| Karst has been the one of the most serious geological disasters of mining engineering, underground tunnels and other works in the world. Large-scale water inrush and burst mud in the construction process not only endanger the safety of tunnel construction,but also make a bad impact of the construction progress. If not handled properly, it often leads to poor operating environment and surface environmental degradation after the lane and tunnel project is completed, these will give significant losses to people's life.In the process of infrastructure construction, the bauxite project of Chongqing branch of Chinalco Co LTD. has suffered karst hazards,particularly the construction of the main transport level hole suffered karst hazards even more.In this paper, using the main transportation in the construction of 575 square hole of Chongqing branch of Chinalco Co LTD. as the basis.Making analyze on the construction process of forming characteristics of karst disaster through the investigation of engineering geological conditions of the main square hole and hydrogeological conditions.Then making a grade of karst hazard.At the same time build the model for calculation and analysis of its mechanism of water inrush.Finally, based on the detection of each cavity development, the paper offers each cavity prevention measures and construction technology, its main contents are:After systematic analysis on the research in the impact of karst on tunnel construction in and out of China and karst water technology. This paper described some construction geological conditions in the mine, such as lithology, topography, geological structure and development conditions and circumstances surrounding rock mass, also described development of the regional aquifer characteristics and the characteristics of karst regions.The system described the major karst geological hazards of the situation, mainly analyzes the water characteristics of karst, filling characteristics, connectivity characteristics and some other hazard characteristics, also evaluated the geological hazard site in the main level, classified the initial segment of roadway to mileage KO+650 as medium risk paragraph karst section, classified the mileage KO+800 to mileage K1+100 as a serious risk karst section.The model is builded by ANSYS and then imported into FLAC3D By themodel,analyzing the effect of karst development to main drift and water inrush mechanism.According to different section of karst, puting forward a corresponding control measures and construction techniques. Based on the riginal transportation routes,the long pipe combined with short pipe pass through karst cave from inside to out at the K0+481 cave; at the K0+644, we used full-sectional grouting assisted steel arch, anchor,reinforced concrete to support drift, and this supporting scheme mainly based on plugging,so that it can cross karst cave; at the K1+058～K1+121, we set some drain chambers,added weep hole to release the preasure,and by using anchor fixation,injection grouting, steel arch and reinforced concrete to support. |
PDF Full Text Request