Specialty Geotechnical Contractor DBM was excavating a drilled shaft for the I-5 interchange in Ridgefield, Washington when they dug up something unusual at a depth of 30-ft. At first the WSDOT inspector thought it looked like wood, but then called in a WSDOT archaeologist who took the fragments to University of Washington’s Burke Museum of Natural History and Culture. The tusk is believed to belong to a Columbian Mammoth and date to approximately 13,000 to 15,000 years ago. Story and image from The Columbian.
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.