Geomechanical Properties of Coal Mine Roof Rocks in Illinois

Abstract

Geomechanical properties of rocks are important parameters in the design procedure and construction of various geotechnical projects such as underground excavation, rock slope stabilities, and blasting in rock medium. These parameters have also wide applications in the mining industry since they are employed in the rock mass classification of coal mine roofs and roof control design. The strength indexes of the rocks are affected by changes in their moisture contents. Understanding of this correlation for rock medium is critical for mining companies during mine development. In this paper, an extensive database containing geomechanial properties of three different rock units including shale, limestone, and claystone is developed by collecting and performing tests on roof core samples of a coal mine in the Illinois Basin. These properties include moisture content, unit weight, unconfined compressive strength, indirect tensile strength index, axial point load index, diametral point load index, and slake durability index. In this study, a correlation between moisture content and strength of examined rock samples is investigated. It is also discussed how the results could affect the timing for the development of mine panels, keeping the main entries open and dealing with moisture sensitive rocks during the mining activity.