The effect of loading rate on bearing capacity and tensile resistance of piles

摘要

The bearing capacity and tensile resistance of piles have been evaluated based on static vertical loading tests. However, external forces acting on piles are not only static but may also be dynamic, for example, in the case of earthquake. In the case of large earthquake, dynamic loads dominate the design considerations. Although loading rate dependency on soil behavior and bearing capacity and tensile resistance of pile is well understood, there are relatively few studies and quantitative evaluation methods on bearing capacity and tensile resistance of piles considering loading rate have not been proposed yet. The purpose of this study is to investigate the effects of loading rate on the bearing capacity and tensile resistance of piles for seismic design. The model loading tests under a centrifuge acceleration field varying loading rate were conducted to investigate the effect of loading rate on the bearing capacity and tensile resistance of piles. The results suggest that the bearing capacity and tensile resistance, and the stiffness at pile head increase with increasing the loading rate.