Abstract:Based on the existing railway arch bridge paving tunnel, the typical characteristics of tunnel water damage is summarized through on-site investigation and geological analysis, simulation method is to explore and clarify the regular characteristics of internal force, displacement and seepage field of tunnel structure under high water level after heavy rainfall, and discusses the remediation effect of drainage tunnel engineering. The results show that the sudden rise of the groundwater level of the Karst formation under continuous heavy rainfall, the blockage of the drainage system during the operation period and the risk of water damage caused by excessive water discharge measures in the cave are the main reasons for the occurrence of water damage in the case tunnel. Through simulation numerical simulation research, the scientific and reasonable spatial location and section of the new drainage hole adjacent to the existing high-speed rail tunnel are innovatively proposed, which effectively solves the operational safety problem.After the drainage hole is remediated, the external water pressure (especially the bottom of the tunnel) is significantly reduced, and the upright arch uplift is effectively controlled. Even in the face of high water tables, the structural safety and stability of the operating tunnel can be guaranteed. It has certain practical guiding significance for the design and construction of Karst tunnels in the later stage, innovates and improves the level of underground Karst development and groundwater exploration in Karst development areas, scientifically optimizes the tunnel structure design, and ensures operational safety.