Influence of textural characteristics and mineral composition on the acoustic behavior under acoustic integrated uniaxial compression

This paper presents acoustic integrated uniaxial compression tests on 11 types of rock specimens to investigate their acoustic behavior and brittleness properties. Thin section analysis was used to characterize the mineral composition and structural characteristics of the rocks, and their grain uniformity was quantified using the weighted variable coefficient. The acoustic signals of the 11 types of rock specimens during uniaxial compression were monitored and recorded in real time using ultrasonic and acoustic emission (AE) testing technologies. The relationships between grain characteristics, mineral composition, and acoustic behaviors were investigated. The results showed that the centroid frequency ( F cf ) and transmission coefficient ( T cf ) of the rocks were generally positively correlated with grain uniformity, and mineral grain size had different effects on igneous and sedimentary rocks. The ultrasonic ( V p , , F cf , T cf ) and damage ( D 3 ) characteristics were significantly influenced by the three main mineral compositions (quartz, plagioclase, and k-feldspar). Additionally, differences in the percentage growth of F cf and T cf in igneous, sedimentary, and metamorphic rocks were explored and attributed to differences in the structural construction and abundance of initial microcracks. A novel brittleness index for rocks was established based on the ultrasonic characteristic parameters and mineral composition, and the existing brittleness index based on AE parameters was improved.