadway

Taking an iron mine roadway as the engineering background, in view of the safety problems of adjacent roadway that are prone to spalling and roof fall under the influence of blasting mining disturbance, FLAC3D numerical software was used to simulate and analyze the variation characteristics of displacement, stress and plastic zone of the surrounding rock of the adjacent roadway under the action of self weight stress and blasting load, and compared with the field measured vibration data. The results show that: compared with the self-weight stress state, the maximum horizontal displacement, the maximum tensile stress and the volume of plastic zone of the surrounding rock under the influence of blasting load are increased to a great extent, with the increase of 68.2%, 58.6% and 76.5%, respectively, and the probability of instability and failure of the adjacent roadway is significantly increased. The influence of blasting mining activity on the stability of the middle and upper part of the straight wall of the existing roadway is the largest, the influence of the surrounding rock at the vault and the foot of the wall is the second, and the influence of the surrounding rock far away from the blasting source is very small. In order to avoid the instability of nearby existing roadway caused by blasting, it is necessary to strengthen the monitoring and support of the dangerous parts such as the middle and upper part of the straight wall of the existing roadway, and timely take effective support measures such as plain shotcrete or anchor net shotcrete in the weak geological conditions area.