Experimental study on bearing behavior of large-diameter post-grouted rock-socketed pile in strongly weathered rock formations

被引：0
|
作者：
Rao S. [1 ]
Wan Z. [2 ,3 ]
Luo Z. [1 ]
Liu P. [1 ]
Dai G. [3 ]
Hu T. [3 ]
机构：
[1] Shenzhen Talents Housing Group Co., Ltd, Shenzhen
[2] School of Transportation Engineering, Nanjing Tech University, Nanjing
[3] School of Civil Engineering, Southeast University, Nanjing
来源：
Jianzhu Jiegou Xuebao/Journal of Building Structures | 2022年 / 43卷
关键词：
bearing behavior; combined post-grouting; field test; improvement coefficient; large-diameter bored pile; strongly weathered rock formation;
D O I：
10.14006/j.jzjgxb.2022.S1.0031
中图分类号：
学科分类号：
摘要：
To study the influence of combined post-grouting on the bearing behavior of large-diameter rock-socketed piles in strongly weathered rock formations, large-tonnage static load tests were conducted on two rock-socketed cast-in-place piles with a diameter of 2 800 mm in super high-rise buildings in Shenzhen. The load-bearing characteristics, deformation characteristics, and load transfer mechanism of ungrouted piles and combined post-grouted piles under high-level loads were compared and analyzed. The obtained test data were compared with the current specifications and recommended values in the geological survey report. On the basis of statistical analysis, the improvement coefficients of side resistance and base resistance of large-diameter post-grouted piles in strongly weathered rock strata were given. Finally, its rationality and reliability were verified. The results indicate that the side resistance and base resistance of combined post-grouted piles are substantially improved compared with those of ungrouted piles, and the load transfer characteristics of the rock-socketed pile are significantly affected by combined post-grouting, yielding higher load-bearing and deformation control capabilities of the combined post-grouted pile in strongly weathered rock formations. Under the ultimate load, both the ungrouted pile and the combined post-grouted pile are end-bearing friction piles, while the combined post-grouting cannot change the bearing behavior of the large-diameter rock-socketed pile. In addition, the calculation method in Chinese technical code for building pile foundations underestimates the actual side resistance of large-diameter rock-socketed piles, and the value ranges of improvement coefficient of side resistance and base resistance of strongly weathered rock formations are 2. 49-3. 05 and 2. 24-2. 43, respectively, which is more reasonable and feasible. © 2022 Science Press. All rights reserved.
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页码：287 / 295
页数：8
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