大跨小净距隧道侧穿既有桥梁桩基影响研究

Study on the Influence of Long-span and Small Clear Distance Tunnel on the Pile Foundation of Existing Bridge

随着交通建设的进一步发展,大量的隧道不断修建,其在施工的过程中很可能对近接的既有建筑物产生影响。研究隧道施工对近接既有桥梁桩基础力学性能的影响,以某大垮小净距隧道侧穿既有桥梁桩基工程为对象,开展了三维数值模拟分析。结果表明:采用CRD方法可以较好的控制隧道开挖对桩基础的影响,无论产生的位移还是应力都处于安全范围内。通过不同开挖顺序的对比,发现先开挖左幅即靠近桩基础一侧的隧道优于先开挖右侧隧道,且按左幅隧道左侧上部→右侧上部→左侧下部→右侧下部的开挖顺序为最优开挖顺序。所得结论可为类似工程提供一定参考和借鉴。

With the further development of traffic construction,a large number of tunnels are continuously built,which is likely to have an impact on the adjacent existing buildings in the process of construction.The influence of tunnel construction on the mechanical properties of pile foundation close to the existing bridge is studied.Taking a large collapse and small clear distance tunnel side crossing the existing bridge pile foundation project as the object,the three-dimensional numerical simulation analysis is carried out.The results show that CRD method can better control the influence of tunnel excavation on pile foundation,and the displacement and stress are in a safe range.Through the comparison of different excavation sequences,it is found that the left tunnel,that is,the tunnel close to the pile foundation side,is better than the right tunnel,and the excavation sequence of the left tunnel is the optimal excavation sequence:Upper left→upper right→lower left→lower right.The conclusions can provide some reference for similar projects.