地裂缝对隧道衬砌结构的作用和工程措施

Effect of ground fissures on lining structure of tunnels and engineering measures

西安地裂缝广泛分布于区域内黄土梁凹交接部位。地裂缝活动经历了发生发展、剧烈活动、缓慢变形及稳定阶段。在确定各地裂缝上、下盘相对沉降位移量的基础上,提出了地裂缝隧道采用扩大断面和设置变形缝的结构措施,分析了随着地裂缝上、下盘相对沉降变形的发展,分缝衬砌结构既产生竖向错动位移,又产生旋转的运动特征。为了可适应地裂缝活动,满足地铁运行空间要求,针对隧道内侧拱腰部位产生拉应力集中分布区域和分缝衬砌结构运动,提出了沥青混凝土密封变形缝防止地下水渗漏的工程措施,进行了沥青混凝土密封变形缝的模型试验验证。

Under the influences of tectonic movement and groundwater change,the fissures in Xi’an area are widely distributed at the concave junction of loess beam.The monitoring results of ground fissure movement show that the ground fissure movement has experienced the stage of development,violent activity,slow deformation and stability.On the basis of determining the relative settlement displacement of the upper and lower discs of the fissure movement,the structural measures of the tunnel with ground fissures adopting the expansion section and setting the deformation joints are put forward.With the development of the relative settlement deformation of the upper and lower plates of ground fissures,the lining structure of joints produces vertical staggered displacement and rotational motion characteristics.In order to adapt to the displacement of ground fissures and to meet the requirements of subway operation space,the concentrated distribution area of tensile stress and the movement of lining structure of joints are produced in the inner arch waist of tunnel.The engineering measures of asphalt concrete sealing deformation joints to prevent groundwater leakage are put forward.