跨海大桥沉井水中沉放流场及水流力模拟研究OACSTPCD
Numerical analysis on flow field and current force of caisson in submersion stage
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.
欧阳石;李勇海;杨嘉毅;严冰;欧阳群安;李泽
中铁四局集团有限公司,合肥 230023交通运输部天津水运工程科学研究所 港口水工建筑技术国家工程研究中心 工程泥沙交通行业重点实验室,天津 300456
交通运输
设置沉井水中沉放流场特征水流力数值模拟跨海大桥
embedded caissonsubmersionflow structurecurrent forcenumerical simulationcross-sea bridge
《水道港口》 2024 (003)
339-349 / 11
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)
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