Analysis of vertical bearing capacity of super-long piles in more fractured and softer rock masses

Previous studies capacity of rock-socketed piles have focused on the load bearing characteristics of intact and more intact rocks embedded in the pile end, while this paper focuses on the vertical load bearing analysis of piles in more fractured rock masses. Combined with the static load test on a high-rise project in Wuhan, the pile bearing capacity is estimated by different codes and compared with the measured results. The results show that: “Technical Code for Building Pile Foundations” and “Standard for Geotechnical Investigation of Tall Buildings” have a high estimate of the bearing capacity, which is on the dangerous side, while “Technical Code for Building Foundation in Hubei Province” has a small estimate of the bearing capacity, which is 2.4 times of the measured value. Pile length, pile diameter, rock socket depth and bedrock strength directly affect the estimation of bearing capacity, for the softer rock masses in the super-long pile codes estimation value deviation is large, must use static load test to determine the ultimate bearing capacity. The test results can be used as a reference for the design of super-long piles in more fractured and softer rock masses.