People interested in geotechnical engineering are watching closely the colliery landslide at Hatfield Stainforth, in Northern England that is still in progress. Since February 13nth reports and photos on the landslide’s progress are coming in.
Thanks to Prof. Dave Petley’s (Durham University UK) landslide blog, the info and the photographs are really spectacular. According to his first estimation the size and the geometry of the toe bulge suggest a bearing capacity failure. The very wet weather of last few months, triggered the landslide with a rotational geometry.
Due to the size of landslide mass, stabilization will be highly difficult. The railway line is expected to be closed for some time.
In these cases where the amount of soil mass is prohibiting, it might be better to wait for the landslide system to find progressively its own balance, before intervening with further stabilization measures.
Another eruption of Etna volcano started on Tuesday Feb 19, 2013 from the SE crater. Volcano eruption of Etna happened with 4 paroxysms so far, with lava fountains, lava flows and tall ash plumes.
Mount Etna is an active volcano on the island of Sicily. The volcanic activity of the area is a result of the convergence of the African Plate and the Eurasian Plate. Mount Etna is one of the most active volcanos on Earth. Numerous volcano eruptions of Etna have taken place in historical and recent years.
During historical years is reported that in 396 BC the volcano eruption of Etna prevented the Carthaginians to advance on Syracuse. One of Etna’s most destructive eruptions took place on 11 March 1669. In recent history the 1928 volcano eruption led to the destruction of village Mascali. Other major 20th – century eruptions occurred in 1949, 1971,1981, 1991, 2001, 2007 and 2011.
According to scientists from University of Utah, a “super-volcano” is forming deep below the Earth’s crust at the area north of New Zealand. This kind of volcano eruption can destroy life as we know it. However this event is not likely to happen for another 100-200 million years according to the scientists that studied this phenomenon.
University of Utah seismologist Michael Thorne has been studying seismic waves through the Earth’s crust and has come to the conclusion that such a volcano eruption can happen. According to his study deep beneath the Pacific Ocean, near Samoa, two continent – sized piles of rock were colliding moving at the lower part of Earth’s mantle.
This way new volcanic “hotspots” are formed leading to huge volcano eruptions giving magnificent features and formations i.e. Yellowstone National Park, Wyoming.
This study includes the largest set of data ever used to map the lower mantle in the Pacific region, using 4.221 seismograms from seismometers around the world that detected 51 deep earthquakes originating more than 100 km under the surface.
An expressway tunnel in central Japan whose ceiling collapsed in December, killing nine, became fully operational Friday after a 68-day hiatus, its operator Central Nippon Expressway Co. said.
The nearly 5-kilometer-long Sasago Tunnel in Yamanashi Prefecture became fully usable again ahead of the previously targeted reopening date later this month as restoration work was hastened ahead of the upcoming long weekend when traffic is expected to increase.
The Ministry of Land, Infrastructure, Transport and Tourism gave its go-ahead on the grounds that all safety issues have been cleared.
Some bereaved relatives of the victims are taking issue, however, with the road operator’s policy to prioritize the tunnel reopening before the cause of the fatal accident has been fully clarified.
The tunnel restarted partial operation on Dec. 29 after tunnel collapse with half of the lanes reopened to traffic.
Tunnel collapse can happen for a number of reasons such as: inadequate ground investigation, shallow ground conditions, inadequate support measures, cost optimization, inexperienced contractors, inadequate supervision, delays of excavation and support erection.
A moderate 5.7 magnitude earthquake in Chile, happened on Sunday 10 February 2013, according to USGS. There are no immediate reports of casualties or damage.
The epicenter of the Chile earthquake was approximately 24 kilometers northwest of Cartagena kai 4o kilometers south of Valparaiso.
In February 2010, a massive 8.8 magnitude earthquake hit Chile at central Maule region, generating tsunami waves, killing 500 people.
Chile is a country with a huge seismic history, considering that lies above the converge of the Nazca Plate and the South American plate. For this reason Chile has been the site of many historical earthquakes, including the largest earthquake ever recorded.
On Monday afternoon (28/1/2013), three buildings collapsed after subsidence in Guangzhou. The incident happened near a metro tunnel construction site.
It is reported that metro workers spotted land subsidence near the project site and immediately the area was evacuated, hence no casualties have been reported. The subsidence area was about 10m deep and extended about 100m2.
It is also reported that the area is temporary stabilized by backfilling concrete into thesubsidence. The site is monitored for risk assessment.
Tunnel construction with a fast pace and lowered standards could lead to disaster. Land subsidence can be caused by a variety of factors. Tunneling in urban areas always includes careful consideration and monitoring of land movement.