Pounding Analyse And Control Of City Viaduct Under Earthquake Excitation

Following the development of the modern city, it is more and more important of traffic network in the whole lifeline of city for earthquake and hazard resistance system. However, severe earthquakes cause tremendous damage to structures such as highway, railroad, viaduct and crossroads in recent 20 years. A great deal of evidences from the earthquake disaster show that pounding between girders during a severe earthquake may severely impair the safety of bridges, as girders may collapse or be unseated as a result of collisions with each other. Moreover, a bridge might be destroyed from the viewpoint of serviceability due to pounding, such as failure to expansion joints, even though the bridge structure itself is not heavily damaged.In recent years, vibration control technologies have been improved rapidly in both research and engineering application. Semi-active control has become an attractive research field because it can reach to the nearly same effect of active control with less energy. MR dampers has become a typical representative of semi-active controllable devices with simple structure, controllable damping force, rapid response, strong damping force, and less energy consumption. The application of MR damper has become more and more widely.The aim of this paper is to analyze the negative effects of collisions at expansion joints induced by earthquake, and the effectiveness of MR dampers control is then investigated in terms of the reduction of responses with semi-active method. The following items will be investigated:1. Investigate the response of viaduct caused by pounding under earthquake. The ANSYS finite element computer code is utilized for the two-dimensional model building and analysis of the bridge including nonlinearity, the effectiveness of parameters in pounding element and gap in expansion joints is then investigated.2. Investigate the responses of viaduct with active control. Control the viaduct in earthquake using active control method, LQR and LQG control algorithms are employed, and the effect of two methods is discussed.3. Analyze the responses of viaduct with semi-active control using MR...