3 July 2019

Mizoram: three apartment buildings partially collapse after being hit by a landslide

Posted by Dave Petley

Mizoram: three apartment buildings partially collapse after being hit by a landslide

In Mizoram in India, several large residential buildings were struck yesterday by a substantial landslide.  Three of these buildings underwent collapse of their lower floor, although they fortunately remained upright, killing three people and injuring a further ten.  Two of the victims were children. Images of the site suggest a dramatic event – the best set of images that I have seen are on the East Mojo website, which includes this overview of the landslide site:-

Mizoram landslide

The aftermath of the landslide at Aizawl in Mizoram, India on 2nd July 2019. Image via East Mojo.

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The landslide appears to be translational nature and to have occurred in residual soil and weathered rock.  Note the smaller landslide scar, with a similar shape, to the right of the site of the slide event yesterday, also directly behind one of the apartment blocks.  The image below shows that the three blocks were pushed forwards, with the lower floor collapsing in each case in a manner that is similar to a soft storey failure in an earthquake:-

Mizoram landslide

The collapse of the lower floor of the apartment blocks after the landslide at Aizawl in Mizoram, India on 2nd July 2019. Image via East Mojo.

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Reports suggest that construction of these blocks began in 2009, but that progress had been slow such that the residents may have moved in last year.  The landslide appears to have been triggered by heavy rainfall in the early part of the monsoon.  Inevitably in an event like this there will be a focus on the degree to which the slope was cut to create the bench on which the apartment blocks were constructed.  The houses were reportedly constructed by the National Project Construction Corporation (NPCC) as part of a government programme to provide accommodation for poor people in urban areas.

This Google Earth image appears to show the site of the landslide:-

Mizoram landslide

Google Earth image of the site of the landslide at Aizawl in Mizoram, India on 2nd July 2019.

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The slope that failed looks concerning, and there is a hint of slope modification in the image, but this needs further investigation.