Over the last few years, there have been advancements in the areas of bridge design, engineering and construction in India with the adoption of latest technology and smart construction materials. Also, by using innovative assessment tools that can predict the remaining life expectancy of bridges, monitoring has become much more streamlined. The upcoming bridge projects are not
only aimed at connecting remote areas, but also becoming tourist destinations for their engineering uniqueness.
Digital technology
The bridge design and construction process has evolved significantly with the introduction of smart digital technologies. Building information modelling is one such technology, which covers the architecture, engineering as well as construction segments. By presenting information in 3D, it becomes easier to navigate to specific places and check for collisions. Precast segmental construction technology also gained popularity as it is used to achieve accelerated bridge construction, better quality control, and reduced life cycle cost. In addition, congested reinforcement can be handled at the ground level.
The Ministry of Road Transport and Highways has set up a bridge monitoring system to identify the bridge assets across the country. All key features of bridges and structures, and their conditions are monitored regularly by field inspection. The majority of the long-span,
important and strategic bridges are provided with strain gauges and monitoring systems for online monitoring of their health and condition.
Also, maintenance of bridges has been made safe and secure with a photonic monitoring system to prevent incidents. The use of high performance concrete with reduced permeability is the topmost mitigation strategy with respect to corrosion management. Stainless steel is another option for reinforcement in extremely harsh environments. In addition, it is also exceptionally adherent, inert and self-repairing.
Key upcoming projects
Indian Railways is constructing a bridge on the Chenab river in Reasi district of Jammu & Kashmir. It will be the highest railway bridge in the world. The most sophisticated Tekla software is used for structural detailing. With Tekla Structures, users can create a constructible, parametric model, which means each object holds its own data. This data can then be used for fabrication, erection, construction on-site and asset management during the maintenance of the bridge.
The upcoming Majuli Bridge over the Brahmaputra river is being constructed using new technology. The distance between two pillars will be 120 metres instead of 30 metres and the casting of the upper beams will be in steel and fibre. This has resulted in significant cost reduction. The bridge will connect the world’s largest river island, Majuli, with Jorhat in Assam.
The work for the construction of the New Pamban Bridge was delayed because of the Covid-19 pandemic. Once completed, it will be the country’s first vertical lift railway sea bridge. The new bridge will help the railways to operate trains at a higher speed, carry more weight and increase the volume of traffic between Pamban and Rameswaram.
Sustainability
Several attempts have been made to reduce the environmental effect of concrete, which is used in volumes second only to water. These include the use of industrial by-products called supplementary cementing materials such as fly ash and slag cement. The first geogrid reinforced fly ash approach embankment was constructed for the Okhla flyover bridge in Delhi.
Further, to alleviate the problems of scarcity of natural materials and reduce greenhouse gas emissions, alternative materials such as manufactured sand and iron, steel and copper slag aggregates are being used for bridge construction. Different types of concrete are being developed, which includes self-compacting concrete, high performance concrete, fibre reinforced concrete and ultra high performance concrete. Fibre-reinforced bridges could practically last for the longest time as they are completely non-corroding in nature, while wooden and steel bridges typically need refurbishment. The viaduct piers of the upcoming Chenab bridge are made of concrete, while the piers near the arch are of steel.
The way forward
The evolution of bridge engineering has been strongly linked to the key advances in materials, construction processes and modelling. The future of bridge design requires reinventing this collaboration through the use of new platforms for developing and delivering the design materials. Going forward, sustainability and environment-friendly interventions will continue to drive the bridge construction process. Further, advanced modelling techniques, material choices and analysis methodologies will be adopted for building bridges across the country.
