Air blowing method for controlling vortex-induced vibration of large-span bridge steel box girder

Abstract

The present invention discloses an air blowing method for controlling vortex-induced vibration of a large-span bridge steel box girder at a low wind speed. According to the air blowing method, when the steel box girder has a large vortex-induced vibration amplitude, air blowing devices arranged at two sides of the steel box girder are utilized to blow air at the leeward side of the steel box girder, so as to disturb the formation of a vortex shedding phenomenon at the leeward side of the steel box girder structure, thereby avoiding vortex-induced resonance of the steel box girder; wherein a vibration sensor arranged on the steel box girder is used to monitor vortex-induced vibration response of the steel box girder in real time, when the measured vortex-induced vibration amplitude of the steel box girder is greater than a preset amplitude threshold, a control system calls real-time monitoring data of a wind speed and wind direction sensor, starts the air blowing devices at the leeward side and automatically adjusts the air blowing speed. The air blowing method is mainly applied to control for vortex-induced vibration of the large-span bridge steel box girder, is high in automation degree and obvious in control effect, and provides a brand new effective means for the large-span bridge steel box girder in a strong wind / typhoon high frequency region to resist the vortex-induced vibration.

Description

technical field [0001] The invention relates to the field of wind resistance of long-span bridges in civil engineering, and is suitable for controlling the vortex-induced vibration of steel box girders of long-span bridges in strong / typhoon-prone areas. Background technique [0002] In recent years, many long-span bridge projects across rivers and seas have been built at home and abroad, and their structural forms are mainly suspension bridges and cable-stayed bridges, such as Akashi Kaikyo Bridge, Xihoumen Bridge in Zhoushan, China, Sutong Bridge, Runyang Bridge, etc. For these long-span cable-supported bridges, as the span increases, the structural rigidity decreases significantly, so that wind load often becomes the control load, and wind-induced vibration also becomes the main factor that threatens the safety of the bridge. [0003] Wind disasters are the most frequent natural disasters. According to statistics, the annual losses caused by wind disasters in the world rea...

AI Technical Summary

Problems solved by technology

Flow control can be divided into passive flow control and active flow control. Passive flow control is to change the flow environment through passive control devices. This kind of control is preset. When the flow field deviates from the design state, the best control effect cannot be achieved.

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