Drilled Shaft Design and Construction – Part I

Course Outline

Once considered a specialty foundation for urban settings where vibrations could not be tolerated or where shallow foundations could not develop sufficient capacity, the use of drilled shafts as structural support have recently increased significantly due to heightened lateral strength requirements for bridge foundations and the ability of drilled shafts to resist such loads, especially enormous lateral loads from extreme event limit states often governing bridge foundation design, such as  vessel impact loads. Drilled shaft construction is relatively unaffected by scour depth requirements and the tremendous lateral stiffness has made it the preferred foundation type for bridge foundations by many designers. Further, recent developments in design and construction methods of drilled shafts have provided considerably more economy to their use in all settings, including foundations for bridge piers, abutments, high mast lighting, cantilevered signs, cellular phone and communication towers.  This course is entirely based on US Department of Transportation Publication No. FHWA-NHI-10-016, Drilled Shafts: Construction Procedures and LRFD Design Methods. This two-part series discusses both construction and design of drilled shafts, and addresses the applications of drilled shafts for transportation structure foundations; general requirements for subsurface investigations; construction means and methods; LRFD principles and overall design process; geotechnical design of drilled shafts for axial and lateral loading; extreme events including scour and earthquake; LRFD structure design; field loading tests; construction specifications; inspection and records; non-destructive integrity tests; remediation of deficient shafts; and cost estimation. This is part two of the series that covers the following Chapters:

Chapter 10 - LRFD for Drilled Shaft Design
Chapter 11 - Design Process
Chapter 12 - Lateral Loading
Chapter 13 - Axial Loading
Chapter 14 - Design of Groups of Drilled Shafts
Chapter 15 - Design for Extreme Events
Chapter 16 - Structural Design

This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of course materials.

Learning Objectives

At the conclusion of this series, the student will learn:

• Definitions and terminologies;
• Historic background;
• Types;
• Applications;
• Advantages and limitations;
• Geotechnical site conditions;
• Geomaterial properties;
• Construction methods;
• Tool and Equipment;
• Drilling;
• Grouting;
• Casing and liners;
•  Drilling fluid;
•  Rebar cages;
• Placement of concrete;
• Concrete mix design;
• LRFD design concept;
• LRFD design procedures;
• Lateral load design;
• Axial load design;
• Load combinations;
• Group effect;
• Scour design;
• Seismic design;
• Vehicle collision Design;
• Structural design; 
• Design approach;
• Structural design;
• Loading test;
• Inspection;
• Deficient drilled shafts;
• Specifications; and
• Cost estimate.

Intended Audience

This course is intended for geotechnical engineers, civil engineers, structural engineers, construction professionals and contractors.

Benefit to Attendees

The attendees will gain a general knowledge of the design, construction and performance of drilled shaft foundation system.

Course Introduction

Drilled shafts are deep, cylindrical, cast-in-place concrete foundations poured in and formed by a bored (i.e. “drilled”) excavation. They can range from 2 to 30 feet in diameter and can be over 300 feet in length. Drilled shafts are typically high-capacity deep foundation elements constructed using an auger. A hole having the design diameter of planned shaft is first drilled to the design depth. If the hole requires assistance to remain open, casing or drilling fluid is used. Full-length reinforcing steel is then lowered into the hole and the hole is filled with concrete. The finished foundation element resists compressive, uplift and lateral loads. The technique has been used to support buildings, tanks, towers and bridges.

Course Content

The course content is entirely based on US Department of Transportation Publication No. FHWA NHI-05-039, Micropile Design and Construction.  For this course, you are required to study Chapters 10 to 16 of the following document.

USDOT Publication No. FHWA-NHI-10-016, Drilled Shafts: Construction Procedures and LRFD Design Methods (30 MB PDF Document)

Please click on the above underlined hypertext to view, download or print the document for your study. Because of the large file size, we recommend that you first save the file to your computer by right-clicking the mouse and choosing "Save Target As ...", and then open the file in Adobe Acrobat Reader from your computer.

Course Summary

This course presents the general guidelines on micropile selection, application, benefit, design, construction, cost and testing of micropile foundations.

Once you finish studying the above course content you need to take a quiz to obtain the PDH credits.

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DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDHonline.org or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered professional engineer. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.

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