Foundation Design using SAFE

1A)

AIM:-

To model the isolated footing by using SAFE and to analyze and to design it to verify the size, depth and calculation of steel provided

INTRODUCTION:-

All the steps are going to be mentioned along with step by step procedure.

PROCEDURE:-

• Open SAFE software
• Create a new model
• Edit the settings
  • Edit the structural geometries and properties as per the previous problem which is given below:-

• Size of column = 400 mm * 400 mm

  Unfactored gravity load (DL+LL) = 2000 KN

  Safe bearing capacity of soil = 150 KN/m^2

  Assume M25 grade concrete and Fe 500 HYSD bars

  Settlement = 50 mm

  Take FOS = 3

  Sub- grade modulus = FOS* Safe bearing capacity/settlement = 150*3/0.05 = 9000 KN/m^3

  Unfactored gravity load = 2000/1.5 = 1333.33 KN

  Dead load = 1333.33/2 = 666.6 KN

  Live load = 1333.33/2 = 666.6 KN

  Yield strength of steel , fy = 500 N/mm^2

  Ultimate strength of steel, fu = 575 N/mm^2

  Area of footing = 1333.33/150 = 8.88 m^2

  Size of footing = L = B = √(8.88) = 3 m

  Adopt 4 m * 4 m for square footing

• Assign the area spring property
• Run the analysis

Here the displacement for both dead and live load is within the limit

• Check for bearing pressure under serviceable limit stage

Here the maximum soil bearing pressure is 84 KN/m^2 within the permissible limit i.e. 150 KN/m^2

• Again unlock the model
• Create design strip for design footing

• Again run the analysis
• Check the flexural reinforcement

Here the maximum reinforcement is 1269.58 mm^2 per metre

• Check for punching shear

Punching shear is 0.792 N/mm^2 which is less than 1. Hence it is safe.

RESULTS:-

Isolated footing has been analysed by using SAFE software.

2A)

AIM:-

To model analyse and design the pile cap on SAFE software and to evaluate the pile group, depth of pile cap and calculation of longitudinal steel on top and bottom face in both directions

INTRODUCTION:-

All the steps are going to be mentioned along with step-by-step procedure.

PROCEDURE:-

Size of column = 600*600

Unfactored gravity load (DL+LL) = 1175 KN

Length of pile = 16 m

Diameter of pile = 500 mm

Load carrying capacity = 200 KN

Assume M25 grade of concrete and Fe 500

No of piles = 1175/200 = 6

Modulus of Elasticity, E = 5000*√(fck) = 5000*√(25) = 5000*5 = 25000 N/mm^2

Area of piles, A= 3.14/4*500^2 = 193649.54 mm^2

Spring constant, k = E*A/L = 25000*193649.54/16000 = 306796.15 N/mm = 306796.15 KN/m

Spacing of piles = 2.5*500 = 1250 mm with 150 mm projections on either side

Length of pile cap = 1250+1250+(250+150)*2 = 3.3 m

Width of pile cap = 1250+2*400 = 2.05 m

Thickness of pile cap = 2*Diameter of pile + 100 = 1.1 m

• Open SAFE software
• Create new model template

• Draw the circular object and rectangular object for specified points which are been defined.

• Assign the joint springs for pile caps.

• Check the model and run the analysis

Here the maximum deflection comes to around 4 mm which is safe.

• Check for reaction

Here the reaction comes it around 288 KN

• Untick the model and create the design strips

• Run the analysis
• Check its flexural reinforcememt

• Check for punching shear

Hence it is safe within its permissible limit

RESULT:-

Pile foundation has been analysed by using SAFE software.