Hailang Dam (VPHEP)

Home / Projects / Hailang Dam
Dam Restoration

Vishnugadh Pipalkoti Hydroelectric Project

Restoration of the damaged portion in the gate groove area of the Diversion Tunnel at the under-construction VPHEP (444 MW) on Bhagirathi River, District Chamoli (Uttarakhand). The dam site is located near Helang. Work executed in two distinct phases during lean season.

Client
THDCIL
Location
Helang, Chamoli, Uttarakhand
Capacity
444 MW on Bhagirathi River
DT Discharge
50-60 Cumec during lean season
Hailang Dam VPHEP
Project Details

Salient Features & Scope

Two gates provided in the 10.50m × 10.50m box-type portion of the Diversion Tunnel at a distance of ~16m from the DT portal and ~50m from the DT intake. The repair of gate's groove, pier and side walls executed in phasing — Phase 1 for right side gate & Phase 2 for left side gate.

  • Removal of debris from top slab of DT
  • Cutting of DT top slab by Diamond wire saw cutter
  • Coffer dam with boulder-filled MS boxes in 50-60 cumec flow
  • Lowering MS boxes by crane into flowing Alaknanda River
  • Scaling & removing loose concrete by breaker
  • Drilling, anchoring & fixing new reinforcement steel
  • Pouring Micro Concrete above & under water
  • Sealing cracks, honeycomb with Epoxy Putty
  • Concrete surface repair with Epoxy Mortar
  • 3-component Epoxy grout in gate groove & T guide plate
  • Removal of boulder-filled MS boxes
  • Fabrication & fixing of MS cover plate over slab cutting
Phase 1 — Right Side Gate January 2024 — March 2024

Repair of Right Bay & Gate Groove

Phase 1 focused on the right side gate repair during lean season (Jan–Mar 2024). Operations included cutting the DT slab for access, making temporary diversion inside the tunnel, and complete reconstruction of the pier and side walls.

Debris RemovalRemoval of debris from DT
Marking for CuttingMarking for DT slab cutting
Opening MadeOpening made by cutting DT slab
Damage Inside DTDamages inside diversion tunnel
Temporary DiversionTemporary diversion for right bay repair
Reinforcement & ConcretingReinforcement & concreting through hopper
Pier RepairPier reinforcement fixing
ConcretingConcreting through hopper & pipe
Repaired Gate GrooveCompleted — Repaired gate groove
Phase 2 — Left Side Gate December 2024 — March 2025

Repair of Left Bay & Gate Groove

Phase 2 focused on the left side gate repair during the next lean season (Dec 2024 – Mar 2025). Involved cutting the left side DT slab for approach, making temporary diversion, rebaring in damaged portions of the left side wall, and underwater micro concrete pouring.

Left Side Slab CuttingLeft side DT slab cutting for approach
Slab AccessMaking approach to damaged area
THDC InspectionInspection by THDC & temporary diversion
Diversion Inside DTTemporary diversion inside tunnel
RebaringRebaring in damaged left side wall
Underwater ConcretePouring underwater micro concrete
MS Slab CoverFabricating MS DT slab cover
Slab Cover PlacedPlacing slab cover over cut portion