Study on the optimum proportioning of coal rock similar materials based on orthogonal experiment

ZHU Changxing; LIU Xu; ZHAO Weihao

doi:10.16186/j.cnki.1673-9787.2022090049

Abstract：Objectives To explore the optimal ratio of similar materials of coal rock,Methods the natural apparent density,uniaxial compressive strength,and modulus of elasticity of coal samples from Zhao Gu I mine were used as simulation indexes,and the orthogonal design method was used to carry out the similar material ra-tio test.Calcium carbonate,cement,fine river sand,coal powder,and distilled water were selected as raw ma-terials,and nine groups of similar materials were prepared according to a 4-factor,3-level orthogonal propor-tioning scheme,using the aggregate to binder mass ratio,the binder inter-component mass ratio,the aggre-gate inter-component mass ratio,and the water blending rate as the control factors.Results The test results show that the physical and mechanical parameters of similar materials vary greatly under different ratios,and the effect of each factor on the simulated indexes is regular,and the bone and glue ratio plays a control-ling role on the simulated indexes of similar materials,and the natural apparent density,uniaxial compres-sive strength and elastic modulus all decrease significantly with the increase of the bone and glue ratio.The optimal ratio of similar materials was obtained by multivariate linear regression analysis as calcium carbon-ate∶cement∶river sand∶coal dust∶water=1∶4∶0.9∶5.8∶3.3,and it was verified that the specimens made by this ratio could simulate the raw coal well in terms of physical and mechanical parameters,uniaxial com-pression curves and damage morphology.Conclusions This research adopted a combination of theoretical and experimental methods which is effective and feasible to find the optimal ratio,and can provide some ref-erence for the research in the field of coal rock similar materials.