Work for Clogged River Channel Site due to a Large-scale Slope Failure


Akadani No. 2 Check Dam

Typhoon No. 12 of 2011 caused a number of large-scale slope failures in the Kii Peninsula, causing massive damages. EJEC was involved in the works to control further damage occurrence through on-site surveying and monitoring the clogged river after slope failure.
Our work involved the planning and design of check dams to deal with the clogged river channel in the Akadani District.

Large-scale slope failure and river channel blockage

With a deep-seated landslide, deep ground forms the sliding surface and the resulting large volume of collapsed sediment can clog the river channel, creating a water covered area in the upstream.

  • Large-scale slope failure and clogged river channel site

  • Flooded area due to clogged river channel

Akadani No. 2 Check Dam

At the clogged river channel site formed by a large volume of collapsed sediment, it was assumed that the accumulated water held in the upstream could overflow, eroding the clogged site and causing a new collapse.
For this reason, the Akadani No. 2 Check Dam was planned and designed to anchor the leg section of the clogged river channel for stabilization while preventing erosion by an overflow.
Of the three planned check dams, the Akadani No. 2 Check Dam to anchor the leg section of the clogged river channel has been completed (March, 2016).

Work title Design Work for Erosion Control Facilities to deal with Landslide Dams in the Akadani District
Location Shimizu area, Ohto Town, Gojo City, Nara Prefecture
Duration June 15, 2012 to March 29, 2013
Implementing body Kii Mountains Erosion Control Office, Kinki Regional Development Bureau, MLIT