隐伏断层错动对盾构隧道影响的模型试验研究

为了探究隐伏断层错动下盾构隧道结构受力特点及地层破坏模式，基于盾构隧道纵向等效连续化模型，开展隐伏断层错动对盾构隧道影响的模型试验. 研究隧道结构纵向受力特征、环缝接头张开量与断层错动的关系，采用数值模拟手段验证模型试验结果的合理性. 试验及数值计算结果表明，隐伏断层错动下隧道结构纵向受力变化明显，断层错动对隧道结构纵向受力的影响范围小于60 m. 在断层顶部投影面附近的盾构管片环缝存在明显的张拉变形，在正断层错动下盾构环缝接头更容易产生张拉大变形. 正断层错动工况下的隧道结构纵向呈偏心受拉状态，逆断层错动工况下的隧道结构纵向呈偏心受压状态. 在正断层错动下地层发生明显的剪切变形，呈现倒三角形剪切变形扩展规律，地表产生横向贯穿裂缝，逆断层错动下的地层剪切变形相对较弱.

Model experimental study on influence of buried fault dislocation on shield tunnel

The model experiment on influence of buried fault dislocation on shield tunnel was conducted based on the longitudinal equivalent continuous model for shield tunnels in order to analyze the mechanical properties of shield tunnel structure and stratum failure mode under buried fault dislocation. The relationship between the longitudinal mechanical properties of the structure, the opening of circumferential joint and the fault dislocation was analyzed. The rationality of the model experiment result was verified by numerical simulation. The experimental and numerical results show that the longitudinal stress of tunnel structure changes obviously under buried fault dislocation, and the influence range of fault dislocation on the tunnel structure is within 60 m. The circumferential joints near the projection plane at the top of the fault obviously produce tensile deformation, and the circumferential joints are more likely to produce tensile deformation under normal fault dislocation. The longitudinal tunnel structure under normal fault dislocation is in eccentric tension state, and the longitudinal tunnel structure under reverse fault dislocation is in eccentric compression state. Shearing deformation occurs obviously in the strata under normal fault dislocation, and the propagation law of inverted triangular shearing deformation appears. The surface ground transverse cracks develop significantly. The shearing deformation of strata is relatively weak under reverse fault dislocation.