抄録
Structural health monitoring is a method of estimating the presence of the damage of the structure, and its position and degree by the change of static and dynamic characteristics before and after the secular change or the action of external force. However, the static and dynamic characteristics of the actual structural fluctuate on daily, seasonal and diachronic variations basis without depending on damage or not. These characteristics of reinforced concrete lighthouse were observed for about one and a half year by the authors. This paper presents long-term variations of crack widths, inclination angles, temperatures and natural frequencies of this lighthouse.
