Monitoring system of the Akashi Kaikyo Bridge and displacement measurement using GPS

With the goal of diagnosing the soundness of the world longest Akashi Kaikyo Bridge with a center span length of 1,991 meters, advanced monitoring system was installed; these include seismometers, accelerometers, anemometers and so on. First, the overall monitoring system of the bridge is described. One characteristic of suspension bridges is that temperature constitutes the major factor affecting their configurations under normal load conditions. Temperatures and the positions at 3 locations measured by GPS (global positioning system) has been recorded since September 1, 1998. Through continuous measurement of bridge positions and temperatures, along with the use of statistical methods, possibility to evaluate the configuration of a suspension bridge as a whole from the temperature at representative points is shown. Through this method using GPS, possibility to identify the location when deformation is caused by an earthquake or typhoon or when the measured values are off by normal observation is indicated.