LIU J X, ZHAO Y, SHEN Y C, et al. Study on the differences in mechanical properties and energy evolution of unfilled and gypsum filled pre-cracked granite［J］. Journal of Henan Polytechnic University(Natural Science)，doi: 10.16186/j.cnki.1673-9787. 2024040009.

doi: 10.16186/j.cnki.1673-9787. 2024040009

Received： 2024-04-05

Revised： 2024-06-14

Online： 2025-03-28

Study on the differences in mechanical properties and energy evolution of unfilled and gypsum filled pre-cracked granite（Online）

LIU Jixiang¹, ZHAO Yue¹, SHEN Yancheng¹, ZHAO Ercheng¹, ZHANG Chunyang², TAN Tao²

1. Lanzhou Engineering & Research Institute of Nonferrous Metallurgy Co. Ltd. Lanzhou 730000,Gansu,China; 2. School of Resources and Environmental Engineering, Wuhan University of Technology,Wuhan 430070,Hubei,China.

Abstract: Objectives Cracks have adverse effects on the mechanical properties and stability of engineering rock masses, and filling materials can play a strengthening role to a certain extent. In addition, the energy evolution law of fractured rock masses during the failure process reflects the reinforcement mechanism of filling materials. Therefore, in order to explore the differences in mechanical properties and energy evolution of pre-cracked granite specimens with and without filling materials, Methods granite specimens with different pre-crack inclination angles including central circular holes were prefabricated, and their mechanical behavior and energy storage characteristics were explored by uniaxial compression test considering the influence of gypsum filling state. Results The results show that the peak strength and elastic modulus of unfilled and gypsum filled granite increase linearly with the increase of pre-crack inclination angle, while the peak total input energy and energy storage limit increase exponentially with the increase of pre-crack inclination angle. It can be seen that gypsum filling does not change the influence of pre-cracks on the peak strength, elastic modulus, energy absorption, and storage evolution of granite. However, the gypsum enhances the integrity of the specimen and can absorb external input energy, resulting in an increase in the energy required for its failure and energy storage level. This enhancement effect is more significant when the pre-crack inclination angle is 0-60°, and weakens when it is 60-90°. In addition, in order to characterize the energy evolution of the specimen during the failure process, a corresponding elastic strain energy evolution model was proposed based on the energy suppression principle, and the reliability of the energy model was verified. Conclusions The research results can provide theoretical guidance for grouting reinforcement of fractured rock masses.

Key words: pre-cracked granite specimen; gypsum filling; uniaxial compression test; mechanical properties; energy evolution law