The Colorado Geologic Survey has a very comprehensive overview of the geologic hazard of rockfall in all its many forms in their latest issue of RockTalk newsletter. The entire 24-page newsletter is devoted to various aspects of the problem, mitigation options and case studies all with excellent photos. I highly recommend that you check it out. Click through for the link. (Photo by CGS)
Our monthly update on new and revised ASTM standards that relate to geotechnical engineering, materials testing, hydrogeology, geosynthetics and related disciplines. This month there are a few notable revisions, including D1452 for Auger Borings, D3385 for Double-Ring Infiltrometer and D4595 for determining tensile properties of geotextiles by the wide-width strip method. There are also a few other geotextile, groundwater, lime, masonry and terminology standards that were added or updated. Click through for the full list.
Dr. Peter Rankilor, a pioneer in the geosynthetic, geotextile and geomembrane industry was recently sentenced to 10 years in prison as a result of his January conviction on “indecent assault and incest” charges stemming from […]
Its been a while since I’ve posted in Rockman’s ramblings. But tonight as I try to wind down from a stressful drive back to Tucson from Phoenix on a very windy night, I feel the muse at work. Maybe the martini is helping too! Tonight was a meeting of the Arizona Section of the Association of Engineering and Environmental Geologists (AEG). The speaker was the 2009 AEG Jahns Distinguished Lecturer, Dr. Edmund Medley of Geosyntec Consultants.
He’s perhaps best known for coining the phrase “bimrocks” for block-in-matrix-rock. He’s also written and presented some stuff on terrestrial 3d photogrammetry for geological engineering. He’s an incredibly colorful, energetic, and genuine man who is a very entertaining and gifted writer and presenter. I was glad to meet him after trading a few emails previously. I’m not sure how he would feel about this comparison, but for some reason he reminded me of Bilbo Baggins. (Photo from EdMedley.com)
[Editor] Last week was the International Foundation Congress and Equipment Exposition in Orlando, Florida. The event was co-sponsored by the Geo-Institute, ADSC and PDCA. Perhaps at the next event I’ll be able to attend and provide some comprehesive coverage via GeoPrac. In the meantime, I am very appreciative of Robert Thompson of Dan Brown and Associates, PLLC. who was among the attendees (and a presenter?). He was kind enough to provide GeoPrac readers a summary of the event. Click through for more on this tremendous conference. (Photo by Robert Thompson, Dan Brown and Associates, Inc. ) [/Editor]
The latest information to come out of the collapse of a subway tunnel excavation in Cologne, Germany is that investigators are evaluating the ground anchors or tiebacks that were holding open the subway tunnel excavation. There doesn’t appear to be much information available to the public yet, and the New Civil Engineer article mostly quoted academics saying an anchor failure “could” have caused the collapse. Apparently at the time of the collapse, the excavation had reached the bottom depth after the slurry walls had been constructed along with the ground anchor system. Crews were supposedly working on the base slab which would have undoubtedly stiffened up the whole system. For what its worth, an anonymous comment left at the bottom of that article indicated that after half of the debris had been excavated, the diaphragm walls were still intact and without apparent displacement. So what other theories have been floated? Read on for more info. (Image Credit: New Civil Engineer)
A colleague of mine sent me an amazing video of a culvert failure and subsequent road collapse in Freeport Maine during a storm. The culvert was unable to accommodate the high volume of water, and it was backing up behind the roadway embankment like a dam, and spilling out onto the roadway. In a span of about 3 minutes, the entire section of road collapsed and was washed downstream. I don’t know the exact date the video was taken, but it appears to be in August of 2008. Click through for the video.
Urban miners have been busy constructing a new water supply tunnel underneath New York City to supply the megalopolis with the water it needs. The miners, or sandhogs as they are known, are about halfway complete with the new tunnel which is expected to be in service by the year 2020. Work on the 60-mile tunnel began in 1970 and the total projected cost is $6 billion and is widely regarded as one of the most complex public works projects in the western hemisphere. When complete, it will help deliver 1.2 billion gallons DAILY to 8 million New Yorkers. The city currently gets its drinking water from two water supply tunnels that were constructed in the early 20th century and have not been inspected or repaired since then. More after the break. (Image credit History.com)
The USGS has a documentary on landslide video on landslide danger in the San Francisco Bay area entitled “Riding the Storm”. I think the target audience is more general than geologist or engineer, but it is still interesting. The bullet points from the USGS site:
- A catastrophic 1982 rainstorm triggered 18,000 landslides in the Bay Area, claiming 25 lives and causing $66 million in property damage
- The combination of steep slopes, weak rocks, and intense winter storms make Bay Area uplands an ideal setting for landslides
- Landslides include both swift, potentially deadly debris flows and slower, but destructive deepseated slides
- Learn what USGS scientists have discovered about landslide dynamics and which slopes are most susceptible to sliding
- Hear the devastating stories of Bay Area residents affected by landslides and learn to recognize the danger signs
Click through to view the trailer and for links to download the full video. (Image credit: USGS)