刷方减重下隧道-滑坡平行体系变形演化试验研究

刷方减重工艺在大型复杂滑坡治理中发挥越来越重要的角色。通过室外模型试验，以加载诱发滑坡滑动变形，造成对隧道的破坏影响，以减载的方式模拟刷方减载工艺对隧道的受力变形影响进行研究。结果表明：（1）隧道-滑坡平行体系单滑面情况下滑坡推力在滑体内产生应力效应有一个时间传递变化的过程，即时间效应;（2）滑坡推力对隧道作用沿纵向变形差异大，初步的试验反映出拉压过渡段的位置与滑坡推力的大小相关，滑带位置附近的土体最先达到应力幅值，引起隧道的拉压变形过渡，距离滑带较远位置滑体逐渐达应力幅值过渡;（3）隧道横断面环向应力都是拱顶应力较拱底应力大;（4）隧道环向断面应力呈对称分布，隧道底部受压侧，顶部为受拉侧，底部应变量级小于拱顶，且隧道的变形是不可恢复的;（5）刷方减荷在不同工况下对抑制滑坡变形有不同程度的效用，使隧道应变减小，尤其是滑带附近效果更加显著，这都印证了刷方减重对隧道-滑坡治理的突出效果。

Experimental Study on Deformation and Evolution of Parallel System of Tunnel-Landslide under Excavation and Load Reduction

Excavation and load reduction is play an increasingly important role in the treatment of large and complex landslides. In this paper, outdoor model tests are carried out to study the influence of landslide slip caused by loading on the tunnel and the influence of damage on the tunnel by loading. The results show that: (1) The time-dependent effect of landslide thrust in the sliding body caused by the sliding effect of the landslide parallel to the slip surface has a time-varying effect. (2) The influence of landslide thrust on the deformation of the tunnel varies greatly along the longitudinal direction. The preliminary test shows that the location of the transition zone is related to the magnitude of the landslide thrust. The soil around the sliding zone first reaches the stress amplitude, leading to the transition of tension and compression; the sliding body distant from the sliding zone gradually reaches the transition of stress amplitude. (3) Tunnel transverse circumferential stress is larger than the arch crown stress. (4) The stress in the circumferential section of the tunnel is symmetrical. The bottom of the tunnel is under compression whereas the top is under tension; the strain at the bottom is less than that at the dome, and the deformation of the tunnel is not recoverable. (5) The load reduction of excavation under different working conditions has different degrees of effect to suppress the landslide deformation; this reduces the strain of the tunnel, especially in the vicinity of the sliding belt, which confirms the significant effect of excavation and load reduction on tunnel-landslide control works.