Research on acoustic emission characteristics of metagabbros with different felsic development under splitting load

Abstract

The acoustic emission (AE) characteristic signal can reveal the mechanical properties of rock materials and the development characteristics of internal microcracks. Rocks with different mineral development characteristics produce different AE signals during fracture. This study selected variable metagabbros with varying feldspathic development for AE tests under splitting load. The results demonstrated that the characteristics of AE ringing counts during the Brazilian fracture of metagabbro were closely correlated with the content of felsic minerals. The cumulative AE ringing count of metagabbros with feldspar nondevelopment exceeded 250 000, while those of metagabbros with feldspar development did not reach 200 000. As the feldspathic mineral content increases, the AE ringing counts of metagabbro exhibit an increasing trend in the high-energy (1e6–+∞ aJ) and high-amplitude (90–100 dB) intervals. With the development of feldspar minerals, the fracture mode of metagabbro gradually changed from shear failure to tensile failure. The higher the development of felsic minerals, the higher the stress level corresponding to the maximum fractal dimension, the greater the energy released by rock failure, and the more severe the damage. This study is of great significance for revealing the mechanism of rock rupture.