关键词: 端部摩擦效应, 真三轴, 中间主应力, 接触问题, FLAC3D

Abstract:

End friction effect is one of common problems in triaxial test. In the Mogi-type true traxial test, two pairs of loading platem need to beset on four ends of quadrate sample, which means that the end friction effect is more significant than that in conventional triaxial tests. This study aims at revealing the extent to which the end friction influences rock strength and deformation behavior. True triaxial tests are simulated using FLAC3D where Mohr-Coulomb ideal yield criterion is adopted. The simulation results indicate that the end friction can also lead to illusive effect of intermediate principal stress, even though the rock has no intermediate principal stress effect, the intermediate principal stress will still cause the increase of maximum principal stress, and this tendency become more obvious with the increasing of friction coefficient. Then, the reasons of the results and tendency are analyzed; and the importance of reducing end friction effect in the true triaxial test should be pay much more attention to.

Key words: end friction effect, true triaxial test, intermediate principal stress, contact problem, FLAC3D