Construction of the Foundations of Mega Sea Bridge of India

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The paper describes foundation and substructure construction for Package 1 of the Mumbai Trans-Harbour Link, a major sea bridge connecting Sewri in Mumbai with Navi Mumbai. This package includes the Sewri interchange and 10.38 km of bridge. Construction takes place across intertidal and marine zones with soft marine deposits over weathered basalt, in an environmentally sensitive area crossed by navigation routes and seabed utilities.<br /><br />The bridge’s 148 foundations generally use groups of four piles, 1.5 or 2.2 m in diameter, drilled 20–40 m to bedrock. In the intertidal zone, where water access is unavailable at low tide, a temporary access bridge with working platforms enables equipment and crews to reach pile locations. Reverse-circulation drilling requires a recirculating water system, while excavated material is collected and disposed of at designated offshore locations.<br /><br />In the marine zone, jack-up barges provide stable platforms for pile installation despite waves, currents, and wind. Careful planning, surveying, and anchoring help protect seabed pipelines and cables. Marine batching plants supply concrete for piles and pile caps.<br /><br />To avoid ground-supported falsework and limit environmental disturbance, pile-cap formwork is supported by steel brackets welded to pile liners. For large navigational-span pile caps, precast shells serve as sacrificial forms, with protective rings designed to reduce vessel-impact damage.<br /><br />The authors conclude that site-specific, lean construction methods enabled work under difficult geological, tidal, and ecological conditions. Aside from some pile-liner settlement, no significant construction problems were reported.

Keywords

Mumbai Trans-Harbour Link

foundation construction

substructure

Sewri interchange

marine zone

intertidal zone

pile foundations

reverse-circulation drilling

jack-up barges

environmentally sensitive area