Yamuna Bridge Retrofit — submerged grouting program

The Problem

A key Yamuna crossing built in the 1960s was showing distress on routine biennial inspection: scour at two piers had exposed foundation material, several bearings had seized from corrosion, expansion joints were leaking onto the substructure, and identified pier columns showed live crack patterns requiring structural intervention.

The brief covered underwater foundation grouting, bearing replacement, deck joint renewal, and column strengthening — all while maintaining partial traffic flow across the bridge.

How We Approached It

Underwater grouting was executed by certified commercial divers using anti-washout cementitious grout injected through pre-installed sleeve pipes at the affected piers. The divers worked from a barge-mounted platform during the low-flow season.

Bearing replacement was staged one pier at a time, with temporary jacking supports maintaining structural integrity during the changeover. Carbon fiber wrapping on identified columns was completed during a planned night-time lane closure.

Specification

• Underwater grouting: BASF Masterflow 920 anti-washout cementitious grout with 90-day strength gain monitoring
• Bearings: POT-PTFE bearings sized to original design load, with stainless steel sliding surfaces
• Deck joints: Modular strip seal expansion joints with watertight anchorage
• Column strengthening: Mapei Carboplate E170 CFRP laminate bonded with Mapei Adesilex PG1 epoxy adhesive
• Concrete repair: Polymer-modified mortar on all identified spalled areas with bonding agent primer

The Result

The retrofit was completed within the nine-month program window, with traffic maintained throughout (single-lane closures only during specific operations). Post-completion inspection at six months confirms the grout consolidation, bearings functioning as designed, and deck joints watertight. The bridge is now expected to deliver another 25+ years of service before any major intervention.