TUNNEL STABILITY ANALYSIS USING RMR METHOD, Q SYSTEM, AND FINITE ELEMENT IN TUNNEL 2, KCJB, JATILUHUR, PURWAKARTA DISTRICT, WEST JAVA

• Main Author: Ngestitama Faradewi, Ananda
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/69437
• Institution: Institut Teknologi Bandung

The Jakarta-Bandung High-Speed Rail Tunnel (Jakarta-Bandung HSR) is part of a national strategic project. In a tunnel construction project, there will be differences in lithology, discontinuities, rock weathering levels, and groundwater conditions which have potential to become obstacles. However, this can be handled by classifying rock mass to produce correct type of reinforcement for the support system. Methods used in this study, namely RMR (Rock Mass Rating) and Q-system, are empirical calculations to identify support system's accuracy level. This tunnel is divided into four zones based on bore data, namely tunnel entrance (inlet), tunnel 1 center, tunnel 2 center, and tunnel exit (outlet). Observations of rock outcrops were carried out using scanline method of classifying rock masses. Based on bore data, core rock was examined to obtain an overview of subsurface lithology, UCS (uniaxial compressive strength), and groundwater level elevation. Rock mass class quality are used in calculations to get rock mass engineering property values. Then, using the software-based finite element method, numerical modeling was performed to obtain ratio of induced stress to in-situ stress, plastic zone, displacement, and strength factor (FK) related to the tunnel stability level of each rock mass classification method for comparison. Evaluation of stability level of tunnel has FK > 1.25 to be confirmed according to the results of support capacity analysis. Value of rock strength in claystone and claystone with sandstone insertion is included in class of weak rock (weak rock). Value of rock mass class on claystone and claystone with sandstone insertion is included in inferior rock mass class. The results of application of reinforcement type based on RMR value and Q-system show FK value > 1.25. This value states that rock mass classification is more suitable to be used is RMR classification with type of rock mass collapse which is dictated by the needs of support system in Jakarta-Bandung HSR tunnel.