Nonlinear Dynamic Response Analysis of Oil/Gas Pipeline under Seismic Loads

摘要

For the vast territory of China,numerous oil and gas pipelines have to pass the high incidence area of earthquake,which has great menace to the safety of oil and gas pipelines in these areas.In the paper,the finite element model (FEM) is established to obtain the nonlinear dynamic response model of pipeline under seismic loads.The numerical methods are used to solve the model.At the same time,a field pipeline is calculated as an example.Moreover,the effects of seismic intensity,spring stiffness,resistance ratio,and site type,etc,on the response law,stress,deformation,and acceleration of pipeline are studied.The results show that the seismic response of pipelines increases as the increase of earthquake intensity.When the damping ratio keeps stationary,the seismic response of pipeline increases with increasing stiffness coefficient,whereas the displacement decreases gradually and basically has an inverse proportion with stiffness coefficient.The seismic response of the pipeline increases with increasing damping ratio,and the displacement and the stress gradually decrease under the same stiffness coefficient.The seismic response of pipeline has a relation with field.When the site soil gradually transits from the hard soil or rock to soft soil,the maximum displacement of the pipeline does not become larger,indicating the soft soil could reduce the damage of pipeline in earthquake.