In this construction video tutorial presented by the renowned engineer S.L.Khan, one can learn how to estimate steel quantity for rounded column or pier which contain spiral as ties.

In the video, the solution is provided for the following problem:-

Problem: Compute the steel for a circular pile having length 20 meter. Overlap for spiral is taken as 40D per 30 meter length of spiral.

The estimate for main bar is started with the following formula:-

Total length of main bars = No’s of bars x Length of one bar

Total length = 23 x (20) [total numbers of bars are 23 numbers with 26 mm diameter)

There is no additional length for hooks or other things.

So, total length = 460 m

The following formula is used to determine the weight of bar:-

Weight of bar = D²/162.196 x L (this formula is specifically applied for finding round shaped mild steel bar in kg)

= 26²/162.196 x 460

= 4.167 x 460 = 1917.2 kg

To convert the amount in ton, just divide it with 1000 i.e. 1917.2/1000 = 1.917 tons

To be familiar with other approaches, watch the following video tutorial.

Video Courtesy : SL Khan