哑铃形咬合桩围堰水流力作用试验研究

Experimental Study on Current Force of Dumbbell Type Occluded Pile Cofferdam

内陆河流的桥梁基础在施工期间可能遭遇洪水侵袭,对围堰基础和内部支撑产生影响。桥梁围堰水流力的研究对围堰的设计、施工具有重要的理论意义和实用价值。针对哑铃形围堰,开展1∶100模型试验,将数值模拟结果与试验结果进行对比验证,分析哑铃形围堰结构在水流作用下的受力特点,研究其在不同流速、吃水深度、水流夹角下的水流力作用。研究结果表明:试验中较高流速下的水流力系数基本平稳,且水流力与流速平方成正比;水流力与吃水深度几乎成正比关系;随着流向角增大,顺向水流力减小,横向水流力非线性增大;试验结果与采用原始比例的数值模拟结果基本吻合。

The bridge foundations of inland rivers may encounter flood during construction,which will affect the foundation and internal support of cofferdam.The research on the current force of bridge cofferdam has important theoretical significance and practical value for the design and construction of cofferdam.Aiming at the dumbbell cofferdam,a 1∶100 flume model test is carried out.The numerical simulation results and experimental results are validated and the force characteristics of the structure under the action of current are analyzed,and the hydraulic coefficients of the structure subjected to different flow velocities,draft depths and flow angles are studied.The results show that the current force coefficient at a higher velocity is basically stable,and the force is proportional to the square of the velocity.The current force is almost proportional to the draft depth.As the flow angle increases,the longitudinal force decreases and the transverse force increases nonlinearly.The experimental results are in good agreement with the results of the numerical simulation with original ratio.