建筑结构学报2024，Vol.45Issue(4)：155-165,11.DOI:10.14006/j.jzjgxb.2023.A042
分布式后压浆超长大直径灌注桩竖向承载性能试验研究
Experimental study on axial bearing behavior of super-long and large-diameter bored pile with distributed post-grouting
摘要
Abstract
In-situ static load tests on two super-long and large-diameter bored piles before and after grouting were conducted on the basis of the Xiaoqing River re-navigation project in Shandong Province.The influences of the distributed post-grouting on the bearing deformation behavior,load transfer characteristics,side resistance and tip resistance of the super-long and large-diameter bored piles were studied by comparing and analyzing the bearing behaviors of the combined post-grouted and distributed post-grouted piles.The results show that compared with the case before grouting,the bearing capacity of the combined post-grouted pile and the distributed post-grouted pile increases by 39.6％and 52.2％,respectively,which shows that the bearing behavior of the distributed post-grouted pile is better than that of the combined post-grouted pile.Distributed post-grouted pile also significantly improves the load transfer characteristics of pile foundation.Under the ultimate load,the side and tip resistances of the combined grouted pile and the distributed grouted pile are significantly improved,which effectively improves the boundary conditions between the pile side and soil and the load bearing conditions of the pile end,and improves the strength and stiffness of the soil at the pile side and end.Moreover,the improvement coefficients of the ultimate side resistance for the distributed post-grouted pile are slightly larger than that of the combined post-grouted pile under the same conditions,and the improvement coefficient of the ultimate side resistance increases with the increase of the buried depth,and the improvement coefficients of the ultimate side resistance has a depth effect.In addition,the transparent soil visualization model test further confirms that the cement grout injected into the distributed post-grouted pile covers the surface more evenly along the pile shaft due to its small spacing,multi-section,high density and multi-depth grouting,forming a more compact and stable pile-grout-soil interaction system,and thus improving the bearing behavior of pile foundation more significantly.关键词
钻孔灌注桩/分布式后压浆/组合式后压浆/现场足尺试验/桩侧摩阻力/桩端阻力Key words
cast-in-place bored pile/distributed post-grouting/combined tip-and-side post-grouting/field full-scale test/side resistance/tip resistance分类
建筑与水利引用本文复制引用
王卫国,万志辉,戴国亮,钱晓楠,胡涛,周峰,张鹏..分布式后压浆超长大直径灌注桩竖向承载性能试验研究[J].建筑结构学报,2024,45(4):155-165,11.基金项目
国家自然科学基金项目(52008100),江苏省自然科学基金项目(BK20200400),中国博士后科学基金面上项目(2022M723534),江苏省碳达峰碳中和科技创新专项(BE2022605). （52008100）
