With the vigorous development of China's economic construction, especially since the western development, needs of traffic tunnel construction are increasing, a large number of tunnels will be built in the mountainous with deeply buried and high water pressure, it is an urgent problem about research on the groundwater environment and the ecological environment in the tunnel site area causes of tunnel construction. The Songpan County Mounigou tunnel located in the high altitude alpine region, regional and environmental geological conditions are complicated, the strata in the tunnel site area is aquifer, and developed faults fractures and fissures, tunnelling will lead to groundwater dewatering and cause the deterioration of the groundwater environment, Then great collapse, burst mud and water gushing will occur during the tunnel construction due to the enrichment of groundwater in tunnel site. Take a research on numerical simulation of groundwater flow in the tunnel site area, the tunnel excavation will form a larger catchment corridor, the impact is bound to the tunnel site hydrogeological conditions in the sphere of influence may appear to lower the groundwater level, seisensui drawdown or part of the dry, provide the basis for tunnel construction.

No abstract

In addition to the gas tunnel in coal strata, there are a large number of gas tunnel in non-coal strata, these tunnels itself do not through the coal strata, but all encountered the gas problem in the construction process. Because of not a full understanding and preparation on gas of tunnel in non-coal strata zones, and the gas emission is random, uneven distribution of the characteristics, so the gas disaster hazard is larger in such gas tunnel, study on its formation mechanism is great significance. Based on the study of a lot of the gas tunnel has been constructed, summed up three genetic types of the non-coal strata gas tunnel: one type is structural connectivity, according to the different structure types, can be divided into fracture connectivity type, fault type and fold connected connectivity type; Second is surrounding rock metamorphic type; third is compound effects type.