25 July 2016
Gangotri – a very nice rockslide video from India
As Asia reels under extraordinary rainfall under strong monsoon conditions, three new, interesting landslide videos have been posted on Youtube. The first shows a rather elegant rockslide on the highway to Gangotri in Uttarakhand in northern India:
This is a classic of its type – a translational rockslide on a joint system dipping out of the slope. It is likely that trimming of the slope to create the road has removed the natural buttress at the toe of the slide, allowing slip to occur on the existing weakness when pore pressures are high.
Note also the very large amounts of dust generated by the landslide.
A spectacular landslide from China
The magnitude of the landslide is very large. Note that both section of the landslide occurred on slopes that have been cut to create the road bench, and then reinforced to provide stability:-
The aftermath of a landslide in China
And finally, CCTV has now posted a very nice video of the aftermath of the widely circulated video of a landslide destroying houses in a rural village in Hunan Province:
This is the original video:
In this case there is a railway line running across the slope – the failure appears to have occurred at the tunnel portal:
It’s hard to know whether earthworks for the line played a role in the landslide, but it seems like a prime candidate:
These three landslides all rather nicely illustrate the ways on which poor slope management is exacerbating landslide problems in upland areas of Asia.