As a structural engineer or site engineer, we frequently work with various types of designs and details. One word, “development length,” or the denotation “Ld,” is mentioned in the drawing.
Do you understand what “development length” means? Where should development length be provided and why should we supply it?
as well as how to determine development length.
What Is Development Length?
To achieve the appropriate bond strength between steel and concrete, the minimum length of the steel bar needs to be firmly attached to the column.

The strong link between column-to-footing and column-to-beam structural elements is caused by development length