Shaking Table for the Analysis of Pillars with Top Mass

Abstract

In this paper, we present a shaking table designed by the authors, used in laboratory experiments to simulate earthquakes. This equipment makes possible studying the dynamic behavior of civil engineering structures subjected to seismic motion. Among these structures, bridges won a special attention, because they are easily harmed during earthquakes. In addition, bridges have importance in assuring a facile communication in the case of hazards. The most sensitive bridge element is the pillar, which supports important bending moments if horizontal forces act on his top. The shaking table developed by the authors is designed to analyze the dynamical behavior of pillars with a tip mass that represents the superstructure. The soil displacement is simulated by the main plate, actuated by an electric engine which ensures different excitation frequencies. The analyzed pillar is mounted on the main plate via a reinforcement element, in order to increase its stability. Tests were performed with different frequencies, in order to find out the actuation precision. During tests, the accelerations at the base and the top of the pillar were acquired with the LabView program of National Instruments, and the results shows that the shaking table can be controlled with high accuracy.