Dextra supplies Mechanical Rebar Couplers and Post-Tensioning Bar Systems to new Zuari Bridge in Goa

Manoj Nayak, Application Engineer, Dextra India

An 8-lane cable-stayed bridge being constructed over the river Zuari in South Goa, has taken engineering to new heights. This is the second longest and widest cable-stayed bridge in India; it will serve Expressway NH-66 that runs between Panaji and Margao over the Zuari river. While the bridge is 640m in length, the approach roads stretch from near the Bambolim crossing in North Goa to (near the) Verna industrial estate in South Goa, covering over 13km.


Design & Construction
The project comprises of 3 sections:

• an 8.2 km highway from GMC Bambolim to Goa Velha
• a new 1.08 km Zuari Bridge (Cortalim – Tiswadi)
• a 3.6 km highway to Verna.

The new Zuari cable-stayed bridge will be 640m long with a central span of 360m and end-spans of 140m on either side – making it the 2nd longest cable-stayed bridge in India. The bridge will have 27m wide dual carriageways and a center median of 10.7m. Its deck will be a composite structure of steel and concrete. A tourist observatory and a revolving restaurant at the 110m high tower is planned on the bridge, along with allied parking facility which will be developed at the Agasiam Village.

Design	Cable-Stayed Bridge
Length	640 meters
Width	27 meters, 8 Lane
Height	103 meters
Designer	INGEROP, France and Infinite Civil Solutions, India.
Contractor	DBL – MBZ JV (Dilip Buildcon and Mostobudivelnyi Zahin
Authority Engineer	S. N. Bhobe Associates, Goa
Project Cost	Rs. 2701 crores

Construction began in the year 2016. Precast yards were set up near the site for making the viaduct. The approaches used the Spine & Wing concept of superstructure. In this modern system, the spine segments of 10m width were assembled either on ground support system (GSS) or by launching a girder and joining with epoxy and temporary prestressing for post tensioning with HT strands.

Complete prestressing was applied on the spine structure and support system released and moved to the next span. With the help of wing lifters, cantilever wings were lifted and held in position for casting of in situ stitch joints between spine and wings. After adequate strength was gained of the cast in place joint, transverse prestressing was applied to complete construction of the superstructure.

Dextra’s involvement
For this massive project, Dextra has been supplying its popular parallel-threaded rebar splicing solutions Bartec for Fe 500 and Fe 600 Grade steel. More than 160K Bartec couplers are getting installed in the Pile cages, Pile caps, and Pylon. This is an iconic bridge project with Fe 600 grade steel as part of the Pile caps and Fe 500 grade steel in piles up to 48 meter deep. Pylon is 103 meters in height and designed with Fe 600 grade steel as well.

Bartec is a full performance mechanical rebar coupler, with no reduction of cross-section area of the bar thanks to their parallel threads. This characteristic makes the rebar connections a strong point of the structure and can also simplify the project’s inventory: one type of coupler for both standard and position applications. The bar-end preparation is also supported by three high-productivity machines which prepare each bar in sequence: Cutting, Cold Forging, and Threading.

In addition to Bartec couplers, for the bridge’s precast segments, the contractors also opted for Dextra Post-Tensioning Bar Systems. These PT bars help the project’s stakeholders carry out erection of precast segments and casting of the segments on time and in a quality-controlled manner.

Product	Qty. Supplied
BS Coupler	104500
BF Coupler	62000
PT Bar Systems	3839

Dextra has supplied 830/1030 grade Fully Threaded Bars of lengths up to 7meters to Dilip Buildcon for yard applications and for launching of viaducts. Also, for phase III of the project, Dextra has supplied to NRS for PT bars and accessories.