In the maintenance of highway bridges, vertical load of supporting by bearings is very important. If the value becomes far from the considering in design, it may become a main factor of many damages of bridge. However, there has not been a particular technology to measure the actual vertical load in the long time continuously.
Therefore, our group is now developing the system, which enables to measure superstructure load working on the bearings anytime and furthermore, enables to collect data easily with wireless radio system by building the sensor in rubber bearings. Advantages of the system are, for example, 1) it can be possible to have construction management when installing. Monitoring of bearing reaction force during jack-down can prevent initial error. 2) It can be possible to have bridges monitoring easier. Wired or wireless data collecting system makes maintenance work effective dramatically. 3) Damages of a bridge can be found at an early stage. It can be possible to detect abnormality and damages at an early stage by accumulation and management of long time-series data.
In this paper, we are going to focus on the performance of the sensor built-in rubber bearing and among the other factors composing this system as reporting its principle and actual data examples measured in Japanese highway bridges.