Research On Groundwater Drainage Prevention And Utilization In Tongzi Tunnel

This research is based on the major science and technology project of Guizhou Province,"Research and Demonstration of Key Technologies for Efficient Construction and Smart Operation and Maintenance of Super-long and Large-Span Highway Tunnels in Complex Geology" [2018] 3011-007,with Tongzi Tunnel as the research object,through field sampling and theoretical analysis,Laboratory experiments,mathematical statistics and numerical simulation,etc.,carried out research on the impact of groundwater prevention and drainage on the environment and groundwater utilization during the construction of the Tongzi Tunnel.The main research work of the thesis is as follows:(1)The water inflow of the Tongzi tunnel was calculated through empirical formulas,the tunnel's waterproof and drainage system was elaborated,the drainage technology of the reverse slope construction section of the Tongzi tunnel was improved,and two reverse slope drainage schemes were simulated using EPANET software,and the pumping analysis of different pump combinations was realized.Hydraulic calculation accuracy.(2)Using the attribute mathematics theory to construct an evaluation index system for the impact of Tongzi tunnel excavation on the groundwater environment,the weight of the evaluation index is calculated by the analytic hierarchy process,and the confidence criterion is used to identify the impact of the Tongzi tunnel on the groundwater environment.(3)In July(summer)and October(autumn)of 2020,the research team collected groundwater leakage in the tunnel and surface water in the tunnel area,conducted water chemical composition testing experiments,counted the main components in the water,and analyzed the water chemical types in the study area The main source of ions in the water and the water,and the corrosiveness of groundwater to the anti-drainage structure was discussed according to the specification.(4)Two methods recommended by the standard were used to evaluate the water quality in the study area.The single-factor water quality evaluation results are mainly class ? water and class ? water,and the F value method evaluation result is mainly class ? water.The evaluation results of the two are relatively close.(5)The use of groundwater was discussed,and the water quantity and quality requirements of groundwater as a fire-fighting water source for the tunnel were analyzed.The fire-fighting water supply method was hydraulically calculated through EPANET,and the fire conditions were simulated.The Tongzi tunnel adopted the method of “divisional water supply” to reduce pipes.The water pressure of the network system increases the water storage capacity of the fire fighting water and improves the fire rescue capability.