Micropile Design and Construction – Part I
Worldwide use of micropiles has grown since their original development in the 1950s, and in particular since the mid-1980s. In general, micropiles are applicable when there are problems with using conventional deep foundation systems like driven piles, drilled shafts, or augercast piling. Mircopiles are primarily used as elements for foundation support to resist static and dynamic loading conditions, and less frequently as in-situ reinforcements for slope and excavation stability. Micropile can be designed as soil frictional piles or rock socketed piles either under tension or compression. The advantages of micropiles are that their installation procedure causes minimal vibration and noise, they can be installed in difficult ground conditions, and they can be used in areas with low headroom and restrictive access. This makes micropiles the preferred choice of foundation system for retrofitting existing structures in challenging areas. This course is entirely based on US Department of Transportation Publication No. FHWA NHI-05-039, Micropile Design and Construction. This two-part series discusses micropile classifications, design concepts, problems associated with the common installation methods, specifications, construction control and performance of this pile system. This is part one of the series that covers the following Chapters:
Chapter 1 Introduction
Chapter 2 Micropile Classification System
Chapter 3 Micropile Applications in Transportation Projects
Chapter 4 Construction Techniques and Materials
Chapter 7 Pile Load Testing
Chapter 8 Construction Inspection/Quality Control
Chapter 9 Contracting Methods
Chapter 10 Cost Estimating
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 micropile foundation system.
A micropile is a small diameter (typically 5" – 12"), drilled and grouted pile with reinforcement. Micropiles are commonly made up of high strength steel casing and rebar, but can also be installed in some soil conditions using pressure grouted all-thread self-drilling hollow bar systems. Designed to carry compressive or tensile loads, micropiles are high-performance piles that can achieve working loads over 200 tons and extend to depths of 200 feet. The load is mainly accepted by the steel casing and transferred via the grout to the surrounding rock or soil by high values of interfacial friction with minimal end bearing components, as in the case for ground anchors and soil nails. The drilling equipment and installation methods allow micropiles to be drilled through natural and artificial ground condition with minimal vibration, disturbance and noise and at any angle below horizontal.
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 4 and 7 to 10 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.