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Chenani Nashri Tunnel Portal (2017)

Slope Stability - Chenani Nashri Tunnel Portal (2017) 2017

Protected area in August 2017

Slope Stability - Chenani Nashri Tunnel Portal (2017) 2017

Overview of the construction site

Slope Stability - Chenani Nashri Tunnel Portal (2017) 2017

Drilling of rock bolts in progress using crane and drilling platform

Slope Stability - Chenani Nashri Tunnel Portal (2017) 2017

Laying of coir mat which shall allow further vegetation and protect against erosion

Slope Stability - Chenani Nashri Tunnel Portal (2017) 2017

TECCO® SYSTEM³ fully installed with coir net during hydroseeding process

Slope Stability - Chenani Nashri Tunnel Portal (2017) 2017

GBE-500A as extra protection against rockfalls installed directly above tunnel portal

Slope Stability - Chenani Nashri Tunnel Portal (2017) 2017

Another view of a GBE-500A rockfall barrier line

Slope Stability - Chenani Nashri Tunnel Portal (2017) 2017

Slopes fully stabilized using TECCO® SYSTEM³, vegetation shows water outbursts

 
 

Year of installation

2017

Initial situation

The site was initially proposed to be treated with shotcrete but persistent seepage of water which caused slope failures and cracks on the portals led the concessionaire to go for an alternate solution which does not only stabilize the slopes but also offers a green solution and allows the hydrostatic pressure to disperse. National Highway Authority of India decided to actively stabilize the tunnel portals. A protective measure had to be selected to stabilize the exposed cutting against superficial instabilities, as well as tilts and slides of individual blocks and rockfalls.

The area of the slopes to be treated and protected amounts to a total of 32'000 m² which includes 4 berms and the top path up to a maximum height of ca. 55 m.

Description

The slope stabilization solution consisted of both active and passive protection measures.The flexible slope stabilization system consisting of TECCO® System and coir mat, system spike plates and soil nails had been selected. 

Each berm is stabilized using rock-bolts of a maximum depth of 20 m in conjunction with high tensile steel wire mesh. Perforated drain pipes, wrapped in geotextile, at an interval of 6.0 x 6.0 m are also installed to allow excess water to pass.

In addition, vertical and horizontal drainage channels are provided to channelize rain and excess water to pass and not accumulate and seep under the slopes. Variable grid patterns of 2.0 x 2.0 m and 2.5 m x 2.5 m are adopted on this project. 32 mm thick, fully threaded rock-bolts were used in this project and total drill lenght achieved is approximately 11'0000 m.

An additional GBE-500A rockfall barrier line was installed which can absorb impact energies up to 500 kJ.

See also our rockfall project Chenani Nashri Tunnel Portal (2)

Customer

N.H.A.I. (National Highways Authority of India)

Protected object

Road, Infrastructure

Corrosion protection

GEOBRUGG SUPERCOATING

Engineering

IL&FS Transportation Networks Ltd.

Other installed applications

Rockfall Protection

Your local contact

Kevin H. Coyle
 

Kevin H. Coyle

Regional Manager Northeast

Natural Hazards
Hydraulic Engineering
Geobrugg North America, LLC,3 Beaudet Terr,Columbia CT 06237 / United States Regional Manager Northeast

E-Mail

Saleh Feidi
 

Saleh Feidi

Regional Manager California

Natural Hazards
Hydraulic Engineering
Geobrugg North America, LLC,8921 Emperor Ave.,San Gabriel, California 91775 / United States Regional Manager California

E-Mail

John Kalejta
 

John Kalejta

Regional Manager Central US

Natural Hazards
Hydraulic Engineering
Geobrugg North America, LLC,3215 67th Avenue Pl,Greeley CO 80634 / United States Regional Manager Central US

E-Mail

Bob Lyne
 

Bob Lyne

Regional Manager Southeast

Natural Hazards
Hydraulic Engineering
Geobrugg North America, LLC,8004 Windspray Drive,Summerfield NC 27358 / United States Regional Manager Southeast

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Pierce Runnels, Civil Engineer
   

Pierce Runnels

General Manager Geobrugg North America

Natural Hazards
Geobrugg North America, LLC,22 Centro Algodones , Civil Engineer General Manager Geobrugg North America

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Tim Shevlin
 

Tim Shevlin

Sales Director

Natural Hazards
Geobrugg North America, LLC,Salem OR 97302 / United States Sales Director

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