Abstract: A numerical model of uniaxial compression is built by FLAC^3D and its validity is proved by comparing with actual test result. The elasticity modulus of element is changed while other material parameters are controlled. To research the effect of element’s elasticity modulus on rock’s uniaxial compressive strength, the elasticity modulus changes in a certain range uniformly, randomly and according to normal distribution respectively. Results show that the better elasticity modulus uniformity is, the greater rock compressive strength will be. The maximum value is equal to the result when elasticity modulus of the whole model is a same reference value. When elasticity modulus of elements changes randomly in a certain range, compressive strength becomes smaller. The greater randomness of elasticity modulus is, the smaller compressive strength will be. In the same range, rock compressive strength when elasticity modulus changes according to normal distribution is greater than that when elasticity modulus changes randomly. Both of them are smaller than the rock compressive strength when elasticity modulus value of the whole model is a same reference value. The relation can be expressed by σ₁≥σ_Enormal distribution≥σ_Erandom distribution≥σ_Euniform distribution.

Key words: uniaxial compression test, elasticity modulus, FLAC^3D