A Simplified Model For The Damage Of Buried Fluid-Conveying Pipeline Under The Condition Of Site Settlement

Mechanical damage analysis of buried pipeline under settlement conditions is the basis of studying buried pipeline failure mechanism.It can effectively prevent buried pipeline accidents.In this paper,the research on the damage of buried pipeline under the settlement site is divided into three parts that is the experimental research on pipe damage,the analysis of numerical simulation and theoretical derivation of corresponding theoretical models.The experimental research on the damage of the buried pipeline can concluded that the curve of the pipeline under the condition of the site is the three function curve;The maximum axial strain occurs at the center of the settlement zone when the pipeline was separated from the lower soil mass in the settlement area;And stress transfer of small diameter is faster than large diameter under the same circumstances.The pipeline diameter is smaller,the axial strain is larger.So the smaller diameter is easy to yield.A numerical simulation model was established,and comparison between the pipeline deformation curves obtained from experiment and simulation curves.Numerical models were established when buried pipeline under the different settlement area length,depth,different diameter and different internal pressure.The relationship between settlement range and pipe strain was studied.And the effects of different depth and diameter on the maximum axial strain magnitude and position were studied.The classical model of elastic foundation beam was established in the non settlement area,and gave the deformation curve function of buried pipeline.According to the category and scope of settlement,the different simplified models of pipeline stress were established to suitable for all kinds of settlement.Finally,the stress failure criterion and the strain failure criterion of the pipeline damage are presented,the evaluation method of the pipeline's anti trap performance was also given.