Load and Resistance Factor Design (LRFD) is the predominant design method utilized today for reinforced concrete and structural steel, and is the primary focus of the AASHTO LRFD Bridge Design Specifications. Historically, micropile design has been performed mainly with Allowable Stress Design (ASD) methodologies, and most of the micropile design manuals and specifications in existence prior to 2008 were based on ASD.
In light of this history of ASD design methodologies, and in spite of the widespread use of LRFD in general structural design disciplines, there have been a number of questions and a great deal of confusion regarding the proper use and implementation of LRFD design methodologies for micropiles. The author, as part of a DFI / ADSC Joint Micropile Committee initiative, developed a presentation in response to these questions and issues which covers the fundamentals of LRFD as it applies to micropiles, and provides an illuminating comparison with ASD methodology.
This paper is a formalized and updated snapshot of the current State of Practice of LRFD for Micropile Design based on the most current information and design codes relevant to micropiles. It will describe the fundamentals of Load and Resistance Factor Design (LRFD), demonstrate micropile design and testing utilizing LRFD, compare the results with historical ASD design, point out the limitations of current LRFD practice relative to micropiles, and finally map out the path forward with regard to proper implementation of LRFD as a true reliability based design methodology for the design of micropiles.
Join me next Thursday in Charleston, WV for the 2018 Terracon Engineering and Construction Exchange. I will be presenting on Micropiles at the event so make sure you register below and get the latest and greatest on Micropiles! Presentation attendees will receive a PDH certificate for continuing education credit. There is no cost for registration so all the better! See you then. #micropiles #geotechnicalengineering #construction
October 24-27, 2018 Hilton Anaheim Anaheim, CA, USA
Mastering the Challenge: Engineering for Complex Loading Conditions in the 21st Century
The Call for Abstracts deadline has been extended by one week from December 15, 2017 to December 22, 2017 so if you haven’t submitted an Abstract already, you have a little more time to do so. Details below taken from the DFI Call for Abstracts document.
This conference will feature technical presentations on innovations and advancements that address performance based design and construction of foundations subject to increasingly challenging structural demands. The 2018 Conference will provide an international forum for a wide range of geo-professionals to present, discuss, and debate all aspects of assessment, development, design and mitigation for complex loading conditions in the 21st Century. A number of sessions will be dedicated to panel discussions in which invited specialists will interact with the audience to examine pressing issues in foundation industry practices.
Abstracts for technical papers and panel sessions can be submitted at www.dfi.org/annual2018, no later than Friday, December 22, 2017. All accepted papers will be published in the Conference Proceedings, and select papers will be presented orally by the author during the appropriate technical session. Proposals for panel sessions are welcomed and encouraged.
Abstracts for papers are welcomed on the following topics:
• Risk Assessment and Mitigation
• Lessons Learned (Case Histories / Innovations / Forensic Work)
• Seismic Design / Soil Structure Interaction / Lateral Loading
• Performance Based Deep Foundation Design
• Ground Improvement
• Innovation Techniques for Earth Retention and Stabilization
• Advancements in Instrumentation and Monitoring
• Analysis, Design and Construction for Extreme Events
• Mega Projects (Projected Work / Risk Mitigation / Contractual Aspects)
• Constructability Issues and Design Aspects
• Other Deep Foundations-Related Topics
If you haven’t visited the Micropile Design and Construction website (micropile.org) for a while, you are in for a surprise! For the first time since its inception in 2009, the site has received a much needed extreme graphical makeover. We’ve updated our website theme and ensured that it is responsive across the various devices out there today. We are really pleased with the new site!
Let us know what you think and if you have any particular topics of interest that you want to see covered in the future. Micropile Design and Construction is committed to providing the highest quality and most practical information on micropiles available in the industry. Exciting things to come in 2018, Stay tuned!