Week 12 Challenge

1. 

Given

Column= 300 mm x 450 mm

Axial Load= 1500 KN

Mu=150 KNm

Assume that the moment is reversible

The safe bearing capacity of the soil= 200KN/m^2

Depth=1 m from ground level

M 25 and Fe 415 for the footing

Procedure:

• Open Staad foundation> Click on general mode> Doundaton plan> Linear grid setup

• Go column position> enter value or click on origin(0,0,0)> Column dimensions> Pedestal and anchor belt> yes put as length= 1m,width=1m,height=1m.

Go to loads and factors> Create new load case> Add column reaction load> Assign to column

Axial load= P= 1500 KN

So Pu= Ultimate axial load=1500x1.5=2250 KN

So 1.5 as partial safety factor as per IS 456:2000

Mu=150 KNm

 Go to generate load combinations> Choose indian> Generate it.

Go soil properties> Choose Bearing Capacity factors> Create new job> Define all design parameters.

Check design>footing is safe our values entered is correct.

Validation by hand calculation

Calculation snaps are attached below:

2. 

Aim- to design Combined footing with given data.

Given-

Two columns C1=400mm x 400mm

Service load= 800 KN

C2= 300mm x 500mm

Service load=1200 KN

The column C1 is flushed with the property line

The columns are at 3.0m c/c distance

the safe bearing capacity of soil is 200 KN/m^2 at a depth of 1.5 m

below the ground levell

Use M20 ad Fe 415 for columns and footing

Procedure:

• Ooen Staad foundation> click on general mode> Foundation plan> Linear grid setup.
• Go to column position > Column dimension as per given> add pedestal and anchor belt.

Create new load case> Add column reaction > Assign load for columns.

For column C1 service load= 800 KN

For column C2 Service load= 1200 KN

Create new job> Combined Footing> Choose Indian> Select column edit current job> Click strip footing setup.

Click create from selected nodes

Go to design parameters> Add cover and reinforcement> add cover and soil > add footing geometry

Add sliding and overturning factors.

Go to design> Click design save ok.