| Karst tunnel geological disasters such as sudden water inrush mud to tunnel construction and operation security caused great threat. How to according to different geological conditions of the different types of karst tunnel using appropriate karst karst hazard control measures to mitigate tunnel is an important problem to be solved. Western hubei mountainous area is carbonate formation, more humid climate, leads to the formation of a surface more karst depressions, mountain water-eroded cave, karst structure such as cavity, underground river is very development, in the process of tunnel construction to meet different types, different distribution pattern of concealed karst cave.Abundant karst cave, vulnerable to tunnel under excavation disturbance mass of sudden water inrush mud, surrounding rock collapse, surface subsidence and other geological disasters, pose a serious threat to the construction security.Therefore, research development characteristics and regularity of karst cave, the analysis of the effect of different types of karst cave in tunnel surrounding rock stability, establish an effective, economic and reasonable tunnel cave comprehensive treatment plan and system, fundamentally solve the problem of concealment and sudden karst hazard, not only to the existing tunnel construction in karst region, technology value and economic significance, built and under construction and for the karst tunnel construction provides an important theoretical basis and practical guidance.Based on COMSOL Mutiphysics field coupling numerical simulation software more quantitative analyzed in different types and distribution form of concealed karst cave surrounding rock under the influence of the changing rule of the seepage field, stress field and displacement field, to explore the different construction steps, the grade of surrounding rock, distance, water pressure, size, shape and location of the concealed karst cave of the effect on the stability of the tunnel. According to the real construction situation of karst tunnel in western hubei mountain area for different types of concealed karst cave specific governance principles and treatment technology are put forward. This paper carried out the main research work is as follows:(1) system to collect data of typical karst cave at home and abroad, and based on the four basic conditions of karst development, according to group of western hubei mountainous area highway project, the characteristics of karst development law in western hubei mountain area and the characteristics of classification will grace to grace guizhou karst tunnel high-speed, high-speed, all22reveals the comprehensive classification of concealed karst cave.(2) based on the western hubei mountainous area of concealed karst cave development condition, the comprehensive construction factors and control measures, the screening of concealed karst cave on stability of tunnel surrounding rock evaluation index, USES the analytic hierarchy process (ahp), concealed karst cave in tunnel surrounding rock stability evaluation model is set up, provide qualitative theoretical basis for the management of karst cave.(3) based on concealed karst cave on the research of the surrounding rock stability influence factors, using COMSOL Multiphysics numerical simulation software in different types and distribution form of concealed karst cave surrounding rock under the influence of the changing rule of the seepage field, stress field and displacement field, reveal containing concealed karst cave tunnel surrounding rock instability mechanism, as to provide theoretical basis for the management of karst cave.(4) combined with the project of grace to Mr Qian highway summary cave treatment principle and treatment technology, in view of the different types of karst cave reasonable treatment measures are proposed, respectively. |
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