根据直墙拱形隧洞爆破振动速度的现场监测数据,文章分析了邻近岩体爆破开挖诱发的隧洞围岩质点振动速度分布规律。在此基础上,采用数值模拟方法研究了在爆破P波作用下邻近隧洞围岩的质点振动速度的缩放效应并分析了其主要影响因素,对比分析了振动速度缩放效应与动应力集中效应的差异。计算结果表明,在P波作用下直墙拱形隧洞靠近振源一侧围岩的质点振动速度大于振源振动速度,而另一侧质点振动速度则小于振源振动速度,围岩质点振速较大的区域的动应力集中系数较低,而围岩质点振速较小区域的动应力集中系数较高。
For two parallel arched tunnels with straight walls, the distribution law of the particle vibration velocity of the tunnel's surrounding rock mass, which is induced by the blasting excavation of an adjacent tunnel, is ana- lyzed based on in-situ monitoring data. The scaling effect of the particle vibration velocity of the adjacent tunnel's surrounding rock under the function of a P wave and its influence factors are studied using numerical simulation, and the differences between the scaling effect of the vibration velocity and the concentration effect of dynamic stress are compared and analyzed. The calculation resuhs show that when the P wave passes through an arched tunnel with a straight wall, the particle vibration velocity of the rock mass at one side of the tunnel wall near the vibration source is faster than that at the vibration source, while it is slower at the other side of the tunnel wall. In the zones of the sur- rounding rock mass where the dynamic stress concentration factor is higher, the rock mass particle vibration velocity is lower, and the rock mass particle vibration velocity is higher in the zones where the dynamic stress concentration factor is lower.