Research on the groundwater transport law during karst tunnel construction

Based on the theory of fluid structure coupling, taking the karst tunnel in Zhongliangshan, Chongqing, as the research object, the numerical simulation method is used to study the spatiotemporal movement law of groundwater during the construction period and its impact on the stability of the tunnel. By comparing the differences in seepage field, displacement field, stress field, and water inflow between the three-step method and the double-sided wall guide method, the influence of the initial water head height and the surrounding rock’s permeability coefficient on the construction process was analyzed. The research results indicate that the double-sided wall guide method significantly reduces the deformation of the surrounding rock through the temporary support system (reducing the arch crown settlement by 48.78% and the arch bottom uplift by 31.13%), making it more suitable for construction in high water pressure and rich water formations. The permeability coefficient and head height have a significant positive impact on water inflow. The research results provide a theoretical basis and technical support for the selection of construction methods and disaster prevention in tunnel construction under complex hydrogeological conditions.