Tunnel design and construction requires a holistic engineering expertise to deliver safe and efficient solutions. From underground tunnels for rails, roads, stations; water and wastewater tunnels; cables and utilities tunnels, these are vital infrastructures that accelerate travel time, connecting communities, improves public health standards, modernising the society with electricity, internet, communication, power and green energy.
At Minconsult, we provide comprehensive engineering services comprising all disciplines under one roof for tunnel and underground infrastructure, covering feasibility studies, detailed design, asset assessment, system upgrading, and construction support.
Our expertise spans tunnelling and underground spaces, tunnel ventilation and smoke management systems, fire-life safety engineering, and underground asset assessments. By leveraging advanced analytical and simulation tools, we develop safe, reliable, and sustainable solutions that meet regulatory and operational requirements while strengthening the long-term performance of tunnel and underground infrastructure.
CONSULTANCY SERVICES FOR THE TUNNEL INTEGRITY INSPECTION AND RISK ASSESSMENT FOR TELOM & LEMOI DIVERSION TUNNEL, ULU JELAI HYDROELECTRIC SCHEME
Client
TNB GENCO
Project Completion
2028
Project Description
The Ulu Jelai Hydroelectric Project includes the transfer of water from the catchments of Telom River and Lemoi River into the Susu Dam reservoir through transfer tunnels of 8.5 km and 7.4 km length respectively. The Lemoi Tunnel was fully excavated by using a Tunnel Boring Machine (TBM), while the excavation work of the Telom Tunnel, which was initially done through TBM up to CH 3710.00. However, the TBM encountered soft soil and unfavorable geological condition, and the method was abandoned. Subsequently the balance of the tunnel section was constructed using Drill & Blast method.
Upon the project’s handover several serious defects were observed, particularly at the boundary limit of drill and blast section, which were subsequently repaired by the Contractor. During the 2021 Warranty Inspection conducted by the client’s Engineering Department, a comprehensive list defects were identified for the total length (8.5 km) Telom tunnel, which need to be addressed and repaired within 2-5 years.
Services Provided
Minconsult’s scope includes to undertake tunnel integrity, safety and risk assessment to determine the root cause of the defects observed at both tunnels and associated area. Subsequently with the collected investigation data which includes Subsurface Investigation, Electric Resistivity Survey, Tunnel Visual Inspection, Site Survey and Mapping Works, Tunnel Non Destructive Test and Partial Destructive Test and Underwater Tunnel Inspection Works, to prepare tender document of rehabilitation works consisting of detailed design drawings, BQ and specification. The service also includes 8 months of supervision works.
Key Significance of the Project
The project plays a significant role in ensuring the structural integrity of the 8.5km Telom Tunnel and 7.4km Lemoi Tunnel, which channelled water from the adjacent catchment to the Ulu Jelai Hydroelectric Power Station with an installed capacity of 372MW that serves the national electricity system.
Minconsult, through its Minconsult Integrated Tunnel Integrity Inspection System (MiTIIS), integrates and deploys advance mobile application operating flawlessly in both online and offline environments as part of the digitalised geotechnical investigation and field geology mapping works for both lined and unlined tunnels using Q-System for rock quality determination, non-destructive subsurface investigation using Schmidt Hammer, Ground Penetrating Radar (GPR) and Electrical Resistivity Imaging (ERI), 3D LiDAR Spatial Scanning, Partial Destructive Test by rock coring and laboratory testing, smart dashboard tunnel asset management and inventory, advance engineering solutions using 3D Finite Element analysis for tunnel risk assessment, etc.
In the challenging environment, the work carries remarkable responsibility – inspecting and assessing the integrity of the tunnel structures for both 8.5km Telom Tunnel and 7.4km Lemoi Tunnel to ensure that the hydropower system continues to operate efficiently and safely. Indirectly, helps families, businesses and the nation continue moving forward.
