Vertical bearing capacity of rock-socketed pile with enlargement at pile end

To better understand the bearing performance of large-diameter piles, pull-out test and self-balanced loading tests were conducted on 3 ordinary bored piles with diameter of 1 000 mm and 4 bored piles with secondary enlargement at the bottom of the pile with diameter of 1 600 mm (2 800 mm). The results show that post-grouting and the grouting amount have influence on both the tip resistance and side resistance of the bored pile. The unit end resistance increases quickly at first and slow down subsequently with the increase of displacement and the critical displacement is different for different types of pile. The critical displacements for piles with pile diameter of 1 600 mm (grouting amount is 4.2 t), pile diameter of 1 600 mm (grouting amount is 9.5 t), pile diameter of 1 000 mm (grouting amount is 2.2 t) are 5.26, 3.48 and 2.34 mm, respectively and the corresponding unit end resistances are 3 414.6, 3 414.6 and 3 668.8 kPa, respectively. The measured uplift unit end resistance is 0.52 times the theoretical calculation values. © 2016, Central South University of Technology. All right reserved.