ADOT put together a great little video embedded below that shows the construction of a drilled shaft foundation, or caisson as they are also known, for a bridge on the Loop 303 project in Surprise, AZ. The foundations shown are 88-feet deep and the rebar cage weighs in at about 20,000 pounds. The hole takes around 80 cubic yards of concrete to fill (that’s 8 concrete trucks). The video shows the fabrication of the cage, drilling the hole, and picking up and lowering the cage. My favorite part is the perspective of the video taken from the top of the cage as it is picked up and lowered, very cool. [Source: ADOT Blog]
Project Related
Lateral Load Testing of Drilled Shafts For Cable Barriers – ADSC Study
ADSC published a summary of some research being conducted by the University of Texas, Arlington (UTA) through funding by TxDOT. The research involves the lateral load testing of drilled shafts that are used for cable […]
Geologic Hazards
Landslide on Arizona SR 87 Closes Highway
On March 21, 2008 a landslide caused the closure of Arizona State Route 87 between Payson and Phoenix near mile post 224. So far there are no official estimates as to the size, but based on aerial photos, it appears to be at least 50,000 sq-ft in plan. The offset at the head scarps was approximately 2-meters (6.6-ft) according to AZGS Geologists on site. It appears to have been a rotational slide as the toe of the landslide heaved the southbound roadway up by as much as 1-meter (3.3 ft). There was an existing soil-nail retaining wall on the slope that was destroyed by the slide as well. Lateral deformations can be seen in photos of the median barrier and the roadway striping. The deformations extended into the northbound lanes as well. More photos and links after the break. (Photo by ADOT)
Miscellaneous
Dr. Jorj O. Osterberg – In Memorium
Dr. Jorj O. Osterberg, inventor of the Osterberg Cell or "O-Cell" used for drilled shaft load tests has passed away at the age of 93. According to the Association of Drilled Shaft Contractors or ADSC, he died peacefully in his sleep on June 1, 2008. The geotechnical community has lost a truly legendary figure in our field.
Osterberg held degrees from Columbia, Harvard and Cornell Universities. He was a Professor Emeritus from Northwestern University. He was a former Chairman of the Soil Mechanics and Foundation Division of the ASCE, an Honorary Member of ASCE, and a member of the National Academy of Engineering. He delivered the Terzaghi Lecture in 1985, and later received the Terzaghi Award. He was one of the last surviving founding members of the International Society of Soil Mechanics and Foundation Engineering. He received the Distinguished Service Award from the Deep Foundations Institute and the Lifetime Achievement Award from the Association of Drilled Shaft Contractors. (Adapted from a bio for the 2001 Burmister Lecture, Department of Civil Engineering and Engineering Mechanics, Columbia University). Read on for more.