大直径浅埋隧道对既有桥梁沉降影响研究

Research on Impact of Shallow Buried Tunnel with Large Diameter on Settlement of Existing Bridge

隧道盾构下穿既有桥施工时,由于土体扰动,盾构法施工对周围土体及既有桥结构基础的影响较为复杂,以某大直径浅埋隧道下穿既有桥为例,在常规地层损失率下,对比分析Peck公式与隧道二维模型的计算结果,验证隧道二维模型参数取值的合理性,在此基础上,建立三维有限元模型,研究同样地层损失率下三维模型的地面沉降及既有桥基础沉降规律。

When the shallow tunnel shield underpasses the existing bridge,the shield tunneling will cause complicated impact on surrounding soil and existing bridge structure foundation due to soil disturbance.In the paper,taking a large diameter shallow tunnel which underpasses an existing bridge as an example,the calculation results of Peck formula and the 2-D model of the tunnel are compared under the condition of conventional strata loss,the rationality of the parameters of the 2-D model is verified.On the basis,the 3-D model is established,the ground settlement of 3-D model and settlement regularity of existing bridge foundation are studied under the corresponding strata loss.