Experiment study on acoustic wave velocity law with temperature variation in coal and rock mass

in order to study the temperature affected to the wave velocity ransmission in the coal and rok mass a sef developed acoustic wave parameter est systen was aplied to the experiment study on the wave veocty law of the coal and rock mass with the temperature vaiation to provide theoretical references to the stutdyon the acoustic wave trasmnission in the coal and rock mass. The study reasuts showed that with the temperature increased,the wave velocity of the P wave and S-wae in the coal and rock samples would in a reduction genfrlly nd would have an undulatory phenomenon.There was a igh postive corelation feature between the wave inmpedance size and wave velocity size of the coal samples.The temperature rose would cause heat exvpansion f differert mineral contens in the cal nd rock mass.Due to the diferent types of the minerals the heat expansion ceficsent would be dfferent,the micro pores and crack n the coal and rock mass oud be inreased and expanded .The porous structure of the coal and ock mass would be varied and the elstic modulus and wave velcity of the coal and ock mass ould be reduc.ed.Meanwhie,the temperature rose would cause the variation of the mineral nd binding material in the cal nd rok mass and thus the elastc modulus and wave velocity of the coal and rock mass would be reduced.