Structure and Bridge Division

Drilled Shaft Installation

Foundations |  Drilled Shaft Installation and Videos |  Subsurface 

Drilled Shaft Installation:  
(presentations, manuals, videos, or photos)
Video - Drilled Shaft Installation.
Basic video on drilled shaft installation. Basically about type of equipment used. Drilling auger. Installation to bedrock. Bedrock plug removal. Shaft hole inspection. Installation of reinforcing steel cage and concreting. 

Drilled Shaft Videos

ADSC-IAFD Website:  Association of Drilled Shaft Contractors Inc. and the International Association of Foundation Drilling has videos on Introduction to Drilled Shafts, Drilled Shaft Construction, Techniques for Excavating Drilled Shafts (5 videos), Techniques for Maintaining Stability of Drilled Shafts (7 videos), and MnDOT Drilled Shaft Inspectors Workshop (February 17, 2011) (13 videos) developed by the Center for Drilled Shaft Engineering (CDSE). 
CDSE Inspection – 01 Drilled Shaft Inspection and CDSE Inspection – 03 Roles of the Inspector are recommended for basic understanding of drilled shafts and the roles of inspectors for drilled shaft construction

Introduction to Drilled Shafts and Drilled Shaft Construction.   What is a drilled shaft and when should drilled shaft foundation be considered?    Drilled shafts require careful construction by experienced and capable specialty contractors.  Inspection should be performed by knowledgeable and experienced inspectors and quality assurance professionals. 

Introduction to Drilled Shaft Construction.   Overview of how a drilled shaft is constructed. Excavate hole maintaining stability using drilling fluid and/or casing for support if needed.  Clean hole and inspect hole. Install reinforcing cage and methods of placing concrete. Finish top of shaft and prep for connection to footing or column. 

Techniques for Excavating Drilled Shafts.  There is a diverse range of equipment available.  It is Contractor’s responsibility to identify and select appropriate equipment for excavating based on subsurface materials, diameter and depth of shafts, and stability requirements.
Techniques for Excavating.  Means and methods, constructability, installation plan, inspection and quality assurance plan.  

Part 1 – Drilled Rig Basics.  Diverse range of equipment available.  Truck mounted, crawler mounted, fixed mast – crawler mounted with casing, low headroom & excavator, oscillator/rotator casing systems, crane operated grabs without casing, and reverse circulation drilling. 

Part 2 – Drill Tool Basics.  Augers & Buckets.  Augers for earth drilling and rock drilling, digging buckets, cleanout buckets, and hammer grab tools. 

Part 3 – Drilled Tool Basics and Other Tools for Excavating.   Core Barrels – single wall and double wall with circulation.    

Percussion Tools.  Percussion tools, reverse circulation tools and manual excavating.

Techniques for Maintaining Stability of Drilled Shaft Part 1.  Stability of the hole is required for safety, adjacent structures, integrity of the ground and integrity of the completed drilled shaft.  Naturally dry, cohesive soil or rock.  Casing (full or partial depth). Fluids (water, minerals (bentonite), and synthetic (polymer).  

Techniques for Maintaining Stability Part 2, Excavation Stability: the Role of Arching in Drilled Shaft Construction.   

Techniques for Maintaining Stability Part 3a.  Maintaining Stability with Drilling Fluids.  Types of drilling fluids (Water, Mineral (typically bentonite), & Polymer).  How different types of fluids maintain stability.  Considerations in the selection and use of different fluids.  

Techniques for Maintaining Stability Part 3b. Types of Drilling Fluid.  Water 

Techniques for Maintaining Stability Part 3c. Types of Drilling Fluid.  Bentonite (slurry).  Use high grade bentonite.  Premix and hydrate with potable water.  Limit bore hole exposure time.  De-sand prior to concrete placement.   

Techniques for Maintaining Stability Part 3d. Types of Drilling Fluid.  Polymer.  Liquid or granular.  Premix with potable water; must control hardness (pH).  Maintain fluid level, viscosity.  De-sand or exchange prior to concrete placement.  Polymer vs Bentonite Slurry.  

Techniques for Maintaining Stability Part 3e.  Construction using Drilling Fluids.   QC/QA aspects. Effects of fluids on behavior.  

CDSE Inspection – 01 Drilled Shaft Inspection. Overview of one day drilled shaft inspection training course.  

CDSE Inspection – 02 Drilled Shafts.   Outline: Basic Function & Performance; Construction Methods (Dry, Wet, Casing (wet or dry), Casing (Temporary or Permanent)); Casing; Equipment & Tooling; Reinforcing Cage; and Concrete & Placement.  

CDSE Inspection – 03 Roles of the Inspector.   Objectives:  Understand Importance of thorough drilled Shaft Construction Method; Basic Roles of Drilled Shaft Inspector; and Qualification of a Drilled Shaft Inspector.  

CDSE Inspection – 04 FADR and Why Drilled Shafts.  Foundation Design and Analysis Report. Geology; Subsurface Investigation (Field Sampling & Testing. Lab Testing); Subsurface Conditions; Foundation Analysis; and Foundation Recommendations (Design & Construction).  Why Drilled Shafts? High lateral strength & stiffness (scour & vessel collision); Resistance developed in rock (scour); and Fewer number of piles (footing size).  

CDSE Inspection – 05 Red Wing Plans.  Drilled Shaft Plans; Main Span Piers; Drilled Shaft Groups; Pier 1; Pier 2; Pier 1 Shaft Details; Pier 2 Shaft Details; Reinforcing Details; Concrete; and Socket Construction.  

CDSE Inspection – 06 Red Wing Specs. Highlights & Keys to Successful Construction. Standard Specifications. Project Special Provisions. Definitions (rock & earth). Submittals: Installation Plan (Equipment; Means & Methods; Construction Sequence; & Contingency Plans). Methods & Equipment. Construction Requirements (Concrete). Materials (Casing, Slurry, Construction Requirements (Cleaning & Inspection). Concrete Requirements (Concrete Bridge Construction, Field Adjustments).  

CDSE Inspection – 07 Installation Plans. Documents the equipment and procedures (i.e., means and methods) to be used for drilled shaft installation. Example information in plan. Review Process.  

CDSE Inspection – 08 Forms. FHWA Drilled Shaft Forms. Drilled Shaft Report. Drilled Shaft Log. Base Inspection Forms. Concrete Forms. Example Placement Log & Curve. Inspector’s Checklist. Pay Items Summary. Installation Plan Summary.  

CDSE Inspection – 09 Inspector’s Tool Box.   FHWA Inspector’s Tools Checklist: Approved Job Information, References, testing Equipment, Blank Forms & Daily Essentials.  Slurry Test Equipment (Slurry Sampler, pH Paper, Marsh Funnel (viscosity), Mud Balance (unit weight), & API Sand Content Kit).  Electronic Monitoring Systems.  Base Inspection Tools (Sounding (Feel): Weighted Tape.  Visual: mini-SID (Shaft Inspection Device).   

CDSE Inspection – 10 Inspect Equipment. Pre-Construction Inspection. Check Contractor Equipment vs Drilled Shaft Installation Plan. Make Inventory of Drill Tools. Check Dimensions. Check Casing.   

CDSE Inspection – 11 Observations During Excavation & Cleanout. Know what to expect. Is this sand or sandstone? Observations During Casing Installations & Overburden Excavation. Observation During Rock Excavation. Excavation Log. Observation During Cleanout. Airlift Discharge. Base Inspection Check List. When leaving a hole open overnight.  

CDSE Inspection – 12 Observations During Placement Of Reinforcing Cage and Concrete. Things to check before the cage is picked. Things to check as the cage is picked and placed. Check List. Required Red Wing Cage Template. Desirable Characteristics of Drilled Shaft Concrete. Self-Consolidating Concrete (SCC): Slump Flow Test: Stability; Bleeding & Segregation; Pass Ability & Cage Construction; Test Shaft with Colored Concrete; Non-Uniform Upward Flow; and Workability Retention. Inspector’s Role During Concrete Placement. Check Tremie Embedment. Make sure Contractor uses a “pig”. Prior to Concrete Commencement. What if there’s a problem? Placement Log & Volume Curve. What is the volume curve telling you? Finishing: Overpour. Finishing: Vac Truck. Check List. Most Common Causes of Real Anomalies.   

CDSE Inspection – 13 Post Installation Integrity Testing.  Most common integrity test methods for drilled shafts: Crosshole Sonic Logging (CSL); Thermal Integrity Profiling (TIP); Gamma-Gamma Logging (GGL); and Sonic Echo/Impulse Response (SEIR).  Red Wing used TIP.  CSL is most common but TIP is up and coming.  Very Conditions by Coring.  Downhole Camera.  Comparison of CSL vs TIP.   

Video - Piling – Access Engineering PLC. Basic bored piling (drilled shafts) installation for buildings and bridges. Installation procedures to include casing installation, drilling process, installation of temporary casing, bentonite slurry, installation of steel reinforcing cage with cover spacers, tremie pipe for placing concrete, placing concrete, and cross-hole sonic logging testing. 

Video - Bored Piling. San Piling Media video for building foundation. Construction method similar to drilled shaft construction. Illustrates casing installation, drilling process, bentonite testing, reinforcing steel installation, concreting, casing withdrawal, cross-hole sonic logging testing and pile load testing.    

Video - Construction Technology Piling Construction.  Construction method for bored cast-in-situ piles (similar for construction of drilled shafts) for building foundation.  Installation procedures to include pre-boring, installation of temporary casing, bentonite slurry, installation of steel reinforcing cage with cover spacers, tremie pipe for placing concrete, placing concrete, extraction of temporary casing, and installation of pile caps.  Also, shows construction of contiguous pile wall.  Note that welding of reinforcing cage sections is not allowed by VDOT unless weldable reinforcing steel is used.  

Page last modified: Dec. 1, 2022