Tensioning-Phase Box Girder Deformation Prediction Model Based on Ant Colony Algorithm and Residual Correction

Table 4

Diagonal crack grading standard.

Diagonal crack scale	Criteria
	Qualitative description	Quantitative description
1	There is no diagonal crack.	- -
2	There are a few slight diagonal cracks, whose width falls within the allowable range.	The crack length is less than 1/3 of the sectional size.
3	There are many diagonal cracks, whose width falls within the allowable range.	The crack length is between 1/3 and 1/2 of the sectional size.
4	There are numerous diagonal cracks, whose width exceeds the allowable range.	The crack length is greater than 1/2 of the section size, and the mean crack interval is less than 30cm.
5	There are numerous through diagonal cracks, whose width far exceeds the allowable range.	The crack width is greater than 1.0mm and the mean crack interval is less than 20 cm.