Temperature control and crack prevention design calculating method used for lining concrete of door-opening-shaped section structure

Abstract

The invention discloses a temperature control and crack prevention design calculating method used for lining concrete of a door-opening-shaped section structure. The method comprises the following steps of (1) determining a temperature control and crack prevention target, (2) calculating the permitted maximum temperature and (3) making a temperature control scheme, specifically, the maximum temperature inside the concrete is calculated, and on the premise that the worked-out maximum temperature is smaller than or equal to the permitted maximum temperature, the temperature control and crack prevention scheme is designed. The calculation formula of the method is simple, the influences of surrounding rock performance, the lining structure size, concrete strength, intro-opening air temperature, water-introducing cooling and water temperature thereof, pouring temperature and the like can be reasonably reflected, the permitted maximum temperature of pouring construction each month in the construction period of the lining concrete of the door-opening-shaped section structure can be rapidly calculated, the maximum temperature inside the lining concrete is calculated rapidly for different temperature control schemes, and a temperature control and crack prevention construction scheme suitable for a project is provided under the conditions that the inside maximum temperature is smaller than or equal to the permitted maximum temperature and economy is achieved. The error is smaller than 3% compared with the simulation calculation result of a finite element method, and the temperature control and crack prevention design calculating method is particularly suitable for optimization and adjustment of primary design and an on-site construction scheme.

Description

technical field [0001] The invention relates to the technical field of temperature control and anti-cracking of engineering structure concrete, in particular to a design and calculation method for temperature control and anti-cracking of concrete lining a door-shaped section structure. Background technique [0002] Cracks are one of the main diseases of concrete. Academician Pan Jiazheng, a famous hydropower expert, asserted that "there is no dam without cracks in the world". 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. For example, with the development of water conservancy and hydropower projects, the scale and cross-sectional size of underground water projects are getting larger and lar...

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 type, lining thickness, and structural scale; secondly, the construction unit calculates the maximum internal temperature of the lining concrete. Error 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

[0007] Based on the above situation, at present, there are no clear requirements and technical standards for temperature control and crack prevention of lining concrete in underground engineering construction; some existing design calculation methods are time-consuming and costly, and cannot be applied to the preliminary design stage without concrete test results Quickly adjust with the plan during construction; some errors are relatively large, and the temperature crack control target cannot be effectively achieved

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