摘要
水中沉放是设置沉井施工的重要环节,明晰沉放过程中周围流场结构及受力特性是开展沉井沉放施工的基本前提。文章以西堠门公铁两用跨海大桥#4墩嵌入式设置沉井为研究对象,通过采用数值模拟方法分析了沉井基坑开挖对周围流场的影响,研究了不同沉深及不同流速条件下的沉井内外流场形态与所受水流力,获得了绕流特征与沉井受力随沉深及流速的变化规律。结果表明:受沉井形态及基坑地形影响,三维绕流特性较为显著;入水沉放深度对竖向绕流形态、紊动强度等参量具有显著影响;不同来流速度下的绕流形态、流场速度分布规律、相对紊动强度较为一致;受尾涡脱落影响,沉井所受横、纵向水流力均会伴随一定幅值的波动,均值与沉深、来流速度具有较好的正相关关系;基坑的存在降低了沉井竖向阻塞作用,会减小沉井所受水流力。
Submersion in water is an important stage of floating caisson construction.To clarify the flow structure around the caisson and current force characteristics during the submersion process is the basic premise of caisson submersion installation.In this paper,embedded caisson of Xihoumen Road-railway Cross-sea Bridge was taken as the research object.By numerical simulation method,the influence of foundation pit on the flow structure was analyzed.The flow pattern around the caisson and the current force under different submersion depths and different inflow rates were studied.The results showed that:influenced by the caisson morphology and foundation pit topography,the three-dimensional flow characteristics are evident;the submersion depth has a significant effect on the vertical flow pattern and turbulence intensity;the flow pattern,relative velocity field distribution and relative turbulence intensity under different inflow rates are relatively consistent;influenced by the wake vortex shedding,the longitudinal and transversal current force on the caisson fluctuates with a certain amplitude,and the mean value has a good positive correlation with the submersion depth and inflow rates;the existence of foundation pit reduces the vertical blocking effect of the caisson and results in a reduction of the current force.
作者
欧阳石
李勇海
杨嘉毅
严冰
欧阳群安
李泽
OUYANG Shi;LI Yonghai;YANG Jiayi;YAN Bing;OUYANG Qun′an;LI Ze(China Railway NO.4 Engineering Group Co.Ltd.,Hefei 230023,China;Tianjin Research Institute for Water Transport Engineering,National Engineering Research Center of Port Hydraulic Construction Technology,Key Laboratory of Engineering Sediment,Ministry of Transport,Tianjin 300456,China)
出处
《水道港口》
2024年第3期339-349,共11页
Journal of Waterway and Harbor
基金
国家重点研发计划项目(2022YFB2602804)
中央级公益性科研院所基本科研业务费专项资金项目(TKS20220103)。
关键词
设置沉井
水中沉放
流场特征
水流力
数值模拟
跨海大桥
embedded caisson
submersion
flow structure
current force
numerical simulation
cross-sea bridge
