Rapid design method for temperature control and crack prevention temperature stress control over tunnel floor lining concrete

Abstract

The invention provides a rapid design method for temperature control and crack prevention temperature stress control over tunnel bottom lining concrete. The rapid design method comprises the followingsteps that step 1, data for calculation of temperature control and crack prevention of the floor lining concrete is collected; step 2, a target of temperature control and crack prevention of the floor lining concrete and values of allowable temperature stress [sigma<max>] are analyzed and determined; step 3, temperature control and crack prevention measure schemes are designed, specifically, thevariables are analyzed, a plurality of floor lining concrete temperature control and crack prevention construction measure schemes are formulated; the maximum temperature tensile stress sigma<max> offloor lining concrete construction periods of the floor lining concrete temperature control and crack prevention construction measure schemes is calculated; and step 3-3, in the case that sigma<max> is less than or equal to [sigma<max>], a measure scheme is optimized according to the principle of simple practical economy for construction application. The rapid design method can quickly calculate the maximum temperature tensile stress in the construction period of pouring lining concrete of a gate hole type tunnel floor structure in any period (season), is small in calculation error, and is especially suitable for the preliminary design and real-time rapid design calculation during the construction period.

Description

technical field [0001] The invention belongs to the technical field of temperature control and anti-cracking of engineering structures, and in particular relates to a temperature-controlled and anti-cracking temperature and stress control rapid design method for tunnel floor lining concrete. Background technique [0002] Cracks are one of the main diseases of concrete. According to the dominant cause of cracks, it can be divided into two categories: structural cracks caused by external loads and non-structural cracks caused by deformation changes. Deformation effects include temperature, drying shrinkage and wet expansion, and deformation of surrounding rock, among which 80% are temperature cracks. In recent years, with the rapid development of water conservancy and hydropower engineering construction, the scale and section size of underground hydraulic engineering have become larger and larger, and the environmental conditions such as geology have become more and more comp...

AI Technical Summary

Problems solved by technology

In doing so, firstly, the temperature control standard for dam concrete cannot be applied to the thin-walled lining structure, and does not reflect the influence of differences in concrete strength, surrounding rock performance, lining thickness, and structural scale; secondly, the construction unit calculates the maximum temperature inside the lining concrete. Large, a large number of coefficient values ​​are highly artificial; the temperature difference between the two aspects may lead to a large distance between the formulated construction plans, and the target of temperature crack control cannot be effectively achieved

In particular, the analytical temperature stress is not calculated

[0007] Based on the above situation, at present, there are no clear requirements and technical standards for temperature control and anti-cracking during the construction period of concrete for the lining of underground engineering floors; there is no simple and high-precision design method, and the finite element method is time-consuming and expensive, and cannot be applied to non-concrete tests. The preliminary design stage of the results and the rapid adjustment of the construction plan; the strong constraint method has a large error, and the temperature stress cannot be calculated; it is difficult to quickly and effectively achieve the temperature crack control goal

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