L2

L0

0.8

0.6

0.4

0.2

00 1 2 3 4 5

Rough Surface

H B

q

pe =

0.75 ATH/B = ∞

H/B

(^) From Poulos and Davis (1974), Figure 5.2(^^) From Poulos and Davis (1974), Figure 5.32

Undrained Elastic Settlement Computation for Uniform Loading on Elastic Layer

Adapted from D`Appolonia` et al. (1971), Foot & Ladd (1981)

Note: σ'vm = σ'p & Cu = Su

Intial Settlement (p1/2)

qBEu Ip

Ip

Strip Loading(^)

Circular Loading(^^)

For Saturated SoilWith ν=0.50

2000

1000800

600

400

200

100

80

60

40

200.2 0.4 0.6 0.8

At τh/cu = 1/3 At τh/cu = 2/3

1000 500

400

300

200

100

0

800

600

400

200

01 2 4 6 8 10 1 2 4 6 8 10

EuCu

EuCu

EuCu

OCR = σ` vm vc/σ` OCR = σ` vm vc/σ`

Applied Shear Stress Ratio τh/cu(1/Factor of Safety)

Eu = 3τh/γ

Cu = (τh)max

τh = Applied Horizontal Shear Stress

γ = Shear Strain

(a) Normalized Secant Modulus vs. Stress Level for Normally Consolidated Soils

(b) Normalized Secant Modulus vs. Overconsolidation Ratio

1

1

2

2

2

3

3

3

4

4

4

5

5

5

6

6

6

7

2

No. Decription Cu/σv̀cPortsmouthSensitive CL Clay

Boston CL ClayLL = 41, Ip = 22

S1 > 10, LL = 35, Ip = 150.20

0.20

3 Bangkok CH ClayLL = 65, Ip = 41 0.27

4Mane OrganicCH - CH ClayLL = 65, Ip = 38

0.285

5 AGS CH ClayLL = 71, Ip = 40 0.255

6AtchafalayaCH ClayLL = 95, Ip = 75

0.24

7 Taylor River PeatWN = 500 %

From Ladd & Edgers (1972)

MIT for Dames & MooreMIT for Haley & Aldrich

0.46

1.0

0.8

0.6

0.4

0.2

S R = Ρ e

/Ρ l

H/B = 0.5

Applied Stress Ratio, q/qu

.25

f = .75

.5

0

00 0.2 0.4 0.6 0.8 1.0

1.0

0.8

0.6

0.4

0.2

S R = Ρ e

/Ρ l

H/B = 1.0

Applied Stress Ratio, q/qu

.25

f = .75

.5

0

00 0.2 0.4 0.6 0.8 1.0

1.0

0.8

0.6

0.4

0.2

S R = Ρ e

/Ρ l

H/B = 1.5

Applied Stress Ratio, q/qu

Relationship between settlement ratio and applied stress ratiofor strip foundation on homogenous isotropic elastic layer.

.25

-.25

f = .75

.5

0

00 0.2 0.4 0.6 0.8 1.0

High IP

0.8

0.6

0.4

0.2

-0.2

0

1 2 4 6 8 10

Low IP

Note : All Data for Unloading From σ'vm

Note : cu = 0.5(σ1 - σ2)f from CKoU Triaxial or Plane Strain Tests, Ko from Brooker and Ireland (1965) for ME. Organic Clay.

OCR = σ'vm vc/σ'

(1 -

K o) vo

2cu

/σ'

f =

Soil Source

MITSkempton &

Sowa(^)

MIT

MITDames &Moore(^^)

Ip(%)

21

24

30 (bulk)

38

41 AIT & MIT

40

Boston Blue Clay

Weald Clay

Varved Clay

Me Organic Clay

Bangkok Clay

AGS CH Clay

(^) 1963 (^^) 1975

Intial Settlement (p 2/2)