Post-peak mechanical properties of rock have important significance to reveal the mechanism of rock deformation, damage and fracture. Based on the conventional triaxial compression test of hard rock of the Tieshan mine, including marble, homogenic migmatite, banded migmatite, gneiss and hematite ore, complete stress-strain curves under different confining pressures are obtained. Post-peak mechanical properties of the rock and fracture characteristics are analyzed according to the test results. The rock subsequent yielding plane model characterized by generalized cohesion (equation) and generalized internal friction angle (equation) is build with the test data. Taking maximum principal strain e as strain softening parameter, (equation) and (equation) were evolved by the piecewise linear functions based on Mohr-Coulomb failure criterion and the friction angle f was deduced in reverse. Then, the model of postpeak stress-strain relationship was build finally. By using test data of marble under s3=10MPa, the model has been validated in a calculation case. The result shows that the model is suitable to describe the post-peak strain softening mechanical behavior under different confining pressure and has some applicability.
Testing Study on Post-Peak Strain Softening Mechanical Behavior of Hard Rock
Gao, F., Zhou, K. P., Cao, P., Wang, P. X., and J. L. Li. "Testing Study on Post-Peak Strain Softening Mechanical Behavior of Hard Rock." Paper presented at the 52nd U.S. Rock Mechanics/Geomechanics Symposium, Seattle, Washington, June 2018.
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