high capacity helical piles limited access projects · 2014-01-13 · high capacity helical piles...
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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
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
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
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
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
6. Limited Access for High Capacity piles
Requires innovative approaches to pile design and the equipment used.
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
Corrosion – Example Life Expectancy Table
• Increase the pipe wall thickness - least expensive • Sacrificial anodes • Coatings – galvanizing and epoxy – most expensive
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 [email protected]
(519) 830-6113