Laboratory measurement of time-dependent deformation properties of muddy siltstone.

Abstract

This paper investigates the time-dependent deformation of argillaceous rocks, drawing principally on laboratory experiments carried out on muddy siltstone recovered from an open pit mine located in the midlands, UK. A series of creep tests were conducted on both intact and fractured rock samples to cover the two ultimate structural conditions of rock mass. Based on the creep test results, the relationship between axial strain and time under different axial and deviatoric stresses was investigated. The creep data of both intact and fractured rock samples was successfully fitted to Burgers model to represent creep behaviours of pre and post failure. The study provides improved representation of the time-dependent deformation properties of rock mass, which is essential to enhance geomechanical modelling of long-term stability of abandoned mines and for the application of underground disposal of radioactive waste.