High Capacity Helical Piles Limited Access Projects

Tel 403 228-1767

Canada, USA, Russia

Brendan ODonoghue

519 830-6113

Presentation Summary 1. Helical piles – Background on large diameter shafts and helices 2. Where are helical piles used? 3. What are helical piles and how do they work? 4. When should I consider using helical piles? 5. Applications – market sector examples 6. Limited Access Case 1 – Big Jerry in Indiana Case 2 – Water, pipes and Texas gators 7. Connections - Pile cap options, corrosion, load testing 8. Cost range per foundation 9. Limitations 10. Key Advantages Questions and Answers

Inventor – A. Mitchell and early lithograph of open sea installation.

1. Helical Piles – Large Diameter shafts and helices Invented in the 1830’s - lighthouse foundations, moorings and piers

Today - Cyntech designs helical piles to carry loads of 650 kips and more.

2. Where are helical piles used? USA – Major remaining wetland areas

Red Dots – critical areas Source: US Fish and Wildlife Mapper

Canada – percent coverage of wetlands

3. What are helical piles? • Hollow steel pipe shaft

with one or more helical plates welded to the pipe shaft.

• Rotated slowly into a good layer of high load bearing soil.

• Shear area is increased

to the cylindrical area between the helical plates.

Pile Diameters 3” to 48”

Pile Lengths 15 to over 100ft

How do helical piles work?

Common Pile Shaft & Helix Diameters

Innovations – High Capacity Loads

Load Range Table - 4 to 870 kips Ultimate Compression Capacity in Kips

4. When should I consider using helical piles?

• Soft soil sites • High water table • Little or No vibration tolerable • Little or No noise tolerable • Limited head room situations • Short construction schedule – speed required • Contaminated soil sites - soil disposal costs high • Lower carbon cost projects - Removable and reusable • Remote locations, modular system – easily transported • Loads up to and over 650 kips = 290 tons = 2,890 kN

Installation Equipment • Excavator • Skidsteer • Boom truck, Drill Rig • Custom frames

1. High Capacity (650 kips +)

Helical Pile Foundations

2. Pipeline Anchors for Buoyancy Control

(tension anchors, square shaft, smaller loads)

3. Tank Repair Services

32 years of expertise Clients globally

5. Applications – Market Sectors • Buildings – permanent and temporary • Infrastructure - bridges, piers, walkways, street lights

and sign bases • Towers – Transmission and Communication towers • Retaining walls, slope stabilization, deep foundations • Power Generation, Substations and Distribution lines • Pipelines - pumping stations, buoyancy control • Skid mounted equipment

Applications • Pipe racks • Substation structures • Emergency response

6. Limited Access for High Capacity piles

Requires innovative approaches to pile design and the equipment used.

Innovations in Rotary Drive Head Sizes

Case 1 – Big Jerry in IN - 300,000 ft*lbs rotary drive head

Longer piles rotated deeper into heavier soils

Pile Type

Axial Compressive Capacity (kips)

Helical Pile Configuration

Working Design Test

A 25 51 75 5-9/19" OD x 0.275"wt shaft, 21' long w/ (2) 14" helices

B 75 151 150 8-5/8" OD x 0.322" wt shaft, 21' long w/ (2) 24" helices

C 100 200 300 8-5/8" OD x 0.322" wt shaft, 23' long w/ (3) 24" helices

D 140 284 420 12-3/4" OD x 0.375" wt shaft, 24' long w/ (3) 28" helices

E 220 478 660 12-3/4" OD x 0.500" wt shaft, 82' long w/ (3) 26" helices

Examples of High Capacity Piles

Innovations - Limited Access Installs - Custom Frames

Frame base lifted into place

Frame Assembly

Case 2 – Water, pipes and Texas Gators

Pile Clusters – Helical Piles, rebar and concrete

Limited Access Installs – Above and Below

Safety must ALWAYS be priority # 1

7. Connections - Pile Caps – Singles & Pile Clusters

Larger pile caps for heavier loads

Corrosion – Example Life Expectancy Table

• Increase the pipe wall thickness - least expensive • Sacrificial anodes • Coatings – galvanizing and epoxy – most expensive

Load Test Beams – High Capacity Piles

8. Cost Range per Foundation Design depends on;

• Soil strata conditions • Loads to be carried • Location Engineered, modular foundations • Material - Design and fabrication Cost Range $ 200 to $ 1,000 to $ 7,000 / pile • Installation Cost Range $ 200 to $ 2,000 / pile

General Rule - Larger diameter, longer piles cost more

9. Limitations • Need soil data and loads of the structure to design accurately • Not applicable in shallow rock or areas with a lot of embedded cobbles

10. Key Advantages of Helical Piles • Safety – fewer people on site for a shorter period of time • Standard construction equipment used to install • Verifiable load bearing capacity during installation • Speed – minutes / pile section vs. hours • Immediately ready to be built on after installation • Modular design allows for quick adaptation in the field • Installs equally well in all seasons

• Cost competitive – lower total installed foundation cost

Thank you

Calgary, Alberta Houston, Texas (403) 228-1767 (936) 894-2181

Brendan ODonoghue bodonoghue@cyntech.com

(519) 830-6113