Dynamic Response Of Buried PE Pipeline Under Blasting Load

In recent years,due to its long life,good hygienic performance,light weight,good corrosion resistance,easy installation,low cost and good hydraulic characteristics,PE pipes have been widely used in many urban pipeline engineering to replace traditional steel pipes.In the process of urban modernization construction,due to the dense distribution of urban pipeline network system in the city,it is difficult to avoid blasting construction projects near buried pipelines.The impact of blasting construction on adjacent buried PE pipes has gradually become prominent.The safe operation of buried PE pipes under blasting seismic effect has become a hot issue in the field of pipeline and blasting engineering.Based on the stress wave theory,the failure mechanism of buried PE pipeline under blasting load is studied by analyzing the interaction between pipe and soil.ANSYS/LS-DYNA is used to establish the finite element model of buried PE pipeline.Through the simulation study of different blasting center spacing and pipe size,the influence of blasting center spacing and pipe size on buried PE pipeline under blasting seismic wave is explored.Similar model experiments were carried out on PE pipes with different sizes under blasting load.The dynamic response law of PE pipes buried under blasting load was explored by changing the charge quantity,the distance between blasting centers and the depth of blasting source.Through the analysis of simulation results and experimental data,the following conclusions are drawn: 1.Under the same conditions of explosion source,the peak value of the annular compressive strain of the buried PE pipe' is the largest.The quadratic polynomial relationship between the peak value of toroidal compressive strain and the peak value of axial compressive strain on the explosive front is obtained from the experimental data..2.The stress,strain and vibration velocity of PE pipes with different diameters have similar growth trend with the increase of charge.PE pipes with larger diameters are more likely to be damaged under blasting load.3.The peak value of circumferential compressive strain and the peak value of vibration velocity along Z axis on PE pipe increase with the increase of the depth of explosion source.The greater the burial depth of explosive source,the faster the peak values of circumferential compressive strain and vibration velocity increase with the increase of explosive charge quantity.4.Based on theoretical analysis and experimental data,the relationshipbetween the toroidal pressure strain and the distance between the detonation centers of PE tubes is obtained.5.The buried depth of buried PE pipeline in Z-axis direction is negatively correlated with the buried depth of pipeline,and both of them are less than the peak value of ground vibration velocity.When the location of the explosion source is fixed,the smaller the buried depth,the faster the peak value of Z-axis vibration velocity increases with the increase of explosive charge.Based on the experimental data,the relationship between the vector of vibration velocity and the peak value of axial tension strain is obtained.