Method for carrying out early warning on damage to steel box girder of long span bridge in operation state

Abstract

The invention relates to a method for carrying out early warning on the damage to a steel box girder of a long span bridge in an operation state. The method comprises the following steps of: a step 1 of arranging steel box girder sensors, i.e. arranging a vertical acceleration transducer, a temperature sensors and an anemoscope at the midspan positions of the steel box girder for respectively monitoring the vertical acceleration of the steel box girder, the temperature of the steel box girder and the wind speed of a region where the steel box girder is positioned, which are caused by a vehicle load; a step 2 of processing monitoring data; a step 3 of establishing a mathematical correlation model of the vibrating frequency of the steel box girder and operation factors in a good state; a step 4 of determining the significance level of a control chart; and a step 5 of carrying out early warning on the damage to the steel box girder. According to the invention, various factors influencing the variation of the vibrating frequency of the steel box girder in the operation state are comprehensively considered, the real-time performance and accuracy of carrying out early warning on the damage to the steel box girder are effectively improved, and the method is necessarily and widely applied and popularized.

Description

technical field [0001] The invention relates to a damage early warning method applied to a steel box girder of a long-span bridge in an operating state, and relates to the field of non-destructive testing of bridge engineering. Background technique [0002] Most modern long-span bridges use steel box girders as the main girder to bear the direct load of vehicles, such as the Second Nanjing Yangtze River Bridge, Runyang Yangtze River Bridge and Sutong Yangtze River Bridge. Steel box girder is a very important structural component in long-span bridges, and its safe state is related to the safe operation of the entire bridge structure. However, the bridge deck of the steel box girder directly bears traffic loads and is more prone to fatigue cracking. At present, steel box girder fatigue cracking accidents have occurred in long-span bridges at home and abroad. my country's Humen Bridge in Guangdong, which was completed and opened to traffic in 1997, has had fatigue cracks in t...

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Problems solved by technology

[0005] Technical problem: The present invention aims at the deficiencies of the existing long-span bridge steel box girder damage monitoring technology, and proposes a lo

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