考虑流固耦合效应的水下盾构隧道受力特性

摘要

In order to investigate the mechanical characteristics of a underwater shield tunnel under fluid-solid interaction during construction stage,a numerical simulation model was established to calculate water pressure on segment lining by taking Shiziyang shield tunnel as an example. Field tests were carried out to measure external and internal loads acting on segment lining structure. The calculated water pressure was acted on the spring-beam model to analyze structural internal forces,and mechanical characteristics of a segment structure under fluid-solid interaction during construction stage were obtained. The research result shows that water pressure fluctuates obviously to the first 3 to 5 rings after the target segment ring lefts the shield tail owing to grouting pressure. When the number of left-shield-tail rings comes to 10 or more,the water pressure gets close to hydrostatic pressure with the dissertation of grouting pressure and the vanishing of fluid-solid interaction.%为探讨水下盾构隧道施工期流固耦合效应对管片衬砌结构受力的影响，以广-深-港（广州—深圳—香港）铁路客运专线狮子洋越江盾构隧道为依托，建立了该盾构隧道数值分析模型，计算作用在管片结构上的水压，并对隧道施工和运营期间管片结构所受外荷载、内力进行了原位测试；将计算水压力施加到梁-弹簧模型上，得到考虑施工期流固耦合效应的盾构隧道结构受力。研究结果表明：受注浆压力影响，目标环管片刚脱环3～5环时，所受水压力波动较大；脱环10环后，随注浆压力的逐渐消散和流固耦合效应的消失，管片所受水压力接近于该处的静水压力。