岩石有效应力系数测试方法与表征模型研究进展
摘要
The effective stress principle is a fundamental methodology for investigating fluid-solid coupling behavior in rocks. Accurately determining the effective stress coefficient (<italic>b</italic>) is a key parameter in effective stress analysis and is crucial for understanding rock deformation and failure mechanisms. This paper systematically reviews both domestic and international research progress regarding testing methods, characterization models, and influencing factors of the effective stress coefficient. A comprehensive comparison of isotropic testing methods, anisotropic testing methods, fractured rock testing methods, and tight rock testing methods is presented, highlighting their distinct applicability: (1) the drainage method exhibits high accuracy across all porosity ranges and can validate other methods; (2) the stiffness matrix method effectively captures the anisotropic effective stress coefficient; (3) for fractured and low-permeability rocks, the equivalent effective stress coefficient method and the cross-plotting method are recommended. Existing characterization models, including the critical porosity model, effective medium theory, and the BISQ model, are evaluated using experimental data. Results indicate that the Biot-squirt (BISQ) model and the isoframe model achieve high precision suitable for accurate calculations; however, their parameter requirements and computational complexity limit practical applications. The critical porosity model, which requires only two parameters while maintaining satisfactory accuracy, is recommended for engineering applications. Key influencing factors include intrinsic factors (such as pore structure, mineral composition, and pore fluids) and external conditions (such as temperature and stress). Intrinsic factors dominate fundamental behavior, while external factors induce microstructural changes that affect the effective stress coefficient. Future research directions should focus on: (1) real-time measurement of t