STMT II-III Hydropower Tunnel Excavation Reached New Record

        The spring has come and the east wind is strong, and it is time to set sail and forge ahead. In April 2024, Steung Meteuk II hydropower station’s excavation speed of the diversion tunnel hit a new high record. The entrance tunnel working face achieved the impressive result of 200.8m of excavation for a single tunnel face in a single month. Steung Meteuk’s hydropower station’s diversion tunnel has a total length of 2454.89m and a designed flow rate of 110.8m³/s. The lithology of the strata that the diversion tunnel passes through is mainly interbedded sandstone and mudstone of the Middle Jurassic System, and the surrounding rock is classified into class IIIA, IIIB and IV as the main types, consist of 25%, 25% and 30% of the tunnel length, and type V surrounding rock 20%。
        In order to ensure high quality, high standard and high progress of the project to complete the task, the diversion tunnel adopts the process of surface blasting, the implementation of 24-hour construction. In view of the section of the tunnel rock are Ⅲ, under the premise of ensuring safety, the project department adopts a long footage (3.5m and 4.0m drilling rod) program, and through strict management process cycle connection (making holes, loading, blasting for about 5 hours, slagging an average of 3-4 hours, about 30m focused on spraying concrete once), and ultimately created 2 days 5 cycles, April 1, 2024 --April 1-30, 2024, the excavation record of 200.8m in a single month! At the same time, the project department deeply promotes the construction of "double prevention mechanism" for safety risk classification and control and hidden trouble investigation and management, increases the dynamic monitoring of risks and hidden dangers and special investigation; regularly carries out the analysis of over-digging and under-digging of tunnels, and through continuous practice, summarization and analysis, precise measurement and sampling, and strict control of the construction parameters of blasting, so that the over-digging and over-consumption indicators are within the control range of concrete. Through continuous practice and analysis, precise measurement and sampling, and strict control of construction blasting parameters, the over-under excavation and over-consumption of concrete indexes are within control.
        In the next step, the project department will meet new challenges and difficulties with a more vigorous fighting spirit and good outlook, raise the awareness of the enormity and complexity of the remaining total volume of work, strengthen the summary of experience, and under the premise of ensuring safety and quality, further tap the potential for construction production and make an all-out sprint to achieve the goals set by the company!

                                                                                                                Contributed by: Steung Meteuk Project Department
                                                                                                                Editor: General Department