HELICAL ANCHORS & FOUNDATIONS
HELICAL C SCREW SC W ANCHORS C O S AND FOUNDATIONS IN SOIL
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Historical Perspective
1st Recorded use of a Screw Pile was by Alexander Mitchell in 1836 for Moorings and was then applied by Mitchell to M li Sands Maplin S d Li Lighthouse hh iin E England l d iin 1838 1838.
In 1843, the 1st Screw Pile Light House in the U.S. was Constructed by Capt. William H. Swift at Black Rock Harbor in Connecticut. Swift used Mitchell Screw Pile Technology.
In the 1840’s and ’50’s, More Than 100 Screw Pile Foundation Light Houses were Constructed Along the East Coast,, the Florida Coast and the Gulf of Mexico History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS Mitchell’s Screw Pile - 1836
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
PRODUCT TYPES
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Square Shaft Helical Screw Foundations & Anchors
A.B. Chance Type “SS” Characteristics
5500 - 20,000 ft lbs. Installation Torque
Design Tension Loads up to 100 kip (445 kN), g Comp. p Loads up p to 100 kip p ((445 kN)) Design Helix Dia: 6” (152 mm) 8” (203 mm) 10” (254 mm) 12” (305 mm) 14” (356 mm)
Type SS5 & SS150 1-1/2” (35 kips) SS175 1-3/4” (50 kips) SS200 22” (75 kips) SS225 2-1/4” (100 kips)
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
SCREW ANCHOR LEAD SECTION
Single, Twin, Triple or Quad Helix Configurations
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
PLAIN EXTENSION SECTION
3’-0 (.9 m), 5’-0 (1.5 m), 77’-00 (2 (2.11 m) & 10’-0 (3 m) Lengths
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
EXTENSION SECTION WITH HELIX PLATES 12” ((305mm)) and 14” (356 ( mm)) Diameter Helix Plates
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS F Foundation d ti Underpinning U d i i Brackets B k t STANDARD-DUTY FOUNDATION REPAIR BRACKET
FOR 1 ½” SHAFT RATED CAPACITIES: 20,000 LB. WITH SS5 ANCHORS 25,000LB. WITH SS150 ANCHORS FOR 1 ¾ ¾” RATED CAPACITY: 30,000LB.
HEAVY-DUTY FOUNDATION REPAIR BRACKET
FOR 1 ¾” SHAFT RATED CAPACITY: 40,000LB.
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Pipe Shaft Helical Screw Foundations A.B. Chance Type “LIFT & 278 C Combo” b ”
Characteristics
5 500 ft lbs. 5,500 lbs Installation Torque To q e Rating
Design Tension Loads up to 30 kip (133 kN), Design Comp. Loads up to 34 kip (133 kN) Helix Dia LIFT: 10” (254 mm) Helix Dia SS5/150 Lead: 6” (152 mm) 8” (203 mm) 10” (254 mm) 12” 10 12 (305 mm) 14” 14 (356 mm) Pipe Shaft Dia: 2-7/8” (73 mm)
Type yp SS5 to 278 “Combo” Pile
LIFT™ Pile LIFT History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Pipe Shaft Helical Screw Foundations A.B. Chance Type yp “HS” Characteristics
11,000 ft lbs. Installation Torque
Design Tension Loads up to 60 kip (267 kN), Design i C Comp. Loads d up to 60 ki kip (26 (267 k kN)) Helix Dia: 6” (152 mm) 8” (203 mm) 10” (254 mm) 12” (305 mm) 14 12 14” (356 mm) Pipe Shaft Dia: 3-1/2” (89 mm)
Type SS to HS “Combo” Pile
Type HS History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
APPLICATIONS FOR HELICAL SCREW ANCHORS
Underpinning - Residential / Commercial
Helical Screw Foundations for New Construction
Tiebacks for Excavation Bracing
Soil Nails for Earth Retention
Seismic Retro-fit
Guyy Anchors & Foundations for Towers History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Foundation Underpinning
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Foundation Underpinning Screw Foundation Installation with Portable Installer
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Foundation Underpinning Raising Building with Repair Brackets
Repair i Brackets k
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Helical Screw Foundations for New Construction
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
New Construction - Slabs and Foundations Screw Foundations Supporting I d t i l Building Industrial B ildi
Screw Foundations Supporting Structural Slab
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
PIPE SHAFT PILES
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
New C N Construction t ti – Connection Details
Pile Cap Detail
Grade Beam Connection Detail
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Helical Screw Foundations for Towers Installation of Screw Foundations with Back-Hoe
Ten Screw Foundations per Tower Leg
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Walkways for Wetlands
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Screw Anchor Tiebacks
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Soil Screws for Soil Nail Walls
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Guy Anchors for Towers Installation of Multiple Screw Anchors for Guy Point
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Guy Anchors for Towers
Single Guy Anchor, Multiple Guy Wires
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
THEORY AND DESIGN OF HELICAL PIER FOUNDATIONS
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Lateral Load Capacity
Grade Beam & Pile Cap
Passive Earth Pressure Resistance Optional Lateral Tieback
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Tieback Screw Anchor Section Detail
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Soil Screw Anchor Section Detail
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
HeliCAPTM Engineering Software Theoretical Bearing Capacity Based on Soil Strength
Available from A. B. Chance Civil Construction Web Site www.abchance.com
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
INSTALLATION TORQUE VS. ULTIMATE CAPACITY
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS TORQUE MOTOR
REACTION BAR
FOOT CONTROL 2,500ft-lbs through 8,000ft-lbs
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS Hydraulic Vehicle-Mounted Hydraulic, Vehicle Mounted
3,500 , FT.-LB. 6,000 FT.-LB. 12,000 FT.-LB. 20 000 FT 20,000 FT.-LB -LB History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS MACHINE
TORQUE MOTOR
CROWD
TORQUE INDICATOR FOUR HELIX LEAD SECTION
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
FIELD MODIFICATIONS Vary
Helix Size
Vary
Helix Numbers
Install
into Better Soil
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Compression Load Test Set Set-Up Up
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
HELICAL PULLDOWN® MICROPILES
Screw Pile Foundation Installation Method Used to Increase the Section Modulus of a Standard SS or Pipe Shaft. Shaft
Patent Protected
U.S. 5,707,180; Methods and Apparatus Other U.S. and Foreign Patents Pending
Method of Displacing Soil Around the Anchor Shaft and Replacing with Grout Column Column.
Soil is Displaced by “Lead Displacement Plate”. “Extension Displacement Plates” Serve as Centralizers and Provide the Means for Which the Grout is “Pulled-Down”.
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
DESCRIPTION
Increased Section Modulus Likewise Increases Lateral Buckling Capacity of the Screw Pile.
Grout Column Provides Increased Compression C Capacity. it
Mobilizes Skin Friction at the Grout/Soil Interface.
Displacement Plates Range in Size from 4” 4 Up to 10” in Diameter.
Required Plate Size is Specified for Each Project G tC Grout Columns l Can C bbe Cased C d when h R Required. i d
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Helical Screw Foundations With Grouted Shafts
HELICAL PULLDOWN Micropile Characteristics
5500 - 20,000 ft lbs. Installation Torque
Design Tension Loads up to 100 kip (445 kN), g Comp. p Loads up p to 200 kip p ((890 kN)) Design Helix Dia: 6” (152 mm) 8” (203 mm) 10” (254 mm) 12” (305 mm) 14” (356 mm)
Prevents Buckling Increases Capacity C Corrosion i Resistance R i
Uses Type SS (Square Shaft) Material
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
HELICAL PULLDOWNTM Micropile MODEL Qt = QH + Qf
Grade
Soft or Loose Overlying Strata Displacement Plates
Qf = Df sLf]
Grout Column Helix Plates
E dB End Bearing i Stratum St t
QH = icCi qiNq History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Installingg Lead Case
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS Pouring Grout
Joint Packingg History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS Installing Top Case
Adding Centralizer History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS Installing Shaft Extension
Grout “Pulled Down” History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Pile Extracted After Test Un-Cased Grout Column
T Case Top C
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
Grout Column With Soil Removed
History, Applications, Design
HELICAL ANCHORS & FOUNDATIONS
History, Applications, Design