GMR Infrastructure has entrusted to Reinforced Earth India for construction of reinforced earth structures for its Hungund-Hospet highway project in Karnataka. The NHAI project involves four-laning of the 99.05km stretch on NH-13 on DBFOT basis. The 19-year concession period includes construction time of 30 months. GMR is developing the project with Oriental Structural Engineers Pvt. Ltd as a consortium partner.
The project comprises construction of two flyovers, two railway over bridges, one vehicular underpass and one pedestrian underpass. All these structures were proposed with reinforced earth structures with overall quantum of work 50,000 sq.m.
Considering the tight construction schedule of the project and complexities involved in the construction of reinforced earth structures, in January 2011, GMR entrusted the project to Reinforced Earth India on the strength of their previous performances and credibility.
A detailed study was carried out by Reinforced Earth India. GeoMega technology with full synthetic connection between panels and Geosynthetic strips was proposed for the project. The heights of MSE wall in ROB and flyover structures were more than 13m. It prompted REI to use +20 and +40 GeoMega sleeves for the first time in India. The wall height upto 9m, normal GeoMega sleeves were proposed, between 9m to 11m wall heights +20 GeoMega sleeves were proposed and beyond 11m heights +40 GeoMega sleeves were proposed. To ensure speedy construction, 180mm thick TerraTee panels were proposed.
The design was carried out considering the angle of internal friction of backfill soil as 32°. However, GMR arranged a backfill soil, which was well graded and the angle of internal friction was 34°. This good quality backfill soil, ensured there is no movement in panel face and no closure of joints. The maximum wall height in the entire project was 13.81m and the project was executed well within the time frame.
The Reinforced Earth wall stands tall as a landmark project in this part of the state.