壁后空洞对衬砌结构力学性能影响的试验研究

The Model Test Study on the Structure Mechanical Properties with Cavity behind Lining

壁后空洞是一种常见的隧道病害形式,对衬砌结构的力学性能有重要影响。以福建省道206线龙门隧道的病害检测与改造工程为背景,设计制作了1/10缩尺模型,完成了10组不同工况下的卧式加载试验,重点关注不同空洞赋存条件下隧道衬砌结构的力学性能。壁后空洞的存在,使得空洞附近的衬砌变形由内侧收敛变为外侧扩张,且随着空洞范围的扩大,扩张趋势进一步加剧。拱顶赋存空洞时,空洞附近的围岩压力显著增大,各测点处的衬砌轴力均出现不同程度增长;但拱腰或边墙赋存空洞时,对衬砌结构力学性能影响较小。以上对壁后空洞赋存条件下衬砌结构力学性能的定性/半定量探讨,也可为后续数值模拟研究和理论分析研究提供必要的对比与验证。

The voids behind linings is a common disease in mountain tunnels,and it takes an important effect on the mechanical properties of lining structure. Based on the inspection and reconstruction project for Longmen Tunnel in provincial road #206,the 1/10 downscaled model was fabricated and then tested on the horizontal loading device.10 conditions with different voids behind linings were tested,and the mechanical properties of lining structure were focused. It shows that the existing of voids behind linings changes the lining deformation from inside convergence to outside expansion in the vicinity of voids,and the tendency of expansion increases with the size of voids. When the voids occurring behind vault,the ground-lining pressure in the vicinity of void increases significantly,and the axial force in lining structure also increases to various extent. On the other hand,the influence of voids behind arch and sidewall on the lining mechanical properties is less important. These qualitative and semi-quantitative discussions on the lining mechanical properties could provide comparison and verification for further numerical study or theoretical analysis.