22 June 2016
Pingle County quarry collapse
Xinhua reported on Monday that a quarry collapse had trapped seven people in Pingle county, Guangxi Zhuang Autonomous Region in China. They provided little detail other than to say that rescue operations were ongoing. However, CCTV has now posted a very high quality video of the site, and of the rescue operations, on Youtube:
Based on the images this looks to be a classic rockslope failure caused by undercutting during the quarrying. This is a still from the video:
I think that on the upper part of the scar the detachment may well be controlled by two large joints. This would explain the very hefty boulders in the rockfall deposit. Note also the very clear horizontal discontinuity running across the lower slope. The rockslope collapse has generated a deposit that is exceptionally coarse-grained:
The ongoing rockfall activity, and the potentially unstable nature of the remaining rock mass, means that the rescue operations are extremely hazardous. Sadly I can think of no examples in which people have been successfully rescued from beneath a deposit of this type. I suspect there may be cases, but they are rare, and they will always require that the survivor was sheltered in some sort of structure.
Once again the desperate need for improved quarry and mining safety in China has been highlighted. The toll from quarry landslides there remains fearsome.
Heavy rains across southern China
Meanwhile, Xinhua is also reporting the terrible toll from the heavy rains that are currently affecting the southern part of China. Floods and landslides are reported to have killed 22 people to date, with another 20 missing. This includes a substantial landslide in a railway construction site in Sichuan Province:
In Xingwen County, southwest China’s Sichuan province, five more bodies were found at a railway construction site, bringing the death toll from landslides in the county to seven. Following heavy rain, a landslide occurred around 3 a.m. Sunday that destroyed workers’ dormitories. Three people were hospitalized, they remain under observation but are in a stable condition.