Correlation between petrographic characteristics and failure duration in clastic rocks

Being the inherent attributes of rock, the petrographic characteristics such as mineral composition and microstructure are the constructive parameters which influence its bursting potential. In the laboratory, rock specimens with different petrographic characteristics are tested to study their rock strength and failure duration, and correspondingly, composition and microstructure of each rock specimen are analyzed in thin sections to determine the mineral composition, content, grain size, cement and contact modes between grains. The results show that the petrographic characteristics of clastic rock have an intrinsic influence on its strength and failure duration. With the increase of the rock detritus content (or quartz), the uniaxial compressive strength increases according to a logarithmic expression and the failure duration decreases according to a negative logarithmic expression. With increasing average size of detritus grains in rock, the stiffness and brittleness of rock strengthens. The uniaxial compressive strength of rock has a logarithmic variation with its average size of detritus grains and the failure duration decreases with its increasing average size of detritus grains according to a negative logarithmic expression.