盾构穿越涉河建筑物时同步注浆压力取值的研究

Research on Grouting Pressure for Shield Tunnel Lining Across Wading Engineering

以上海某穿越区级河道的隧道盾构工程为例,采用由弹塑性理论及土压力基本原理推导的注浆压力临界值公式,计算该盾构工程中同步注浆压力的合理取值范围。并利用Plaxis2D软件模拟计算盾构过程,通过控制防汛墙底板沉降反推临界注浆压力值。理论计算的注浆压力临界值主要由土体主动土压力和被动土压力确定,经数值模拟结果验证了理论公式推算的注浆压力临界值的合理性,因此实际工程中注浆压力可依据公式计算值并考虑安全系数进行选取,在施工时需严格控制注浆压力不超过临界值,以确保在盾构影响下涉河建筑物的变形在规范允许之内。

Taking the typical section of river-crossing shiled tunnel project as the study subject, the theoretical alalysis （elastic-plastic theory） are made on the calculation formula of critical values for grouting pressure.Using Plaxis2D ,the numerical simulation on the shield tunnel excavation is presented while the critical values for grouting pressure are fixed through settlement control of the bottom plate. The predie ted and theoretical alalysis,which means rationality and necessary of choosing values with assurance factors from formula calculating.It is required to keep grouting pressure in control to assure the ground deformation is satisfied.