Study On Global Buckling Analysis Of Submarine Pipeline And Anti-buckling Of Sleeper Laying

In view of the trend of China's oil exploitation industry marching into the sea,the safety of oil pipelines has become an important part.Under the action of high temperature and high pressure,it is easy to cause buckling damage of pipelines,among which sleeper method is an important way to stop buckling.It is of great significance to study the control factors of sleeper buckling effect and the influence of seabed suspension span on sleepers.Firstly,based on the experimental data of Taylor,the finite element model of pipe-soil contact simulation is established,and the reliability of the post-buckling results of the model is verified with the analytical solution,and the curves are in good agreement.In order to study the lateral buckling characteristics of bare submarine pipelines,a model of uplift first and then lateral buckling is established in this paper.By applying disturbing force,the influence of pipelines with different length and diameter-thickness ratio is analyzed.The conclusion shows that the critical buckling temperature will not change when the pipeline reaches a certain length,and the diameter-thickness ratio has less influence on the critical buckling temperature,but has greater influence on the axial force.By establishing a direct lateral buckling model,the effects of friction coefficient,damping,internal pressure and sleeper height with different defects on the lateral buckling of submarine pipeline are studied.Considering the sensitivity of finite element model to stiffness in two directions,two deformation modes of pipeline under geometric straightness are obtained.The research shows that internal pressure has great influence on pipeline deformation and axial force,and the greater the damping,the higher the critical buckling temperature of pipeline.With the increase of sleeper height,the critical buckling temperature first decreases and then increases.Compared with the normal stiffness,the buckling deformation of pipeline is more sensitive to the tangential stiffness.Taking the submarine suspension span as an important parameter,the influence of suspension span on sleeper buckling is studied by establishing the sleeper-suspension span buckling model,and it is verified that when the suspension span around the sleeper is too large or too close,the sleeper can not buckle laterally.Only when the suspension span is less than a certain span,the sleeper can exert the effect of buckling restraint.