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
Pile Diameters 3 to 48 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. Pile Lengths 15 to over 100ft Shear area is increased to the cylindrical area between the helical plates.
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
Excavator Skidsteer Boom truck, Drill Rig Custom frames Installation Equipment
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
Pipe racks Substation structures Emergency response Applications
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
Examples of High Capacity Piles Pile Type Axial Compressive Capacity (kips) Working Design Test Helical Pile Configuration 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
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