Spannovation (formerly MCS) is the construction engineer for a highway infrastructure project in Firozabad District, UP, India across railway tracks. The project, contracted to Galvano India Pvt Ltd for structural steel erection involves the construction of a 2-lane Road Over Bridge (ROB) replacing Level Crossing No. 67C at KM-1239/21-23, at Hirangaon Station. The 112-meter bridge features two steel tied arches with a span arrangement of 50m - 62m and a skew angle of 20 degrees. The structural steel for the bridge weighs approximately 600 metric tons.
The erection methodology for the arches involves sliding preassembled steel along launch rails supported by falsework. This falsework includes girders resting on shoring towers located within the construction easement zones adjacent to the railway tracks. Once the superstructure is shifted to its final position, the supporting falsework below is removed, and the bridge is lowered onto its permanent supports. The tied arches are pulled with wire ropes using two 15 tonne winches. However, the project comes with its share of challenges. The primary challenge involves constructing spans directly adjacent to an active railway station, ensuring safety and minimal disruption to railway operations. In addition, managing limited space and height for construction activities and coordinating work schedules with train timings add to the complexity of the project.
One unique issue involved maintaining four live railway tracks under a 60m span. This required a temporary falsework span of 27m, longer than typically required, and the design of a deeper girder. The increased span led to heavier loads on the shoring towers and larger footings, necessitating 4m x 6m extra-wide temporary footings. Our team has closely collaborated with the contractor, engaging in numerous discussions to align with the stakeholder requirements. This dynamic approach has enabled the project team to collectively devise suitable solutions tailored to stakeholder needs.
The successful launch of the 60m span exemplifies our team's capacity to adapt and deliver in complex situations. Currently, the project is moving into its next phase, which involves launching the 48m span over DFCC tracks.