Every second of October, geotechnical engineers around the world remember Karl Terzaghi on his birthday! Terzaghi is the father of soil mechanics, and I don't think it is cliche to say he is also the father of our profession. So happy KTB 2013! It's a big one for Karl, he would have been 130 today by my calculation!
I always like to celebrate by reading some of his quotes, many of which seem like they could have been written to us today…like this one:
…as soon as we pass from steel and concrete to earth, the omnipotence of theory ceases to exist. In the first place, the earth in its natural state is never uniform. Second, its properties are too complicated for rigorous theoretical treatment. Finally, even an approximate mathematical solution of some of the most common problems is extremely difficult.
Pier 22 of the Leo Frigo Bridge settled 22 to 27 inches last week causing a 400 foot long segment of the bridge to sag dramatically, forcing the closure of the bridge. There were no reports of injuries and there has been no further reports of additional movement of the pier.
The pier is approximately 700 feet from the edge of the Fox River. The pier is a hammerhead-type pier with two columns extending down to the ground. The foundation system consists of footings supported by a group of steel piles 100 feet long. Highway spokesmen would not speculate on the cause of the settlement.
If you look at the photos of the bridge, there does not appear to be any structural damage to the pier, it looks like the entire pier just settled. So this geotechnical engineer’s opinion is that it certainly seems likely this is a geotechnicl type of failure. But we will have to wait until additional information is released.
TRB's National Cooperative Highway Research Program Report 747: Guide for Conducting Forensic Investigations of Highway Pavements explores a process for conducting forensic investigations of pavements that is designed to help understand the reasons behind premature failures or exceptionally good performance. The process also allows for the collection of data for use in developing or calibrating performance-prediction models.
The report includes example forms and checklists for use during the conduct of an investigation. These forms can be modified to suit the particular requirements and procedures for the agency. The example forms are included with the print version of the report in CD-ROM format. [Source: Download the Report and/or CD ISO from TRB. Image: TRB]
THE WOODLANDS, Texas, Sept. 18, 2013 (GLOBE NEWSWIRE) -- Layne Christensen Company(Nasdaq:LAYN) ("Layne") today announced that its Geoconstruction Division received a contract to provide specialized foundation work in connection with the construction of Transbay Tower in San Francisco.
The contract has an estimated value to Layne of approximately $19 million. Work on the project is expected to commence in October 2013 and last approximately 6 months.
[Editor] Read on for more info about the foundations for this new 61 story high-rise in downtown San Francisco. [/Editor]
GeoPrac is very pleased to announce that Keynetix Ltd. has become our newest sponsor! Keynetix is a geotechnical and environmental data management software company headquartered in Redditch, Worcestershire, UK. They are AutoDesk’s Geotechnical Industry Partner, integrating geotechnical data work flows into AutoCAD Civil3D.
Keynetix’ flagship products include HoleBASE SI, for borehole data management, log production, section diagrams, and BIM integration into AutoCAD Civil 3D; KeyLAB for geotechnical laboratory management and control, KeyAGS for creating, importing and exporting of AGS Data and Pocket SI for hand held data collection of site investigation information. Be sure to read more about their products and services at their website!
Last week I attended the AEG 2013 conference in Seattle, Washington. The conference was excellent, with many great presentations and networking opportunities. I have been playing catch-up since I returned, but I have some very interesting things to blog about once I sit down and start writing. Keep watching!
One interesting thing was the view right outside my hotel window. I could see the construction site for a new high-rise building which is currently being excavated by DBM Contractors, a specialty geotechnical contractor based in Federal Way, Washington (Seattle Metro area). I didn’t see mention of this project on DBM’s website, but they did work on a similar project just a few blocks away. It looks like there are soldier pile lagging retaining walls with multiple levels of anchors. I imagine that once they finish the excavation, they will also construct the drilled shaft foundations for the structure as well. I'm guessing they performed some de-watering as well.
Maybe I got a little over-excited, but I don’t see these types of excavations too often in my geotechnical practice!
A dramatic landslide that nearly crushed a car along the Taiwanese coast was caught on video by a dashboard cam. The video has gone viral on YouTube and has over 7 million views since it was posted on Saturday.
ASCE Geo-Institute retaining wall committee Chairman Dimitrios Konstantakos of Deep Excavation LLC has issued a request to the geotechnical community to help identify the "Grand Challenges in Earth Retaining Structures". From his blog post on Linkedin:
Grand Challenge issues are those issues that are transformational in nature. These are issues that if addressed, will have a significant impact on the current approaches to the design and construction of earth retention systems (ERS), and will drive the future direction of our industry.
A team of geologists from the Geological Survey of Denmark and Greenland (GEUS) in Copenhagen, Cardiff University in Wales, Lund University in Sweden and the Institute of Planetary Science in Moscow has found the remains of a giant asteroid impact crater in Western Greenland that is over 3 billion years old! Preliminary size estimates of the impacting meteorite at Maniitsoq suggest it may have had a diameter of approximately 30 km resulting in an impact crater of somewhere around 500-600 km.
If an impact of this size hit the Earth today, it would not only be able to pulverise a medium-sized national state but its global effects would also kill all higher life.