Foundation Design using SAFE

Quetion:1

AIM: Model the isolated footing provided in week 11 challenge on SAFE.

INTRODUCTION: Model the isolated footing provided in week 11 challenge on SAFE. Analyze and design it to verify the size, depth and steel provided as per calculations.

procedure:

checks needs 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.

Question:2

AIM: A column of size 600x600 carrying an unfactored gravity load (DL+LL) of 1175 KN is to be supported on pile cap, which ultimately transfers load to the piles underneath. Piles of 16 metres length and 500 mm diameter are to be used. Each pile has a load carrying capacity of 200 KN. Model, analyse and design the pile cap on SAFE to evaluate

INTRODUCTION:

A column of size 600x600 carrying an unfactored gravity load (DL+LL) of 1175 KN is to be supported on pile cap, which ultimately transfers load to the piles underneath. Piles of 16 metres length and 500 mm diameter are to be used. Each pile has a load carrying capacity of 200 KN. Model, analyse and design the pile cap on SAFE to evaluate the following:

• Pile group to be used
• Depth of pile cap
• Longitudinal steel on top and bottom face in both directions

PROCEDURE:

Data required for safe analysis and design

Unfactored load = 1175 KN

Dead load breakup = 1175/2 = 587.5 KN

Live load breakup = 1175/2 = 587.5 KN

Point spring of pile = A x E /L = 196349 x 25000 /16000 = 306796 KN/M

K for safe analysis = 306.8KN/MM.

Rebar yield strength (Fy) = 500 N/mm2

Rebar ultimate strength (Fu) = say 575 N/mm2

Elastic modulus of M25 concrete = 25000 N/mm2

Data required for SAFE analysis and design

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 b/w piles = 3 x pile diameter(1500mm)

Edge distance from pile center = 1 x pile diameter (500mm)

assumed pile cap depth = 500mm

Checks need to be performed in safe analysis.

1. individual pile capacity under service load.

2. settelement under service load

3.two way shear check(punching shear)

4.flexural reinforcement design for footing slab.