Study On Transverse Mechanical Characteristics Of Positive Buried Pipeline

Analyses of circumjacent earth pressure distribution establish the mechanical model of basic loads about stability,strength and stiffness of pipeline while defmitude of cross section stresses has a bearing on design purposes of production and practicality. Accordingly,based on elastic theory and the theory of finite element,this paper deals with transverse mechanical calculation and its mechanical characteristics of positive buried pipeline,and then discusses reducing loads on it.(1) Based on analyses of some typical calculational method to vertical soil pressure on pipeline,main influencing factors are discussed and some improved ways are brought forward.(2) Respectively by elastic theory analyses and methods of structural mechanics,transverse static analytical equations for flexible pipeline rigid pipeline are established whose outcomes are applied in numerical example to compare those with that by finite element method.(3) Considering interaction of filled soil,pipeline and foundation,with an eye to non-linear soil model,in view of the initial geo-stress field and the effects of interface between soil and pipeline,and by finite element method the calculational model and method are built for transverse stress in pipeline. Then,by the great finite element analytical software ANSYS,those outcomes are applied in calculation example of positive buried pipe to educe the distribution of circumjacent soil pressure and stresses on cross section and to compare it with that calculated by conventional ways before those outcomes are applied in engineering case of positive buried pipe with flexible filled materials to confirm distribution of soil pressures after the measure for reduction and to compare it with measurements .As a result,the model set up in this paper is proved to be applicable after all above-mentioned analyses.(4) On the basis of above mechanical analyses,the measures and materials for reducing vertical soil pressures acting on buried pipe are discussed,and then the calculational model set up in this paper being applied in engineering example of buried pipe with flexible filled materials,the even vertical soil pressure on top of pipe,vertical stresses distribution in the top plane of soil,the distribution of circumjacent soil pressure and the displacement field around pipe are all discussed.This paper can provide a scientific basis for design and construction in reinforcing pipeline foundation,reduction of loads on pipe,section design of pipe,and security evaluation of pipe.