Spatial-temporal Effect Analysis of Surrounding Rock Deformation in Soft Rock Tunnel with Extremely High Ground Stress
In order to explore the temporal-spatial effect characteristics of surrounding rock deformation during tunnel excavation,the methods of indoor model experiment,theoretical analysis and field monitoring are used,the temporal-spatial deformation law of surrounding rock,the types of temporal-spatial characteristic curves and the radial deformation law of surrounding rock in different range from tunnel wall under different excavation methods of the Ningchan Tunnel with extremely high ground stress soft rock are studied.The results show that the temporal-spatial characteristic curves of surrounding rock deformation can be divided into"parabolic"type and"step"type.The"parabolic"curve includes two stages:sharp growth and slow growth,and the deformation law conforms to the quadratic function relation;the"step"curve includes four deformation stages:sharp growth,slow growth,rapid growth and basic stability,and the deformation law conforms to the exponential function relation.Tunnel excavation will cause radial displacement of surrounding rock within 0-2.5 D away from the tunnel wall,and the radial deformation law of surrounding rock in different ranges away from the tunnel wall conforms to the exponential function relationship.The research results have great value to determine the construction process and the best supporting time of extremely high ground stress soft rock tunnel.
tunnel engineeringextremely high geostresssoft rock tunnelmodel experimenttemporal-spatial effect
NETL
NSTL
万方数据
维普
