Dynamic Slope Stability Subject to Blasting Vibrations: a Case Study of the Jakarta-Bandung High-Speed Railway Tunnel

This paper aims to evaluate dynamic slope stability induced by tunnel blast vibration with the help of a combination of geoelectrical techniques (e.g., vertical electrical sounding and electrical resistivity tomography), geotechnical methods (e.g., boreholes, Standard Penetration Test), and laboratory testing to characterize the subsurface conditions of a rock slope near residential houses in the Padalarang sub-district, West Bandung Regency, Indonesia, that is subjected to tunnel blast vibration. The slope is part of the mountain that will be excavated by a drill-and-blast method to provide a passageway for one of the Jakarta-Bandung high-speed railway tunnels. A series of trial blasts have been carried out and blast vibrations have been recorded, resulting in the linear regressions of the peak vector sum (PVS) and peak particle acceleration (PPA). Based on the allowable charge weights per delay, the PPA regression was then used to predict the acceleration that would result from the tunnel blast. The predicted acceleration was then used to analyze the dynamic stability of the slope using the pseudo-static approach. The slope stability analysis shows that the slope has a dynamic factor of safety of 1.3-1.5, indicating that the slope will be stable after experiencing the vibration induced by the tunnel blast. The results of this study show that combining geoelectrical survey with geotechnical methods could help geotechnical engineers to understand the subsurface condition and its complexity, which play vital roles in assessing the stability of the slope, particularly the slope that is subjected to dynamic loading from a tunnel blast.