为研究40°斜穿地裂缝分段式马蹄形衬砌结构受地裂缝影响的变形破坏模式、特殊变形缝的三维变形特征,从西安地铁隧道工程背景和西安地裂缝地质环境出发,根据相似理论设计分段式马蹄形隧道衬砌结构40°斜穿地裂缝的物理模型试验。模型顶面土体沉降、结构底部土压力分布、变形缝三维变形特征表明:分段式马蹄形隧道衬砌结构40°斜穿地裂缝时其破坏模式为顺变形缝发生整体剪切变形破坏,变形缝发生垂直位错、轴向拉伸、水平偏移三维变形分量,管段结构混凝土没有破坏;变形缝拱项处的三维变形分量均分别大于其拱底的,且其分布规律基本一致;上盘侧变形缝垂直位错大于下盘侧,其轴向拉伸变化不大,水平偏移主要发生在地裂缝处,变形缝垂直位错从下盘端部向上盘逐渐增加;根据相似理论推算,原型结构在地裂缝上盘下降90cm时,5处变形缝最大总垂直位错量达72cm,最大总轴向拉伸量达34.5cm,最大总水平偏移量达32cm。
In order to study the three-dimensional(3D) deformation feature of special movement joint and the deformation failure model of sectional horseshoe-shaped tunnel lining structure crossing the ground fissure with 40 °, the sectional horseshoe-shaped tunnel lining structure modelling experiment crossing the ground fissure with 40 ° is designed, which is based on the Xi'an metro tunnel engineering and the geological environment of Xi'an ground fissure and similarity theory. The soil settlements on the top of model, the bottom soil pressure and the 3D deformation character of the movement joint show that the deformation and damage mode of lining structure of sectional horseshoe-shaped tunnel crossing the ground fissure with 40° are shearing failure alone the movement joint in global. The deformations of movement joint include vertical dislocation, axial tension and horizontal offset, but the lining structure concrete is not damaged. The 3D deformation component of movement joint on lining structure crown is larger than that on lining structure soffit, and the distribution rule of deformations both on crown and soffit is the same. The vertical dislocation of hanging side is larger than that of lying side, but the difference of axial tension between hanging side and lying side is small; and the horizontal offset occurs on the ground fissure mainly. According to the similarity theory, when the settlement of hanging side of ground fissure is up to 90 cm, the total vertical dislocation of five movement joints will be up to 72 cm; and the total axial tension will be up to 34.5 cm; the maximum horizontal offset will be up to 32 cm.