Abstract
Sandstone is different from pure brittle rocks such as marble and granite. Its brittleness weakens and then increases with increasing confining pressure. This paper establishes a calculation model of the “brittleness-ductility” energy drop coefficient that characterizes the whole process of sandstone failure from the perspective of energy. The obtained result was compared with the result of traditional calculation model. The results show that the established model is more consistent with the experimental phenomenon and can describe the whole process of sandstone failure more precisely at a macro level. Moreover, the model is more practical since it avoids the tedious integration calculation process. The model and tests have extended the applicable range and applied rock types of the energy drop coefficient and enriched the knowledge system of elastoplastic mechanics. At the same time, they carry important significance for environmental restoration and geological disaster prevention and control in sedimentary rock mining zones, which can promote the sustainable development of related industries in the mining zones.
Highlights
China is one of the few countries in the world which use coal as the main energy source
Conclusions. is paper establishes a calculation model of the “brittle-ductility” energy drop coefficient that characterizes the whole process of sandstone deformation and failure from the perspective of energy based on the stressstrain curves of sandstone samples obtained from triaxial tests
It discusses the influence of confining pressure on energy drop during sandstone failure. e following conclusions are reached: (1) According to the fracture surface characteristics and stress-strain curves of the sandstone obtained from the triaxial tests, as the confining pressure increases, the brittleness of the failed samples diminishes and gradually enhances after reaching the peak. is is different from other rocks such as granite and marble
Summary
China is one of the few countries in the world which use coal as the main energy source. To address these research gaps, this paper obtains the whole stress-strain curves of sandstones under different confining pressures based on triaxial tests and proposes a calculation model of “brittleness-ductility” energy drop coefficient applicable to sandstone. The mechanism of sandstone failure is explained and influence of confining pressure on energy release and dissipation during rock deformation and failure is discussed. Erefore, the actual mechanical energy W absorbed when the test piece reaches the peak pressure can be divided into dissipative energy and releasable elastic energy:. E energy drop coefficient H expresses a proportional relationship between the mechanical energy input into the rock and the releasable elastic energy It demonstrates that the deformation and failure of the brittle rock are the result of energy dissipation and sudden release. H has a certain correlation with the brittle failure of the rock. e larger the H value, the less obvious the brittle stress drop of the rock, and the stronger the ductility. erefore, the energy drop coefficient H has important reference value for characterizing the degree of rock brittle failure
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
