Foundation Design using SAFE

1) AIM & INTRODUCTION: model an isolated footing using safe with respect to previous challenge

PROCEDURE:

Data required for SAFE Analysis & Design:

unfactored load =2000/1.5 = 1333.3 KN

Dead load breakup = 1333.3/2=666.7 KN

Live load breakup = 1333.3/2 = 666.7 KN

Sugrade modulus of soil = safe bearing x factor of ultimate /maximim settlement

= 150 x 3/0.05 = k =9000KN/m3

Rebar yield strength (fy) = 500N/mm2

Rebar ultimate strenth (fu) = say 5.75 N/mm2

Elastic modulus of M25 concrete = 25000 N/mm2

open safe - file - new model - single footing - provide all the necessary dimensions - design strips - add load combinations - show width under design strip pattern

Checks needed to be performed in safe analysis:

1. Safe bearing capacity under service load
2. Settlement under service load
3. Two way shear check (punching shear )
4. Ultimate bending moment
5. flexural reinforcement design for footing slab

safe bearing :

show reaction forces - load combination - settlement - soil pressures - display contours in extrudeed form - user defined - scale factor - 1-apply

acceptable

settlement:

shape deformed shape - settlement - apply

it is okay

2 way shear:

show punching shear design

applied shape stress is less than capacity of the section , section pass in 2 way shear

ultimate bending moment:

switch on design strips - show strip forces - DCONU1 - apply - layer A&B -Apply

flexural reinforcement designshow slab button -input minimum reinforcement - apply

RESULT: modelled an isolated footing using safe with respect to previous challenge succesfully

REPORT FORMAT:

2) AIM & INTRODUCTION: model,analyse and design the pile cap using safe

PROCEDURE:

Data required for SAFE analysis & design:

unfactored load = 1175 KN

dead load breakup =1175/2 = 587.5 KN

Live load breakup = 1175/2 =587.5 KN

Point spring of file = A X E /L =196349 X 25000/16000 = 306796 KN/MM

K for safe analysis = 306.8 kn/mm

rebar yield strenth (fy) = 500N/mm2

rebar ultimate strength (fu) = say 575 N/mm2

Elastic modulus of M25 concrete =25000 N/mm2

number of piles required = unfactored load with self weight addition/individual pile capacity = 1175 x 1.1/200 = 6.5

consider 8 piles for symmetric placement of piles under pile cap

take center to center distance between piles = 3xpile diameter (1500mm)edge distance from pile center =1xpile diameter (500mm)

assume pile cap depth = 500 mm

safe designing :

checks need to be performed in SAFE analysis

1. individual pile capacity under service load
2. settlement under service load
3. two way shear check (punching shear)
4. flexural reinforcement design for footing slab

select - points - assign - support data - point springs

analyse the plan

punching check - ok

reactions - load combination - service - fz - apply

plan view - deformed shape - apply

show slab design - tick layer a and b - apply

RESULT: modelled,analysed and designed the pile cap using safe

REPORT FORMAT: