Analysis Of Deformation And Stability Of Deep Soft Rock Large Cross Section Caverns

Coal industry in our country is in the special period of divertion from east to the west,migration from shallow to deep and development of small fault to large,the research on the large section cavern in deep soft rock of western is the trend of the times.Large cavern in western soft rock with weak rock,large section,large buried depth,which resulting of big surrounding rock deformation,deep plastic zone,long deformation duration,bring great impact on the traditional supporting theroy Therefore,the research of deep soft rock of large section cavern stability influence factors and its control technology is of great significance.This paper in view of the load cavern,lying in the territory of the main slope and bottom coal joint of Hongqingliang coal,Erdos city,Inner Mongolia,whoes sectional area is up to 80m².through geological investigation,indoor physical and mechanical properties experimental analyze the geological conditions and parameters of surrounding rock of large section cavern,for the analysis of the deformation mechanism,support method is put forward,and the determination of simulation parameters to provide data support.?1?Many methods are used to analyze the deformation mechanism of large section cavern:complex function are used to analyze the surrounding rock stress distribution of the load cavern,by virtue of fenner`s formula to analyze the influence of the section size of cavern deformation,X-ray and electron microscope are used to analyze surrounding rock mineral composition and explore its effect on the cavern deformation mechanism.Qualitatively discussed the cross section shape and in a cavern group of interference on the influence of the deformation of large section cavern.?2?Based on the deformation mechanism discussed,the paper explores the deformation process and forms of the cavern roof,floor and two sides,and analyzes the reinforcement mechanism of various main active and passive support mode,and then explore the how to support the large cavern.bolt,cable,metal net,and shotcrete are presented as initial support,reinforced concrete lining+steel beam as secondary support with the theory of reinforced theory.?3?The application of finite difference software FALC^3D are used to actually simulated downhole load cavern to research the cavern surrounding rock and supporting effect,the effect of a careful analysis of the surrounding rock deformation,stress and plastic zone of surrounding rock and supporting structure,which verifies the feasibility of the supporting method,at the same time points out some problems of the supporting and reinforcing measures are put forward.?4?Under the guidance of simulation and experience,the monitoring plan is designed to monitor and evaluate the whole life of cavern stability.monitoring supporting anchor bolts force to appears the underground pressure,the secondary supporting monitoring is applying after coal bunker excavation,the stress of steel bars and concrete strain monitoring are respectively applied real-time monitoring of the secondary lining.