桩基施工对既有通车隧道扰动影响分析

Disturbance Influence of Pile Foundation Construction on Existing Traffic Tunnel

邻近既有隧道桩基施工与列车荷载耦合作用产生的应力波会对既有通车隧道造成扰动影响,甚至会演变成严重的坍塌事故.结合邻近既有通车隧道的某码头打桩工程实际,分析耦合作用下既有通车隧道的动力响应;建立"桩-土-隧道"的三维有限元模型;并采用数值模拟方法找出既有通车隧道的不利振动和应力区域.研究结果表明:(1)隧道最不利的振动范围集中在隧道z方向的整个底部区域;(2)隧道最不利的应力范围主要集中在隧道z方向的右下区域;(3)隧道截面沿x、y方向所受的最大振速为4.6 mm/s,沿z方向所受的最大振速为4.4mm/s.通过确定既有运营隧道最不利振速以及拉应力的区域,为类似工程中通车隧道安全防护提供了技术支撑.

The dynamic response of the existing tunnel under coupling action is analyzed, the three-dimensional finite element model of "pile-soil-tunnel" is established, and the unfavorable vibration and stress region of the existing traffic tunnel is found by numerical simulation. The results show that the most unfavorable vibration range of the tunnel is concentrated in the whole bottom area of the tunnel z direction, and the most unfavorable stress range of the tunnel is mainly concentrated in the tunnel the lower right region of the z direction. The maximum vibration velocity of the tunnel section along the x and y direction is 4.6 mm/s, and the maximum vibration velocity along the z direction is 4.4 mm/s. By determining the most unfavorable vibration speed and tensile stress area of the existing tunnel, it provides technical support for tunnel safety protection in similar projects.