Nagpur Metro constructs Vierendeel Truss at Sitabuldi interchange

Nagpur (urban Transport News): The Maharashtra Metro Rail Corporation (Maha Metro) had to face a multiple challenges while executing the project, but one of the toughest challenge it had encountered was undertaking construction at Sitabuldi Intersection. The Maha Metro today completed construction of Vierendeel Truss at Sitabuldi Intersection. Sitabuldi is one of the busiest junctions in the middle of the city and any elevated interchange station between two corridors and construction work above such a congested road junction had to be an engineering challenge.

The challenge lied in designing the structure as much as it lied in managing the crowd. Sitabuldi Interchange is crucial for Nagpur Metro project as the two corridors cross each other there. The construction work above the road surface requires precision in planning and absolute competence in execution since even a minor error or oversight on the part of the designers and engineers may lead to disastrous results. Thus, the most critical and challenging activity in construction was erecting central portion of station, which had to be constructed on exactly the busiest part of junction.

It was a structural challenge also because of large span of 40m which had to take train loads of two lines above. The solution to this technical challenge was found in Vierendeel truss of 40m span. The Vierendeel frame is a series of rectangular frames which achieves stability by the rigid connection of the vertical web members to the top and bottom chord. It is named after Arthur Vierendeel, a civil engineer, who also held the post of Director for the Ministry of Public Works in Belgium. He had designed the structure for the first time 1895 and was named after him.

This concrete truss (A truss is an assembly of beams or other elements that creates a rigid structure) was constructed in one go. Work on these is in the last stage of completion. The challenge was also to execute work without erecting a pillar at the centre in one of the busiest squares of the city. Presence of a pillar is a hindrance in the smooth flow of traffic. Vierendeel Truss was solution to this challenge. Being one of Nagpur's arterial roads, hundreds of vehicles pass through it every hour. It is hence next to impossible to stop or divert traffic on such a busy road even for short durations.

The platforms of the two corridors are placed one above the other. The location of Interchange Station is important as it is one of the busiest traffic junctions of the city with a cinema hall, food mall and two bank buildings surrounding it. By incorporating Vierendeel Truss in its project at one of the crucial junction, Maha Metro not just ensured stability but also incorporated a unique structure in its project.