Reliability of Applied Semiactive Structural Control System

Research on semiactive control of structures has been carried out actively since the middle of the 1990s. After a theoretical and experimental study, a semiactive structural control system has been applied to an actual five-story building in 1998 by use of a continuous-variable semiactive hydraulic damper that has a maximum damping force of 1,000 kN. For application of the system, health monitoring, fail-safe operation, possibility of power failure, sensor malfunction, control device operation, computer, and communication system, etc., need to be considered. In this paper, reliability of an operational semiactive structural control system is discussed from the view points of health monitoring of the system and fail-safe functions. Power failures, abnormal outputs of sensors, valve damages, and communication errors, are focused as main problems. Dynamic load and forced vibration tests were carried out to determine fail-safe functions. After completion of the system installation, monitoring for earthquake excitation was initiated. Results presented show the effectiveness of functioning of the system. Finally, reliability of the system is confirmed and satisfactory performance is demonstrated.