TERRATEE® STRUCTURES AT KALAMBOLI, MAHARASHTRA

Construction of Yard at Kalamboli in Navi Mumbai in Maharashtra, India.

P R O J E C T  D E T A I L S

System Owner Contractor Construction Year Designer + Consultant
RE Wall Type: TerraTee®
with High Adherence
GeoStrap® and GeoMega®
Connectors
Central Railways GOI MVR Constructions 03/2017 to 11/2017 • Terre Armée (Reinforced
Earth India Pvt. Ltd.)
• IIT Mumbai/
Central Railways

Background

Kalamboli is a railway station on the Vasai Road – Diva – Panvel route of the Central Line, of the Mumbai Suburban Railway network. The yard is being developed at this station for the goods train carrying heavy loads.

The railway line was planned on embankment height varying from 3 mt to 6 mt in height and of 550 mt long. The central railways had approached Terre Armée India to provide an innovative and sustainable solution to build the embankment to support railway loading.

Challenge

The most challenging part was to convince the railway authorities to use Geosynthetic soil reinforcement.

The central railways wanted to finish this project in a duration of 6 months, the total length of RE wall to be completed was 550m.

Central railways were concerned about the drainage system which would be adopted for construction of RE wall.

Economy was a major concern, the system had to be cost effective when compared to conventional retaining system.

The surcharge loading on the RE wall was approximately 48kN/m2.

Since this was the first time, central railways was using Reinforced Earth® wall techniques for supporting railway tracks there were many apprehension from the client on the use of this technique.

Solution

In a detailed design process, Terre Armée India used the in-house technical know-how to design the Reinforced Earth® wall using High Adherence GeoStrap® with synthetic GeoMega® connection system. HA GeoStrap® as soil reinforcement having lateral ribs and made of high tenacity polyester yarns (PET) placed in tension and co-extruded with linear low density polyethylene (LLDPE) to form straps of 50 mm wide. System consists of connection system made of molded polypropylene  sleeve, a totally metallic free connection system. Project made use well graded fill material having angle of internal friction (Ф) > 32o and considering a 32 MT Axle loading as design as per RDSO guidelines.

Failure surfaces through reinforced soil block & extending beyond it or encompassing the foundation soil has been analyzed to ensure sufficient length & strength within the reinforced soil mass. In this project client had insisted on performing the hand calculations and graphical analysis, hence the calculations were performed with Swedish Circle Method.

As an additional safety for such important structure it was suggested to use Geocomposite Drain/Geomenbrane below the ballast on railway track to avoid seepage of water from the tracks.

Surface water runoff drainage system have been adopted near the coping beam on the top with proper gradient to facilitate the additional water coming on the railway tracks.

The foundation here was moderately weathered basalt at a depth of 3m. So the minimum foundation depth considered was 1.7m.

Design by:   Firefly Communications