上海交通大学学报 ›› 2021, Vol. 55 ›› Issue (6): 631-637.doi: 10.16183/j.cnki.jsjtu.2020.108

• •    下一篇

孤立波和海流作用下单桩基础局部冲刷及保护的数值分析

黎蔚杰, 张琪, 廖晨聪, 周香莲(), 刘晨晨   

  1. 土木工程系, 上海 200240
  • 收稿日期:2020-04-11 出版日期:2021-06-28 发布日期:2021-06-30
  • 通讯作者: 周香莲 E-mail:zhouxl@sjtu.edu.cn
  • 作者简介:黎蔚杰(1994-),男,江西省抚州市人,硕士生,从事海洋土力学的研究
  • 基金资助:
    国家自然科学基金(41572243);国家自然科学基金(41727802)

Numerical Analysis of Local Scour and Protection of a Single Pile Around a Seabed Under Solitary Wave and Current

LI Weijie, ZHANG Qi, LIAO Chencong, ZHOU Xianglian(), LIU Chenchen   

  1. Department of Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
  • Received:2020-04-11 Online:2021-06-28 Published:2021-06-30
  • Contact: ZHOU Xianglian E-mail:zhouxl@sjtu.edu.cn

摘要:

采用数值模拟的方法研究了孤立波和海流共同作用下单桩周围海床的局部冲刷.通过求解RNG k-ε湍流模型封闭的N-S方程,准确地模拟了桩周流场的变化情况.泥沙输运模型考虑泥沙的夹带、悬移质输送、沉积以及推移质输送的泥沙冲刷机制.对于斜坡床面,考虑重力对泥沙颗粒的影响,并对临界希尔兹数进行修正.将数值结果与实验数据进行比较,验证了数值模型的准确性.在此基础上,详细分析在不同波高条件下的桩基冲刷发展过程,初步研究了桩基保护层对冲刷的影响.结果表明:波-流共同作用下桩基周围海床的冲刷深度比单纯流或孤立波作用下冲刷深度更大;倾斜海床下的局部冲刷深度更大;保护层的设置可以有效地降低桩周局部冲刷深度,保护层粒径的大小对防护效果的影响较大.

关键词: 单桩, 冲刷, 孤立波, 海流, 冲刷保护

Abstract:

A numerical simulation is conducted to investigate the local scour of the seabed around the pile under the actions of both solitary waves and currents. By solving the N-S equations enclosed by the RNG k-ε turbulence model, the change of the flow field around the pile is simulated accurately. The sediment transport model considers all the sediment transport processes including entrainment, suspended load transport, deposition, and bed-load transport. For the slope seabed, the influence of gravity on the sediment particles is considered, and the shields parameter is modified. The accuracy of the model is verified by comparing the numerical results with the experimental data. Besides, the process of scour development at different wave heights is investigated in detail. The effect of pile foundation protection layer on scour is preliminarily studied. The results show that the combined solitary wave-current conditions have a significant effect on the scour depth around the pile than the current-only or wave-only. The scour depth around the pile on the inclined seabed is larger than that of the horizontal seabed. The setting of protection layer can effectively reduce the local scour depth around the pile. In addition, the particle size of the protective layer has a great influence on the protective effect.

Key words: monopile, scour, solitary wave, current, scour protection

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