| Most underground rock mined in a certain degree of water content. Therefore, the sandstonewere uniaxial compression acoustic emission testing. Water status of these sandstones are different.Study the deformation characteristics of different water content of rock mechanical properties andacoustic emission characteristics. Provide reference and theoretical guidance for engineeringapplication of acoustic emission techniques to monitor the safety of mine pillars and so on. It isimportant for practical engineering.The following main conclusions:(1) Under laboratory conditions, free swelling test sandstone. Free expansion strain found inboth directions, and moisture content showed a good linear relationship. Strain the soaking timeand the expansion in both directions on the logarithmic relationship.(2) For different water status sandstone uniaxial compression tests. The results showed that:the elastic modulus, compressive strength increases as the moisture content decreases, the peakstrain with increasing water content increases. Sandstone in the dry state approaching destructionexhibit plastic deformation. The sandstone natural water content and water saturation state of thisphenomenon has been weakened, with the moisture content increases, the more obviousweakening of the plastic deformation, brittle fracture is more significant.(3) Acoustic emission tests showed: Water on acoustic emission characteristics aresignificantly affected. Acoustic emission parameters with increasing moisture content decreases. Ina precursor to the dry rock destroyed more obvious. Natural state with saturated aqueous shapedrocks have experienced a period of calm before the destruction of the destruction of the precursorshort time, less acoustic emission information.(4) Acoustic emission curve can reflect the evolution of rock samples microcracks. Rockmechanical damage due to external loads generated monotonic Growth. This mechanical damagecan be defined by the ring count and energy count. This reaction can be better inside the rockdamage evolution.(5) RFPA2D uniformity is used to simulate different rock deformation and acoustic emissioncharacteristics. The results showed: under uniaxial compression, less homogeneous rock, the lowerits peak intensity. As the degree of homogenization increases, exhibit very strong brittle rockdamage, and the peak intensity was increased. With the increasing homogeneity of acousticemission signs before more damage is not significant, the phenomenon of rock acoustic emission becomes more concentrated in the moment crushed rock, acoustic emission sudden release ofenergy, reflecting the very strong damaging.(6) Selection of acoustic emission monitors and optical strain gauges on the shaft near thestability pillar joint monitoring, anticipation of the monitoring points in a stable period. |
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