Mechanical properties test and numerical analysis of new axial hollow-wall PVC buried pipe for drainage
In order to study the deformation and mechanical response characteristics of buried Axial hollow-wall plastic drainage pipe,and achieve full utilization of materials and structures,based on the model box test,the mechanical and deformation characteristics of the buried pipeline and the soil around the pipeline under the soil load,ground static load and pipe-soil interaction were obtained.Based on ABAQUS finite element,the stress and deformation properties of the pipe cross section under the action of buried external pressure,drained internal pressure,and the combination of both were analyzed.The conversion relationship equation between the basic mechanical parameters of pipeline under sandbox test and real buried conditions was established.The results show that the soil column method combined with distribution angle method is suitable for calculating the vertical pressure of the pipe top under the static load of the ground,and the load diffusion angle should be 30°-35°.Under static ground loads,the Spangler-Iowa formula in the calculation method of pipeline radial deformation is conservative,and the results calculated by the AWWA M23 specification are in good agreement with the test results.Considering the quasi-permanent value coefficient will lead to a smaller deformation calculation result.Under the external pressure of buried soil,the inner wall of the pipe waist position is prone to compression failure.During drainage,the inner wall at the top position of the pipe is prone to tensile damage.The inner and outer walls play a major load-bearing role and are subjected to significant forces.The intermediate rib mainly plays the role of connection,and the stress increases in a gradient from the neutral axis to both sides when subjected to force.The proposed correction formula for calculation boundary effect is correct and feasible.The research results can provide reference for the structural design,mechanical and damage failure analysis of flexible buried pipelines such as axial hollow wall plastic pipes.