某办公楼牛腿的裂缝分析与处理

钢筋混凝土牛腿受力复杂、应力集中,很容易引起开裂。分析了钢筋混凝土牛腿的破坏机理及产生裂缝的主要原因:荷载过大、基础不均匀沉降、温度变化和混凝土收缩、施工质量控制不当等。根据裂缝特点提出压力灌浆和凿槽嵌补、外包钢加固、增补钢筋加固3种经济合理的裂缝处理方法。牛腿裂缝加固设计时应注意裂缝的稳定性、增补钢筋的应力滞后现象等问题。

Analysis and Treatment of Bracket Cracks of an Office Building

Although a small size,armored concrete bracket always bears some complex force and concentrated stress,which is easy to crack.From the breakdown mechanism analysis of the bracket,main causes of the bracket cracks are found according to engineering examples,such as overloading,base differential settlement,temperature traverse,concrete shrinkage and improper control of construction quality.Three economical methods are introduced to treat the bracket cracks: pressure grouting and gouging-filling,encased steel and reinforced steel bar.The cracks stability and the steel stress hysteresis are critical in bracket cracks design.