地面堆载下盾构隧道不同加固方法的加固效果研究

Reinforcement Eff ect of Various Methods for Shield Tunnels under Ground Surcharge

为研究地面堆载作用下不同加固措施对盾构隧道管片的加固效果,采用有限元进行模拟,设计一组室内模型试验,将相同工况下试验与有限元得到的隧道沉降与变形结果进行对比,以验证有限元模型的可靠性。使用验证后的有限元模型模拟隧道周边注浆加固、内钢圈加固与UHPC加固,分析在地面堆载工况下隧道的沉降与管片变形情况。有限元结果表明:1)采用注浆方法对隧道周边土体进行加固,可以使隧道在堆载作用下的竖向变形比未加固时的竖向变形减小很多,且对隧道沉降有一定抑制作用;2)采用内钢圈与UHPC加固隧道内壁,可以明显降低隧道在堆载作用下的竖向变形,但对隧道沉降影响较小。

Finite element simulation method is adopted to examine the effect of various reinforcement methods on shield tunnel segments under ground surcharge.To validate the reliability of the finite element model,a set of the indoor model tests are designed and conducted.Moreover,the tunnel settlement and deformation obtained by the tests are compared with the simulation results under same working conditions.The validated finite element model is then used to simulate the grouting reinforcement around the tunnel,the inner bonded-steel ring reinforcement,and the ultra-high-performance concrete(UHPC)reinforcement.Additionally,the tunnel settlement and the segments′deformation under the ground surcharge condition are analyzed.The finite element simulation results show the following:(1)The grouting reinforcement for the surrounding soil of the tunnel can reduce the vertical deformation of the tunnel under ground surcharge much than that without reinforcement,and it also has a certain inhibitory effect on the tunnel settlement.(2)The inner bonded-steel ring and UHPC reinforcement can evidently reduce the vertical deformation of the tunnel under ground surcharge condition while has little influence on the tunnel settlement.