Strengthening of flexible pavement using StrataWeb® geocells


Application Strengthening of flexible pavement using StrataWeb® geocells in the hilly terrain
Location Coonoor, Tamil Nadu, India
Client Vitrag Group/Sancheti Architects
Contractor Vitrag Group, Developers and Builders, Coonoor
Project scope Design, supply and supervision with SW 356-150, 200 GSM non-woven geotextile

Project overview

The client proposed the idea of building an access road to the villas in the hilly terrains of the Nilgiris in Coonoor, Tamil Nadu. Coonoor is a hill station in the southern Indian state of Tamil Nadu. It is known for its tea estates in the surrounding Nilgiri hills. The site comprised of subgrade soil with a CBR of 1.5% which had to be improved for smooth movement of traffic and for minimising the effect of ruts due to vehicular passes.

Challenges

  • Deep ruts made it difficult for movement of heavy construction machinery on the hilly terrain
  • Due to improper and insufficient drainage, the movement of the heavy traffic was affected, especially during the monsoons. Therefore there was a need to have a definitive solution for sub-grade improvement

Conventional solution

The conventional approach would have proved to be more costly and would have exhausted more natural resources. Also, there are strict environmental policies governing this region for maximized conservation of natural resources.

Strata’s innovative solution

Strata’s team of geotechnical experts proposed the design using StrataWeb® for the strengthening of the flexible pavement. Introducing StrataWeb® SW 356-150 geocells in a granular base or sub-base not only improved the longevity of the pavement but also economized the overall crust thickness.

StrataWeb® helps in confining the soil due to its three-dimensional structure. It helps in distributing the load to a wider area, thereby reducing stresses on the overall crust thickness. A 200 GSM PP non-woven geotextile was placed below the granular sub-base layer which acted as a separator between the dressed subgrade and the geocell infill material. Locally available infill material was used.

Strata’s value addition

  • Saved approximately 15% of the cost compared to conventional methods.
  • Faster execution of work due to ease of installation of geocells, saving time of the project as the conventional method would have been too time taking.
  • Excellent inbuilt drainage feature of StrataWeb® which allows release of pore water pressure.