26 October 2020
Landslides and roads – recent examples
The recent extreme rainfall in Vietnam has triggered a large number of damaging landslides, with high levels of loss of life. Less well reported is the impact of these landslides on the road network of the country. VNExpress has a nice article today with a gallery of images of the damage caused by these landslides. It reports that:
The government has to spend some VND350 billion ($15 million) to repair national highways that have been destroyed by landslides during the recent floods in the central region.
The image below, which has the following caption “A section of National Highway 12A between Khe Ve Intersection and Cha Lo Border Gate in Minh Hoa District, Quang Binh Province was hit by landslide on October 19. Some 450 meters of it have been destroyed while a 100-meter stretch sank”, is a good example:
This is a classic image of landslide damage. But the damage does not have to come from below. This image shows the impact of slope instability in materials above the road bench:
The caption for this landslide is as follows: A hill collapsed on a section of National Highway 49 in Thua Thien-Hue Province.
Meanwhile, parts of India continue to suffer from the effects of extreme rainfall too. The image below was shared on Twitter by Devakishor Soraisam (@devakishor). It shows a section of the NH2 highway between Senapati and Lairouching in Manipur, NE India. This is an interesting landslide as the retaining wall at the rear of the road bench has remained intact. I wonder if the cause was tipping of fill on the downslope side to widen the road bench, oversteepening and loading the slope?
Quickslide 1: The preferred option for Rest and Be Thankful
The challenges of the landslide problem at Rest and Be Thankful continues with the local authority stating its preferred long term solution. This would be to improve an alternative routes rather than engineering a solution at the site itself.
Quickslide 2: Climate change is increasing rockfall risk for climbers
Outside has a nice article about the effects of climate change on rockfalls, and the danger that this is posing to climbers.