Experimental study on acoustic emission characteristics of loading rupture of tectonic coal assembly
In order to study the effect of coal thickness on the acoustic emission characteristics of tec-tonic coal assemblages during deformation and rupture,laboratory uniaxial compression acoustic emis-sion tests were carried out on seven tectonic coal assemblages,which accounted for 0％,11.11％,20.0％,33.33％,50.0％,62.5％and 100.0％,respectively.The results show that the tectonic coal assemblages have the acoustic emission characteristics of both primary coal specimens and full tectonic coal specimens,that is,the acoustic emission signals of the assemblages are relatively stable in the compaction and elastic stages,and the changes of ringing count and energy are more prominent in the plastic and failure stages.With the increase of the proportion of tectonic coal,the stable region of rin-ging count of tectonic coal composite increases.The acoustic emission peak count and compressive strength of tectonic coal composite specimens decrease with the increase of tectonic coal thickness rati-o,and the variation ranges are 3.24 × 104～1.99 × 104 and 22.94～7.65 MPa.The acoustic emission peak count and the fitting curve between the compressive strength and the thickness ratio of tectonic coal are similar.The failure mode of the tectonic coal body in the composite specimen is mainly tensile shear compound failure and local crushing,and the failure mode of the primary coal body is mainly ten-sile failure.With the increase of the proportion of tectonic coal,the maximum number of AE events dur-ing loading decrease from 1 862 to 1 379,and the failure duration of the assembly becomes longer.With the increase of the thickness ratio of tectonic coal,the number of AE events increases,and the relation-ship of equal proportion increases approximately.Under the same number of acoustic emission events,the thickness ratio of tectonic coal and axial pressure show an equal decreasing trend.
万方数据
维普
