摘要
通过建立二维数学模型,模拟研究了涉河斜交桥梁在不同斜交角度下的壅水及水动力特征。模拟结果表明:在河道宽深比偏小的情况下,保持桥跨不变,随着桥墩布置与水流垂向夹角增大,桥前最大壅水和建桥前后的流速差呈增大趋势,且斜交角越大,增大趋势越强。流速偏转角则随斜交角度的增大先增大后减小,极大值出现在45°左右。工程建设前后桥墩周围流速差的分布规律随斜交角变化,当斜交角度小于等于45°时,工程前、后的流速增大区主要集中在桥孔和近河道两岸的下游地带;当斜交角大于45°时,工程前、后流速变化区主要集中在河道两岸近岸地带及下游桥墩墩周,下游桥墩一侧的近岸上游地带以及上游桥墩一侧的近岸下游地带变化区域显示出较强的对称性。研究成果可为桥梁布设、桥梁壅水、桥梁冲刷和护岸等工程措施提供借鉴。
By establishing a two-dimensional mathematical model,the backwater and hydrodynamic characteristics of river crossing skew bridges at different oblique angles were simulated and studied.The simulation results show that,in the case of a small aspect ratio of the river channel,while keeping the bridge span unchanged,as the angle between the arrangement of bridge piers and the vertical flow direction increases,the maximum damming in front of the bridge and the flow velocity difference before and after the bridge construction show an increasing trend.The larger the oblique angle,the stronger the increasing trend.The flow velocity deviation angle first increases and then decreases with the increase of the oblique angle,and the maximum value appears at around 45°.The distribution pattern of flow velocity difference around bridge piers before and after engineering construction varies with the oblique angle.When the oblique angle is less than or equal to 45°,the area where the flow velocity increases before and after the project is mainly concentrated in the downstream areas of the bridge opening and near the riverbanks.When the oblique angle is greater than 45°,the flow velocity change zone before and after the project is mainly concentrated in the nearshore area on both sides of the river.The upstream area near the downstream bridge pier and the downstream area near the upstream bridge pier show strong symmetry.The research results can provide reference for engineering measures such as bridge layout,damming,scouring and bank protection.
作者
陈素洁
Chen Sujie(Guangdong Hydropower Planning&Design Institute,Guangzhou 510635,China)
出处
《吉林水利》
2024年第9期13-19,共7页
Jilin Water Resources
关键词
壅水
数值模拟
斜交桥
流场
水动力
Backwater
Numerical simulation
Skew bridge
Flow field
Hydrodynamics
