Study on Bearing Capacity and Failure Mode of Multi-Ring Solid Assembly Tunnel Segment with Considering Joint Bolts
Segment lining structure is widely used in subway tunnels and other projects.Its bearing capacity and failure mode under external confining pressure are critical to the safety of tunnels.In order to study the load-bearing capacity and failure mode of the segment lining structure of the shield tunnel,the calculation theory of the external confining pressure loading modes were proposedin this paper.A three-dimensional solid FE model for the three-ring segment structures was established,and the stress and deformation response of the segment under normal loading condition were calculated.The buckling mode of the segment was analyzed.The nonlinear ultimate stability bearing capacity was studied,and the damage mode for the structure was revealed.The research results show that under the normal load condition,the maximum stress value of the structure is 61.5%of the uniaxial compressive strength.The deformation mode presented an asymmetrical ellipse,the amount of which was small,meeting the requirements of the specification.The structure was in a safe working state and there would be no stability problems.The structure was broken when the load factor increased to 2.90,with the maximum stress reaching the ultimate compressive strength and large deformation occurred.The value of ovality for segment liming was 2.23%,far exceeding the standard limit.The concrete showed extensive failure,while the maximum axial stress of the bolt was only 20%of the yield limit,and the failure mode of the tunnel segment structure under the confining pressure is concrete failure.
万方数据
维普
