海底线缆在液化海床中的受力试验及防护固定桩最优间距计算  

Study on Stress Test of Submarine Cable in Liquefied Seabed and Calculation of Spacing Between Protective Fixed Piles

作　　者：李猛 许兴北 田浩 许国辉[1,2] 陈志远 Li Meng;Xu Xingbei;Tian Hao;Xu Guohui;Chen Zhiyuan(Key Laboratory of Marine Environment and Ecology,Ministry of Education,Ocean University of China,Qingdao 266100,China;Key Laboratory of Marine Environmental Geological Engineering,Ocean University of China,Qingdao 266100,China)

机构地区：[1]中国海洋大学海洋环境与生态教育部重点实验室,山东青岛266100 [2]中国海洋大学山东省海洋环境地质工程重点实验室,山东青岛266100

出　　处：《中国海洋大学学报（自然科学版）》2024年第8期142-151,共10页Periodical of Ocean University of China

基　　金：国家自然科学基金面上项目(41976049);中央高校基本科研业务费专项(202061033)资助。

摘　　要：为解决海床液化以后埋置线缆被液化土体携带作近似椭圆的运动而导致其位于液化区域边缘处的部分发生弯折疲劳破坏的问题,本文利用波浪水槽试验,对模型线缆的竖向位移和端部受力进行了监测,结果显示土体液化后的波动造成此2项监测数据均有增大,表明了液化土可能对埋设其中的线缆有损毁作用。本文提出在海床内埋设桩基固定线缆的方案,从而基于悬链线方程,并根据埕岛海域海洋动力环境特征来计算该海域海底电缆的防护固定桩最优间距。计算结果表明,当土体液化后,埕岛海域电缆在无保护措施的情况下可能会发生断裂,当设置防护固定桩间距为300 m时,可起到保护作用。After the liquefaction of the seabed,the buried cable is carried by the liquefied soil to make an approximate elliptical movement,resulting in bending fatigue failure of the part at the edge of the liquefaction area.In order to solve this problem,the vertical displacement and end force of the model cable are monitored by the wave flume test.The results show that these two monitoring data increase due to the fluctuation of soil liquefaction,indicating the possible damage effect of liquefied soil on the buried cable.In this paper,the scheme of embedding pile foundation to fix cable in the seabed is proposed,and the calculation method of pile foundation spacing is given based on the catenary equation.According to the characteristics of marine dynamic environment in Chengdao sea area,the spacing of protective pile foundation of submarine cable in the area is calculated.The calculation results show that when the soil is liquefied,the cable in Chengdao sea area may break without protective measures.And a series of protective fixed piles with a spacing of 300 m can provide protection.

关 键 词：海底线缆 粉质土海床 波致液化 悬链线公式 防护固定桩 

分 类 号：P753[交通运输工程—港口、海岸及近海工程]