SURFACE SUBSIDENCE RESEARCH DUE TO LONGWALL COAL MINING BY USING EMPIRICAL METHOD AND FINITE ELEMENT NUMERICAL METHOD

• Main Author: Febrian, Joshua
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/43807
• Institution: Institut Teknologi Bandung

One of methods in coal underground mining is longwall mining method. Longwall mining method is a well-known underground mining method. Longwall mining is one of caving method. The panel which is already mined out is allowed to fall. Those panel which fell will surely cause surface subsidence above the panel. The surface subsidence could be dangerous to the infrastructures on the subsidence basin. Therefore, it is needed to do a research about surface subsidence prediction and its characteristics. Surface subsidence has three main characteristics, which are maximum subsidence value, surface subsidence area, and surface subsidence profile. By predicting those three characteristics of surface subsidence, it is possible to minimalize and prevent environment and infrastructure destruction which isn’t wanted. To predict the surface subsidence, there are two methods, empirical method by using UK National Coal Board and numerical finite element method by using Phase2 software. The study showed there are some differences of the results between the empirical method and numerical method. Numerical method has a milder maximum subsidence value, wider surface subsidence, and bigger angle of draw compared to the empirical method. Safety Factor (SF) at the edge of the panel has the minimum value and getting bigger along the further the distance from the panel.