Bridge Construction In Challenging Conditions

V.G. Sakthikumar, Managing Director, Schwing Stetter Sales & Services Pvt. Ltd.

A large numbers of Bridges, Flyovers and Elevated MRTS Structures are being constructed all over the country for better and faster commuting. They also provide connectivity to different parts of the city in a country, which needs fast transport system. Most of the bridge structures built in India have been concreted by equipment of Schwing Stetter India.

Bridge construction is most complicated because of the unexpected difficulties faced during construction in challenging conditions and especially during concreting. The latest trends and development in design and technology have lead to many challenges during the construction of bridges.

Challenges Faced in Bridge Concreting
The quality and reliability of the concrete is crucial to safe construction and lifespan of the bridges. To ensure the same, different ingredients of concrete has to be mixed homogenously to produce a perfect mix of concrete and has to be place in short span of time. Bridge concreting is done using concrete mix up to M80 grade and critical requirements like casting blocks need maximum strength in minimum possible time for pre-stressed or post-tension casting.

Some of the other issues and challenges in concreting of bridges are stiff consistency concrete producing, placing concrete girders using cranes (e.g. Metro Projects) along heavily crowded roads & transportation and laying of concrete pipes on the sea or river for concrete placement. To overcome these concreting difficulties Schwing Stetter India not only manufactures different types of advanced concreting equipment but also provides various concreting solutions to its customers.

Equipment Used
The most commonly used Schwing Stetter Equipment to place concrete for bridge projects are: Batching Plants CP30 and M1, which provide a homogenous mix of concrete. Concrete Pumps like BP350, SP1800 and SP3500, which are designed with two valve technologies, Flat Gate Valve (FGV) and Rock Valve, which enable smooth conveying of concrete to long distances and also helps to pump stiff mixes for casting.

Transit Mixer 6m3, 7m3, 8m3, 9 m3, 10 m3 are usually used to transport concrete for bridge constructions. These Transit Mixers come with modern design, simple handling and are cost effective. Separate Placing Boom- 28 metre to 35 metre and Boom Placer- 17 metre to 43 metre are used for faster completion of concrete placement. These equipment take on the challenges posted by the bridge projects.

Concreting Solutions
Schwing Stetter India’s team of concrete experts look into the depth of the problems and provide solutions to guide the customer on easy concreting. Customers call Schwing Stetter India right away to discuss the project before the commencement of construction and to find the possible concrete placing solutions for complicated projects. The team provides the best solution, which would make the most sense and would be most cost effective. Schwing Stetter India have a complete system approach, helping the customer from the beginning of the project.

Some of the concreting solutions given by Schwing Stetter are:

– Selection of equipment for batching, transporting, placing as per the project requirements.

– Use of RVM’s for concrete transfer available for on shore and off shore applications.

– Mounting option for Batching Plant, Transit Mixer, and Separate Placing Boom on barge and on lattice frame.

– Use of minimum space required for setting up Schwing boom placer which is useful in traffic as well as casting yards.

– Pipeline placing and cleaning systems for cast yard, offshore and high structure applications.

Bridge Project by SSI
Schwing Stetter India has contributed in many critical & landmark bridge projects in India. The different types of bridge projects where Schwing Stetter equipment were used are Beam or Girder type Bridges (regular), Cable Stayed Bridge like Bandra Worli Sea Link, Suspension Bridges like Bridge over Ganges in Kolkata, Elevated Highway Bridge like Pune Kothrud Bypass,

11.6 km P.V Narasimha Rao Elevated expressway connecting the Hyderabad international airport with the city at Mehdipatnam, Bangalore Elevated Highway Bridge of 9 kms and Rail bridge for metro & monorail projects in Chennai, Delhi, Bangalore, Kochi and Wadala and Vallarapadam Railway Bridges in Kochi.

Schwing Stetter India has also done bridge projects like Hebbal Flyover at Bangalore, Kosi River Bridge at Bihar, New Brahmaputra Bridge at Guwahati, River bank development at Patna, White House Bridge at Navi Mumbai, Delhi Gate bridge and Sayan Bridge at Surat, to name a few. A closer view in many of our ongoing projects are listed below.

Chenab Bridge
Jammu & Kashmir: The Chenab Bridge is an arch bridge under construction in Jammu & Kashmir, India. It spans the Chenab River between Bakkal and Kauri, in Reasi district of Jammu and Kashmir. When completed, the bridge will be 359 metres (1,178 ft) above the river Chenab and it will be the Highest Bridge in the World. The bridge is part of several bridges and tunnels which makes up the Katra - Laole Section of the JUSBRL Project in Jammu and Kashmir.

Northern Railway owns the total Project, Konkan Railway Corporation is executing the project on behalf of Northern Railways and the Chenab Bridge project undertaking a joint venture company of AFCONS Infrastructure Limited, Ultra and VSL bagged the prestigious project. The project which is constructed using Schwing concreting equipment have done 17,000 m3 of Concrete till date. It is expected to be a total of 66,000 m3 of concrete for the project. M25 and M40 grade of concrete is produced in which M25 grade is used for shotcreting and M40 is used in foundations.

Bogibeel Bridge
Assam: This Gammon India, Rail-cum-road double-decker bridge project is being constructed over river Brahmaputra wherein the piers are being built on the river where the super-structure deck shall be placed later. The is the fourth bridge over river Brahmaputra and the first one in upper Assam, connecting Dibrugarh city in the south bank along with Dhemaji and Pasighat towns in the north bank. Schwing Stetter India equipment in use at this project are thirty AM6SHN2 concrete mixers, four CP 30 batching plant, eighteen SP1800 concrete pump and four BP 350DXT concrete pump with concrete grades of M20, M25 and M35. Total concrete poured and produced in this project is 375,000 m3.

Modus Operandi
– Two 6 m3 capacity concrete mixers & one concrete pump are mounted on one barge. Both the mixers are loaded when they’re berthed in the south bank near a CP 30 batching plant.

– Then the barge moves to the mid position of the river where concrete is required to be poured. During this journey both the mixers are rotating its drums to keep the concrete agitated to be poured out.

– Once the barge reaches the pouring point, then it is anchored and then the pump is started. Concrete from the mixers are poured into the pump hopper one after another. One delivery pipeline is fixed from the output side of the pump which takes concrete up to a height and then it is allowed to flow down towards the end of the barge in an inclined path. A local delivery chute is fabricated at the pipeline end to guide the concrete to the pouring point just outside the barge.

Kankawali Road Bridge Project Ratnagiri: This 250 km road bridge project is located on National Highway 66 Khed To Kudal Road Bridge consisting of 14 Bridges. Depending on the size of one bridge around 2000 m3 concrete is being poured giving a boom output of 65 m3 / hr. Concrete grades used are M 30 and M40. Total concrete poured and produced till date is 12,000 m3. Schwing Stetter India Equipment in use at this project are listed below:

New Brahmaputra Bridge
Guwahati : This upcoming bridge project runs from Jalukbari to Amingaon (including road, flyover & bridge) is being constructed by Gammon. The main flyover is of 488 m long whereas loop 1 is 375 m, loop 2 is 75 m, and loop 3 is 109 m. The main bridge is of 1492.6 m long, road is 4354 m long, Amingaon side flyover is 36 m long while Hajo Road is of 458 m long. Total concrete produced and pumped is 229,978 m3. Concrete grade used in this project are M15, M20, M35, M40, M45, M50.

Second Bhairab Railway Bridge
Ashuganj: This 982.20-metre second Bhairab Bridge will establish link between Kishoreganj and Brahmanbaria districts of Bangladesh. It is being constructed by Ircon - Afcons JV. Total concrete poured and produced is around 42,000 m3. Schwing Stetter India equipment in use at this project are batching plants of M1, CP 30 Compartment, six AM6SHN2 concrete mixers and one SP 1800 concrete pump. SP 1800 also pumped 480 metres with 310 m3 in 12 hours of continuous operation without any breakdown.

The progress of concrete production, pumping, transporting, placing and recycling without any hiccups has helped all these project to progress as per the schedule. The process and the machines also have consumed relatively lower energy and parts to achieve these results. This was possible only by Schwing Stetter state of the art technology and reliable after sales support.