Mechanical properties of altered granite gneiss considering time effect

ABSTRACT

The altered granite gneiss is a special rock with loosely-structured and well-developed pores and cavities. The microstructure and mineral composition of the rock were analysed by SEM-EDS and creep triaxial tests were carried out and the axial and lateral deformations over time were discussed. Both the axial and the lateral creep curves show the typical three distinct creep stages (decay creep, steady state creep, accelerated creep). At a low stress level, the axial creep strain is unnoticeable, and only when loaded at a high stress level will the creep strain increase at an increasing rate until the rock specimen fails. The lateral creep strain is smaller than the axial creep strain, but the creep rate (dε/dt) in the lateral direction is higher than that in the axial direction at all stress levels. The failure pattern, which is affected by many factors, shows a shear failure with rather broken and rough failure surfaces.

KEYWORDS:

• porous medium
• creep and deformation
• failure
• microstructure
• creep test

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Financial support provided by the Qing Lan Project, the Natural Science Foundation of China [Grant Nos. 11572110, 11272113, 51479049 and the Fundamental Research Funds for the Central Universities [Grant No.2016B05314]] is gratefully acknowledged.