杨　昕　梁发云,*

(1.同济大学岩土及地下工程教育部重点实验室, 上海 200092; 2.同济大学地下建筑与工程系, 上海 200092)



桥墩基础局部冲刷抛石防护的研究进展

杨昕1,2梁发云1,2,*

(1.同济大学岩土及地下工程教育部重点实验室, 上海 200092; 2.同济大学地下建筑与工程系, 上海 200092)

摘要抛石作为应用最为广泛的桥墩基础局部冲刷防护措施之一,受到国内外学者的高度关注。系统总结了清水冲刷和动床冲刷条件下的抛石破坏机理,分析了影响抛石稳定性的主要因素,包括抛石粒径、抛石设置位置、抛投范围、抛石层厚度和抛石级配等,对国内外相关研究成果进行了系统评述,并对比分析了抛石稳定性的主要分析方法。针对现有抛石防护方法存在的缺陷,提出了抛石防护未来的研究发展方向和可能的改进措施。

关键词抛石防护, 破坏机理, 稳定性, 影响因素, 研究进展

Reviews on the Development of Riprap Protection to Bridge Piers from Local Scour

YANG Xin1,2LIANG Fayun1,2*

(1.Key Laboratory of Geotechnical and Underground Engineering of the Ministry of Education,Tongji University,

Shanghai 200092,China; 2.Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China)

AbstractAs the most commonly used protection measures to bridge piers from local scour,the riprap protection has attracted a sustained attention from domestic and foreign scholars.The riprap’s failure mechanism under clear-water conditions and live-bed conditions are summarized systematically in this paper.Focusing on the factors which can affect riprap stability,including size,placement level,coverage,thickness and gradation of riprap,the author review the research findings from domestic and overseas researchers.Moreover,the analysis methods for riprap stability are compared.Considering the disadvantages of riprap protection,the future development direction and possible improvement measures of riprap protection are suggested furtherly.

Keywordsriprap protection, failure mechanism, stability, influence factors, review

1引言

冲刷是水流作用引起河床剥蚀的一种自然现象。统计资料表明[1],超过半数的桥梁损毁与冲刷有关,冲刷导致的桥梁桥墩失稳毁坏事故可能造成巨大的人员伤亡和经济损失。

水流对墩周河床的冲刷由前进水流漩涡、下降水流掏底和尾流漩涡冲坑三部分共同作用,在桥墩周围设置防护措施能有效地弱化冲刷作用,提高桥梁的安全性能。根据防护机理的不同,桥墩基础冲刷防护可分为主动防护和被动防护[2-3]。主动防护通过减小冲刷原动力来提高防护能力,主要包括墩前牺牲桩、护圈、环翼式挡板、护壳、桥墩开缝、下游石板等防护措施;而被动防护则从床沙和桥墩入手提高河床材料的抗冲刷性能,主要包括抛石、扩大墩基础、四面体透水框架群等防护措施[3]。……