Reinforced Earth® wall for new Rishikesh Railway Station in Uttrakhand

Reinforced Earth® wall for new Rishikesh Railway Station in Uttrakhand.

Project Details

RE WALL TYPE

TerraClass® with High Adherence GeoStrap® & GeoMega® Connectors

OWNER

Rail Vikas Nigam Ltd.

DESIGNER

Geoquest India (formerly known as Reinforced Earth India Pvt. Ltd.)

CONTRACTOR

VKJ Pvt Ltd.

COMPLETION YEAR

02/2020

Background

Northern Railways under Rail Vikas Nigam Pvt Ltd. (RVNL) had proposed a new route for Char Dham. This new rail link of 125km runs between Rishikesh and Karanprayag via Devprayag in the State of Uttarakhand, India. The Rishikesh–Karnaprayag Railway line will reduce Rishikesh to Karnaprayag travel time from 7 hours to 2.1 hours. This project has 16 bridges and 105 km or 85% of rail alignment runs through tunnels.

Geoquest India was awarded the work by VKG Projects Pvt. Ltd. for construction of 14 m high Reinforced Earth® Wall for proposed Shunting Neck (Railway Siding) at the new rail link. The structure had to be constructed for the Shunting track running parallelly with main railway track which is running in downhill direction towards Haridwar.

Challenge

The Proposed New Rishikesh railway station is in a hilly terrain.

The elevation difference between two railway tracks i.e., the railway main track and the railway shunting neck track is of maximum 13 meters.
Due to high elevation and lack of free space, earthen embankment construction was not possible, and it would have encroached a private
property just besides this new station.
Cost of constructing huge embankment by soil filling was also calculated to be significantly high compared to a RE Wall Structure.
Even RCC Retaining wall was also not viable considering the available space and cost constraints.

The most economical and ideal solution was therefore, to construct a Reinforced Earth® wall to support the shunting line’s rail track. Reinforced Earth ® technology was the most reliable solution, given the time bound construction period.

Solution

Post evaluating the site and project requirement, Geoquest India proposed Reinforced Earth® wall as a solution. The technology is very similar to roadway applications, except that the design of the Reinforced Earth® Wall is customized to comply with the safety requirements for high speed railways. Railways loads differ from highway loads to a larger extent in terms of intensity, frequency and associated vibrations.

In a detailed design process, Geoquest India leveraged the wide experience of successfully completed national , International projects
and in-house technical know-how to design the Reinforced Earth® wall using High Adherence (HA) 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). 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) = 30° and considering a 32.50 MT Axle loading as design as per RDSO guidelines. The use of High Adherence soil reinforcements for structures supporting railways, gives guarantee of minimal deformations under high loads. Structures beneath the tracks are designed to accommodate sudden braking decelerations. Reinforced Earth® tructures absorb the vibrations induced by passing trains inherently well.

The Reinforced Earth® wall structure not only saved the cost of construction, but also was constructed within the limited space without any encroachment.

Special Features and Advantages

Strength – significant load bearing capacity
Resilience – effective absorption of vibrations and an exceptional response to seismic events
Durability – high quality materials, proven track record and ease of inspection
Adaptability – to geotechnical, environmental and architectural site conditions
Low impact – rapid construction, limited land use, no traffic disruption and reduced environmental footprint