Amar Mahal flyover
Dismantling and reconstruction of 3+3 lane superstructure of Amar Mahal flyover in Chembur on Eastern Expressway
Scope of work
Dismantling scheme and design of existing flyover superstructure & detailed design and drawings of new flyover
The project consisted of 3+3 lane flyover (230m elevated length) of the busy Amar Mahal Junction in Mumbai. Existing truss type superstructure was in distress and needed to be replaced with a new plate girder type superstructure and additional substructures. Force was associated with NCC Ltd. from pre-tender stage and after award of EPC contract, was selected as detailed designer.
Most challenging part of the project was the dismantling scheme of damaged existing truss structure keeping in mind the busy junction and limited working space. Detailed stage analysis was carried out for dismantling stages and support requirements were designed.
New superstructure proposed was structural steel composite plate girders with RCC deck slab. Existing substructure was retained with 1 additional substructure constructed to carry the new superstructure. The vertical profile was modified to give a better riding experience and the superstructure had to be adjusted to fit with existing substructure. Steel flaring was used to compensate for variation in road level and existing substructure levels. Each span was unique owing to as built state of substructure which were not standard in span lengths. Existing substructure was checked for design adequacy of new superstructure loads and durability requirements.
Challenges and innovations of this project include:
- Dismantling stage analysis of damaged structure
- Vertical profile improvement
- Designing new superstructure spans that satisfy the structural capacity of existing older substructures
- Geometric fitting of new superstructures over existing substructure using innovative structural elements like steel flaring and camber control