straighten

Plain Concrete Footing

CSA A23.3
v1.0.0
File:
Project:
Designer:
Date:

Footings - Plain Concrete

Section

Width, b:
mm
Thickness or Depth, h:
mm
Section is cast against soil:
Two-way Shear
Perimeter of critical section, bo:
mm

Ratio of long side to short side, Βc:

Material Properties

Compressive Strength, f'c :
MPa
Lambda, λ:

Loads

Bending Moment, Mf:
kN*m
One-Way Shear, Vf:
kN
Punching Shear Point Load, Pf:
kN

Input Values

Section

Width, b: 1000 mm
Specified Thickness, h: 200 mm
Cast against soil: No
Perimeter of critical section: bo = 800 mm
Ratio of long side to short, Βc: 1

Material Properties

Compressive strength, f'c: 25 MPa
Lambda, λ: 1

Loads

Bending moment, Mf: 10 kN*m
One way Shear, Vf: 11 kN*m
Punching Shear Point load, Pf: 12 kN*m

Design

Φc = 0.65
[cl. 22.6.5]
Max stress in tension = 0.37*Φc*f'c = 1.20 MPa
Max stress in compression = 0.75*Φc*f'c = 12.19 MPa
Max design stress, σmax = 1.20 MPa
Design thickness, h = 200 mm

Solution

Bending Moment

Mr = σmax*b*h2/6 = 8.02 kN*m

Mr = 8.02 kN·m

Ratio: Mf / Mr = 1.247

One-way shear

[cl. 22.6.6.1.2]
Vr = 2/3(0.18* λ*φc*f'c0.5*b*h = 78.0 kN

Vr = 78.0 kN

Ratio: Vf / Vr = 0.141

Two-way shear

[cl. 22.6.6.2.2]
Vr = 2/3((1 + 2/ Βc)0.18* λ*φc*f'c0.5*bo*h) = 187.2 kN
Vr max = 2/3(0.37* λ*φc*f'c0.5*bo*h) = 128.3 kN
Vr design = min(Vr, Vr max) = 128.3 kN

Vr = 128.3 kN

Ratio: Pf / Vr = 0.094

Comments

This information must be read or used in conjunction with CAN/CSA A23.3-14 Design of Concrete Structures. In the event of discrepancies, CAN/CSA A23.3-14 shall govern.