Construction of right side service road connecting Nagarbhavi Circle to Vidyagiri Layout along ORR from CH 52+635 to CH 52+850, in Bengaluru city, India.
Project Details
TYPE
Structure Type
TerraLink™ and Reinforced Earth®
OWNER
Bangalore Development Authority (BDA)
CONTRACTOR
PJB Engineers Pvt. Ltd.
CONSTRUCTION YEAR
03/2015 to 01/2016
DESIGNER + CONSULTANT
- Terre Armée (Reinforced Earth India Pvt. Ltd.)
- Bangalore University
Background
The Bengaluru Development Authority (BDA) began construction of Outer Ring Road (ORR) to Bengaluru city to ease traffic in 2005. ORR was connected to the city using service roads at specified junctions. One such junction was located at Nagarbhavi locality for which the service road was not constructed till 2015 due to space constraints. A residential area was developed atop the hillock and excavation on the hill toe was not feasible. At the same time, it was necessary to construct a service road to decongest this junction. Therefore, BDA decided to construct an elevated service road without disturbing the toe of the hillock. This required constructing a retaining structure at the toe of the existing hill. BDA decided to construct a Reinforced Earth® wall. However, adequate space to lay soil reinforcement was not available. Hence Terre Armée in India was consulted and came up with the proposal of TerraLink™, which was accepted.
Challenge
Construction of Reinforced Earth® wall on the entire stretch was not feasible due to space constraints at the toe of the hillock.
During construction, the hillock should not become unstable and safety of the structures built on top of the hillock should not be compromised at any time.
Solution
After completing the site survey, Terre Armée in India proposed Reinforced Earth® walls wherever adequate space was available.
TerraLink™ wall was proposed at places where the toe of the hillock was too close and sufficient space was not available for laying soil reinforcement for a conventional Reinforced Earth® wall. In TerraLink™ Grouted TerraNail are drilled inside the existing slope and then connected mechanically to a Reinforced Earth® wall. Excavation of existing hill toe was not required to create space.
Out of 1,938 sq m, the TerraLink™ system was adopted for 878 sq m and 1,060 sq m was conventional Reinforced Earth® Wall.
TerraLink™ Wall height varied from 3m to 10m. It was designed for 24 KPa loading and designed as per BS 8006:1995, IS 1893:2002 & AFNOR NF P 94-220.
Terre Armée in India was responsible for design, sourcing of specialized materials and on-site technical assistance. The project was completed successfully within 10 months’ time.