摘要
混凝土楔形护板是土石过水围堰较佳的护面方式,其水力特性多限于定性分析。本文采用数值模拟的方法,对过水围堰溢洪进行了计算分析。给出典型工况楔形护板的流场特性,探讨了最不利溢流工况。计算表明:跌坎处出现回流、旋涡现象,顺堰面逐级增大,有利于减轻堰面冲刷。跌坎附近存在负压,设置排水孔将有助于减小作用于堰面的渗透压力。临底水流在衔接处向下弯曲,增强了楔形上块对下块的作用力,有利于堰面稳定。对楔形护板开展水力计算,可为堰面防护提供定量依据。
Protection concrete wedge slab is a good protective facing of overflow earth-rock cofferdam;most of the previous studies of its hydraulic characteristics focused on qualitative analysis.In this work,numerical simulation was used to analyze the overflow of an overtopped cofferdam,and the flow characteristics of protection wedge slabs under the typical flood conditions and the worst operating conditions were examined.The calculated results show that back flow and vortex flow occur behind the step-downs,and their intensities increase along the protective facing,which favors the relief of flow scour.Suction pressure occurs near the step-downs,so the osmotic pressure on the protective facing would decrease if exhaust outlets are located there.The near-bottom flow bends down at the joint of two slabs and can strengthen the force of the upper slab acting on the lower,which favors the stability of protective facing.The present calculation provides a reference for the design of protective facing.
出处
《水力发电学报》
EI
CSCD
北大核心
2011年第3期92-97,共6页
Journal of Hydroelectric Engineering
基金
国家重点基础研究发展计划项目(2007CB714105)
四川大学青年科学基金(校青07074
校青2008038)
关键词
水力学
过水围堰
数值模拟
楔形护板
hydraulics
overtopped cofferdam
numerical simulation
protection wedge slab
