海底管道整体屈曲的枕木-浮力耦合法研究

不埋海底管道在高温高压作用下,易发生水平向整体屈曲。实际工程中,常通过在管道路由上设置整体屈曲触发装置,实现对水平向整体屈曲的有效控制,其中以枕木法的成功应用最为多见。本文分析了枕木法的主要影响因素并验证了采用枕木法会出现管道屈曲段应力集中的现象,对比了枕木法、分布浮力法和枕木-浮力耦合法对管道整体屈曲变形规律的影响,采用数值模拟方法系统研究了枕木及浮力参数对管道水平向屈曲和后屈曲的影响规律。研究表明,在枕木两侧设置浮力段的人工触发装置可有效触发管道整体屈曲,同时促使管道虚拟锚固点间轴力的释放,降低了管道中屈曲段的应力,相较枕木法,枕木-浮力耦合法可将管道中的最大应力降低23%。

Study on sleeper-buoyancy coupling method for global buckling of submarine pipelines

Unburied subsea pipelines operating under high temperatures and high pressures are likely to exhibit lateral global buckling. In actual engineering applications, a global buckling trigger device is often installed on the pipeline route to achieve an effective control of the lateral buckling. In line with this, the sleeper method is the most common application. This study analyzes the main influencing factors of the sleeper method and verifies the occurrence of the stress concentration phenomenon of the pipe buckling section when the sleeper method is used. The effects of the sleeper method, distributed buoyancy method, and sleeper-buoyancy coupling method on global buckling are compared, and a numerical simulation method is used to systematically examine the effects of sleeper and buoyancy parameters on the lateral buckling and post-buckling of pipelines. Our results show that artificial trigger devices with buoyancy sections on both sides of the sleeper can trigger the global buckling of the pipeline and promote the release of axial force between the virtual anchor points of the pipeline, reducing the stress in the buckling section of the pipeline. Compared with the sleeper method, the sleeper-buoyancy coupling method can reduce the maximum stress in the pipeline by 23%.