Problem: Slope Protection & Stabilization
The area near the Rougnichu hydro project is high sinking zone which is causing settlement of road due to the river flow downstream side which is eroding the toe of the slope. The zone is needed to be stabilized by reinforcing the slope to stop settlement so that National Highway 31 do not gets damaged. This work of stability by reinforcing the soil at Madhya Bharath HEP was given to Geo Spar Infra Pvt Ltd.
Solution suggested by us:
The engineers from Geo Spar inspected the site to see the geology and to take the section for carrying out slope analysis. The analysis is carried first on natural slope which was coming out to be less than 1.35 which was the targeted factor of safety. The slope is reinforced by installing anchors and different trails was performed to achieve to target factor of safety. The execution team carried out installation of anchors of 100 ton capacity on the area to be stabilized as per the design. The anchors are first fabricated after which drilling of hole is conducted by mustang. The anchors are lowered into the hole and with the help of grouting machine the anchor the grouted up to the bond length. The anchor spacing was kept 3×3 meters. The anchors are stressed and locked off at design loads after grout attains its strength. The anchor system provided on the area is capable enough to counter the active earth pressure and stopped the sinking problem.
Difficulties faced while execution:
The mobilization of machine for execution of slope protection at the anchoring level is very challenging. The mother rock with high shear strength is located very deep inside the slope, so we have to drill very deep inside the slope which makes anchoring very hard to do.
By providing anchors on the slope we were able to counter river scouring effect which was causing road sinking, thus we protected the National Highway 31.