关键词: 极限承载力, 双曲线法, 桩, 竖向静载荷试验, 荷载－沉降曲线

Abstract: From the analytic geometry's point of view,the asymptotic which parallel to the settlement axis had been employed to determine the bearing capacity in the traditional hyperbolic method.In this paper the maximum curvature point of hyperbolic was used to ultimate bearing capacity of single pile.In practical application,the traditional methods were analysed comparing with the method proposed.The results showed that the ultimate bearing capacity Qu calculated by the method in this paper was equivalent to Qult reduction which was calculated by the traditional method.The flatter the curve was,the more the reduction.In the relationship of the ultimate bearing capacity and the load series,maximum curvature method agreed with traditional method; the ultimate bearing capacity would be stable and large with the increasing numble of the load series．

Key words: ultimate bearing capacity, hyperbola method, pile, vertical static load test, loading-settlement curve