管道型岩溶隧道衬砌结构受力特征试验研究

为了研究管道型岩溶对隧道衬砌结构的影响,以郑万线典型岩溶隧道为依托,开展管道型岩溶隧道衬砌结构受力特征试验研究,分析岩溶管道发育位置、管道尺寸及管道内水头高度对衬砌内力的影响。结果表明:当岩溶管道位于隧道拱顶或仰拱中心时,衬砌轴力及弯矩沿隧道轴线呈对称分布,当岩溶管道位于隧道边墙中部或边墙脚时,存在岩溶管道的一侧轴力显著大于另一侧区域;随着管道内水头高度及管道直径的增加,岩溶管道与衬砌相交处的轴力及弯矩均大幅增加;岩溶管道与隧道相交处的衬砌内侧承受较大的正弯矩,衬砌内侧被拉裂的风险较高。研究结果可为管道型岩溶隧道的结构设计及施工提供指导。

Experimental Study on the Mechanical Characteristics of the Lining Structure of Pipe-type Karst Tunnel

This paper presents an experimental study on the influence of the pipe-type karst on the mechanical characteristics of tunnel lining structures. Based on the typical karst tunnel of Zhengzhou to Wanzhou high-speed railway, the effects of karst pipeline position, pipeline size, and water head height on lining internal force were analyzed. The results show that the axial force and bending moment of the lining are distributed symmetrically along the tunnel axis when the karst pipeline is located at the center of the tunnel vault or invert. In contrast, the axial force on the side with karst pipeline is significantly greater than that of the other side when the karst pipeline is located in the middle or foot of the sidewall. As the water head height and the diameter of the pipeline increase, the axial force and bending moment at the intersection between the karst pipeline and the lining increase greatly. The inner side of the lining at the intersection between the karst pipeline and tunnel bears a large positive bending moment, resulting in a high risk of cracking inside the lining. The research results can provide guidances for the design and construction of pipe-type karst tunnels.