Abstract:

In order to reflect the characteristics of strength and deformation of stratified rock mass under true triaxial compression, the calculation model is founded by numerical analysis method to obtain the stress and deformation responses of rock samples with different structure plane inclinations ?. The analysis results show that: (1) in the initial loading phase, the initial elastic modulus for samples with ? = 0° and ? = 90° are larger; with the increase of sample deformation, the elastic modulus of rock samples with ? = 90°, 60°, 0° decrease gradually; the brittle characteristics of samples with ? =90° and ? =0° of structure plane are obvious; (2) with the increase of surrounding stress ? 3 =? 2, the compressive strength ? 1 increases correspondingly; the surrounding stress does not have great effect on the location where the peak strength occurs; (3) for the situation of minor principal stress parallel to the structure plane strike, with the increase of intermediate principal stress ? 2, the compressive strength of rock samples shows the trend of first increase then decrease; with the increase of the minor principal stress ? 3, ? 1 increases gradually; when ? 3 is small, their relationship meets in the linear way; but with the increase of ? 3 their relationship transfers to the nonlinear way; and the rock sample with the failure model of slipping along structure plane shows the more obvious nonlinear characteristic; (4) for the situation of minor principal stress perpendicular to the structure plane strike, the compressive strength of stratified rock mass shows the obvious linear relationship with intermediate principal stress and minor principal stress.

Key words: stratified rock mass, effect of structure plane, true triaxial compression, strength, deformation