In the excavation process of a drilling and blasting tunnel, it takes multiple blasting excavations to form, so it is inevitable to produce multiple blasting impact loads, which will cause certain vibration damage to the surrounding rock-support structure. To solve this problem, based on the attenuation formula of blasting vibration wave and considering the cumulative effect of short footage blasting load, the radial displacement formula of surrounding rock particles is derived, and the analytical solution of vibration velocity field is obtained by using the method of separating variables. Then, taking Cuobuling station of Qingdao Metro as the engineering background, the finite element software is used to simulate the tunnel excavation process under the action of short footage multiple blasting. The vibration damage impact of multiple blasting loads on the surrounding rock-supporting structure is analyzed from the accumulated displacement value and vibration velocity cumulative value of the excavation tunnel. The results show that the damage accumulation effect is produced in the surrounding rock of each section during the blasting construction, among which the accumulation is the largest at the arch bottom. With the increase of blasting times, the damage of the surrounding rock is still accumulating gradually. Compared with the first blasting, the peak value of vibration velocity of the second blasting increased by 114%, and with the increase of blasting times, the variation trend of maximum vibration velocity of the measuring point showed an upward trend, but the subsequent vibration acceleration decreased. Under the condition of grade V surrounding rock, when the thickness of the concrete spray layer is 350 mm, the maximum displacement cumulative value of each measuring point in profile 1-1 is reduced by about 50.4% compared with that without support. According to the displacement nephogram of the concrete spray layer, the displacement of the concrete spray layer accumulates after three times of blasting, which affects the stability of the supporting structure. Finally, an example analysis is carried out and compared with the analytical model results to verify the accuracy of the mechanical model.

中文翻译：

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短时爆破荷载对隧道围岩支护结构振动影响的研究

在钻爆巷道的开挖过程中，要进行多次爆破开挖，因此不可避免地会产生多次爆破冲击载荷，这会对周围的围岩结构造成一定的振动破坏。针对该问题，根据爆破振动波的衰减公式，考虑短时爆破荷载的累积效应，推导了围岩颗粒的径向位移公式，并利用该方法得到了振动速度场的解析解。分离变量。然后，以青岛地铁错库站为工程背景，利用有限元软件对短时多次爆破作用下的隧道开挖过程进行了模拟。从开挖隧道的累积位移值和振动速度累积值，分析了多次爆破载荷对围岩支护结构的振动破坏影响。结果表明，爆破施工过程中各段围岩均产生损伤累积效应，其中拱底累积最大。随着爆破次数的增加，围岩的破坏仍在逐渐累积。与第一次爆破相比，第二次爆破的振动速度峰值增加了114％，并且随着爆破次数的增加，测量点的最大振动速度的变化趋势呈上升趋势，但随后的振动加速度增大。减少了。在V级围岩条件下，当混凝土喷涂层厚度为350 mm时，轮廓1-1中每个测量点的最大位移累积值与没有支撑的情况相比降低了约50.4％。根据混凝土喷涂层的位移云图，经过三次爆破后，混凝土喷涂层的位移累积，影响了支撑结构的稳定性。最后，进行实例分析，并将其与分析模型结果进行比较，以验证机械模型的准确性。根据混凝土喷涂层的位移云图，经过三次爆破后，混凝土喷涂层的位移累积，影响了支撑结构的稳定性。最后，进行实例分析，并将其与分析模型结果进行比较，以验证机械模型的准确性。根据混凝土喷涂层的位移云图，经过三次爆破后，混凝土喷涂层的位移累积，影响了支撑结构的稳定性。最后，进行实例分析，并将其与分析模型结果进行比较，以验证机械模型的准确性。