Temperature control and crack prevention design calculation method for lining concrete with round cross section structure

Abstract

The invention discloses a temperature control and crack prevention design calculation method for lining concrete with a round cross section structure. The temperature control and crack prevention design calculation method comprises the following steps of determining a temperature control and crack prevention target; calculating a permitted highest temperature; drafting a temperature control scheme; calculating the highest temperature inside the concrete; and designing a temperature control and crack prevention scheme on the premise that the calculated highest temperature is smaller than or equal to the permitted highest temperature. According to the method, calculation formulas are simple; influences of surrounding rock performance, lining thickness, concrete strength, air temperature in a tunnel, water cooling and water temperature, pouring temperature and the like can be reflected reasonably; the permitted highest temperature of pouring construction in each month of the construction period of the lining concrete with the round cross section structure can be calculated rapidly; the temperature control and crack prevention construction scheme applicable to a project is provided on the condition that the inside highest temperature is smaller than or equal to the permitted highest temperature and the economic requirement is met; the error between the result of the method and the result of simulating calculation of a finite element method is smaller than 5%; and the temperature control and crack prevention design calculation method is particularly applicable to primary design and optimization and adjustment on an on-site construction implementation scheme.

Description

technical field [0001] The invention relates to the technical field of engineering structure concrete temperature control and crack prevention, in particular to a design calculation method for temperature control and crack prevention of circular section structure lining concrete. 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 larger, a...

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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

[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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