Date of Graduation
Statler College of Engineering and Mineral Resources
Syd S. Peng.
Many coal seams have weak shale immediate roofs that cause ground control problems. Therefore, it is important to know the mechanical properties of these shales so that preventive measures can be developed in advance. However, it is sometimes hard to understand this rock type due to its unpredictable behavior. A good example of this situation is found with the shale roof strata in two coal mines located in the Illinois coal basin---Herrin No. 6 seam. Although these mines are located very close to each other, one of them has many roof falls, whereas the other has no measurable ground control problems.;The aim of this thesis is to explain why and how one shale roof behaves worse than the other. Laboratory tests, including point load strength index, slake durability index, moisture activity index, weatherability index, water (moisture) content determination, swelling strain and x-ray diffraction tests were performed to analyze the shale properties. As a result of these tests, strength, durability, water (moisture) content and absorption, weatherability, swelling and mineralogy of weak shales were analyzed. According to these analyses, some useful correlations were found between the engineering properties, moisture-sensitivity indices, and weathering properties of shales. Finally, mine and support design considerations based on the test results were discussed and recommendations to prevent ground control problems were given.
Gurgenli, Hakan, "Geomechanical and weathering properties of weak roof shales in coal mines" (2006). Graduate Theses, Dissertations, and Problem Reports. 1730.