I saw this device (well, a model of it and a presentation) at a recent geotechnical conference and I was very impressed. One of the challenges with the QC of drilled shafts is that you don’t always know the condition of the bottom of the shaft. The Shaft Quantitative Inspection Device (SQUID) measures the thickness of the debris layer above the bearing strata and the strength of the bearing layer itself. The results are presented on output in numerical and graphical format in real time. The device attached to the rig’s Kelly Bar and is deployed with minimal effort. [Source: Pile Dynamics YouTube Channel. Image: Pile Dynamics]
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FHWA NHI Manual: Drilled Shafts Construction Procedures and LRFD Design Methods
The FHWA has released for download a comprehensive update to the 1999 O’Neil and Reese manual “Drilled Shafts: Construction Procedures and Design Methods”, lovingly referred to in the industry as the “Brown Book” or the “Drilled Shaft Bible”. This 2010 manual from the National Highway Institute (NHI) of the FHWA is entitled “Drilled Shafts: Construction Procedures Procedures and LRFD Design Methods” and was authored by Dan A. Brown, Ph.D, P.E. of Dan Brown and Associates, John P. Turner, Ph.D, P.E. of the University of Wyoming, and Raymond J. Castelli, P.E. From an FHWA Memo on the manual:
Distributed with this memorandum is the publication entitled "Drilled Shafts: Construction Procedures and LRFD Design Methods" (FHWA-NHI-10-016). This manual is the reference text used for the National Highway Institute (NHI) course numbered 132014 on Drilled Shafts. The publication will become the tenth in the series of geotechnical engineering guidelines called "Geotechnical Engineering Circulars." Geotechnical Engineering Circular (GEC) No. 10 is prepared as a significant revision and update to "Drilled Shafts: Construction Procedures and Design Methods" (FHWA IF-99-025), and reflects the standard of practice for the design, construction and inspection of these features. The guidance is developed following Load and Resistance Factor Design (LRFD) procedures and will enable engineers to identify and evaluate technical feasibility and potential applications. The text is developed with a sufficiently broad scope to be of value to a wide range of transportation specialists responsible for assisting with selection, design, development of materials specifications, construction monitoring, and contracting methods for Drilled Shafts.
Click through for the download link and some preliminary comments on what has been updated in this significant new publication in the drilled shaft construction industry as well as the geotechnical engineering profession.