盾构施工对孔压扰动的三维流固耦合分析

如何对盾构施工过程中的孔压监测数据进行实时分析是工程实践中的难点问题。结合上海虹桥迎宾三路隧道工程，首先建立了包括各种盾构施工参数影响的分析模型，并将不同施工参数情况下超孔压计算结果与实测值进行了对比，验证了模型的合理性。之后分析了开挖面推力、注浆压力、掘进速度、开挖面水头、隧道埋深以及土体渗透系数等参数对隧道周围最大超孔压的影响，获得了最大超孔压拟合计算公式，与现场实测和解析解的对比说明三维流固耦合计算可更合理分析盾构施工对孔压的扰动。同时，较大的超孔压值对应于较大的地表沉降，因此可将实测孔压值与数值计算结果进行对比，从而进行施工参数的调整。在上海虹桥迎宾三路隧道工程试验段的施工过程中，现场监测数据表明可根据孔压监测值调整施工参数，最终减小地面沉降。

3D coupled mechanical and hydraulic analysis of pore water pressure disturbed by shield tunnelling

It is a difficult problem to analyze the pore water pressure monitored in the field while tunnelling. Based on the tunnel constructed in Shanghai of China, a finite element model for shield tunnelling is established, which can study the effects of construction parameters. The model is validated by comparing the calculated results with the data monitored in the field. The effects of the construction parameters including the face thrust force, grouting pressure, excavation rate, water head at the face, cover depth and soil permeability on the maximum excess pore water pressure are analyzed. Then a fitting formula for the pore water pressure is obtained based on the calculated result. By comparison between the analytic solution and the data monitored in the field, it is obtained that the 3D coupled mechanical and hydraulic method is a good way to analyze the pore water pressure disturbed by shield tunnelling. The larger the maximum pore water pressure, the larger the ground settlement. So the pore water pressure monitored in the field can be used to analyze the fitness of the construction parameters. For Yingbinsanlu tunnelling project in Shanghai, the monitored pore water pressure is compared with the numerical results, and it is concluded that the construction parameters can be changed in time to decrease the ground settlement.