Interval uncertainty analysis on mechanical behavior of segmental lining of shield tunnel

DOI：10.7511/dllgxb201903001

 作者 单位 冉春江,杨海天,陶越

以琼州海峡盾构隧道为研究背景，基于梁-弹簧有限元模型，考虑初始设计阶段中相关参数的不确定性，将侧向土压力系数、地层抗力系数、接头等效抗弯刚度考虑为区间不确定性变量，建立了管片衬砌结构区间不确定性问题的数值求解模型，推导了影响度计算公式，可估计轴力、弯矩、安全系数的上下界．通过数值分析，探讨了各区间变量不确定性对管片衬砌结构力学行为的影响．数值结果表明：所取参数的不确定性对轴力影响较小，但对变形和弯矩影响较为明显；两种荷载模式对应的管片安全系数区间相差较大，在设计中应妥善考虑．研究结果有望为管片衬砌鲁棒优化设计提供参考．

With the consideration of the uncertainty of parameters concerned with the preliminary design of segmental lining of Qiongzhou Strait shield tunnel, the coefficients of lateral earth pressure, subgrade reaction and the equivalent flexural rigidity of segment joints are regarded as interval uncertain variables, and a beam-spring finite element model based numerical framework is built up for the interval uncertainty analysis. A formula to estimate the degree of influence of interval parameters is derived. Upper and lower bounds of axial force, bending moment and safety factor are provided, and the impact of an individual interval variable uncertainty on the mechanical behavior of segmental lining is evaluated by utilizing numerical analysis. Numerical results indicate that the axial force of the segmental lining is less impacted by uncertainty of considered coefficients, but the deformation and bending moment are considerably impacted. In addition, a significant difference between intervals of safety factors of segment given by two loading modes is observed, and is necessarily taken into account in design. The work presented is hopefully valuable for the robust optimization design of segmental lining.