Vishnugad Pipalkoti Hydro Electric Project
The Vishnugad Pipalkoti Hydro Electric Project (4 x 111 MW) is located on Alaknanda River, a major tributary of river Ganga, in district Chamoli in the state of Uttarakhand. The nearest railhead is Rishikesh (225 km) and the nearest Airport is Jolly Grant, Dehradun (240 km). The project is approachable by an all-weather road (National Highway No. 58).
The project envisages a run of river scheme with the construction of a diversion dam of 65 m height across the Alaknanda River for power generation harnessing a gross head of 237 m. The reservoir will have a gross storage capacity of 3.63 million cum, out of which 2.47 million cum shall be live storage. A diversion cum spill tunnel of 10 m dia. shall divert the discharge of 725 cum/sec during the construction period. The water conductor system comprises of 3 nos. intake tunnels, 3 no. underground sedimentation chambers, a headrace tunnel, a surge shaft, 2 no. pressure shafts bifurcating into 4 no. penstocks. The powerhouse comprises two separate underground caverns for the installation of turbines and transformers.
The complete instrumentation & monitoring work for the Pipalkoti Dam project was awarded to Encardio-rite. The scope of work included:
- Supply of all instruments
- Installation & monitoring of geotechnical instruments installed on surface & for underground works
- Preparation of monitoring reports including data interpretation and analysis where required
- Calibration, testing, and maintenance
Encardio-rite was awarded the contract for a complete monitoring program for the project. List of instruments included:
- Piezometer to monitor sub-surface water pressure
- Center hole Load Cells to monitor load developed in rock bolts
- Shotcrete Strain Meter to monitor total pressure/stress in concrete
- Concrete Pressure Cells to monitor total pressure/stress in concrete
- Borehole Extensometer (3-point) to monitor deformation of rock mass
- Borehole Extensometer (4-point) to monitor deformation of rock mass
- Perimetric Joint Meter (3-D) with waterproof Sensor
- Temperature meter
- Plumbline (normal and inverted)
- Water Level Indicator
- Portable Read-out Unit
- Bi-reflex target for deformation/displacement in excavated surface
An automatic Data Acquisition System was installed and commissioned to collect data from the above geotechnical instruments. The data was collected automatically at required intervals.
An automatic Weather Station was also supplied, installed, and commissioned to co-relate the data with weather conditions.
Encardio-rite provided a comprehensive monthly monitoring report, combined for geotechnical and geodetic monitoring data on a weekly and monthly basis. Monitoring reports included interpretations of variations observed in instrument data with respect to the construction progress in the respective area.