摘要
海底桩基础在海洋工程中被广泛应用,然而,对于淹没桩基础结构局部冲刷问题的研究较少。基于一系列实验室水槽试验,研究了在波浪和水流共同作用下淹没单桩和群桩基础周围的局部冲刷问题,分析了局部冲深历时特性、影响因素及冲刷坑形态特征。研究结果表明,对于单桩基础,床粗糙度K_(d)的增大削弱了波流工况的差异,当结构比K_(h)在1.00~2.33范围内时,相对时间尺度T_(c)逐渐增大,而当K_(h)>2.33时,T_(c)开始减小。对于群桩基础,群桩的冲刷深度历时特性与单桩相似,但排列的群桩对桩基底部水流的紊动有抑制作用,并且在桩间距系数K_(sp)较小时形成整体冲刷坑,在K_(sp)较大时局部冲刷坑有逐渐分离的趋势;随着K_(h)和K_(sp)的增加,T_(c)增大,但K_(sp)的增加使T_(c)的增长速率减小。提出采用K_(h)、K_(d)、K_(sp)预测平衡冲刷深度的修正方程,可较准确地预测文中试验中波流作用下单桩与群桩基础的平衡冲刷深度。
Pile foundations beneath the seabed are extensively utilized in marine engineering;however,research on localized scour around submerged pile foundations remains limited.Based on a series of laboratory flume experiments,this paper investigates the localized scour around submerged single and group pile foundations under the combined action of waves and currents.It analyzes the characteristics of scour depth over time,influencing factors,and the morphological features of scour pits.The results indicate that for single pile foundations,an increase in bed roughness Kd attenuates the difference in wave-current conditions.When the structural ratio K_(h) ranges from 1.00 to 2.33,the relative time scale T_(c) gradually increases,whereas T_(c) begins to decrease when K_(h)>2.33.For group pile foundations,the evolution of scour depth over time is similar to that of single piles.However,the arrangement of pile groups suppresses the turbulence of the flow at the foundation’s base.Additionally,when the pile spacing coefficient K_(sp) is small,a collective scour pit forms,showing a trend of gradual separation into individual scour pits as K_(sp) increases.With the increase in K_(h) and Ksp,T_(c) increases,but the growth rate of T_(c) decreases with the increase in K_(sp).A modified equation for predicting the equilibrium scour depth using K_(h),K_(d),and K_(sp) is proposed,which can accurately predict the equilibrium scour depth of single and group pile foundations under wave-current action as demonstrated by the experiments conducted in this study.
作者
付亦鹏
朱成浩
孙元
王仁刚
李祺恒
武闻禹
FU Yipeng;ZHU Chenghao;SUN Yuan;WANG Rengang;LI Qiheng;WU Wenyu(Qingdao Geotechnical Investigation and Surveying Research Institue,Qingdao 266033,China;College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China;Cheng’an Engineering Technology Group Co.,Ltd.,Qingdao 266555,China)
出处
《海洋工程》
CSCD
北大核心
2024年第6期71-82,共12页
The Ocean Engineering
基金
国家自然科学基金资助项目(41572247)
中央高校基本科研业务费专项(202061027,202261063)。
关键词
波流作用
桩基础
冲刷坑形态
时间尺度
平衡冲刷深度
wave-current action
pile foundation
scour pit morphology
time scale
equilibrium scour depth
