In order to study the failure mechanism of the composite lining structure of a shield tunnel using HDPE double wall winding pipes as the lining,this paper uses the railway section of the Taopu Wastewater Treatment Plant's initial rainwater regulation and storage project to conduct a full-scale experimental study.The following conclusions are obtained:(1)The failure process of the composite lining structure undergoes a coordi-nated deformation stage and a self-bearing stage.The elastic limit point is the peeling of the interface at the top and bottom longitudinal joints,leading to successive damage to the longitudinal joints and the pipe body.The concrete filling layer at the longitudinal joint experiences either tensile shear or compressive shear failure.(2)The weakest points of the composite lining structure are the interface and the concrete filling layer at each longi-tudinal joint,with the top and waist longitudinal joints being particularly vulnerable.(3)The interface failure and filling layer failure patterns at different positions of longitudinal joints in composite lining structures are all due to the stiffness difference caused by the rotation deformation of the longitudinal seams,which leads to the sudden change of the interface stress and the filling layer stress.
High density polyethylene(HDPE)pipeLiningComposite lining structureUltimate bearing capacity
维普
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