Analysis of destabilization and slump model of overlying stratum structure of shallow tunnels

摘要

In order to effectively control the stabilization of heading face of shallow tunnel and avoid risk in geotechnical environment and during construction,based on the overlying stratum structure model, and considering that soil in relaxation zone behave as granular material when losing stabilization and slumping,the concept of Spheroidal body is proposed, and the correlation between unlined length of heading face and slump height is presented too; it is concluded that the type of destabilization of tunnel is local destabilization when in general stratum,and is overall destabilization when in complicated stratum. It is proposed that unlined space in heading face is the key factor of slumping of tunnel, and the destabilization and slumping of tunnel is decided by physical parameters of stratum but unrelated to depth of tunnel,all of these standpoints, which further prove that stratum prereinforced structure is the key to construction of tunnel, are meaningful to the construction of tunnel.