A Model Test of the Dynamic Stiffnesses and Bearing Capacities of Different Types of Bridge Foundations

Abstract

With the rapid development of traffic infrastructures in developing countries, the evaluation demands for the vertical capacities of in-service bridges are increasing. The feasibilities of the transient response method (TRM) and index of dynamic stiffness for evaluating pile foundations are proven. However, their applicability to other types of bridge foundations must be investigated, and the correlation between the dynamic and static stiffnesses is also needed for analysis. In the present study, model tests were performed in a laboratory for various types of bridge foundations. A total of eight foundation models were fabricated for three types of bridge foundations. Both TRM and static loading tests were applied on each model. The influence of the foundation constraint state was tested as well. The results show that there is an obvious correlation between the dynamic and static stiffnesses and that the index of dynamic stiffness can reflect the foundation bearing capacity. Accordingly, the TRM can be employed to evaluate different foundation types, including spread, caisson, and pile foundations.