浸水条件对浅埋湿陷黄土隧道受力性状影响的大型模型试验研究

Large Scale Model Test Study on the Influence of Soaking Conditions on the Mechanical Behavior of Shallow Buried Collapsible Loess Tunnel

黄土隧道基底岩含水率发生变化会导致拱脚和墙脚失稳甚至坍塌,因此,黄土隧道尤其是整体处于湿陷性黄土地层中的隧道受力性状特性研究已经引起工程技术人员高度重视。为了研究湿陷性黄土地层隧道基底承载力及其湿陷变形问题,通过室内大型模型试验方法,研究了天然基底浸水和不浸水工况下基底受力变形性状。研究结果表明:隧道基底压力径向表现为非均匀分布,在仰拱中间位置处最小,墙脚位置处最大;隧道周边切向应力变化规律与径向应力变化规律基本类似,但变化幅度较小;隧道切向压力与径向压力基本一致,浸水完成后各测点应力值都有所增大。

The change of water content in the basement rock of loess tunnel will lead to the instability and even collapse of arch foot and wall foot. Therefore, the research on the mechanical properties of loess tunnel, especially the tunnel in collapsible loess stratum as a whole, has attracted great attention of engineers and technicians. In order to study the bearing capacity and collapsible deformation of tunnel base in collapsible loess stratum, the stress and deformation characteristics of natural base under water immersion and non water immersion conditions were studied through indoor large-scale model test. The results show that the radial distribution of tunnel base pressure is non-uniform, which is the smallest in the middle of inverted arch and the largest at the foot of wall. The variation law of tangential stress around the tunnel is basically similar to that of radial stress, but the variation range is small. The tangential pressure and radial pressure of the tunnel are basically the same, and the stress values of each measuring point increase after immersion.