Settlement Analysis

Settlement Analysis

1. Determine the initial conditions

2. Determine the geometry and magnitude of the applied loads

3. Estimate the change in stress within the compressible layers

4. Estimate the preconsolidation pressure

5. Calculate the consolidation settlement

6. Estimate the time rate of consolidation settlement

7. Estimate the magnitude and rate of secondary compression

8. Estimate the immediate or distortion settlement

Boussinesq Point Load

3

2 32zP zR Rz

r

R

P

Boussinesq Point Load

202z

Prz

z R

P

Stress on this plane, z

PB z L z

Rectangular Footing (2:1)

0

0.5

1

1.5

2

2.5

3

3.5

4

0 0.2 0.4 0.6 0.8 1I

z /

B

1

1 1I

z zB B

z oq I

Boussinesq Line Load

3

4

2z

P zR

z

r

R

P

Stress on this plane, oPqB

Stress on this plane, z

PB z

P is a force per unit length

Strip Footing (2:1)

0

0.5

1

1.5

2

2.5

3

3.5

4

0 0.2 0.4 0.6 0.8 1I

z /

B

1

1I

zB

z oq I

Load qo per unit area

;x ym nz z

I = 1

2 22 2 22

1 1 1 tan2 1 11 1

mn mnm nm m nn

I z oq

Mistake in the textbook

b a

Rigid Foundations

Flexible Foundations