Study On The Effect Of Blasting Vibration On GAS Pipeline

Pipeline transportation is an important transportation of oil and gas today, so keeping the security of oil and gas pipeline transportation is very important. During the construction process of tunnel blasting, it often encountered the problem of blasting vibration on the pipelines. Because the substances of oil and gas pipeline transportation are flammable, explosive and toxic materials, when the oil and gas pipeline damaged, it will release a large number of flammable gases and harmful substances, it may cause a fire or even an explosion, it could cause immeasurable damage to nearby areas. At home and abroad, the control standard of surface vibration speed is greatly different, it can’t control the blasting construction accurately and effectively.therefore the study of the influence of blasting vibration on the buried pipeline is of great significance.The tunnel which located in Xi’an to Chengdu high-speed railway buried beneath the gas pipeline. Blasting vibration generated in the tunneling construction process is likely to endanger the safe operation of underground natural gas pipeline which above the tunnel, using ANSYS/LS-DYNA finite element software to establish a three-dimensional finite element model, Comparing the simulation results with the monitoring vibration data, not only the accuracy of simulation results was tested, but also the model was improved.In this paper, the main research of the Pipeline vibration velocity, Vibration velocity of soil around pipe, as well as the pipeline is above the surface vibration and pipeline safety assessment. By analyzing the data results:Three different cross sections, The face just above the bottom of the pipe Y direction of maximum velocity. Different locations in the same section:Y direction pipeline vibration velocity is greater than the vibration velocity of soil around the pipe, The vibration velocity of the soil around the X and Z direction is greater than that of the pipeline vibration velocity. When the surface vibration velocity is 3.99cm/s, its maximum Superimposed stress is 92.56MPa, which is much less than the allowable stress value of pipe 464.4MPa, The vibration produced by blasting will not affect the safety of the pipeline.Analysis of different single explosive quantity amount and different tunnel buried depth, Influence of blasting vibration on underground natural gas pipeline. With the increase of the amount of single explosive quantity, The vibration velocity of the soil around the bottom of the pipe and the bottom of the pipe is increased, The peak velocity of the pipeline is larger than that of the peak vibration velocity of the soil around the pipe; Pipeline superposition of maximum stress and the face just above the surface of pipeline vibration velocity increases. With the increase of tunnel depth, The vibration velocity of the soil around the bottom of the pipe and the bottom of the pipe will be reduced, and the peak velocity of the pipeline is larger than the peak velocity of the soil around the pipe; Pipeline superposition of maximum stress and the face just above the surface of pipeline vibration velocity decreases. The amount of explosive and the tunnel depth are different, Comparison of the vibration velocity and the vibration velocity of the soil around the pipeline:Both of them with the single section of the explosive charge and the tunnel depth increase or decrease trend, Because of the practical engineering, the measurement of the vibration velocity of the pipeline is difficult, So the vibration velocity of the pipeline can be estimated by measuring the vibration velocity of the soil around the pipe.Through single explosive quantity and superposition of maximum stress force fitting relationship, single section charge quantity and the surface vibration velocity fitting relationship, tunnel depth and maximum stack should force fitting relationship, the tunnel depth and surface vibration velocity fitting relation. To predict and control the influence of blasting vibration on the buried natural gas pipeline and ensure the safe operation of the buried gas pipeline.