STABILITY ANALYSIS OF THE NANJUNG T2 DIVERSION TUNNEL BASED ON THE RESULT OF CONVERGENT MEASUREMENTS

• Main Author: Nabila Rusfa, Sindi
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/40290
• Institution: Institut Teknologi Bandung

The Nanjung Diversion Tunnel is a twin tunnel that is used to drain the water of the Citarum River in Curug Jompong, Kecamatan Margaasih, Kabupaten Bandung. At the time of excavation there will be a voltage redistribution until a new equilibrium condition is reached. In the process of achieving this equilibrium, there will be a displacement event in the opening hole besides the presence of a large and continuous displacement rate which, if not driven and intervened, could potentially cause tunnel collapse or collapse. In this final project, we will analyze the stability of the tunnel by measuring the relative displacement between the two points on the excavation limit, or called the convergent measurement. The stability analysis criteria to be used are based on the size of the displacement with the concept of critical strain and convergent velocity. From the analysis of stability criteria, the Nanjung T2 Diversion Tunnel can be said to be sta.ble or not have a significant buffer problem if the large strain is smaller than 1,026% or below 1%. While based on the criteria for conventional speed stability are divided into 3 categories, namely stable, relatively stable, and unstable. For the horizontal side of the tunnel it can be said to be sta.ble if the convergent speed is smaller than the critical velocity of 0.2 mm / day and is not sta.ble if it is greater than the maximum critical velocity of 1.1 mm / day and can be said to be sta.ble when the speed converges smaller than 0.12 mm / day and is not sta.ble if it is greater than 0.9 mm / day.