Passive fire-resistant structure of steel structure bridge and installation method of passive fire-resistant structure

Abstract

The invention relates to the fields of fire-fighting technologies, bridge technologies and the like, in particular to a passive fire-resistant structure of a steel structure bridge and a mounting method thereof. The steel structure bridge comprises a dry root steel beam; the section of the steel beam is in an I shape, and the steel beam comprises a lower flange and an upper flange which are located on the lower portion and the upper portion in the horizontal direction respectively. And the web plate is connected between the upper flange and the lower flange along the vertical direction. The passive fire-resistant structure comprises a keel frame connected between adjacent steel beams; the fireproof layer is fixed below the keel frame and extends in the horizontal direction, and the lower flange of the steel beam and the keel frame are separated from the space below the bridge. According to the structure, under the condition of not depending on any active fire extinguishing system, the heating strength of the lower flange of the steel beam can be remarkably reduced, and the temperature rise speed of the lower flange of the steel beam is delayed, so that strength attenuation or overall instability of the steel beam caused by high temperature in a short time is avoided, and the structural safety and disaster resistance toughness of a steel structure bridge under the extreme fire working condition are improved.

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