2020 年 8 巻 1 号 p. 26-34
Author Hideyuki Honda has experimented on actual modern timber bridges using glulam timber to investigate their structural rigidity as well as the static and dynamic characteristics of their structural performance for over 24 years. He has also evaluated the structural performance of modern timber bridges based on accumulated field test data and three-dimensional static and eigenvalue analyses. Atsushi Toyoda examined the structural performance of the static and dynamic characteristics based on those data. This study investigated the structural characteristics measured by field tests on 23 modern timber bridges immediately after completion, and then evaluated actual structural performance of those bridges based on the static and dynamic characteristics, such as static deflection, static rigidity, natural frequency, damping coefficient, dynamic increment factor (impact factor), vibration serviceability, and so on. The results clearly showed that the static flexural rigidity of modern timber bridges under actual service conditions was bigger than the rigidity in the design, and that the fundamental vertical natural frequency was almost equivalent to general highway bridges, such as steel and concrete bridges. New tables and figure have been added to the ones released in the past and an estimated equation of curve of the decrease of structural rigidity stiffness over time is proposed.