Mechanical Modeling of Multiple Trench Friction Pendulum System With Multi-Intermediate Sliding Plates

In order to upgrade the seismic resistibility of structures and enhance the functionality of an isolator, a new sliding type base isolator system called the multiple trench friction pendulum system (MTFPS) with multi-intermediate sliding plates is proposed. The MTFPS isolator is composed of a trench concave surface and numbers of intermediate sliding plates in each of two orthogonal directions. Mathematical formulations have been derived to examine its characteristics of the proposed MTFPS isolator. Based on mathematical formulations, it can be inferred that the natural frequency and damping effect of the MTFPS isolator change continually during earthquakes. Furthermore, results from shaking table tests demonstrate that the proposed isolator provides good protection to structures for preventing damage from strong earthquakes.