大型立交桥牛腿病害特征分析与加固技术研究——以厦门海沧大桥东渡立交为例  

Research on disease characteristics and reinforcement technology of corbel of large overpass——Take Dongdu interchange of Xiamen Haicang Bridge as an example

作　　者：林俪昕 LIN Lixin(Xiamen expressway construction and Development Co.,Ltd,Xiamen 361016)

机构地区：[1]厦门市高速公路建设开发有限公司,福建厦门361016

出　　处：《福建建筑》2022年第11期113-119,共7页Fujian Architecture & Construction

基　　金：福建省自然科学基金计划项目(2022J011252);厦门市建设科技计划项目(XJK-2021-9)。

摘　　要：为科学合理地对厦门海沧大桥东渡立交的牛腿结构进行加固,通过现场调查,分析病害成因,初步确定相应的加固方案,采用数值模拟方法对加固后的牛腿结构进行受力分析。研究表明:(1)下牛腿倒角处横向开裂并延伸至腹板,为典型的剪切受力裂缝;(2)箱梁上、下牛腿主要采用张拉斜向预应力方式进行加固,从梁顶原牛腿实心段腹板宽范围内斜向钻孔,钻孔横桥向按间距65 cm控制,穿束并张拉Φ^(S)15.2-4预应力钢绞线;(3)牛腿翼缘板新增50 cm×50 cm混凝土肋,内置Φ^(S)15.2-8预应力钢绞线。计算及实践表明,东渡立交牛腿加固方案可行,可供同类工程参考。In order to strengthen the corbel structure of Dongdu interchange of Xiamen Haicang Bridge scientifically and reasonably, the disease investigation and cause analysis of the bridge were carried out by using the field investigation and testing methods, and the corresponding reinforcement scheme was preliminarily determined.The stress analysis of the reinforced corbel structure was carried out by using the numerical simulation method.The results show that:(1)the transverse crack at the chamfer of the lower bracket extends to the web, which is a typical shear stress crack;(2)The upper and lower corbels of the box girder are mainly reinforced by means of tensioning and diagonal prestressing.Holes are drilled obliquely from the beam top within the width of the web of the original corbel solid section.The horizontal spacing of the drilled holes is controlled at 65 cm in the bridge direction, and the tendons are penetrated and tensioned Φ^(s)15.2-4 prestressed steel strand;(3)Bracket flange plate increased by 50 cm×50 cm concrete rib, built-in Φ^(s)15.2-8 prestressed steel strand.The calculation and practice show that the corbel reinforcement scheme of Dongdu interchange is feasible and can be used as a reference for similar projects.

关 键 词：立交桥 桥梁牛腿 加固 数值分析 斜向预应力加固 

分 类 号：U44[建筑科学—桥梁与隧道工程]