ABSTRACT
Currently a number of suspended swaying pedestrian bridges are constructed and planned in Korea by mainly local governments. However, the structural behavior of these bridges is not completely known or analyzed and maintenance system has not been implemented yet compared to other road and railway bridges. In this study, various monitoring sensors and systems are applied on a typical swaying pedestrian bridge and longterm monitoring data are collected to investigate the behavior and performance of the bridge. To find the displacement and location movements, GNSS system has been installed on the two locations of the bridge: one at the center of the bridge and the other at anchorage of the bridge. Since the swaying bridge has the shape of suspended cable, the sag is very important static characteristics of the bridge and it can be effectively measured using GNSS system. Dynamic vertical and lateral displacement can also be monitored using this system. To collect the vibration and other environmental data such as wind and temperature, IoT (Internet of Things) system are proposed and installed on the same swaying bridge together with GNSS system. IoT system can measure the accelerations and inclinations as well as strains, temperature and wind speed and direction using its digital and analog inputs. IoT system also has a capability of transmitting data into any data storage via Wifi or LTE connection. Acceleration data may be used to calculate the dynamic characteristics such as natural frequencies and damping ratios. Together with the temperature and wind data, the variance of the sag, static and dynamic characteristics of the bridge may be investigated effectively. The results of this study can be used to develop the comprehensive design and evaluation criteria for swaying bridges.
