Effect Analysis of Confining Pressure on Young's Modulus

Based on the effect of rock specimen on Young's modulus,the influence mechanism of confining pressure on Young's modulus is discussed.The increase of confining pressure,resulting in the decrease of the micro-crack density and the closure of the crack,and the fictional sliding effect between crack and slip surface are main causes of the increase of Young's modulus.Through the analysis of test data,it is concluded that the Young's modulus increases with the increase of confining pressure.While the confining pressure becomes bigger than the compacting strength,the increasing of Young's modulus becomes diminished and tends to be a definite value gradually.The formula of the relation between the rock Young's modulus and the confining pressure is determined,which reflects the characteristic that the micro-crack density decreases in an exponential relationship with the increase of confining pressure.