STABILITY ANALYSIS OF UNDERGROUND TUNNEL DUE TO THE EFFECT OF TOPOGRAPHY AND GEOLOGICAL MODELS CASE STUDY IN “FM” TUNNEL

• Main Author: Mulyana, Fadlilah
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/41951
• Institution: Institut Teknologi Bandung

Tunnel is a hole that is commonly used for transportation, drainage, cable lines, mining, and others. In this modern life, the tunnel has become an essential thing. The construction of the tunnel has a considerable risk associated with the stability of the tunnel. Topography and geological models are things that influence stability in tunnel construction. Therefore, the authors aim to analyze the stability of topographic tunnels and geological models and provide recommendations in tunnel support. The data used are topographic data and geological cross section as well as property data from the rocks, namely density, young modulus, poisson ratio, cohesion, and friction angle. The data is processed using the boundary method to Phase2 software. From the results of data processing and modeling, there are 3 stress distribution models consisting of model 1 which are only affected by overburden from a flat surface, model 2 which is affected by overburden from the undulating surface, and model 3 which is affected by overburden from the undulating surface and differences in lithology. In model 3 a 2 lane simulation is made, namely lane 1 which is flat and is above the layer boundary and lane 2 which rises and is at the boundary of the layer. Line 1 consists of samples T1, T2, T3, T4, T5, T6, and T7 as well as line 2 which consists of samples LI, L2, L3, L4, L5, L6, and L7. In each sample there are 7 review points on the legs , top, wall and base of the tunnel. From Mohr Coulumb failure criterion analysis has failure in each sample on line 1 and line 2 so that line 1 and line 2 are unstable. Line 1 and line 2 require a support tunnel in the form of supporting a minimum of 8 cm of concrete to prevent failure of the tunnel. After Mohr Coulumb failure criterion analysis line 2 is more stable compared to line 1 after support.