THE UPSIDENCE MODELING AT THE BOTTOM OF VALLEY WITH LONGWALL COAL MINE ACTIVTIES UNDERNEATH USING ANALYTICAL, PHYSICAL, AND SYNTHETICAL SEISMIC MODELS APPROACH

• Main Author: D Kusumo, Adriyanto
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/55580
• Institution: Institut Teknologi Bandung

The transition mining system from the surface mining into the underground mining method requires,the understanding of longwall coal mine impact such as the presence of upsidence. It occurs at the bottom of valley which is located above the longwall coal mine. Upsidence study in this research is conducted by understanding the rock properties in South Kalimantan some experiments using analytical model, physical model, and synthetic seismic model. The two main parameters of rock characteristic which are collected in this research are rock strength and rock elasticity. The rock comparison with other locations shows that the modulus elasticity of rock in South Kalimantan shows a high value compared to rocks from Australia. The analytical models are conducted using the plate buckling theory. The experiment result from the analytical model shows the correlation with valley width, critical layer thickness, horizontal stress, and Young’s modulus. The physical models are conducted using base friction method. The experiment result of physical model shows there is a correlation with Hoek and Brown’s equation. The result also shows that the occurrence of upsidence are influenced by: the slope angle is greater than 800, the thickness layer in the valley is less than 3 cm, and the maximum slope height is 10 cm. The synthetic seismic models are conducted using both of crosshole-downhole seimic reflection and seismic tomography. The thin layer, which is one factor to generate upsidence, can be clearly detected using the crosshole-downhole seismic reflection method.