Foundation Design using SAFE

Answer-1

AIM- To know the general design procedure of spread footing with safe software.

Data required for safe analysis & design-

Column Size- 400x400 mm

Comperssion axial load for the load combination of (1.5DL+1.5LL) = 2000 kN

Factored Load = 2000/1.5 = 1333.3 kN

Dead Load = 1333.3/2 = 666.7

Live Load = 1333.3/2 = 666.7

Safe soil bearing capacity = 150 kN/ Sq m at 2 mtr depth below EGL

Assumed Concrete grade- M25.

Footing Size- 3200X3200 mm, Footing Depth- 500mm

Sub grade Modules of soil = SBC X Ultimate factor /Maximum Settel ment = 150X3/0.05 = 9000 kN/cum m.

Fy = 500 N/ Sqmm, Fu= 545 N/Sqmm

Elastic modules of conc = 5000 X Fck^0.5 = 5000X 5= 25000 N/ Sqmm

Safe Design Procedure-

Go to safe software -file-new model-choose type of footing-enter dimension and load value -ok- define- material-slab section-spring area-then asign all property- run ananlysis.

Checks to be performed in safe-

1. Safe bearing capacity under service load.

Result- Here reactions forces is less than 150 so it is ok.

1. Setelment under service load

Result- Check doformed displacement it is less than 50mm so it is ok.

1. Two way shear check

Result- As per my design punching shear is 0.8 and safe design is less than, so it is ok.

1. Ultimate bending moment

1. Flexyral R/f design for footing.

Answer-2

AIM- To know the general design procedure of Pile software with safe software.

Data required for safe analysis & design-

Unfactored load = 1175 KN, DL= 1175/2 =587.5, LL= 1175/2=587.5

Pile dia =500 mm

Length of pile = 16000mm

Point Spring of Pile = Area of pile X Elasticity of modules/Length of pile = 196428x25000/16000 x 1000 = 306.92 KN/m

Fy = 500 N/Sq mm, Fu 575 N/Sqmm.

Individual pile capacity = 200 KN

Nos of Pile required = unfactored load with selfweight/individual pile capacity = 1175+117.5/200 = 6.5 nos . So consider 8 nos piles due to symmetric

Here self weight taken 10% of unfactored load

Spacing of pile As per IS -code 2911

Take c/c distance pile = 3 X pile dia = 3 X 500 = 1500 mm

Edge distance from pile center = 1X Pile dia = 1 X 500 = 500 mm

Assume pile cap depth = 500mm.

Safe Design procedure-

Go to safe software -file-new model-choose grid -enter dimension -draw pile cap-draw point and pile and--ok- define- material-slab section-spring area-define load pattern- load case-load combination column --then asign all property- run ananlysis.

Checks to be performed in safe-

1. Individual pile capacity under service load.

Result- Here the value is less than 200 kN, so it is safe

1. Setelment under service load

Result- It is less than 25 mm, so it is ok.

1. Two way shear check

Result- It is less than 1

1. Flexural R/f design for footing.