Research On Influence Of Vibration Induced By Subway On Buried Gas Pipeline

Currently, the subway has become a main mode of transport in people’s live, it can well meet the demand of people’s travel for its advantages of higher transportation capacity, high speed and comfortable. However, with the rapid development of metro has brought a series of negative issues, the problem of vibration induced by the subway has aroused wide concern. In addition to impact on the ground surface buildings, the subway vibration, it is also likely to affect the buried pipeline near the metro tunnel, especially the buried gas pipeline which over the tunnel, has aroused the attention from gas operator. But there is no published safety assessment of buried gas pipeline under subway vibration. In this paper, the influence of vibration induced by subway on the buried gas pipeline which over the metro tunnel have studied by numerical simulation method, and the gas pipeline would be checked in the most unfavorable conditions.In this paper, ANSYS software is used to simulate the response of buried gas pipeline under vibration induced by subway. Firstly, the vehicle-track coupling dynamic model is established to calculate the bearing reaction force of the rail fastening and the three-dimensional finite element model of the tunnel foundation-lining-soil layer is established. Secondly, the vibration response of the pipeline is calculated by the finite element model with the bearing reaction force of the fastener, and the calculation results are analyzed. Finally, the vibration response of buried pipeline is calculated with one of the most unfavorable working conditions, and the safety of gas pipeline under subway vibration is checked from vibration intensity scale and axial strain of buried gas pipeline induced by vibration with reference to the relevant codes and references.It can draw some conclusions from the calculated results. With the horizontal distance between buried pipeline and the tunnel increases, the value of pipeline vibration response decreases. The tunnel distance closer, the vibration attenuation is faster. The vibration of buried pipeline belongs to low frequency vibration, and the vibration effect of low frequency range is large. The rebound phenomenon will occurs at a distance of 20 meters from the tunnel. The vibration response of buried pipeline is related to the depth of the tunnel and the speed of the train. The deeper the tunnel is, the smaller the vibration response is. The faster the train, the greater the vibration response. Under the most unfavorable conditions, according to the railway vibration intensity scale, the vibration intensity of buried gas pipeline was lower than I magnitude number, and the axial strain of buried gas steel pipe induced by subway vibration is less than 4% of the allowable axial strain of the pipeline. The results indicate that the impact of the vibration induced by subway on buried gas pipeline is insignificant.