Funding Agency: Government of Nepal
Client: Vidhyut Utpadan Company Limited, Kathmandu
Date: Nov 2025 – May 2026
The Kimathanka Arun Hydroelectric Project in-situ rock mechanical testing assignment is a specialized geotechnical investigation commissioned by Vidhyut Utpadan Company Limited (VUCL) to support the design and construction of major underground components of the 454 MW Kimathanka Arun Hydroelectric Project in Sankhuwasabha District, Nepal. The project focuses on determining critical in-situ rock mass properties—specifically stress conditions, deformation modulus, stress–strain behavior, creep characteristics, and principal stress orientations—through hydraulic fracturing tests and borehole dilatometer tests conducted in a dedicated test adit and chamber at the powerhouse site. These investigations are essential in the Himalayan geological context, where complex tectonic stresses and heterogeneous gneissic rock formations directly influence the stability and design of underground caverns, tunnels, and foundations. The scope includes core drilling, execution of tests in accordance with ISRM standards, careful data acquisition and interpretation, and comprehensive reporting of results to provide reliable geotechnical parameters for safe, efficient, and sustainable hydropower development in a remote and geologically challenging region.
Objectives of the project:
The primary objective of this project is to determine reliable in-situ rock mass parameters required for the safe and optimized geotechnical design of underground and surface structures of the Kimathanka Arun Hydroelectric Project. Specifically, the project aims to measure the in-situ stress magnitude and orientation at the powerhouse site through hydraulic fracturing tests, and to evaluate the stress–strain behavior, deformation modulus, and time-dependent (creep) characteristics of the rock mass using borehole dilatometer testing. These parameters are essential for assessing rock mass strength, deformability, and stability, and for understanding the influence of Himalayan tectonic stresses on underground excavations such as the powerhouse cavern, headrace tunnel, and associated structures. The outcomes of this project will directly support engineering design decisions, construction planning, and long-term structural safety of the hydropower facilities.
Description of actual services provided by your staff within the assignment: Scope of Work;
