Crack width checking and control method of underground continuous wall

Abstract

The invention discloses a crack width checking and control method of an underground continuous wall. The method is characterized in that a maximum bending moment under the characteristic combination of some working condition at a foundation pit construction stage is adopted, and a minimal protective cover thickness and a suggested component height are substituted into a formula required by a standard for checking until reinforcing bars of the underground continuous wall meets the requirements; the checking specifically comprises the following steps: calculating widths of primary reinforcing bars and cracks, thickness of a protective cover and height of a component, reinforcement ratio, equivalent stress of reinforcing steel bars, non-uniform coefficient of stress and maximum crack width. Compared with the prior art, the method has the advantage that on the premise of meeting and ensuring the safety of the structure, the waste of reinforcement for the underground continuous wall is reduced to the greatest extent, so that the engineering cost is further lowered.

Description

technical field [0001] The invention relates to the technical field of concrete structure design, in particular to a method for checking and controlling the crack width of an underground diaphragm wall. Background technique [0002] With the rapid development of my country's technology and economy, the application of underground diaphragm walls in deep foundation pits is becoming more and more extensive. As a reinforced concrete structure, the underground diaphragm wall is allowed to have cracks. Usually, the check of the crack width is carried out using the "Code for Design of Concrete Structures". According to the experimental research method, since the thickness of the protective layer and the diameter of the steel bars of the underground diaphragm wall are large, and a maximum bending moment is to be experienced during the construction stage, the maximum bending moment in the general construction stage is greater than the final bending moment under long-term use conditio...

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Problems solved by technology

[0003] The crack width checking formula in existing design codes is based on the maximum bending moment. However, the maximum bending moment of the underground diaphragm wall often occurs in a certain working condition during the construction stage, and the duration of this working condition basically varies from a few days to a few weeks. etc., is a short continuous process, so when the formula recommended by the code is used to check the crack width, the result is often too large, resulting in a waste of ground wall reinforcement

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