SLOPE STABILITY ANALYSIS OF SOIL AND ROCK AROUND BOHONG MOUNTAIN, PADALARANG DUE TO BLASTING AT TUNNEL #11 HIGH-SPEED RAILWAY JAKARTA - BANDUNG

• Main Author: Dwifajar Prabowo, Jerry
• Format: Theses
• Language: Indonesia
• Subjects: Pertambangan dan operasi berkaitan
• Online Access: https://digilib.itb.ac.id/gdl/view/51988
• Institution: Institut Teknologi Bandung

Excavation for Tunnel # 11 of the Jakarta - Bandung High-Speed Railway using mechanical excavation methods for relatively weak rocks (Silty Clay and Gravelly Clay) and blasting methods for relatively hard rocks (Breccias and Andesites). The vibrations arising from this detonation will affect the environment. This study aims to determine the effect of blasting to the stability of the slopes in the residential areas. The research began with monitoring the vibrations caused by the blasting of Tunnel #11-1 excavation. The transverse PPV result at a distance of 100 m is 0.365 mm/s. The PPV results are used as a reference for predicting the amount of PPV and PPA that will arise at a certain distance and predicting the magnitude of the blasting load that will be used in modeling. The horizontal PPV result from the numerical model is 0.372 mm/s with a predicted blasting load of 0.091 MPa from 0.8 kg of explosives. Then the prediction results are used to predict the magnitude of the blasting load in Tunnel #11 (main tunnel). Based on recommendation design with explosives per delay time of 2.4 kg for Tunnel #11, the value of the slope safety factor around the residential areas is 1.36 and has the largest permanent displacement of 0.41 mm. This safety factor is above the value of the SNI 8460:2017 which is 1.1 for pseudo-static analysis. However, based on the value of permanent displacement of the slope, what happens is that the slope only experiences ground vibrations.