高烈度地震区山岭隧道模型试验研究

以雅泸高速公路高烈度地震区某山岭隧道为背景,对山岭隧道结构地震动力响应进行了大型振动台模型试验研究。试验表明,在隧道洞口段模型土表层裂缝均先从隧道拱顶偏向两侧45°角位置出现,然后斜向向上扩展;在隧道洞身段进出口纵向及斜向裂缝数量较多,大部分裂缝延伸至环向裂缝后终止。在隧道洞身段试验中,拱顶内缘和两侧边墙中部衬砌外缘出现拉裂性裂缝;在仰拱部位出现剪裂性裂缝或压裂性裂缝,并有不同程度的错动,是受地震影响最大的部位。

Model Test for a Road Tunnel in the Region of High Seismic Intensity

With a road tunnel in the region of high seismic intensity on Ya'an-Luzhou expressway as the back-ground,a large-scale model test was conducted on a vibration table to study the seismic dynamic responses of the rock tunnel structure.Results indicated,cracks in the surface soil layer of the model on the tunnel entrance ap-peared firstly at positions of 450 to the crown and developed upward along inclined direction.On the portal sec-tions of the tunnel there appeared a lot of longitudinal and oblique cracks,most of them extended and terminated at transverse cracks.On the main tunnel section,tension cracks appeared on internal surface of crown and external surface of side walls at mid-height.Shear cracks and compression cracks appeared in the invert together with dislo-cations.This was the region most severely affected by the quake.