钻孔灌注桩钢筋笼保护层设置的研究

Research on the Setting of Reinforcement Protection Layer of Bored Pile

针对钻孔灌注桩桩体出现露筋的质量问题,结合实际工程,提出了一种新型保护层设置措施,在不同场地条件下,从露筋率、承载力、低应变检测桩身完整性三个方面与现有保护层设置进行对比分析。结果表明,新型保护层设置在实际工程应用中,操作简便、经济实用、安全可靠,能显著降低或达到零露筋,防止钢筋锈蚀、保证结构耐久性及有效截面面积,使得结构的承载力正常发挥,消除结构安全隐患。在遇到严重液化等不良工程场地时,可采用规范要求的定位钢片和钢筋锚固段外扩相结合的措施降低露筋率。

Based on the problem of steel bar exposure of bored piles,this paper presents a new method of protection layer setting combined with the practical engineering.Under different site conditions,the comparison and analysis of the existing protection layer are carried out from the three aspects of the exposure rate,bearing capacity and low strain detection.The results show that the new type of protective layer design is easy,simple to handle,economic,practical,safe and reliable.What's more,this protective layer can reduce exposed reinforcing bar remarkably and achieve zero exposure rate.It can protect reinforcing bars from corrosion,ensuring durability and effective sectional area,which makes the bearing capacity of structure work normally and eliminates structural safety risks.In the case of serious liquefaction and other undesirable engineering sites,the method of combining the positioning steel plate with the reinforcement bars can effectively reduce the risk of reinforcing bar exposure.