等效荷载法在超大断面公路隧道爆破数值计算中的适用性

为了探究选取最优的计算方法研究超大断面公路隧道爆破施工对先后行隧道的影响，分别采用流固耦合法、初始体积分数法和等效荷载法建立单孔爆破有限元模型模拟单孔耦合装药情况下的爆破过程，从岩体破碎效果、计算效率等方面对比选定等效荷载法为最优的计算方法，并建立隧道数值模型应用等效荷载法计算研究后行隧道爆破对先后行隧道结构的影响，结果表明：（1）后行隧道爆破施工时先行隧道综合振速显著区域出现在隧道掘进方向上，逆隧道掘进方向隧道衬砌动力响应程度较小；（2）先行隧道受影响最大位置为迎爆侧右边墙，影响最小位置出现在背爆侧左拱脚；（3）后行隧道监测断面振速最大值出现在左拱腰位置，施工时要重点监测。

Applicability of Equivalent Load Method in Numerical Calculation of Blasting of Super Large Section Highway Tunnel

In order to explore and select the optimal calculation method to research the influence of blasting construction of super-large cross-section highway tunnels on successive tunnels, the fluid-solid coupling method, initial volume fraction method and equivalent load method are used to establish a single-hole blasting finite element model to simulate the blasting process under the condition of single-hole coupling charge. The equivalent load method is selected as the optimal calculation method from the aspects of rock mass crushing effect and calculation efficiency, and the tunnel numerical model is established to calculate and research the influence of subsequent tunnel blasting on the structure of successive tunnels by using the equivalent load method. The results show that : (1) During the blasting construction of the backward tunnel, the area with significant comprehensive vibration velocity of the preceding tunnel appears in the direction of tunnel excavation, and the degree of dynamic response of the tunnel lining in the reverse direction of tunnel excavation is small; (2) The most affected position of the leading tunnel is the right wall on the blasting side , the minimum impact position appears at the left arch foot on the back burst side; (3) The maximum vibration velocity of the rearward tunnel monitoring section appears at the left arch waist position, which should be monitored during construction.