Field Tests And Finite Element Numerical Simulations Of Frpm Pipe Culvert

At present,the research of FRPM pipe culvert on road performance mostly stay in the test in our country.It is not common for the research of FRPM pipes in soil,under the action of differet load(static)styles,the same diameter(inner-diameter)of different pipe thicknesses and interaction among them.In this paper,the mechanical properties,buried pipeline under vertical static load were discussed through theoretical analysis,field tests and numerical simulations.It carried out a detailed study of stress and deformation of the pipe culvert and pavement and studied the way to improve the performance of them,so that,It can greatly enhance the engineering application of FRPM pipe,which has practical significance for the design and production.The main work in the paper includes the following aspects:(1)The basic theory of finite element method and single layer glass fiber reinforced plastic material was introduced,and the numerical models were established by using it;(2)Through the field static mechanical tests of FRPM pipe,diameter 1.50 m and pipe thickness 38 mm,eight points of circumferential and axial strains of FRPM pipe in the inner middle section were collected,the variation trend of the changes of the diameter of pipe and the vertical soil pressure changes with the load levels around the pipe were discussed;(3)On the basis of introduced theory and experiment,the numerical model of field tests using FEM software was established.Contrasting the difference between the field tests results and the numerical simulation results,the results show that the variation trend is consistent and the simulation error is small,which shows that the numerical model has a good accuracy;then on the basis of the original model,the numerical model,whose filling height was 0.5m and 1.5m,pavement structure was AC-10(4cm),AC-20(6cm),cement-stabilized macadam(20cm),was established.By changing the vehicle axle loads,and the thicknesses of pipe wall and other factors,the stresses and deformations of the pavement-pipe-soil under static loads were analyzed in detail.The main conclusions are as follows: in the number of different types of axles and axle load of vehicle,the maximum axial loads,under the premise of meeting the culvert pavement structure layer flexural tensile stress at the bottom of the design requirements,were confirmed;when the pipe diameter is constant,the influence of the wall thicknessse on the deformation and the stress of the pavement structure is studied,and the optimum diameter thickness ratio range of the pipe culvert is obtained;at the same time,by setting the bias load,studying on the deformation response of pavement-pipe-soil entire model at different locations,and by changing the quality of the pipe side backfill,the minimum requirements of the backfill for the pipe to be achieved in the normal driving requirements is studied.