Detailed analysis of rock failure in laboratory compression tests
Controlled experiments were conducted: (1) to establish the details of fracture development and the complete strength characteristics of rocks in uniaxial compression and triaxial compression at low and intermediate confining pressures, (2) to evaluate the effect of some common methods designed to eliminate the effect of frictional restraints in uniaxial compression tests, and (3) to determine the deformation characteristics of rocks in uniaxial, straight- pull tension. In uniaxial compression, rock failure occurs in 2 modes, local axial splitting and shear. Local axial splitting determines the onset of failure and the compressive strength in coarse-grained materials. The development of macroscopic, continuous failure phanes is governed by shear. Local axial splitting is a localized stress-relieving phenomenon. The experiments have indicated that it is directly related to the grain size of the rock, and consequently, is absent when the grain size is small. In general, the compressive strength of rocks can not be correlated with the appearance of fully collapsed specimens.
- OSTI ID:
- 5203401
- Country of Publication:
- United States
- Language:
- English
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