海底悬空管道弹性约束静态分析

Static analysis of hanging submarine pipeline with elastic constraint

由于海浪的冲刷,海底管道会出现悬空段,当悬空段较长时,管道在波浪及海流的作用下将会发生破坏。对海底悬空管道所受的环境载荷进行了计算,把海底土壤对管道的约束视为弹性约束,推导出了弹性约束时的系数矩阵,建立了相应的有限元分析模型,并开发了相应的计算机软件。该软件不仅可以计算立管与水平管连接处悬空管段的强度,还能计算静强度下的临界悬空长度。将弹性约束与刚性约束时的计算结果进行了对比,结果表明,当海底地层较硬时,弹性约束与固定端约束的计算值相差不大;当地层较软时,弹性约束时管道中的最大应力比固定端约束的要大,而临界悬空长度相差不多。

Because of the waves flush, the submarine pipeline will appear the hanging segment. When the hanging segment is longer, the breakage will take place under the loads of the wave and ocean current. The calculation of the environment loads being exerted on the hanging pipeline was discussed. Taking constraints of sea soil layer to the pipeline as the elastic constraints, the coefficient matrix for elastic constraint was deduced. An analysis model was built up, and the homologous computer software was developed. The software can compute the static strength problem of hanging segment between vertical and level pipeline, and still compute the critical length of hanging segment under the static strength. The comparisions of calculation results between the two constraints show that when the sea soil layer is harder, the difference is not much. When the sea soil layer is ,softer, the greatest stress for elastic constraints is larger than that for fixed one. The difference in critical length of hanging segment is not much.