Dynamic Response Of Surrounding Rock Under Transient Unloading Action In Deep Rectangular Roadway

The exhaustion of resources in the shallow,the boom of mining,hydropower and traffic engineering have tremendously facilitated large-scale tunnel excavations extending to depth.The coal in the deep is in the special geophysical environment and the complex stress field.Deep excavation is widely different from that is in the shallow,owing to the special geological environment in deep location.Traditional theories and experiences from the engineering in the shallow is no more suitable.Therefore,based on the conditions of a coal mine underground engineering in China.The numerical simulation software FLAC 3D is employed to model and simulate the dynamic response of surrounding rock under transient unloading action in deep rectangular roadway with Taking the rectangular roadway of brittle coal as the research object.The main research contents and works are summarized as follow:(1)The mapping function can be created by using the Laurent series and conformal transformation theory,and can map the external zone of a rectangle to the internal zone of a unit circle.The function can be solved by using the conditions of the boundary and corresponding points between domain and domain.The solution of surrounding rock stresses in the rectangular roadway is solved by using the complex function theory based on plane assumption.(2)The numerical simulation software FLAC 3D using finite difference is employed to model and simulate the dynamic response of surrounding rock under transient unloading action in deep rectangular roadway.The simulation results are analyzed depending on the dynamic theory.Combined with a roadway excavation engineering example,the results are also verified.(3)The dynamic response of the surrounding rock under different unloading conditions including in-situ stress distribution,excavation area,different aspect ratios,the distance from the heading face and unloading time have been analyzed.The research results can provide a reference for the research on the transient unloading of brittle rock in the future,and also from the basis for the tunnel excavation and other engineering construction at the same time.