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Slideshow on the use of Pile Joint Product from SPE-USAwww.canadianpile.com
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John C. Ryan, Ph.D., P.E.
Ryan Structural Engineers
Mt. Pleasant, SC
Design, Testing, and Use of an Innovative Prestress Concrete Pile Joint
• Handling equipment relatively large• Special permit loads• Escort requirements
Long Pile Handling
Driving Long Piles
Pile Installation
-2 Cranes-Power Pak /Air Compressor-Hammer and Leads-5 or 6-man crew
-Difficult Handling-Fuel for 3-Large Engines-Maintenance of 3 Machines
& Hammer
Up to 65 ft-long pile segments:
(4
Fork-truck and spreaderfor unloading & staging
Spliced-Pile Alternative
Spliced-Pile Alternative
110-ft Spliced Pre-stress Pile:
-Purpose-built driving rig-2-man crew
-Reduced Fuel Cost-Reduced Transportation Cost-Reduced Maintenance-High Production Rate-Increased Job Site Safety
Emeca Pile Joint
Male Stud
Female Socket
Locking pin hole
Cover Plate
Reinforcing
Emeca Pile Joint
Automated Robotic Fabrication
Tension
Limit States 3. & 7.: Weld rupture at reinforcing/locking mechanism interface
Note: Welds are designed to develop reinforcing
Butt-Joint at female socket
Lap-Joint at Male Stud
Structural Analysis
1. Develop loads to be transferred across splice
- L-pile analysis (bending, shear)- Driving stresses (compression, tension)- Structural uplift requirements (tension)
2. Provide splice that adequately transfers:
- Compression
- Shear
- Tension
- Bending
Compression
Compression is transferred directly through bearing of
faying surfaces
Assembly Diagram of Emeca Joint
Shear
• Shear capacity is typically controlled by the shear capacity of the reinforced concrete section
• Shear capacity at the splice is based on shear yield mechanical fixture:
Shear failure plane
Tension
Tensile Limit States
1.&9. Transfer tensile force from prestress to mild reinforcing
2.&8. Tensile yield of mild reinforcing
3. Weld rupture at female socket
4. Tensile rupture of female socket
5. Shear rupture of pin
6. Tensile rupture male stud
7. Weld rupture at male stud
Tension
Limit States 1 & 2:
CASE 2: Lembed. < Ld for strand:
* Bond Limit (Strand)
OR
Mild Reinforcing Steel Limit * Ref: ACI 12.9.1
CASE 1: Lembed. ≥ Ld for strand:
Rupture Limit (Strand)
OR
Mild Reinforcing Steel Limit
Tension
In General:
When mechanical joining mechanism are designed to develop reinforcing:
(1) strand slip,
(2) strand rupture OR
(3) yield of reinforcing will control over all tensile limit states
Auxiliary Reinforcing
Auxiliary Reinforcing
Auxiliary Reinforcing
Tension
Summary:
• Welds and locking mechanisms develop reinforcing
• Controlling Limit States:
(1) Strand slip (2) Strand Rupture, or (3) Yield of Reinforcing
• With Auxiliary Reinforcing, (1) Strand Slip will NOT control
• The limits states of the tension component of the bending couple are analogous
Bending Analysis at Joint
Critical Sections:
S2-Prestress Section
S1-Section at Joint
Bending Analysis at Joint
S1- Reinforced Section (12-in. pile)
Bending Analysis at Joint
S1- Reinforced Section (12-in. pile)
Mn = 41.7 ft-k
Bending Analysis at Joint
max. stress in strand = fps = 173 ksi
S2- Prestress Section (12-in. pile)
Bending Analysis at Joint
S2- Prestress Section (12-in. pile)
PCI Figure 4.12.4 (p. 4-122)
30 in.
173 ksi
Bending Analysis at Joint
fps = 173 ksi Mn = 33.5 ft-k
S2- Prestress Section (12-in. pile)
Analysis at Joint
Summary:
12-in. Pile Splice
14-in. Pile Splice
Limit
Tension - Tn 95.6 kips 150 kips Yield of Mild Reinforcing
Bending - Mn 33.5 ft-kips 55.2 ft-kips Strand Slip
reinforcing added - Mn
41.5 ft-kips 73.7 ft-kips Yield of Mild Reinforcing
Shear - Vn 19.0 kips 26.4 kips Shear Capacity of Pile
Unreduced Capacities of Pile at Joint
Interaction of 12-inch Piles vs. Emeca Joint
Cross Section
Interaction of 14-inch Piles vs. Emeca Joint
Cross Section
Bending Tests – University of South Carolina
Test Set-up:
Recorded Data:- Load- Displacement at ¼ points- Rotation at Joint
Loading Protocol:- Quasi-static loading
Bending Tests – University of South Carolina
Test Specimens (12 Total):
I. Splice only
(6) 28-ft. long piles, spliced at midpoint
(3) 14-in. Specimens (6 strand) (3) 12-in. Specimens (4 strand)
II. Splices with “Auxiliary Reinforcing”
(6) 28-ft. long piles, spliced at midpoint
(3) 14-in. Specimens (6 strand) (3) 12-in. Specimens (4 strand)
Auxiliary reinforcing – (4) #5’s x 60”
Bending Tests
Results:
Failure Mode 1:
-Exhibited by all Type I Specimens
-Characterized by strand slip at critical bending section (S2)
Failure Mode 2:
-Exhibited by all Type II Specimens
-Characterized by rupture of mild reinforcing at critical section (S1)
Bending Tests
Moment Strength Results (ft-kips):
Theoretical Test Results Mean Low
Mn Mn′ Mean Low Mn′ Mn′
Splice Only12 in. 37 47 53.6 52.7 114% 111%
14 in. 61 79 85.4 77 108% 97%
Auxiliary Reinforcing
Added
12 in. 37 53 63 59.7 119% 112%
14 in. 67 93 99.3 90.5 107% 97%
Mn′ –Calculated theoretical moment using tested material strength:
Fy = 73 ksi fc′ = 7,000 psi
Recommendations for Use
1. SDC C: Pile joints must be located > 20 ft below pile cap
2. SDC D, E, and F: Pile joints must be located outside of the “ductile-zone” in defined in IBC 1809.2.3 (35 ft below pile cap, minimum)
3. Mn (joint) > 50% Mn (pile)
4. Minimum 28-day compressive strength of concrete = 6,000 psi
5. Design strength of pile at the splice can be determined using:
- Strain compatibility, and- Standard ACI development length formulation (for prestress & mild reinforcing)
General:
Vitol Oil - Port Canaveral, FL• 6,300 - 100-ft spliced piles• Spliced pile solution saved $10M+• 30%-35% cost savings to project
Emeca Pile Joint PDCA National Project of the Year, 2008
Casting Splices
Casting the Emeca Pile Joint:
• Casting guides used to square and center joints in piles• Proper production fit-up between any two piles is facilitated with use of casting guides
Casting Splices
Piles removal from forms:• Pile handling efficiency greatly improved• Removal can be done with small machines
Casting Splices
Piles stored after casting:• No match-casting• Any two piles can be spliced
Casting Splices
Preparation after casting:•Strands ground flush •Square end verified
Installation
Production:• 30 – 100 ft. long spliced piles / rig / day• 2 men per rig
Installation
Pile Splicing in the Field:• Precision fabrication facilitates proper fit-up• Splicing piles takes 3-5 minutes
Projects
Owner: Vitol Oil CompanyContractor: Sun MarineProject Status: CompleteEmeca Product: 12-in. Pile JointsNotes: 6300, 100-ft-long piles installed
Vitol Oil Tank Farm, Seaport Canaveral, FL
Projects
Owner: Northrup GrummanContractor: Ford Pile FoundationsProject Status: ActiveEmeca Product: 12-in. Pile JointsNotes: Piles and splices designed to resist hydrostatic tension
Northrup Grumman Naval Shipyard - Dry Dock Facility, Newport News, VA
Projects
Contractor: Junttapojat OyEmeca Product: 14-in. Pile JointsNotes: - 8000 Emeca Pile Joints used on project - 656,000 total pile length - Up to 105 foot long piles driven in 3 sections - Battered piles driven at 4V:1H
Vousaari Harbor Project for the Port of Helsinki, Helsinki, Finland
Projects
Contractor: Aarsleff PilingStatus: CompleteEmeca Product: 16-in. Pile JointsNotes: 50 wind turbine foundations constructed using 85-ft-long,16-in. spliced piles
Wind Farm, Ransonmoor, Finland
Projects
Contractor: Kiewit ConstructionProject Status: ActiveEmeca Product: 14-in. Rock Points customized for 30-in.-square concrete piles Notes: Piles driven through concrete mooring anchors at approximately 30-ft.
Brayton Point Cooling Tower, Summerset, MA
Projects
Anacostia Naval Station Drainage Phase IV, Washington, DC
Owner: NAVFACProject Status: Completed August 2008General Contractor: Corinthian ContractorsPile Contractor: Coastal Pile Driving, Inc.Property Manager: Whiting-Turner ContractingProduct: 12-in. Pile JointsNotes: Up to 83-ft-long spliced piles