逐级加载下浅埋软岩隧道动力破坏振动台试验  

Shaking Table Test for Seismic Damage of Shallow Tunnel Subjected to Incremental Loading in Soft Surrounding Rock

作　　者：郭子红 罗茹月 李堂勇 邹高强 杨涛 Guo Zihong;Luo Ruyue;Li Tangyong;Zou Gaoqiang;Yang Tao(College of Civil Engineering,Sichuan Agricultural University,Dujiangyan,Sichuan 611830,P.R.China)

机构地区：[1]四川农业大学土木工程学院

出　　处：《地下空间与工程学报》2019年第4期1081-1090,共10页Chinese Journal of Underground Space and Engineering

基　　金：四川省教育厅资助科研项目(11ZB055);国家自然科学基金(51708373,41672304)

摘　　要：浅埋隧道围岩的质量普遍较低,整体稳定性差,隧道震害表明强震作用下浅埋隧道极易发生震动破坏。通过开展V级围岩条件下浅埋隧道在小震下的震动响应和逐级加载下的震动垮塌振动台试验,研究了小震作用下围岩加速度沿地层的分布、衬砌结构的内力变化和围岩内部的水平位移变化规律,强震作用下衬砌结构裂缝开展和围岩震动垮塌。结果表明:围岩加速度随距地表距离的减小而增加,地表加速度约为拱顶处加速度的1.63倍,相同高度平面内靠近隧道的围岩振动具有一定的加强;隧道拱顶围岩内部的水平位移大约是拱腰围岩内部的1.23倍,围岩内部位移随着远离隧道而逐渐减小,随着震动烈度的增加而不断增加;隧道拱顶上方垮塌区形状近似漏斗,震动引起隧道衬砌结构拱脚处的轴力和弯矩变化最大,且拱肩和拱脚处裂缝分布最多,应加强拱肩和拱脚处结构的抗震性能。Surrounding rock of shallow tunnel is mostly of a low grade,and its stability is poor. Seismic damages of the tunnel show that shallow tunnels are susceptible to earthquake. The shaking table test of shallow tunnel in grade V surrounding rock was carried out to analyse the acceleration distribution in surrounding rock, the seismic displacement,the collapse of surrounding rock,the inner forces and cracks in lining. The results show that the acceleration of surrounding rock increases with the decrease of the distance from the ground surface,the acceleration at the ground surface is about 1. 63 times at vault,and the acceleration keeps increasing lightly while the location moves to the tunnel at the same height. The horizontal displacement of surrounding rock at the vault is approximately1.23 times at the hance,the displacement of the surrounding rock keeps decreasing when its location moves away from the tunnel,and the displacement at each point increase with the shaking times and shaking intensity. With seismic intensity’s increase,in the ground appeared a collapse area,similar to the funnel. Under seismic loading,the axial force and bending moment changes most obviously at spandrel and arch foot of tunnel,and the most cracks appear at the spandrel and the arch foot where the lining should be strengthened.

关 键 词：浅埋隧道 振动台试验 震动垮塌 逐级加载 软弱围岩 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]