Research On Isotope Tracer Of Karst Water In Maoba Syncline Of Yuanliangshan Tunnel

The most important task object of all in the process of tunnel construction is Karst groundwater. Without investigating thoroughly basic condition and dealing appropriately with drainage problems, enormous economic loss would be occurred with hazards to tunnel construction. Generally, common geohydrology means only resolve partly the problems mentioned above, whereas, the isotope geohydrology plays an important role unrepiaced with other techniques in the research of Karst groundwater.Facing on Karst groundwater in the process of Yuanliangshan tunnel construction, we have collected the samples of the regional karst water and the pressure-bearing karst water, and have calculated d value with analyzing 6 D, 6 18O, T value. According to Theory of the environmental isotope tracer and Theory of deuterium excess (d-excess) parameter with the atmospheric water and the groundwater, the dissertation has comprehensively researched on the regional karst water and the pressure-bearing karst water in deep Maoba syncline in virtue of routine geologic and geochemistry investigation. The following results have been obtained.1. On the regional Karst water, it has been primarily clarified that the distributing trait, the cause of formation, and the environment background, and it has been confirmed that the source, the height, and the location about the Karst groundwater replenishment. We have found out the relationship of developing circulation among the atmospheric water, the surface water, and the groundwater in the research area, and have compartmentalized the different geohydrology structures about the Karst water.2. The deep Karst groundwater has been clearly investigated on dynamics characters such as the retention time, the transportation speed, the flowing directionetc, and on the hydrodynamic connection with other groundwater aquifers. The farther knowledge has been acquired that pressure-bearing Karst water in deep Maoba syncline is replenished by the atmospheric water from both east wing and west wing of Maoba syncline, but which from east wing is more, and it is impossible that the pressure-bearing Karst water from west wing rounds to replenish east wing.3. With the deuterium excess(d-excess) parameter, the conclusion that the tunnel location lies on the watershed between south and north geohydrology structures is validated.All of these are the important evidences and thoughts to a further research.