高应力软岩近距离巷道工程的掘进扰动与稳定性

针对高应力近距离巷道工程的开挖掘进及稳定性问题,进行了理论分析、数值计算及现场监测等一系列研究。首先,在某矿山深部巷道工程的地质与施工条件基础上,采用理论方法分析了掘进爆破扰动应力传播规律及其对邻近巷道或硐室围岩稳定性的影响,并给出了扰动波在岩体中的衰减方程。然后,根据相关理论,采用FLAC软件进行了一次爆破掘进长度和开挖工序等掘进方案的数值分析,结果表明：在动荷载（爆破掘进）作用下,由施工巷道开挖时所产生的变形会直接影响到邻近硐室或巷道周边岩体,应力释放区域较大；当一次爆破掘进长度较小时,由于整段巷道的扰动次数较多而会引起变形增大,但初始速度较小,则反之。最后,采用监测的方式,对施工巷道进行了开挖扰动分析,结果表明：相距为20 m左右的两条巷道,开挖爆破扰动程度较大区域在后掘巷道掘进工作面的前后10～20 m范围之内,而对本条巷道扰动程度较大范围一般距掘进工作面25 m左右；并按照扰动程度大小可分为破坏区、影响程度较大区和影响程度较小区,破坏区和影响区一般位于掘进面30 m以内。

Excavation disturbance and stability of short-distance roadway with high stress and soft rock mass

According to the excavation and stability problem of short-distance roadway with high stress and soft rock mass, theoretical derivation, numerical calculation and field monitoring are made. At first, the propagation law of disturbance stress in excavation blasting and its stability influence on the surroundings of short-distance roadways or chambers are analyzed based on the geological and construction conditions of deep roadway in one mine. An attenuation equation for the disturbance waves in rock mass is given. And then, the FLAC software is used to numerically analyze different excavation projects including lengths of one blasting and excavation steps. The results show that the induced deformation in the excavation process can directly affect on the surrounding rock of the adjacent roadways or cambers under the action of dynamic load (development blasting), and stress release area is greater. The deformation of the whole roadway increases because of many disturbance times when the length of one blasting is smaller, but its initial velocity is less, while vice versa. Finally, the way of field monitoring is adapted to analyze the excavation disturbance to constructing roadway. The results show that the greater degree area of blasting disturbance is about 10～20 m of heading face of the nearby excavated roadway to two roadways with a distance of20 m. But for this project, it is about 25 m. The disturbance area includes failure zone, greater effect degree zone and less effect degree zone according to different degrees. The failure zone and the effect zone lie in the area of heading face with a distance of 30 m.