摘要
南京长江大桥是长江上第一座由中国自主设计和建造的双层公铁两用特大桥,其南、北引桥及回龙桥含多跨双曲拱桥结构。由于南京长江大桥通车已有50年,双曲拱桥结构出现多处病害,需进行维修加固。维修加固方式为增大拱肋截面,采用研发的微膨胀高性能低含气量的自密实混凝土材料,通过增设植筋将新旧混凝土连成整体,在新旧钢筋间设牺牲阳极锌块延缓钢筋锈蚀。结合人工电锤+高压水冲洗的综合凿毛方式、限位卡片和木条限位的植筋精准定位法、压灌结合混凝土浇筑等施工技术,实现了实桥新旧混凝土良好结合,新增混凝土强度稳定、密实无孔洞,钢筋保护层合格率高的效果。
The Nanjing Changjiang River Bridge is the first Changjiang River bridge that has been independently designed and constructed by China.The south and north approach bridges as well as the Huilong Bridge contain multiple spans of double-curved arch bridge structure.The bridge has been in service for nearly 50 years,whose double-curved arch bridge structure has suffered deteriorations in many places,needing maintenance and strengthening.The maintenance and strengthening way chosen was to enlarge the arch rib cross section.The self-compacting concrete material featuring micro-expansion,high performance and low air content was prepared,reinforcement were added to connect the new and old concrete to be a whole,and sacrificial anode zinc lumps were installed between the new and old reinforcement to protect the reinforcement from corrosion.A series of measures were taken to realize the good connection of the new and old concrete,including the comprehensive rough chiseling method using electric hand hammer and high-pressure water cleaning,the accurate reinforcement positioning by stoppers and wooden sticks,grouting combined with concrete casting.The newly-added concrete owns stable strength and is dense,no voids are observed.And the qualified ratio of concrete cover for reinforcement is high.
作者
吴中鑫
陈进
龙安
WU Zhong-xin;CHEN Jin;LONG An(Wuhan Erhang Road and Bridge Special Engineering Co.,Ltd.,Wuhan 430063,China)
出处
《世界桥梁》
北大核心
2019年第2期83-87,共5页
World Bridges
基金
南京市科技计划项目(201727002)
关键词
双曲拱桥
拱肋
增大截面
高性能自密实混凝土
压灌结合
加固
double-curved arch bridge
arch rib
enlarged cross section
high performance self-compacting concrete
combination of grouting and concrete casting
strengthening
