Isotope And Geochemistry Study On Seepage Water Of F29 Fault Of The 11 Th Tunnel In The Irrigation Districts Of Xiaolangdi

As one of Henan’s most important grain production area, the north bank of the Xiaolangdi irrigation area is of positive significance to speed up the construction of production in Henan Province grain core area, to improve the comprehensive grain production capacity and to ensure national food security. In recent years, with rapid development, the contradiction between supply and demand of water resources in Jiyuan is extremely outstanding and need to open up new sources of water. The maim aim of first-stage construction of the north bank of the Xiaolangdi irrigation area is water supply from Xiaolangdi reservoir to Jiyuan city, but the No. 11 tunnel gushing problem decides whether the whole engineering can proceed smoothly. The tunnel is affected by regional fault and distributed secondary faults and fissures of the north bank of the Xiaolangdi irrigation area on a larger scale and facing the problem of tunnel water gushing. Tunnel water gushing is a common geological disaster in tunnel construction and operation process and is a common geological disaster in tunnel construction and operation process. Tunnel water gushing seriously endanger the safety of tunnel construction, the progress of tunnel construction, and if improper tunnel construction measures are taken, the tunnel operation environment will turn bad and cause surface deterioration of the environment, which will cause major losses to the people’s production and life. Therefore, it is of important theoretical and practical significance to the engineering safety and the problem of water supply.Applying the environmental isotope and hydrogeochemical method under theconstriction of regional hydrogeological condition and making the groundwater recharge, runoff and discharge conditions as the main line, we studied the surrounding groundwater recharge, runoff and discharge conditions of F29 fault; hydraulic relationship between precipitation, upper weathering fissure water, the lower structural fissure water; the source and the mixing ratio of tunnel water gushing; hydrogeological significance of fault. These study can supply Isotopic hydrogeochemistry evidence for hydrological research on groundwater geochemistry and water chemistry formation; characteristics of δD、δ18O、 3H and other environmental isotope in groundwater in the study area; the recharge source and water recharge elevation of F29 fault; the mixing ratio of contribution of different flow system for tunnel water gushing and potential water inflow and other related hydrological geological problems. The practice proved that the combination of environmental isotope and hydro geochemical showed strong tracer effects to solve the tunnel water seepage problem and can be widely used in hydraulic engineering tunnel water seepage and hydrological geological problems.