隐伏地裂缝扩展引起分缝式隧道衬砌结构力学性状研究

隐伏地裂缝活动引起的地面与地下建筑物破坏问题较为突出。基于隐伏地裂缝地层中黄土结构损伤问题,将黄土结构损伤研究与数值分析方法结合,分析隐伏地裂缝活动引起的上覆地层渐进性破坏发展规律,研究隐伏地裂缝扩展引起的分缝式隧道衬砌结构力学性状。结果表明:隐伏地裂缝扩展过程中,地裂缝区域隧道衬砌结构错位位移远小于地裂缝自由场地地层错位位移。隐伏地裂缝从隧道仰拱底部扩展至地表过程,下盘第一节衬砌结构受拉破坏尤为突出。隐伏地裂缝引起分缝式衬砌结构受拉破坏是地裂缝区域隧道衬砌设计的关键问题之一,地裂缝处上盘与下盘第一节衬砌结构增加端部厚度与配筋率,需满足衬砌结构抗拉强度。

Mechanical Properties of Split-Tunnel-Lining Structures Caused by Buried Ground Fissure Propagation

The damage caused by underground fissure propagation prominently affects the stability of ground surface and underground buildings. Based on the damage caused by underground fissures to loess structures, the study of loess structural damage was combined with numerical simulations to analyze the development law of progressive failure of overlying strata due to underground fissures. The mechanical behavior of split-tunnel-lining structures was also discussed. The results show that during the process of underground fissure propagation, the dislocation displacement of the tunnel-lining structures in the ground-fissure area is smaller than that in a ground-fissure-free site. When the underground fissure extends from the bottom of the tunnel to the ground surface, the first section of the lining structure of the foot wall is particularly damaged. Tensile failure of the split-lining structure due to ground fissures is one of the key problems in the design of tunnel lining in ground-fissure areas.