Drilled Shaft Design and Construction – Part I
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 one of the series that covers the following Chapters:
Chapter 1 - Overview - Selection and Use of Drilled Shaft Foundations
Chapter 2 - Site Characterization
Chapter 3 - Geomaterial Properties
Chapter 4 - General Construction Methods
Chapter 5 - Tools and Equipment
Chapter 6 - Casing and Liners
Chapter 7 - Drilling Fluids In Drilled Shaft Construction
Chapter 8 - Rebar Cages
Chapter 9 - Placement and Design of Concrete for Drilled Shafts
This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of course materials.
At the conclusion of this series, the student will learn:
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.
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.
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 1 to 9 of the following 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.
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.