Condition Assessment of RCC Structures of Tapovan Vishnugad Hydro Power Project (4 X 130 Mw) affected by Unprecedented Massive Glacial Debris Flow
National Thermal Power Corporation (NTPC) is constructing a 520 MW hydro-electric power plant located downstream on the Alaknanda River at Tapovan, Joshimath, Uttarakhand. For this power plant, a dam is under construction across the Dhauliganga River with a catchment area of 3,100 km2. The dam main structure consists of barrage structure, intake structure, desilting structure, and tunneling. An unprecedented massive glacial debris flow occurred on 7th February 2021 and the subsequent devastating flood full of debris/silt/boulders/ice/rock pieces/soil/trees etc. flooded the barrage under-construction. Due to this natural disaster, all the dam structures were severely damaged and the bridge deck slabs, head operating rooms, and radial gates were washed away, one breast wall was completely sheared off, and the other breast walls were severely damaged.
Dam Structure (Before Deluge)
Dam Structure (After Deluge)
Typical Damages of Dam Structure
The problem was referred to CSIR-SERC by NTPC to assess the condition of various dam structures including barrage, intake, and de-silting chambers, to have confidence for using the dam structure further.
NDT & PDT Investigation at Site by CSIR-SERC Team
CSIR-SERC took this challenging project of National Importance and carried out detailed scientific investigations on the dam structure consisting of (i) visual observation of dam structure, (ii) evaluation of concrete quality and integrity through NDT, (iii) ensuring the vertical and horizontal alignment through Total Station Survey, (iv) assessment of geological parameters, (v) providing quality assurance and quality control methodology, on war footing basis and provided appropriate remedial solutions to NTPC based on which the damaged dam structure of the Tapovan Vishnugad Hydro Power Project is being restored.