盾构隧道施工地表沉降数值分析研究

隧道施工引起的地层损失所导致的地表沉降变形预测和控制，是隧道工程领域重要的研究课题之一。以盾构隧道开挖引起地表沉降变形为研究对象，采用有限元数值分析软件模拟盾构隧道施工过程，分析盾构隧道引起的土体应力场、位移场变化，对比分析不同的地层损失、不同的土体本构模型、土体排水和不排水条件下隧道施工引起的地袁沉降变形规律，并进行了不同影响因素的敏感性分析。结果表明，地表沉降槽近似正态分布曲线，地表沉降的主要影响因素依次为隧道埋深、内摩擦角、压缩模量、粘聚力和泊松比；提出了盾构隧道施工引起的地表沉降计算模型，并采取有针对性的措施来减少地表沉降，减小对周围环境的不良影响。

Numerical Analysis on the Ground Settlement Induced by Shield Tunnel Construction

Forecast and control of the deformation caused by stratum loss in the tunnel construction is one of the important research issues in the field of tunnel engineering. The ground settlement induced inevitably by shield tunnel excavation is taken as a study object. The process of the shield tunnel excavation is simulated by FEM, the variation of the stress and displacement field caused by tunnel excavation is analyzed, and the ground settlement induced by the stratum loss is studied. The ground settlement of the different soil constitutive equations, soil drained and undrained is compared, the sensitivity of the main influence factor of the ground settlement is analyzed.The results show that the transverse distribution of the groove of the ground settlement is the same as the Gaussian distribution. Main influence factors of the ground settlement are embedded depth, inner friction angle, modulus of compression, cohesive and Poisson ratio in file. The calculating model of the ground settlement induced by shield tunnel construction is proposed. And the correlation measures reducing the ground settlement and diminishing the badness influence on the surrounding environment may he taken.