Capacity expansion characteristics of granite under triaxial compression
ZHU Zeqi1, 2, 3*, TIAN Kiawei1, 2, SHENG Qian1, 2
(1. State Key Laboratory of Geomechanics and Geotechnical Engineering Safety, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei 430071, China; 2. University of Chinese Academy of Sciences, Beijing 100049, China;
3. National and Local Joint Engineering Research Center for Underwater Tunnel Technology, Wuhan, Hubei 430071, China)
Abstract：To study the capacity expansion characteristics of rock, this research uses Dagangshan granite as a case study. Various tests, including porosity tests, triaxial compression tests, acoustic emission tests, and CT scanning, were conducted to investigate the crack propagation and capacity expansion characteristics of granite during triaxial compression. A calculation method for rock pore volume deformation was developed, along with an evolution equation for porosity during triaxial loading. Based on the principle of strain equivalence, the relationship between the total volumetric strain of the rock sample, the volumetric strain of the rock skeleton, and the volumetric strain of the pore was analyzed to derive a relationship expression between rock porosity and bulk modulus. By integrating the porosity evolution equation, a constitutive model that accurately reflects the expansion characteristics of granite was established, which was preliminarily validated through comparison with experimental results.
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2026, Vol. 45 
