Abstract: The uniaxial loading acoustic emission test under different displacement loading rates was carried out by the RMT-150b rock mechanics rigid servo machine.The acoustic emission characteristics of limestone and sandstone during the process of deformation and destruction were tested and analyzed.The results show that when the loading rate increases,the uniaxial compressive ultimate strength and the ringing count of the limestones with the strength of 148.89~202.02 MPa will increase first and then decrease.The frequency of ringing count will decrease first and then increase.Then the uniaxial compressive ultimate strength of the sandstones with the strength of 77.52~94.59 MPa will decrease when the loading rate increase.At the same time,the extreme value of ringing count will firstly decrease and then increase.The acoustic emission activity is active in the rock damage stage when the loading rate is lower.In this case the frequency of the ringing count is higher and the distribution is uniform.After the rate increases,the ringing count is easier to increase sharply,and the frequency of ringing count is relatively smaller with uneven distribution characteristics.The change rule of acoustic emission energy is same with the rule of ringing count.The the above study results has a certain reference significance for predicting the instability and damage of mine surrounding rock by the acoustic emission monitoring technology.

Key words: Rock mechanics,Uniaxial compression,Loading rate,Acoustic emission technique