Nikachhu Hydropower Project

Nikachhu Hydropower Project is a run-of-the-river project located between the junction of Nikachhu/Chhunabchhu and Nikachhu/Mangdechhu in Trongsa District, Bhutan. It is located almost 3 km from Chhunabchhu junction downstream. 

Dam: 38 m high concrete gravity dam

Head Race Tunnel (HRT) : Diameter 4 m ; Length 12,144 m

PowerHouse: Design discharge hits two Pelton turbines with a capacity of 118 MW. The water is then discharged into the reservoir of Mangdechhu Hydropower Project

The complete instrumentation & monitoring work for the Dam, Power House, and Head race tunnel project was awarded to Encardio-rite. The scope of work included:

• Supply of all instruments
• Installation & monitoring of geotechnical instruments installed on surface & underground works 
• Preparation of monitoring reports including data interpretation and analysis where required
• Calibration, testing, and maintenance 

The instrumentation consisted of hundreds of geotechnical sensors including:

• Piezometer
• Uplift pressure cells
• Automatic water level recorder
• Digital Inclinometer
• Load cell, center hole
• Strain gage - rosette with no stress-strain gage
• Concrete pressure cell
• Shotcrete pressure cell
• Joint meter – linear
• Joint meter – tri-axial
• Temperature meter
• Borehole Extensometer (Multi-point)
• Plumbline – normal and inverted
• Bi-reflex target
• Automatic data acquisition system
• Automatic weather station
• Strong motion accelerographs

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. 

Encardio-rite provided a comprehensive monthly monitoring report, combined with geotechnical and geodetic monitoring data on a weekly and monthly basis. Monitoring reports included interpretations of variations observed in instrument data concerning the construction progress in the respective area.