隧道穿越防护通道受不同钻爆方式作用下岩体动态回应分析

本文以石景山铁路隧道近距离下穿人防通道为例，应用hypermesh联合ansys16.0/ls-dyna进行隧道爆破仿真模拟，采用流固耦合的模拟方法，建立直孔延时起爆，直孔同时起爆以及斜孔延时起爆三种不同爆破方式的本构模型，对直孔延时起爆方式与实测振动波形、质点数值模拟振动波形叠加对比，验证仿真的有效性；根据岩石非对称中心回应变化规律，研究三种不同爆破方式下引起的防护通道P1、P2两点的振动速度、加速度振动衰减规律，将实测振动与模拟振动波形、振动速度、加速度时程曲线以及峰值对比，以获得引起防护通道振动回应最小的最优掏槽孔爆破方式，为铁路隧道下穿既有结构物的支护结构设计、爆破参数及开挖方法设计、隧道规范的修订提供了有利依据。
Abstract：Based on the example of Shijingshan railway tunnel excavation beneath crossing a closely located antiaircraft tunnel,the tunnel blasting was simulated by using the Hypermesh combining with the ANSYS 16.0/LS-DYNA,considering the effect of fluid-solid coupling.The constitutive models for three different blasting types were established,i.e.,the vertical delay blasting,vertical hole simultaneous blasting and inclined hole delayed blasting.For the vertical delay blasting type,by superposition comparison,a real vibration wave shape and the corresponding mass points numerical simulated vibration waveform were contrasted to test the effectiveness of the simulation.According to the response changing principke at the asymmetric centre of rocks,the vibration velocity and the acceleration attenuation at points P1 and P2 on the antiaircraft tunnel under the three different blasting types were investigated.Through the comparison of the vibration waveform,vibration velocity,acceleration curve and peaks between real conditions and simulation ones,the optimal cuthole blasting type can be found out.The results provide references to the structure design for railway tunnel excavation crossing existing construction,blasting parameters selection and excavation method design.