关键词: 岩石, 应力-化学-渗流耦合过程, 化学势, 应力, 化学动力学, 溶解速率

Abstract: Based on the chemical thermodynamics and chemical kinetics, transition state theory, rock mechanics, a dissolution kinetic model of rock under stress is established; the effect of stress on solid activity and dissolution rate is analysed; the mechanism of water-rock interaction under stress is discussed. It reveals that: chemical potential difference induced by the stress difference between rock and surrounding fluid is the driving force of rock dissolution. Stress greatly enhances the rock solid activity, hence speeds up the mineral dissolution rate. There are two meso models of rock dissolution which are water film diffusion model and island-channel model, respectively. The differences between the two models are stress distribution in solid-fluid interface and preferential dissolution site. Water-rock interaction under stress raises a mechanical-chemical-hydraulic coupled problem. Stress motivates chemical reaction. Chemical reaction alters the rock surface configuration. Local stress distribution and magnitude change with the surface variation, which return to cause the change of chemical reaction region and process. Meanwhile, it also influences seepage path evolution

Key words: rock, mechanical-chemical-hydraulic coupling, chemical potential, stress, chemical kinetics, dissolution rate