Numerical simulation study on the influence of crack characteristics on mechanical properties and impact failure of rock

Abstract

The rock mass in nature have different degrees of crack development. The different crack characteristics affect the mechanical properties and stability of the rock mass. This paper uses PFC simulation software to perform uniaxial compression tests on rock specimens with different crack characteristics and analyzes the influence of the crack characteristics on the mechanical property, impact energy index, and failure characteristics. The sensitivity analysis is used to analyze the influence degree of crack characteristics. It is concluded that the peak strength is directly proportional to the crack angle and inversely proportional to the crack length, the crack number, and the crack width. The peak strain is directly proportional to the crack angle, the crack number, and the crack width and is inversely proportional to the crack length. The impact energy index of rock specimen increases gradually with the crack angle, crack number, and crack width. The influence degree of crack characteristics is divided into four grades by sensitivity analysis. The crack angle has a more significant influence on the peak stress, peak strain, and impact energy index, and the crack width has a more minor influence on the peak stress and peak strain. The research results can provide the theoretical basis and guidance for preventing the instability and failure of the rock mass with different crack characteristics. KeywordCrack characteristic • Mechanical property • Progressive instability • Impact energy index • Sensitivity analysis * Tan Li