Abstract: According to in-situ self-balancing static loading test of uplift pile in moderately weathered rock, a FLAC^3D numerical analysis model of rock-socketed uplift pile is established based on reasonable rock mechanics parameters and test data together with the geological condition of the project. By using this model, three uplift piles undergone self-balancing test until failure were simulated to determine the ultimate bearing capacity of each pile and to further examine the influence of rock socket depth on the ultimate bearing capacity of uplift pile and the variations of lateral resistance and axial force of pile with external load. Results demonstrate that: (1) The shear modulus and volumetric modulus of rock should be reduced by 1/10 of test values when building a rational numerical model. (2) The ultimate bearing capacity of rock-socketed uplift pile is mainly affected by the socketed depth of rock. Under the same condition, the ultimate bearing capacity of rock-socketed uplift pile increases with the socketed depth of rock and the length of pile, and the rock-socketed depth of pile should not be too small. (3) With the increase of rock-socketed depth, the side resistance of pile increases first and then decreases, and the middle resistance of pile contributes the most remarkably to the ultimate bearing capacity. (4) The diameter of uplift pile has size effect on ultimate bearing capacity.

Key words: rock-socketed piles, self-balancing test, load-bearing characteristics, ultimate bearing capacity, rock-socketed depth, FLAC^3D numerical simulation analysis