DETERMINATION OF THE UNIAXIAL COMPRESSIVE STRENGTH OF COAL WITH INDIRECT TESTS

The uniaxial compressive strength (UCS) is one of the important input parameters used in rock engineering designs of underground spaces, or rock blasting, drilling, slope stability, excavation rate and many other civil and mining operations. Although, the method is relatively simple, it is time consuming and expensive; also, it requires well prepared rock cores. Therefore, indirect tests are often used to predict the UCS, such as Schmidt hammer, point load index and sound velocity. Besides, these indirect tests can usually preferred for coal, because preparing core sample from coal is so difficult. The main objective of this study is to evaluate these simple methods of estimating the UCS of coal. The result of uniaxial compression test carried out on 46 different coal samples were compared with the corresponding results of the point load, the natural density, the Schmidt hammer and the sound velocity tests. The data were analyzed to determine the correlation of results for each test.