ENGINEERING GEOLOGICAL CHARACTERISTICS OF COAL DEPOSIT DIMNJAČE (BUGOJNO BASIN)

The paper presents results of research of engineering geological and geomechanical characteristics of the open pit coal mine Dimnjače. Detailed engineering geological and geomechanical research was conducted in 1981 and 1988, and the additional in 2016 and 2019. Based on the results of engineering geological mapping of the terrain, exploratory drilling and laboratory tests, the heterogeneous geological-lithological structure of the terrain was determined. In the area of the coal deposit, when it comes to recent engineering-geological processes in the eastern part, where the elevation of the roof of the coal seam is closer to the surface, landslides and smaller ditches are noticeable, as well as colapses (subsidence) in the southeastern and southern part. One of the causes of slope instability in the eastern part of the deposit is a very pronounced angle of the existing slope. It should be mentioned that the old underground mining works significantly disrupted the natural structure of the deposit and stability of the slopes, which is directly related to the safety of employees and mining machinery when working on coal exploitation.