The Study On The Mechanical Properties And Acoustic Emission Characteristics Of Different Particle Size Under The Condition Of Uniaxial Compression

In order to recognize the mechanical properties of filling body and the characteristic of acoustic emission, along with discussing the influence of rock material with different particle size on AE quiet period, this paper has conducted the uniaxial compression AE test on five different size filling bodies: 0.074-0.08mm、0.08-0.16 mm, 0.16-0.25 mm, 0.25-0.5mm and full taillings, which has the cement sand ratio 1:4, concentration70% and a 28 days` maintenance period. The indoor test combine with theoretical analysis was applied in the test, research and discussion were done mainly from the following several aspects: firstly, the mechanical property test of filling body with different particle size under uniaxial compression, including deformation properties, destruction form and strength characteristics; secondly, the acoustic emission characteristics of filling body with different particle size under uniaxial compression; thirdly, the study on emission quiet period of filling body with different particle size. Conclusions as follows:(1) Filling bodies with different particle size have the same deformation characteristics, undergoing four deformation characteristics: ①initial compaction; ②elastic deformation; ③plastic deformation(the generation and expansion of crackle); ④crackle expand quckily to failure. The destruction form of filling body with different particle size almostly unanimously, and represent fine ductility after failure.(2) The uniaxial compressive strength of the filling body with the particle size of 0.074-0.08 mm, 0.08-0.16 mm, 0.16-0.25 mm are respectively 2.358 MPa, 3.124 MPa, 3.772 MPa, but that of 0.25-0.5mm is 2.602 MPa, which get the conclusion that the filling body with the particle size of 0.25-0.5MPa has a negative influence on the compressive strength.(3) The particle size has a big effect on the quiet period of acoustic emission. Obvious calm period phenomenon in acoustic emission was not monitored in the acoustic emission test of filling body with the particle size of 0.25-0.5MPa.(4) The range of stress percentage of calm period in the filling body with the particle size of 0.074-0.08 mm, 0.08-0.16 mm and 0.16-0.25 mm are respectively 87.5%-95.3%, 50.6%-97.6%, 64.4%-84.3%. The scope of stress percentage of calm period increase with the particle size rise.(5) Duration of calm period and the peak value of stress time ratio have no obvious rule with the particle size of filling body.