Engineering geological investigations for evaluation of excavation method and stand-up time of the DK99-DK100 Jakarta – Bandung high-speed railway tunnel, Indonesia

This paper presents the investigation of surface geology and subsurface engineering to analyze excavation method stand-up time DK99-DK100 Jakarta-Bandung high-speed railway Tunnel, Indonesia. Rock mass quality, tunnel method, determined using Geological Strength Index (GSI), Basic Quality (BQ) systems, converted Mass Rating (RMR) The Japan Society Civil Engineering (JSCE) for comparison. result shows that study area consists slightly completely weathered andesite breccia lava. rock masses at elevation had very poor quality were associated with high weathering degrees. recommended based on GSI is digging. RMR multiple drifts, top heading, bench, while JSCE bench cut method. 30 minutes - 2 hours RMR, it predicted be unstable without support BQ. design expected applied effectively according geological conditions. It understand better in masses, especially