Method for estimating fire temperature field in wall thickness direction of immersed tunnel protected by fireproof plate

Abstract

The invention relates to a method for estimating a fire temperature field in the wall thickness direction of an immersed tunnel protected by a fireproof plate, and belongs to the field of tunnel engineering. The method comprises the following steps that S1, a fireproof plate protection immersed tunnel tube wall temperature field solving model is established; S2, a temperature distribution function on a fireproof plate back fire surface boundary under the action of a fire source function is established; S3, a cavity heat flow attenuation coefficient expression between a fireproof plate and a tube wall is established; S4, a temperature field solving mathematical model of the immersed tunnel tube wall under the combined action of a fireproof plate back fire surface temperature and cavity attenuation is established; and S5, the temperature value of any position at any moment in the thickness direction of the tube wall is solved. According to the method for estimating the fire temperature field in the wall thickness direction of the immersed tunnel protected by the fireproof plate, the problem of solving the temperature field of the tube wall of the immersed tunnel protected by the fireproof plate is simplified into two one-dimensional transient heat transfer problems. The first problem is solved through fire test data before the fireproof plate is installed; the second problem is solved by an analytical method. According to the method for estimating the fire temperature field in the wall thickness direction of the immersed tunnel protected by the fireproof plate, the solving model is simpler, and the solving result is more visual.

Description

technical field [0001] The invention belongs to the field of tunnel engineering and relates to a method for estimating the fire temperature field in the wall thickness direction of an immersed tube tunnel protected by a fire prevention board. Background technique [0002] The high temperature of the fire will lead to concrete bursting and deterioration of mechanical properties. Accurate and rapid calculation of the temperature field distribution in the thickness direction of the tunnel lining structure after the fire is of great significance to the evaluation of the bearing capacity of the pipe joint structure. At present, there are mainly three methods for measuring and calculating the temperature field distribution of the immersed tube tunnel wall protected by fireproof boards: indoor model test method, field test method and numerical simulation method. Time-consuming and labor-intensive problems, and because the actual location of the fire is uncertain, and the fire-proof...

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Problems solved by technology

At present, there are mainly three methods for measuring and calculating the temperature field distribution of the immersed tube tunnel wall protected by fireproof boards: indoor model test method, field test method and numerical simulation method. Time-consuming and labor-intensive problems, and because the actual location of the fire is uncertain, and the fire-proof performance of the fire-proof panels of different models, sizes and installation methods is different, the calculation results of the above method are not universal.

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