深圳地区灌注桩抗拔性状分析

Analysis of Uplift Resistance of Cast-in-place Piles in Shenzhen

针对本地灌注桩抗拔力检测不合格率较高的现状,本文将近三年的受检桩按单位工程、桩型、桩径及单桩承载力、上拔位移等作出统计,分析其分布规律和不合格率;通过对2015年全部抗拔试验实测数据的计算和统计分析,得出嵌入硬质岩和软质岩泥浆护壁灌注桩嵌岩段抗拔综合系数、非嵌岩桩强风化段抗拔系数;探讨挖孔桩的承载力和上拔位移分布;给出若干建议供设计施工参考。

For the high failure rate of the uplift resistance testing of cast-in-place piles,the distribution law and the unqualified rate were analyzed for 3 consecutive years. The classification includes unit project,pile type,pile diameter,bearing capacity of single pile,and the uplift displacement. Based on the hard-rock-socketed and soft-rock-socketed cast-in-place piles with mud protection,uplift resistance co- efficient of rock-socketed segment,uplift resistance coefficient of strong weathering section of non-rock-socketed pile were obtained through the calculation and statistical analysis of pullout testing in 2015. The bearing capacity and the uplift displacement of manual hole digging piles were introduced. Suggestions for design and construction were given.