Multi-site network hybrid testing of a multi-span bridge system

Abstract

Experimental research is often carried out using a scaled-model test specimen due to the high cost of full-scale testing, the limitations of test equipments, and physical restrictions imposed by the size of laboratories. In order to allow testing of full-scale structures, which might not be possible otherwise to be conducted at any one individual laboratory, many research efforts have been focused on the development of hybrid experimental techniques in recent years. Because of the complexity and wide range of differences in the operation requirements of different testing equipment and facilities, there are the needs of a standardized platform and protocols for efficient set-up of collaborative network based multi-site hybrid experiments, and standardized protocol procedures for efficient data exchange. The aim of the current study is to establish a robust standardized procedure for laboratories at multiple sites to network their testing facilities in order to perform collaborative experiments. A collaborative research project is established between Canada and Taiwan to develop modules for control and instrumentation based on the use of standardized software interfaces. Pseudo-dynamic tests on a four-pier bridge system were performed using the developed protocols. The sub-components of the prototype bridge system were tested at three remote sites over long distance. Two of the remotes sites were in Taiwan and the third remote site was in Canada. Three double-skin concrete filled tubular (DSCFT) columns, which is an innovative design for bridge piers at high seismicity area, were constructed and tested at the participating laboratories. The fourth pier and the bridge decks were simulated by a numerical model. The Internet-based Simulation for Earthquake Engineering (ISEE) platform was employed for data repository and communication among laboratories. The design of hybrid test set-up and procedures, and the test specimens are described. Three analytical models were constructed for predicting the nonlinear behaviour of the DSCFT columns, and two of the analytical models were implemented in the ISEE environment to calculate the nonlinear responses of the bridge during the experiment. Selected 2D plots of analytical and experimental results, 3D visualization of the deformed prototype bridge, and the videos of the test specimens are broadcasted through the World-Wide Web in real-time, which allows outside researchers to be able to participate in this experiment through tele-presence. This is the first cross-continent collaborative networked hybrid test on large scale specimens, which has successfully demonstrated the potentials and future direction of experimental research of large size structures and civil infrastructure systems.