| China has the largest karst distribution area in the world, the karst on the groundalone accounts for13.5%of the total area of the country, underground karst distributionis more extensive, southwest region (mainly in southern guangxi, guizhou and yunnan)distribution is more serious. Along with our country comprehensive national strengthincreasing, the development and utilization of underground space is increasing,especially since the construction of west development, due to the collapse in karst areaconstruction, rock burst, mud and water gushing of geological disaster are countless.Asualties, economic loss and ecological environmental damage are more incalculable,the karst water inrush disasters are more frequent and severe. Therefore, systemlytostudy the effect of karst water bursting in the tunnel construction, and to explore itsregularity, in karst tunnel construction safety and prevention of water inrush disastershas great practical value.According to karst tunnel water inrush disasters problem, and on the basis ofsummarizing the predecessors’ research results, using theoretical analysis and numericalsimulation analysis method, this paper has analyzed and summarized the basicmechanical characteristics and regularity of karst tunnel water inrush mechanism of thewater inrush disaster, water inrush disasters prevention and control measures, etc,selective analysed the tunnel construction in karst effect on the mechanics and stabilityof surrounding rock and its structure. And according to its influence law to explore lawof karst water bursting to provide the reference for karst tunnel water inrush disastersprevention. Mainly three types of karst tunnel (at the top of the karst, the karst and theside at the bottom of the karst) are studied by using numerical simulation method underthe condition of different influence factors (karst tunnel and spacing, and the size of thekarst, the karst water pressure) of mechanics and stability of tunnel surrounding rockand its structure are studied. The results are as follows:The smaller the distance between the soluble tunnel, karst scale is big, the stabilityof tunnel wall rock is more adverse. Because of the karst is a weak zone, when thetunnel excavation stress release directly affect the karst region, will cause the tunnelsurrounding rock deformation failure, resulting in water and mud bursting phenomenon.When the surrounding rock caused by tunnel excavation effect of stress release area inthe wall, tunnel surrounding rock is still in elastic state, without the occurrence of plastic deformation, will not occur the phenomenon of water gushing. But for karstwater pressure, the pros and cons of the surrounding rock’s stability should also becomprehensive analysis and judgment according to actual situation. |
PDF Full Text Request