Poroelastic properties play an essential role in interaction between deformation and fluid pressure change in porous rocks. These properties can be affected by microstructural evolution such as porosity change and micro-cracks growth. In this study, the modification of poroelastic properties of a hard rock (granite) is investigated in terms of thermally induced micro-cracks. Granite samples are first subjected to a heating–cooling treatment with different values of temperature. The variations of bulk modulus, stiffness of solid grains and Biot’s coefficient of thermally treated samples are determined and analyzed. It is found that both connected and occluded micro-cracks are generated in granite samples. The bulk modulus of porous material is affected by the connected micro-cracks, while the stiffness of solid grains is influenced by the occluded micro-cracks. The Biot’s coefficient is affected by the connectivity of micro-cracks. All poroelastic properties evolve with effective mean stress and a non-linear poroelastic law should be defined.

孔隙弹性特性在多孔岩石的变形与流体压力变化之间的相互作用中起着至关重要的作用。这些性质可能会受到微观结构演变（例如孔隙率变化和微裂纹增长）的影响。在这项研究中，从热致微裂纹的角度研究了硬岩（花岗岩）的孔隙弹性特性的变化。首先对花岗岩样品进行不同温度的加热-冷却处理。确定并分析了热处理样品的体积模量，固体颗粒的刚度和比奥特系数的变化。发现花岗岩样品中同时产生了连接和闭合的微裂纹。多孔材料的体积模量受连接的微裂纹影响，而固体颗粒的刚度则受封闭的微裂纹的影响。比奥系数受微裂纹的连通性影响。所有的孔隙弹性特性都随着有效平均应力而变化，并且应该定义非线性孔隙弹性定律。