Method for calculating residual bearing capacity of concrete T-shaped beam by considering influence of fire crack

Abstract

The invention discloses a method for calculating the residual bearing capacity of a concrete T-shaped beam by considering the influence of a fire crack, and relates to the technical field of methods for calculating the bearing capacity of buildings after a fire. The calculation method comprises the following steps: 1, calculating the depth and width of the fire crack; 2, according to the calculation result of the depth and the width of the fire crack, carrying out analog calculation on the section temperature field of the concrete T-shaped beam with the crack; and 3, calculating the residual bearing capacity of the T-shaped beam after the fire according to the temperature field of the section of the concrete T-shaped beam with the cracks and the comprehensive influence factors, and obtaining a residual bearing capacity prediction simplified formula. According to the method for calculating the residual bearing capacity of the concrete T-shaped beam with the cracks after the fire, the influence of high temperature and the cracks on the residual bearing capacity is comprehensively considered, the simplified calculation formula of the residual bearing capacity of the concrete T-shapedbeam after the fire considering the crack influence is obtained, and the calculation precision of the residual bearing capacity is effectively improved.

Description

technical field [0001] The invention relates to the technical field of calculation methods for the bearing capacity of buildings after fire, in particular to a calculation method for the residual bearing capacity of concrete T-shaped beams considering the impact of fire cracks. Background technique [0002] In the prior art, a method for calculating the residual bearing capacity that is often used is to calculate the bearing capacity proposed by the known static load test of the existing reinforced concrete rectangular beam after fire. This calculation method is derived from the balance equation of the concrete beam : [0003] [0004] In the formula: is the compressive strength of the concrete at the corner of the fire-facing surface of the test beam section after the fire; b i is the width of the i-th layer of the converted concrete section; Δh is the height of each layer of the converted concrete section, Δh=h / n; h' is the height of the compressed concrete of the k-...

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Problems solved by technology

[0010] The calculation method of the above-mentioned bearing capacity has a great disadvantage, that is, the existence of cracks can significantly increase the temperature of the T-shaped beam, and ignoring the influence of cracks will lead to inaccurate calculation of the cross-section temperature field, which will affect the calculation accuracy of the post-disaster residu...

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