非对称沉降盾构隧道平面模型的内力分布规律研究

Research on Internal Force Distribution Regularity in Shield Tunnel Plane Model with Asymmetrical Subsidence

以西安地铁2号线工程盾构隧道穿越典型黄土地层为研究对象,分别采用考虑结构与地层相互作用的修正自由变形法和梁-弹簧有限元模型法进行内力的理论分析及对比,探讨衬砌变形的分布和变化规律。通过与实测内力值进行对比,指出此盾构隧道结构设计中考虑典型黄土地层非对称沉降的必要性,揭示其结构性能及与地层的相互作用特征。利用梁-弹簧有限元模型法分析盾构穿越地层地下水位变化引起非对称沉降作用下衬砌的内力分布规律,可提升盾构隧道结构设计的安全性和经济性,达到优化和指导此地层条件下衬砌结构适应性设计的目的。

Taking the shield tunnel passing through the typical loess stratum in Xi＇an metro line No.2 engineering as the research object,the theoretical analysis and comparison of internal force were conducted with the modified free deformation method and beam-spring finite element model method considering the interaction between structure and strata,and the distribution and variation regularity of lining deformation were discussed.Compared with the measured value of internal force,this paper reminded that the asymmetric subsidence in typical loess stratum should be considered in the shield tunnel structure design for revealing the structure performance and its interaction characteristics with the strata.By using the beam-spring finite element model,the internal force distribution regularity of lining under action of asymmetric subsidence caused by groundwater level change was analyzed when the shield passes through the strata /which could improve the safety and economy of the shield tunnel structure design to optimize and guide the adaptability design of lining structure under the condition of this stratum.