Design of Shallow Foundation (Isolated Footings)

Q.1 Design of Foundation in STAAD Foundation.

(i) AIM:  Using STAAD Foundation designing Isolated Footing

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 = 200 KN/m^2.
Depth = 1 m from ground level.
M 25 and Fe 415 for the footing

Procedure:

* Open staad foundation -> Click on general mode -> Foundation plan -> Linear grid setup.

* Go column position -> Enter value or click on origin (0,0,0) -> Column dimensions -> Pedestal and anchor bolt-> yes put as length = 1 m, width = 1 m, height = 1 m

* 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 = 1500 x 1.5 = 2250 KN.

> So 1.5 as partial safty factor as per IS 456:2000.

> Mu = 150 KNm.

* Go 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.

(ii) Aim: Design of Foundation in STAAD Foundation Combined Footing.

 Given :- 

Two columns C1 = 400 mm x 400 mm.
Service load = 800 kN.
C2 = 300 mm x 500 mm.
Service load = 1200 kN.
The column C1 is flushed with the property line.
The columns are at 3.0 m c/c distance.
The safe bearing capacity of soil is 200 KN/m^2 at a depth of 1.5 m below the ground level.
Use M 20 and Fe 415 for columns and footing.

 Procedure:

* Open staad foundation -> Click on general mode -> Foundation plan -> Linear grid setup.
* Go to column position -> Column dimension as per given -> Add pedestal and anchor bolt. 

* 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. 

* Generate load combination -> add indian load combinations.

* 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.

Result:

Hence both isolated and combined footing design using STAAD Pro foundation is done as per given data.