Feasibility study on fully-mechanized technology based on rock mechanics parameters of roof and floor

In order to provide a scientific basis on the determination of fully-mechanized mining in Fengyang Coal Mine,sixty groups of rock samples from roof and floor seam in two mining area were collected for uniaxial compression test.The rock mechanics parameters of No.21 coal seam were obtained.The experimental results show that the stress-strain curves of four categories of rock samples presented four stages of compaction,elasticity,yield and failure during the uniaxial compression test.The elastic modulus and compressive strength of the same category of rock were roughly identical,while the compressive strength of them in different regions showed great discrepancy.The average compressive strength of mudstone,sandy mudstone,siltstone (fine sandstone) and sandstone were 29.3,46.5,76.9 and 108.1 MPa,with an average elastic modulus of 7.5,9.6,18.9 and 23.3 GPa respectively.The mudstone belonged to soft rock,sandy mudstone belonged to medium hard rock,while sandstone (fine sandstone) belonged to hard rock.There was a good linear relationship between the compressive strength (peak strength) and elastic modulus of different rock.The areas where mudstone and sandy mudstone with the Protodyakonov coefficients lower than 6 were suitable for fully-mechanized mining,while the others whose Protodyakonov coefficients were higher than 6 may not good for that technology.