Analysis of surrounding rock stability and supporting effect of shallow buried tunnel
In this paper,the shallow buried section of a tunnel in Quanzhou is taken as the research object,and the discrete element simu-lation software is used to study the variation law of surrounding rock deformation,surface settlement,surrounding rock stress and plastic zone volume under four working conditions of surface inclination angle of 30,45,60 and 90 degrees.Based on the above research,the in-fluence of shotcrete-bolt support and grouting reinforcement on the deformation and mechanical properties of surrounding rock is analyzed.The research shows that the surrounding rock of the soil shallow tunnel section has no self-stability ability and the surface slope is prone to large-scale subsidence or even landslide without support.With the increasing of surface dip angle,the volume of plastic zone,surface subsidence and surface subsidence range increase.Bolting and shotcreting support can significantly reduce the surface subsidence,reduce the influence range of surface subsidence,greatly inhibit the deformation of surrounding rock and reduce the volume of plastic zone,but it does not completely change the risk of instability of surface and tunnel surrounding rock.The reinforcement ring formed by grouting rein-forcement improves the mechanical parameters of surrounding rock,and the self-stabilization ability of surrounding rock is improved.Spray anchor support can provide more safe space for long-term creep of surrounding rock.
tunnel excavationshallow tunneldiscrete element simulationstability of surrounding rocksurrounding rock support
万方数据
维普
