DMRC Phase 4 DC-02 - Yamuna River Bridges

The project involves the construction of an elevated viaduct from Maujpur (excluding) to Majlis Park (excluding). This includes a bridge across the river Yamuna, an integrated elevated viaduct with a PWD flyover at the lower deck, and a metro line at the upper deck from Yamuna Vihar to Bhajanpura. It also includes eight elevated stations from Chainage 0.0 M to 12098.520 M of the Majlis Park - Maujpur Corridor of the Delhi MRTS Phase-IV project.

Our team performed an Independent Design Review for two adjacent four-span balanced cantilever bridges across the Yamuna River. While both bridges have the same 60m - 80m - 80m - 60m span configuration, they differ in ground conditions. Consequently, each bridge necessitated individual analysis and capacity evaluation.  The superstructure was composed of a cast-in-situ single cell box girder, constructed using a form traveler system in a balanced cantilever manner. The girder's depth varied from 6.264m at the main piers to 3.264m at the mid-span and the bridge ends. The main piers were supported by 15 to 18 bored piles, each 1.8m in diameter and an unsupported length of about 35m in the river.

The substructures were highly susceptible to substantial forces due to thermal effects and creep/shrinkage. This was due to the relatively short pier heights, four-span pan configuration, and a contractual requirement to avoid twin-blade piers. These factors made the substructures' design through standard methods impractical. As expert advisors, we recommended applying a pre-compensation force prior to the casting of the key/closure segment, effectively pre-stressing the structure and offsetting expected stresses, making the design feasible while reducing material quantities.