土木分野におけるセンサ技術の利用と可能性(1)

[CS9-07] The freezing effect on natural frequencies of a model bridge in low-temperature range

〇Akihiro Iseki¹, Yoshihide Endou¹, Takatoshi Yamagishi¹ (1.Nohmi Bosai Ltd.)

Keywords:Model bridge, Temperature change, Freezing, Natural frequency, Indoor experiment, Accelerometer

The authors aim to develop a health-monitoring system for bridges using MEMS accelerometer. Our previous results of long-term monitoring for existing bridges showed that the natural frequencies of the bridges in cold weather were shifted more than expected. In this study, in order to clarify the cause of these natural frequencies shifts, a vibration experiment with accelerometer was carried out using a 9-meter model bridge, which was built in a room with air conditioner set from -15 to 15 degrees Celsius. The result shows that the natural frequencies of the paved model bridge including water was shifted much higher than those without water, due to the freezing at low temperature.