摘要
桥墩局部冲刷一直是影响桥梁安全的最大自然灾害,抛石防护是最普遍的冲刷防护形式之一。在总结已有冲刷机理的基础上,分析了包括墩前河床底部流速和墩侧河床底部流速的桥墩局部流速,并给出了桥墩冲刷防护石块起动的简化公式。结果表明,墩侧河床底部流速大于墩前河床底部流速,墩侧防护石块更易走失。当行近流速小于3m/s时,可采用抛石进行桥墩局部冲刷防护,抛石直径约为0.2m;对于行近流速为3～5m/s时,建议采用其它冲刷防护措施。
The bridge local scour is the largest damage to the bridge safety,and the riprap protection is the widespread method for scour protection.Based on the existing scour mechanism,the bridge local velocity of flow is analyzed,including the bottom velocity in front of and around the bridge pier.The simplified formula is put forward for the incipient motion of rocks for bridge local scour protection.The result shows that the bottom velocity in front of the bridge pier is larger than that around it.When the approach velocity is smaller than 3m/s,the riprap protection can be used,with the rock diameter of 0.2m.When the approach velocity is ranged from 3m/s to 5m/s,the riprap protection is not recommended for local scour protection.
出处
《泥沙研究》
CSCD
北大核心
2013年第4期63-67,共5页
Journal of Sediment Research
基金
国家自然科学基金项目(51208078)
关键词
桥梁
局部冲刷
抛石防护
石块起动
bridge
local scour
riprap protection
incipient motion of rock
