Abstract: Static uplift tests were performed on four short piles with enlarged bottom to investigate the uplift bearing characteristics of rock-socketed short piles with enlarged bottom. The Q-s curves of single pile obtained from the tests were analyzed in detail, and the field test result was compared with the ultimate uplift bearing capacity calculated by current codes. The field test results were verified consistent with numerical results by PLAXIS 3D. On this basis, the influence of horizontal load on the uplift bearing capacity of short pile with enlarged bottom was examined. The Q-s curves of short piles with expanded-bottom are steep, and the average ratio of uplift displacement to pile diameter is 1.94% in limit state. The calculation results of present codes are too conservative. Comparing with other codes, the calculation results of highway codes are closer to the test results. When η, the ratio of horizontal load to uplift load was 10%, 20% and 30%, respectively, the ultimate uplift bearing capacity of the pile decreased linearly by 8.3%, 16.7% and 25.0% respectively compared to that when η=0.

Key words: rock-socketed, short pile with enlarged bottom, uplift bearing behavior, field test, numerical simulation