Foundation Design using SAFE

PROCEDURE:-

Open the YouTube software and create a new model and select the editor option in the settings

• 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

• 

• Now we have to define materials and add new materials property for m25 concrete
• After adding the material property for fe 500 Steel bar define the step property data and sign the spring properties

• Assign the load assignment force

• Define the load combinations as shown below

• Check the model

• Now we have to do the analysis by clicking on the run analysis

Now here is the displacement for the both dead load and the live load within the limits

• Now we have to check the pairing pressure under the limits

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

• Now again run the unless is and 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.

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

Now we have to define the properties as shown below

• Define slab property type

• Draw by points

• Drag it to the four points for creating pile cap
• Draw the points for creating pile caps at specified offset distance
• Draw the column at mid point for specified offset distance
• Draw the circular object and rectangular object for specified points which are been defined

• Assign the joint springs for pile caps
• Assign the spring constant value for Z azis is 30796.15 KN/m which has been calculated earlier i.e. k
• Assign the joint assignment force for column both dead load and live load

• Define load combinations

• Check the design concrete slab preferences as per IS code 456-2000

• Check the automatic mesh options

• 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

• Click the model and check its design for both column strip

• 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.