Analysis On Effects Of The Buried Pipeline Under Rail Trafic Loads

In recent years,the destruction of buried pipelines has led to a growing number of reports of casualties and property damage.Although there are many literatures on buried pipelines,there are few reports on the effects of traffic loads,especially rail load.The importance of the large-scale rail transit network construction and the surge of buried pipelines,and the influence of the secondary vibration induced by the buried traffic in the rail transit load are gradually paid more and more attention.Based on the vibration principle of the chain system of vibration source,propagation path and structure,this paper attempts to use the method of theoretical analysis and numerical simulation to carry out the influence of rail traffic load on the dynamic influence of buried pipeline,which will provide a theoretical basis for better solving the problem of buried pipeline damage caused by rail traffic load,and provide scientific basis for further study of safety criteria for buried pipelines,which has important practical and social significance.Firstly,the dynamic response of the rail transit system as a source of vibration is studied.Based on three different train-track simplification models,the research model of the rail transit system is established,and the semi-analytical solution of the vertical displacement dynamic response of the contact surface between the track and the soil under the train moving load is deduced.And study the critical velocity of the orbit under the action of rail transit and the forced vibration characteristics under the coupling of the orbit.Using the self-made MATLAB program,combined with the existing literature verification method and numerical simulation of the correctness of the vertical displacement of the track.Secondly,the dynamic response of the soil under the action of simple harmonic load is studied.Simulation of train load with rectangular harmonic load;based on the Navier 's dynamic equation and Biot' s theory,the viscoelastic half-space body and the transversely isotropic saturated soil control equation under the rectangular harmonic load are established.The vertical displacement response of the lower viscoelastic half-space and the dynamic response of the horizontal and vertical displacements of the transversely isotropic saturated soils under the simple harmonic load of the rectangular motion are analyzed by numerical simulation.Finally,the influence of orbital load on the dynamic response of buried pipeline in transversely isotropic saturated soil is studied.The model of buried pipeline under three kinds of space positions is established,which is vertical,parallel and oblique in the saturated soil.The initial parameter method is used to analyze the displacement and internal force of the buried pipeline,and the buried pipeline in the saturated soil is deduced(depth and horizontal distance),train load(size and speed),and piping and orbital space position(depth and distance),and the method of numerical analysis and analysis of pipeline and orbit space position(depth and horizontal distance),train load(size and speed)and pipeline cross section(rectangular and circular)and other factors on the dynamic response of the buried pipeline,and some conclusions have some practical significance.