Estimating Sheet

# How to determine the cutting length of a trapezium stirrup

Construction Software In this exclusive civil engineering tutorial, you will learn how to determine the cutting length of a stirrup with trapezium shape.

The detail calculation is made based on the following data :-

Length of total column = 600 mm
Clear cover (from concrete phase to exterior most steel) = 40 mm
Main steel bar = 20 mm

Center to center distance of main bar is arranged in equivalent spacing and it is calculated as follow :-

600 – (2 x clear cover) – (2 x stirrups dia) – (2 x half of main bar) / 3 (there are three divisions of main bars)
600 – (2 x 40) – (2 x 8) – (2 x 10) / 3 = 161 mm
Now, the length of the base of the stirrup is taken as A.
The length of the top portion is taken as B.
The hypotenuse length is taken as C.

The value of A is determined as follow :-

600 – (2 x clear cover) = 600 – (2 x 40) = 520 mm

The value of B will be calculated as follow :-

C/C distance of main bar + (2 x half of main bar) + (2 x stirrup dia)
= 161 + (2 x 10) + (2 x 8) = 197 mm

### Also Read: How to calculate the volume of concrete in a trapezoidal footing

The value of C will be calculated as follow :-

Height = 400 – (2 x clear cover) = 400 – (2 x 40) = 320 mm
Base = C/C distance of main bar + (half of main bar) + dia of stirrups
= 161 + 10 + 8 = 179 mm
C = √(Base)2 + (perpendicular)2
= √(173)2 + (320)2
= 367 mm

So, the cutting length will be calculated as follow :-

A + B + (2 x C) + (Hook) – (Bend)
= 520 + 197 + (2 x 367) + (2 x 10 x 8) – (4 x 3 x 8) – (1 x 1 x 8) [diameter of hook = 10d; 4 bends with dia 3d]
= 1507 mm = 1.507 meter

Video Source: L & T - Learning Technology 