Alternative Tunnel System for a 8.5km long road tunnel through the Himalayas
by Florian Krenn, Geoconsult India
The Qazigund – Banihal road tunnel is part of the four-laning of the highway from Jammu over Ramban to Srinagar, to improve connectivity to the Kashmere Valley. Two long tunnels, namely the Chenani – Nasri tunnel and the Qazigund – Banihal tunnel with 9.2km and 8.5km length respectively are part of this project. The Qazigund – Banihal tunnel under the Pir Panjal mountain range will replace the Jawarhar tunnel (built in the 1950s) and apart from being an all-weather connectivity, will reduce the travel time substantially.
Almost parallel to the road tunnel is the Pir Panjal railway tunnel T-80, with its 11.2km length currently the longest railway tunnel in India under operation.
The project was tendered in 2009/2010, under a DBFOT (Design Build Operate Transfer) scheme. Since the tunnel is being a twin-lane system (both the long tunnels were planned to be twin lane only), the originally proposed tunnel system was a large single tube tunnel which housed the ventilation ducts and the escape route. After the award an intensive review of the tunnel system in respect to operational safety was conducted, as the Contractor and the Designer both agreed that the tender scheme was improvable and presented an alternative to the Client. The alternative solution is based on the European Directive for Road Tunnel Safety and splitted the large two lane tunnel into two single lane tubes with cross passages; the ventilation system was also changed – from fully transversal to semi transversal.
The construction works started in 2011, and the excavation works have been finished. Currently the inner lining works are being finished and the electromechanical installations are being done.
Florian Krenn has got 20 years experience in tunneling and geomechancial engineering. After graduation in Civil Engineering from the Technical University Graz in 1999, he obtained a Ph.D. in Mining Engineering at the University of Leoben. In 2004 he joined Geoconsult where he worked on different aspects of heavy construction engineering with emphasis on tunnel design in all phases of a project. He was involved in the preliminary design of the Brenner base tunnel, geotechnical construction supervision of soft ground and hard rock tunnel drives in the Inn valley and at the Koralm Tunnel exploratory drive. Since 2009 he is Managing Director of Geoconsult India. The projects Geoconsult India has successfully completed are the oil storage caverns in Vizag and Padur, the NATM implementation at the Jorethang Loop HEP, consultancy services in Delhi Metro Phase 3 and the detailed design of Metro Lucknow. Geoconsult is involved in different underground projects in India, namely the Qazigund - Banihal Road tunnel, Metros in Mumbai, Ahmedabad and Pune and a number of railway tunnels in the Northeast.