双层衬砌输水盾构隧道鲁棒性设计方法

双层衬砌输水盾构隧道设计需要考虑其施工过程及受力特性，同时地层的不确定性也影响结构的安全性能. 为此结合双层衬砌输水隧道的受力特点，基于极限状态设计原则，采用两阶段法分别计算外衬单独承担外压及内外衬共同承担内外压两种受力状态，对截面受力、收敛变形及最大裂缝宽度均加以安全性约束，建立了双层衬砌输水盾构隧道横断面鲁棒性设计方法及流程，并结合实际工程案例进行了结构设计参数的优化. 研究表明：鲁棒性设计方法综合考虑隧道建设成本及结构对外部参数变异的敏感性，引入约束多目标优化算法可以获取完整三维Pareto前沿面. 采用赋权重的方法统一两种极限状态下的鲁棒性指标，可以实现成本-鲁棒性的二维优化 . 通过将隧道分段并提取典型断面优化的方式可有效解决纵向不同区段参数变异性较大的问题，保证掘进中的参数统一及隧道安全.

Robust Design Method of Water Conveyance Shield Tunnel with Double Lining

The construction process and mechanical characteristics of a double-lining water shield tunnel should be considered in the design, and the uncertainty of the stratum also affects the safety performance of the structure. Therefore, combined with the stress characteristics of double lining water conveyance tunnel, based on the limit state design principle, the two-stage method is adopted to calculate the two force states, which include the outer lining bearing the external pressure alone and the inner and outer lining bearing the internal and external pressure together. The section force, convergence deformation and the maximum crack width are all constrained in safety. The cross-section robust design method and the process of double lining water conveyance shield tunnel are established, and the structural design parameters are optimized combined with the actual engineering case. The results show that the robust design process takes into account the sensitivity of the structure to the variation of stratum and the cost of materials, and introduces the constrained multi-objective optimization algorithm to obtain the complete threedimensional Pareto front surface. The two-dimension optimization of cost-robustness was realized by unifying the robustness indexes under the two limit states by the weighting method. By dividing the tunnel into sections and extracting typical sections, the problem of parameter variation in different longitudinal sections can be effectively solved to ensure the unification of parameters in tunneling and tunnel safety.