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This paper reports on the results of a laboratory investigation on the shear behaviour of the interface between granite rock and cemented paste backfill (CPB) reinforced with different amounts of fibre (F-CPB) and cured at room temperature for different lengths of time by performing direct shear tests. Moreover, various microstructural analysis techniques are also used to characterise the degree of cementation of the cemented matrix, as well as the microstructure of the interface. The results indicate that the shear properties and behaviour of the F-CPB/rock interface are a function of the fibre content (optimal fibre content) and reduce the contraction at the interface. It is also found that the optimal fibre content is a function of the curing time and applied normal stress. The shear strength envelopes indicate that the friction angle at the interface is larger in the sample that contains fibres, whereas fibre reinforcement reduces the interface adhesion. The results of this research will contribute to improvements in the design and stability assessments of fibre-reinforced cemented-backfill structures.

Recently, issues pertaining to surface disposal of coal-mine wastes, particularly environmental pollution, have been the focus of increasing national and international concern. Solid backfill mining (SBM) method provides environmentally, economically and technically acceptable solutions to these issues by, inter alia, significantly increasing waste-disposal capacities, improving resource recovery rates and reducing levels of ground deformation. In the current study, the physical and mechanical properties of waste rock obtained from seven different locations in China have been described and assessed. A previously developed theoretical solution has been fitted to the nonlinear stress-strain relationship, as derived from testing, resulting in a satisfactorily high level of correlation. Additionally, a basic method for simulation of solid material consolidation via dynamic parameter updates has been expounded and shown to be feasible. Results of the current study may prove extremely useful, particularly in mining applications, engineering design and prediction.