“Looking Back and Looking Ahead” · “Looking Back and Looking Ahead” How Iowa State Shaped...

“Looking Back and Looking Ahead”

How Iowa State Shaped a Career in Geotechnical Engineering

Alan LuteneggerP.E. PhD. F. ASCEProfessor of CEE

University of Massachusetts

My Personal-Professional Journey

1975 BS. Construction Engineering

1977 M.S. Geotechnical Engineering

1979 PhD. Geotechnical Engineering

1980 PostDoc Iowa State

1982 NAS Bulgaria

1984-1989 Associate Prof. Clarkson College

1989 – Professor Univ. of Massachusetts

Coordinator – GT Program -10 Years

Department Head - 6 Years

1. Understand the Fundamentals of Soil Mechanics & Soil Behavior

You Don’t Know What Path Your Career Will Take So Learn Basics

Composition

Shear Strength

Consolidation

Modification/Stabilization

2. Understand How Composition May Influence Soil Behavior and

That Soils Are Inherently Complex

Time (min.)

0 500 1000 1500 2000 2500 3000

Sp

ecim

en H

eig

ht

(in

.)

0.750

0.760

0.770

0.780

0.790

0.800

0.810

0.820

0.830

0.840

0.850

Mt. Union, Ia. Paleosol

Initial Dry Unit Weight (Mg/m3)

1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0

Sw

ell

Pre

ssu

re (

kP

a)

0

200

400

600

800

Buckshot Clay

Heiden Clay

34/218 YSP

NLYSP

Vertical Stress (ksf)

0.1 1 10

Se

cim

en H

eig

ht

(in

.)

0.600

0.620

0.640

0.660

0.680

0.700

0.720

0.740

0.760

S.E. Iowa LoessW = 12.7%

Dry Density = 87.2 lbs/ft3

3. Don’t Be Afraid to Be an Expert Witness

Especially if You Think You Can Help Someone

“The Day the House Fell Again?”

4. Understand Surficial Geology

The Best Way to Understand Surficial Geology is to Go Look at it!

5. Be a Life-Long Student and Take Advantage of Opportunities to Learn

Something New

You Won’t Learn Everything at University and You Simply Can’t Learn Everything

Anyway

6. Understand and Appreciate the Classic GT Literature

A Lot of Really Good Fundamental Work Has Already Been Done – But Isn’t in

Textbooks

1960 – 3 GT Journals2017 – 27 GT Journals

Often Simple is Best

Free Swell Test

Linear Shrinkage Test

Fall Cone Test

SPT-Torque Test

Free Swell Test 1956

Lime Content (%)

0 2 4 6 8 10 12 14 16

Fre

e S

we

ll In

dex (

%)

0

200

400

600

800

1000

1200

1400

SWy-2

API-26

34 YSP

TS

Linear Shrinkage Test 1958

Fall Cone1915 & 1951

Age (Hours)

0.1 1 10 100 1000 10000

Undra

ined S

hear

Str

ength

(kP

a)

0

2

4

6

8

10

12

14

16

18

20

Texas Sodium

RS-101

RS-102

Theile RC-32

Gooselake

SHCa-1

SAz-1

Age (Hours)

0.1 1 10 100 1000 10000

Th

ixo

tro

pic

Str

en

gth

Ra

tio

1

2

3

4

5

6

7

8

Texas Sodium

RS-101

RS-102

Theile RC-32

Gooselake

SCHa-1

SAz-1

Water Content (%)

20 40 60 80 100 120 140 160 180 200

Und

rain

ed S

he

ar

Str

en

gth

(kP

a)

1

10

100

1000

10000

0% Lime

2% Lime

6% Lime

SPT-Torque Test - 1988

N60 (blows/0.3m)

0 10 20 30 40 50 60

f s (

kP

a)

0

50

100

150

200

250

300

fs = 4.1 N60

Std-1

Std-3 (donut)

Std-4 (Safety)

Std-2

What’s Going on Now and What’s In the Near The Future?

Finishing Academic Work at UMass - 2018

Completing Several Projects

Helicals & Jacked Piles in Clay

Adhesion of Drilled Piles in

Clay

Changes in Clay Behavior from Bored

Piles

(Meyerhof & Murdock 1949)

Grout Migration

Distance from Grout/Soil Interface (in.)

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0

Wate

r C

onte

nt (%

)

22

23

24

25

26

27

BBC 0 psi

BBC 5 psi

Distance from Grout/Soil Interface (in.)

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0

Po

cke

t P

en

etr

om

ete

r (t

sf)

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

BBC 0 psi

BBC 5 psi

Liquidity Index

-0.6 -0.4 -0.2 0.0 0.2 0.4

Cha

ng

e in

Wate

r C

on

ten

t at

So

il/G

rout

Inte

rfa

ce

(%

)

-4

-2

0

2

4

6

8

W/C = 0.6

Tomlinson (1957)

Parsons & Peck (1957)Chicago Clay S

t = 1.8

Water Content (%)

24 25 26 27 28

Undra

ined S

hear

Str

ength

(psf)

1000

Undisturbed

Remolded

104 Days

410 Days

Orrje & Broms (1967)Brunnsbo S

t = 30

Water Content (%)

70 72 74 76 78 80 82 84

Undra

ined S

hear

Str

ength

(ts

f)

0.001

0.01

0.1

1

Undisturbed

Remolded

9 Months

Flatte - 1972

Pipe Piles in Clay

HHF Extraction Piles Oct., 2016

Water Content (%)

15 20 25 30 35 40 45 50 55

De

pth

(ft

.)

0

1

2

3

4

5

6

7

8

9

10

BH1

2875C-1

2875C-2

BH-2

4.5 Open

6 Open

H-Piles in ClayHHF Extracted Piles 2016

Water Content (%)

20 25 30 35 40 45 50 55

Depth

(ft.)

0

1

2

3

4

5

6

7

8

W8 At Pile Surface

W8 At Failure Surface

BH1

BH-2

Soils and Geotechnology in Construction

June 2017

In Situ Testing Techniques in Geotechnical Engineering

December 2017

Design, Installation and Applications of Helical Piles and Anchors

June 2018

Lessons I was Taught(but didn’t know it at the time)

1. Understand the Fundamentals of Soil Mechanics

2. Understand How Soil Composition May Influence Soil Behavior and That Soils are Inherently Complex

3. Understand Surficial Geology

4. Don’t Be Afraid to be an Expert Witness

5. Be a Life-Long Student & Take Advantage of Opportunities to Learn Something New

6. Understand & Appreciate the Literature

Remember

It’s The Journey!