Problem: Slope Protection and Stabilization
In the dam area along the spillway access landslide occurred. This area has variable strata which is very prone to landslide. Due to the presence of this landslide prone area there are only two options left, first is to change the spillway access and next to protect that area. The changing of main spillways access is not feasible, so decision to protect the landslide prone area along the spillways was chosen.
Solution suggested by us:
The slope protection work was awarded to Spar Geo Infra Pvt Ltd and the team visited the site and took sections of the slope for analysis. The analysis of slope was carried out and was found that soil nails are not so effective in this variable strata, therefore anchors with cladding wall was proposed for the slope protection. Geo Spar designed the wire anchors for the slope by taking proper factor of safety and optimum performance by keeping safety and economic considerations in account which will prove to be best for client. The anchor of 100 ton capacity of 20 meter length at the inclination of 150 with spacing of 3×3 meters are purposed and will be tested for the design loads as per the codal provisions. The thickness of cladding wall 500 mm.
Difficulties faced while execution:
The area comprises of 30 to 35 meter over-burden due to which drilling of anchors was very difficult. To overcome these difficulties, tools were imported. While driving casing, case shoe was getting damage due to the presence of variable strata in which boulders were encountered during the process of driving of casing.
Extra Technology used for execution:
Spar Geo Infra Pvt Ltd used special machines of Atlas Copco to execute the slope stability work in this variable strata which have boulders present in between them.
The beauty of this project is that the slope stability system withstood an earthquake of magnitude 7 on the Richter scale whose epicenter was near the site caused major damage to the dam body as well as spillway. This shows our solution reliability and success of our design as well as our perfect execution of slope stability work.