the use and construction of drilled shaft...
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The Use and Construction of Drilled Shaft FoundationsPrepared By:
ADSC Northeast ChapterA Regional Chapter of the ADSC
The International Association of Foundation Drilling
In Cooperation With:
ADSC:The International Association of Foundation Drilling
8445 Freeport Parkway Suite 325· Irving, TX 75063Telephone: (469) 359-6000 · Fax: (469) 369-6007
E-mail: [email protected]
THE HISTORY AND OBJECTIVES OF THE ADSC
The Association was founded in 1964 and is comprised of foundation drilling, anchored earth retention and geo-support contractors (Contractor Members), manufacturers and suppliers to the industries (Associate Members), andengineering and design professionals (Technical Affiliate Members), and students enrolled in construction and/orengineering related programs.
The work of the ADSC…
1) Establish Standards and Specifications for the Foundation Drilling, Anchored Earth Retention and Geo-Support Industries
2) Conduct Design, Construction and Inspection Seminars worldwide3) Hold Meetings4) Fund and conduct original research5) Promote ethical practices6) Develop technical materials7) Serve as clearing house for information8) Provide educational scholarships9) Interface with corresponding industries10) Establish international labor-management agreements11) Provide a forum for the free flow of ideas12) Stimulate industry growth13) Government liaison task force
THE HISTORY AND OBJECTIVES OF THE ADSC
The ADSC’s publications include:
FOUNDATION DRILLING Magazine, published eight times per year, is a colorfulmagazine dealing with the latest developments in the foundation drilling, anchoredearth retention and geo-support industries. Subscriptions are available. Contact theADSC International office for fees and further information.
The ADSC has published a complete Technical Library Catalog available free uponrequest from the ADSC office. It contains a description of all technical materialsavailable, plus management aids, films, videos, slide presentations, and books.
ADSC: The International Association of Foundation Drilling is a trade associationcomprised of people working together to advance all aspects of the industries it serves.To learn more about how you can become a Contractor, Associate, or TechnicalAffiliate Member of the ADSC, please contact our International Office or any member.
Design for Constructibility
•Engineering design cannot be separated from the construction of drilled shafts.
•Construction methods and materials will influence the capacity, load-displacement characteristics, and economics of drilled shafts.
Definition of Drilled Shaft Foundation
(Drilled Pier, Bored Pile, Cast-In-Drilled-Hole, Drilled Caisson, etc.)
1) Excavate a cylindrical hole in the ground.
2) Fill excavation with concrete, usuallyreinforced.
Advantages of Drilled Shafts
When properly designed and constructed:
1).Reliability
3).Versatility
2).Economy
SOIL EXTRACTEDON OPEN-FLIGHTAUGER.
SINGLE DRILLED SHAFT FOUNDATION
TRANSMISSION LINE PROJECT
SHORINGSYSTEMS
HIGH-RISEPROJECT
BRIDGE STRUCTURE OVER WATER
OFFSHORE DRILLING
HILLSIDE DRILLING
SEISMICRETROFITBUILDING
SEISMICRETROFITBRIDGE / VIADUCT
RESIDENTIAL
BATTEREDPILE FOUNDATIONS
PERMANENTRETAININGWALLS
DEEPBASEMENTEXCAVATIONS
TUNNEL ACCESS SHAFT
Construction of Drilled Shafts
•Construction Methods
•Construction Equipment
•Design for Constructibility
DRY METHOD OF CONSTRUCTION
OPEN HOLEEXCAVATION
SLURRY METHOD OF CONSTRUCTION
SLURRYDISPLACEMENTMETHOD
PROPERTIESOF SLURRY
Functions of Slurry
1) Maintain the stability of the excavation
2) Prevent suspended particles from settling out
3) Allow clean displacement by concrete
4) Allow easy pumping
SUGGESTED SPECIFICATIONSFOR BENTONITE SLURRY (1)
Property Range @ 20º C Test Method
Density less than 1.10 g/ml mud density balance
Viscosity 30 to 90 seconds Marshal funnelless than 20 cP Fann viscometer
Shear Strength 4 to 40 N/m2 shearometer1.4 to 10 N/m2 Fann viscometer
PH 9.5 to 12 pH indicatorpaper strips
(1) FEDERATION OF PILING SPECIALISTS
MUD DENSITY BALANCE
MARSH FUNNEL
FANN VISCOMETER
SHEAROMETER
LITMUS TEST (pH)
SLURRYPROCESSING PLANT
CASING METHOD OF CONSTRUCTION
TELESCOPINGCASING
Construction of Drilled Shafts
• Construction Methods
• Construction Equipment
• Design for Constructibility
DRILL RIGS
Kelly Bar
Power Unit
RotaryTable
CRANE MOUNTED ATTACHMENT
TEXOMA 600 (TRUCK-MOUNTED)
TRUCKMOUNTEDDRILLING UNITS
“BIG STAN”
TOP-DRIVEDRILLING UNITS
LONG REACHDRILLING UNITS
CRANE MOUNT
CASINGOSCILATOR
CASING ROTATOR
LOW OVERHEAD DRILLING
DRILL TOOLING
AUGERS
AUGERS
ROCK AUGER
DOUBLE-FLIGHTED AUGER
BOULDER ROOTER -“CHRISTMAS TREE” AUGER
DIGGING BUCKETS
BELLING BUCKETS
CORE BARRELS
AIR CIRCULATIONCORE BARRELS
ROCK CORING
CLUSTER DRILL
DOWN-THE-HOLE HAMMER
CHURN BIT
TRI-CONE ROLLER BIT
GRABBUCKETS
INSTALLATIONOF
TEMPORARY CASING
CASING TWISTER
STARTER CASING
TELESCOPINGCASING
SLEDGE &POWER SWIVEL
TOP DRIVE
CASING OSCILATORWITH GRAB BUCKET
VIBRATORY HAMMERS
CLEANING-OUTTHE BOTTOM
OF THE DRILLED SHAFT
CLEAN-OUTBUCKETS
HYDRAULIC PUMP
AIR LIFT -“PORTUGUESE PUMP”
HAND -CLEANING
INSTALLATIONOF REINFORCING
STEEL CAGE
REBAR CAGEFABRICATION
REBAR CAGEINSTALLATION
LIFTING OF LONG REBAR CAGE
REBAR CAGEPOSITIONINGDURINGCONCRETEPOUR
FINALPOSITIONINGOF REINFORCING CAGE
Concrete Placement: Key Factors
• Concrete should be placed as soon as possible after the hole is completed
• The concrete should have good flow characteristics
• The concrete placement techniques must result in complete filling of the excavation without segregation
FREE-FALL METHODS
CONCRETEBOOM-PUMP
TREMIE POUR
FINISHEDCUT-OFF
Construction of Drilled Shafts
• Construction Methods
• Construction Equipment
• Design for Constructibility
Design for Constructibility
Remember:
“Do Not Design on Paper WhatYou Have to Wish into the Ground”
- KARL TERZAGHI
Design for Constructibility: The Keys
• Subsurface Investigation
• Appropriate Concrete Design
• Appropriate Steel Design and Tolerances
• Inspection
CIRCA 1920’s
This presentation has been prepared specifically for use by the Association of Drilled Shaft Contractors West Coast
Chapter and the International Association of Foundation Drilling.
Duplication, modification, or use of this presentation by others, is strictly
prohibited without the expressed written permission by the Association of Drilled Shaft Contractors or the International
Association of Foundation Drilling.