1

Understanding of Foundations:

Success of a Civil Engineer….!

SRIDHAR VALLURI

14TH OCT 2017

IIT Gandhinagar

Introduction of Keller

2

3

2002

Acquired

McKinney

(US)

2006

Acquired Piling

Contractors

(Australia)

2007

Acquired HJ

Foundation

(US)

2009

Acquired

Resource Piling

(Singapore)

2010

Acquired

Waterway

Constructions

(Australia)

2013

Acquired

Geo-Foundations

(Canada)

Acquired

Keller Canada

(Canada)

Acquired

Franki Africa

(South Africa)

NOW

c.9,000 employees

Offices in

>40 countries

Revenue £1.6bn

2001

Acquired

Suncoast

(US)

1994

Acquired

Case (US)

IPO on London

Stock Exchange

1990

Management

buyout from GKN

plc

1984

Acquired

Hayward Baker

(US)

1974

Acquired Johann

Keller

in Germany

marking

international

expansion

1960’s

Expansion into

a UK national piling

& ground

improvement

company

1958

Est. 1958 Ground test

services

Only larger and most recent acquisitions shown

Keller Group - History of Keller

From 1860

4

APAC EMEA North America

Asia-Pacific region Europe, Middle East,

Africa & Latin America USA & Canada

40 Countries of Operations 10,000 Employees ₹ 16,000 Cr. Turnover

51% 20% 10% 10% 9%

PILING GROUND IMPROVEMENT SPECIALITY

GROUTING

POST

TENSION

CONCRETE

ANCHORS

NAIL,

MINIPILES

ACTIVITIES

3

5

APAC Keller Foundations S.E.A. Pte Ltd., Singapore

Resource Piling Pte. Ltd., Singapore/Malaysia

Keller Ground Engineering India Pvt Ltd.

Keller (M) Sdn. Bhd., Malaysia

Ansah Asia Sdn. Bhd., Malaysia

Keller Foundations Vietnam Co., Ltd

Keller Foundations S.E.A. Pte Ltd., Indonesia

PT. Frankipile Indonesia

Keller Ground Engineering Pty Ltd, Australia

Keller Foundations, Australia

Frankipile Australia Pty Ltd

Vibropile (Australia) Pty Ltd

Piling Contractors Pty Ltd, Australia

Waterway Constructions Pty Ltd, Australia

Austral Construction Pty Ltd

Keller New Zealand

INDIA

NEW ZEALAND

FOUNDATIONS

Asia-Pacific

6

Presence in India

Completed Projects

Ongoing Projects

Keller Offices

4

7

• Vibro Compaction

• Wet Vibro Stone Columns

• Dry Vibro Stone Columns (Vibrocat & Alpha S)

• Vibro Sand Columns

Ground Improvement

• Bored Piles

• Contiguous Bored Piles

• Diaphragm Wall

• Sheet Piles

Heavy Foundation

• Ground Anchors

• Micro Piles

• Compaction Grouting

• Permeation Grouting

Small Diameter

• Foundation Interface (Raft & Pile Caps)

• Tank Sand Pads

• Earth works

• Approach Road Works

Foundation

Civil Works

Foundation Services

Product Portfolio

8

Client Portfolio

International

Indian Government Owners

Local Big Private Owners

Local Big Main Contractors

Local Entrepreneurs

Contributed in building 3 LNG Terminals, 3 Large Refineries, 200 Storage

Tanks, 10,000 MW Power Plants, 6 Sea Ports, 20 Metro Stations, 2 Air Ports

and Real Estate developments

5

What is Soil Structure Interaction……?

Understanding of Foundations:

Success of a Civil Engineer….!

10

Understanding of Poor Soils

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11

Poor Soils

Loose sands

• Usually reclamation fills (recent fills)

• CPT qc: < 6 MPa, Friction ratio < 1%

• Relative density: 30 to 40%

• Typical depths: 10 to 30m

Challenges:

Bearing Capacity

Settlement

Liquefaction

12

Poor Soils

Loose silty sands

• Alluvial deposits

• E.g. river delta

• Silt & clay content < 20%

Challenges:

Bearing Capacity

Settlement

Liquefaction

7

13

Poor Soils

Soft and “ultra-soft” silts

• Usually sedimentation deposits

• cu = 5 to 20 kPa

Challenges:

Bearing Capacity

Settlement

14

Poor Soils

Soft and very soft marine clays

• Found in coastal areas

• SPT N = 1 to 2 blows

• Permeability, k= 10-8 to 10-9 m/sec

• Plasticity Index > 50%

Challenges:

Bearing Capacity

Settlement

8

15

Poor Soils

Organic soils, Peats

• Naturally formed, of decayed vegetation

• Cause for concern: Organic content > 10%

• Engineering concern: stability of foundations/structures

Municipal Wastes, Landfills

• Manmade

• Locations: metropolitan cities, dumping yards Challenges:

Bearing Capacity

Settlement

Overall stability

Liquefaction

16

What are the troubles with poor soils….?

• Low Bearing Capacity of foundation soils

• Settlement due to weak layers

• Slope Stability of high embankments

• Liquefaction during earthquakes

9

Understanding of soil structure interaction…..

Understanding of soil structure interaction…..

10

• Understanding of behaviour of foundations (15 min)

• Engineer’s Choice of Foundations (15 min)

• Ground Improvement Techniques ( 40min)

Today’s take home…

Behaviour of foundations…

11

Bearing Capacity Failures

Settlement Failures (Illustration 1)

12

Settlement Failures (Illustration 2)

Slope Stability (static or seismic)

13

Liquefaction

• Liquefaction is a phenomenon in which the strength and stiffness of a soil is

reduced due to earthquake shaking or due to other rapid loading.

• Liquefaction occurs in saturated soils

• Soil particles lose contact with each other

• Earthquake shaking cause increase in water pressure to the extent where the

soil particles readily move (float) with respect to each other

What is Liquefaction….?

14

How to Address Geotechnical Challenges…..?

Options for Intelligent Engineer:

• Savings in construction cost

• Fast completion (savings in time)

• Savings in materials & less carbon footprint

No Worries General Solution

What does this mean to a civil engineer…..?

15

Engineer’s Choice of Foundations…

Ground Engineering & Foundation Systems

Foundation Engineering

Shallow Foundations

Foundations on Virgin Soils (Un-Improved Soils)

Good Bearing Strata

Less Load Intensity

Settlements within Tolerable Limits

Foundations on Weak Soils (Improved Soils)

Ground Improvement Techniques

Deep Foundations

Bored Cast In-Situ Pile Foundations

Friction Piles

End Bearing Piles

Friction & End Bearing Piles

Driven Pile Foundations

Steel Piles

Pre Cast Piles

Driven Cast In-Situ Piles

16

Part A: Ground Improvement Techniques

Ground Improvement

Open Foundations

Deep Foundations

Ground improvement is defined as the controlled alteration of the state, nature or

mass behavior of ground materials in order to achieve an intended satisfactory

response to existing or projected environmental and engineering actions.

Source: CIRIA Publication

What is Ground Improvement…?

17

33

Types of Ground Improvement

Densification

• Principle: Reduction of voids between particles (coarse grained soils)

• Example: Vibro Compaction, Blast Densification, Compaction Grouting

Reinforcement

• Principle: Introduction of reinforcing element to carry the loads

• Example: Vibro stone columns, geogrids

34

Types of Ground Improvement

Consolidation

• Principle: Shortening of Drainage Paths + Increase of Effective Stress

• Example: PVD + Surcharge; Vacuum Consolidation

Chemical Modification

• Principle: Introduction of Chemical Binder that causes with time

• Example: Injection Grouting, Deep Mixing, Jet Grouting

18

Ground Improvement Methods

Ground Improvement

Densification

Vibro Compaction

Dynamic Compaction

Blast Densification

Compaction Grouting

Consolidation

PVD + Surcharge

Vacuum Consolidation

Vibro Replacement

Chemical Modification

Deep Soil Mixing

Jet Grouting

Permeation Grouting

Reinforcement

Vibro Replacement

Geosynthetic Reinforcement

Rigid Inclusions

Compaction Grouting

Others

Removal & Replacement

Thermal

Electrical

Deep Vibro Techniques

19

h Before

After

Vibro Compaction (VC)

Vibro Replacement (VR)

Concept of Deep Vibro Techniques

Process of Vibro Compaction

20

Wet Top Feed Method

Dry Bottom Feed Method

Process of Vibro Stone Columns

Process of Vibro Compaction

21

Process of Vibro Stone Columns

Mechanism of working of stone columns

22

Unit cell concept

• Key index for effectiveness of improvement

• Area Replacement Ratio (ARR) = Area of column, Ac/Area of grid, A

For 2.2m x 2.2m grid (Area of grid, A = 4.84 m2),

• Area of 1.0m diameter column, Ac = 0.785 m2 ARR ~ 16%

Area Replacement Ratio (ARR)

23

• Improved ground is considered as a composite ground with

composite/improved parameters.

Weak Ground

•su = 10 – 20 kPa

•Φ = 0o

•Ds = 1 – 4 MPa

“Composite parameters”

c’ = 5 – 10 kPa

Φ’ = 20o – 30o

Ds = 3 – 10 MPa

Stone Columns

•Φ = 42o – 44o

•Ds = 100 – 150 MPa

Concept of soil model

Design Methodology (Priebe’s)

24

47

Settlement

control

Increased

Stability/ bearing

capacity

Accelerated

consolidation

Liquefaction

mitigation

Key mechanism Reinforcement Reinforcement Shortened

drainage path

Reinforcement +

shortened

drainage path

Key properties Stiffness,

diameter, length,

area ratio

Stiffness,

diameter, area

ratio

Diameter, length,

area ratio, column

material

Stiffness,

diameter, area

ratio, column

material

Controls Construction amps, “termination” amps, column length, column continuity,

stone consumption, column numbering, stone grading curve

Other

considerations

Rate of loading Drainage platform

quality

Lateral extent of

treatment zone

How do vibro stone column works?

48

Choice of Technique

• Suitability of technique

• Is the soil and the technique fundamentally compatible?

• Technical compliance

• Does the technique provide the strength, stiffness or permeability required?

• Availability of material

• Is the material (stone, cement, geotextile) readily available?

• Cost

• Is it within budget?

• Protection of the environment

• Does the technique reduce or avoid pollution? Is the technique resource efficient?

25

Applications

Embankments Buildings

Reinforced

soil walls

Airport Runways

LNG Tanks

Part A: Ground Improvement Techniques: Case Studies

A. Improving Bearing Capacity` : Case Study 1

B. Settlement Control : Case Study 2

C. Liquefaction Mitigation : Case Study 3

D. Liquefaction, BC & Settlements : Case Study 4

E. Industrial structure : Case Stuey 5

26

A: Improvement of Bearing Capacity

• Project : Tank Farms at HPCL Terminal

Ennore, Chennai

• Structure : Tanks (max. 32m dia & 15m height)

18 - Floating roof storage tank

4 - Fixed roof storage tank

3 - Fire water tanks

• Bearing Capacity : 20T/m2

Challenges:

Bearing Capacity

Settlement

Technical Solution

• Type of GI : Wet Vibro Stone Columns

• Area Replacement : 25%

• Interface : Sand Pad

27

Performance

• Improved BC : 20T/m2

• Settlement : < 300mm (during Hydro test with full load)

0

2

4

6

8

10

12

14Tank 1

Tank 2

Tank 3

Water Fill

Hei

ght

(m)

-300

-250

-200

-150

-100

-50

0

18-A

ug-1

1

23-A

ug-1

1

28-A

ug-1

1

2-Se

p-11

7-Se

p-11

12-S

ep-1

1

17-S

ep-1

1

22-S

ep-1

1

27-S

ep-1

1

2-O

ct-1

1

7-O

ct-1

1

12-O

ct-1

1

17-O

ct-1

1

22-O

ct-1

1

27-O

ct-1

1

1-N

ov-1

1

6-N

ov-1

1

11-N

ov-1

1

16-N

ov-1

1

21-N

ov-1

1

26-N

ov-1

1

Sett

lem

ent

[mm

]

Days

Completed Structure

- In India, Over 200 Tank Foundations are built successfully on Ground Improvement at

various Tank Farms (HPCL, IOCL, MRPL, SHELL LNG, etc.)

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B: Liquefaction Mitigation

• Project : Construction of Indira Sagar

Polavaram Dam at

Andhra Pradesh

• Structure : Multipurpose Dam across

the River Godavari near

Polavaram village

• Relative density : < 60 %

• Seismic Zone : Zone III

Challenges:

Liquefaction

Bearing Capacity

Dam layout & Plan view

Proposed ECRF dam location

29

Typical Cross Section of ECRF Dam

15m

315.75m

EGL +2.15m

45m

Soil Profile across the dam

30

Technical Solution

Vibro Compaction

31

Vibro Compaction Works

Performance

32

Challenges:

Settlement

Bearing Capacity

• Project : Urban Tree Residential

Project “INFINITY” Chennai

• Structure : Stilt + 4 floors with 198 flats in

over site area of 2.5 acres

• Settlement : < 100mm as per IS 1904-1986

C: Settlement Control

Vibro Stone Columns

33

Technical Solution

• Type of GI : Dry Vibro Stone Columns

• Area Replacement : 20%

• Interface : Raft

Performance

• BC of improved ground : > 15T/m²

• Long-term settlement : < 100mm (monitoring for past 1 year)

0

10

20

30

40

50

60

70

80

90

100

0 2 4 6 8 10 12 14 16 18 20

Se

ttle

me

nt,

m

m

Load in T/m²

Routine Single Column Load Test

0

10

20

30

40

50

60

70

80

90

100

0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80 84 88 92 96 100 104 108

Sup

er str

uctu

re l

oad

(kP

a)

Settlement Results - All Pours

Load vs Time Curve

0

10

20

30

40

50

60

70

80

0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80 84 88 92 96 100 104 108

Sett

lem

ent 'm

m'

Time in Weeks

Point: P1S1 Point: P1S2

Point: P3S2 Point: P4S1

Point: P4S3 Point: P6S3

Predicted settlement

Settlement vs Time Curve

34

Completed Structure

- Dry Vibro Stone Columns as Optimal Foundation Solution alternative to Piling

- Delivered Foundation works in 6-weeks instead of 6-months for Piling solution

• Project : Umang Realtech Pvt Ltd,

‘SUMMER PALM’, Haryana

• Structure : Stilt + 14 floors over site

area of 12 acres

• Bearing capacity : 15 T/m2

• Settlement : < 100mm as per IS 1904-

1986

• Seismic Zone : Zone IV, 0.24 g

D: All Applications (SBC, Settlement & Earthquake)

Challenges:

Bearing Capacity

Settlement

Liquefaction

35

Vibro Stone Columns

Technical Solution

• Type of GI : Dry Vibro Stone Columns

• Area Replacement : 20%

36

0

5

10

15

20

25

30

0 50 100 150 200 250 300

Se

ttle

me

nt

in 'm

m'

Load in 'Tons'

Performance

Load Intensity Settlement @

Design Load

Net

Settlement

All. Settlement as per

IS 15284 (Part 1): 2003

150 kPa 10.2 mm 6.7 mm 30 mm

Completed Structure

37

• Project :

• Structure :

• Bearing capacity : 15 T/m2

• Settlement : < 100mm as per IS 1904-1986

• Seismic Zone : Zone IV, 0.24 g

E: Industrial Structure (SBC, Settlement & Earthquake)

Challenges:

Bearing Capacity

Settlement

Liquefaction

Vibro Stone Columns

38

Technical Solution

• Type of GI : Dry Vibro Stone Columns

• Area Replacement : 20%

Performance

39

Deep Soil Mixing

• Strengthens / stiffens the in-situ soil

• Results in relatively rigid foundation system

Concept of Deep Soil Mixing

40

Mechanical Cutting

Mechanical Mixing

Full Completed DSM Column

Process of Deep Soil Mixing

Process of Deep Soil Mixing

41

Applications

• Improving Bearing Capacity

• Settlement Control

• Excavation Support

D-Walls

Bored Pile Walls

DSM Walls +

Steel bar

DSM Block Walls

Bending Bending Gravity

Earth Retention – Physics

42

• Project : Construction of Music Academy, Poland

• Structure : Music Academy, Poznan, Poland

Excavation Support – Bending Rigidity

6m

Fill

Sand

Stiff Clay

DSM with I

sections

Excavation Support System: Strut-free Concept

Challenges:

Overall Stability of Excavation

Technical Solution

• Type of GI : Compound DSM (DSM + I-Sections)

• Depth of Treatment : 10m

IPE 300

80 cm DSM

600

43

Excavation Support – Bending Rigidity

Excavation Support – Bending Rigidity

44

• Project : Fraser Biz Park, Kuala Lumpur

• Structure : Commercial Complex (2B+G+3F)

• Excavation Depth : 7m (perimeter ~ 700m)

Excavation Support – Gravity Wall

Challenges:

Overall Stability of Excavation

Technical Solution

• Type of GI : DSM Gravity Wall

• Depth of Treatment : 8m

• Designed UCS value : 1MPa

Plan Section

45

Excavation Support – Gravity Wall

• Achieved UCS value ~ 1-3MPa

• Observed Movement ~ 20mm

Grouting Techniques

46

• “Grouting in ground engineering can be defined as controlled injection of

material, usually in a temporary fluid phase, into soil or rock, where it

stiffens to improve the physical characteristics of the ground for

geotechnical engineering applications”

• “Grouting techniques started from practice, not from theory”

Concept of Grouting

Grouting Techniques

Perm. Grouting

Penetrating the voidswith grout

TAM

Bohrloch-zementierung

Penetrating the voidswith grout

TAM

Bohrloch-zementierungBohrloch-zementierung

Erodingandmixingthesoil with

grout

Hydrostatischer

Druck

Düsgestänge

Erodingandmixingthesoil with

grout

Hydrostatischer

Druck

Düsgestänge

Rock Grouting:

Filling offractured rock

with grout

TAM

Bohrloch-zementierung

:

with grout

TAM

Bohrloch-zementierungBohrloch-zementierung

Jet GroutingComp Grouting:

Displacementof soil

with grout

:

with grout

47

Applications

• Seepage Control

• Soil Arching

• Settlement Control

• Impermeable deep cut-off

• Project : Construction of Low Dam IV for Hydro Power Plant, WB

• Structure : Teesta Low Dam IV

Seepage Control – Permeation Grouting

Challenges:

Seepage Control

(permeability requirement of 10-6 m/sec)

48

• Type of GI : Permeation Grouting

• Depth of Treatment : 22m

Technical Solution

Performance

49

• Project : DMRC Saket, Delhi

• Structure : Twin Shaft NATM Tunnel for Metro Rail

• Soil Arching : To support 8m dia NATM Construction

Soil Arching – Compaction Grouting

Challenges:

Soil Arching

(Settlement Control)

Soil Arching – Compaction Grouting

50

• Type of GI : Compaction Grouting

• Mix ratio : 1:3 Cement Mortar

• Depth of Treatment : 8m

Technical Solution

Performance

• Post SPT N value ~ 20 to 30 (above requirement line)

• As SPT value increases lateral confinement also increased to ensure

required Soil Arching

51

• Structure : Cut-off wall for Cofferdam

Impermeable deep cut-off – Jet Grouting

102

What is Jet Grouting (Soilcrete) ?

• Jet Grouting is a process consisting of

the disaggregation and partial

displacement of soil and its mixing by a

cementing agent

• The disaggregation is achieved by a

high energy jet of a fluid which can be

the cementing agent itself or water

• Jet grouting can be executed using

o T-System (0.8m to 1.2m dia.)

o D-System (1.5m to 2.2m dia.)

Grouting:

Penetrating

the voids

with grout

TAM

Bohrloch-zementierung

Grouting:

Penetrating

the voids

with grout

TAM

Bohrloch-zementierungBohrloch-zementierung

SoilcreteTM:

Eroding and

mixing the

soil with

grout

Hydrostatischer

Druck

Düsgestänge

SoilcreteTM:

Eroding and

mixing the

soil with

grout

Hydrostatischer

Druck

Düsgestänge

SoilfracTM:

Fracturing of

the soil,

with grout

TAM

Bohrloch-zementierung

SoilfracTM:

Fracturing of

the soil,

with grout

TAM

Bohrloch-zementierungBohrloch-zementierung

52

103

Process of Jet Grouting (Soilcrete)

104

Jet Grouting (Soilcrete) Systems

T-System

Triple fluid system erodes the soil with an

air shrouded water jet of min. 100 m/sec

exit velocity. Grout is injected

simultaneously through an additional

nozzle located below the water jet nozzle.

D-System

Double Direct Process – operates with a

grout jet of min. 100m/sec exit velocity

for simultaneous cutting and jetting of

the soil.

53

105

Proposed Scheme

Deviated Jet Grouted Column (Typ) – No Gap between the columns.

Large Diameter

107

Typical Drilling Operation

54

108

Drill

Bit

Reaming

Tool

Monitor

Double

Jet

Grout

Rod

Jet Grouting Plant & Equipment

109

Typical Jet Grouting Pump

55

110

Typical Site Set Up

111

QA - Site Validation Testing

56

112

Project Photographs

Compaction & Jjet Grouting for Faraday Launching Shaft

• Ground Improvement Techniques can be used to provide Optimal

Solutions

• Design & Build expertise will ensure savings in Cost & Time

• Execution of Specialized Foundation Techniques requires state-of-the-

art experience with Operational Excellence and Best Practices

• International standard of practices using latest equipment ensures the

success of a project

• Safety goal of zero accidents is possible with dedicated safety systems

and motivated leadership

Conclusions

57

Keller’s Ideal Worker (Kelwin)

All the best & Good Luck…..!

58

Thank you for your kind attention…….!

What Keller do…….?

BCIS Piles

Soil Anchors

DSM

Micro Piles

Grouting

Tank Foundations Stone Columns

Driven Piles

117