Research On The Surrounding Rock Stability And Supporting Structure Optimization Design Of The Large Underground

The stability of large underground caverns has always been a complicated nonlinear mechanics problem,and it’s concerned by theoretical and engineering.Large underground cavern has various depth,and has layout density,through the formation is complicated,the weak structural plane,such as folds,faults,joints,stratification,fissure,etc.Those problems make the process of design and construction of underground cavern became complex and variety,and there is less engineering analogy and no standard to follow.The bad geological phenomenon deformation causes various failure forms,and there deformation failure mechanism is complex,become the major geological problems or engineering problems in the process of survey,design,and construction.But,people for the research of large underground caverns is not enough,especially for the stability analyze,the influence law of stability influence factors,caverns structure optimization design and so on are less system analyze.Hence,it is important to deeply analyze the buckling characteristic of the large underground caverns and supporting optimization design in practical engineering stability analysis and control.This thesis main includes four parts.(1)Making a research summary to instability criterion of large cavern surrounding rock,and concluded that the main instability criterion has four kinds:surrounding rock strength criterion,the ultimate strain criterion of surrounding rock,displacement of surrounding rock into the hole criterion,criterion based on catastrophe theory,and then make every kind of instability criterion condition to discuss.(2)According to an engineering example,combined with engineering drawing up construction progress and excavation scheme,and then analysis of surrounding rock stability,lastly,it is concluded that in the process of the excavation of surrounding rock stress field,strain field and plastic failure characteristics of the change.(3)Combination the engineering instance of "Hanjiang-to-Weihe River" project,the cavity may way of supporting structure optimization are analyzed,and on this basis,the recommended according to the engineering practice of supporting parameters,supporting time,recommended according to the engineering practice of supporting parameters,supporting time,construction excavation process.