Abstract:Taking the load test of the main pier pile foundation of a bridge as an example, the working principles, characteristics and test essentials of pile foundation load test by the double-load box self-balancing method are introduced. The test result shows that the double-load box method has the obvious superiorities in the test of large-pier pile foundation and the study of pile bottom pouring effect. This technology can solve the problems hard to solve by the traditional static load test and single-load box test, provide a way to solve problems for the practical engineering application, and has the wide application prospect in the pile foundation of bridge.