Clays are among the main mineral components of shales and play a significant role in mechanical properties and anisotropy. However, it is difficult to quantify the impact of clay minerals on the mechanical properties of rocks because of the complex influence factors. In this study, we construct two artificial clay-rich shale samples containing kaolinite and smectite, respectively, and prepare one natural sample to study the static and dynamic responses of dry samples containing different types of clay during confining loading and unloading. The physical and mechanical properties of shales can be greatly affected by the type of clay minerals due to their structural difference. The kaolinite-rich sample exhibits higher porosity and permeability than those in smectite-rich sample. Both the static and dynamic linear compressibility of our samples generally decrease with confining pressure and display obvious anisotropy. The static compressibilities are larger than dynamic compressibility during loading; however, static compressibilities are not always larger than their equivalent dynamic compressibilities due to the elastically response of samples during early unloading stage. The damage parameters based on the existence of crack-like pores are used to explain the observed nonlinear elastic behavior, and the hysteresis in elastic properties can partly explain the difference in damage parameters between loading and unloading.

粘土是页岩的主要矿物成分，在机械性质和各向异性中起着重要作用。然而，由于复杂的影响因素，很难量化粘土矿物对岩石力学性能的影响。在这项研究中，我们分别构建了两个分别包含高岭石和蒙脱石的富含粘土的人造页岩样品，并准备了一个天然样品，以研究含有不同类型粘土的干样品在围岩装卸过程中的静态和动态响应。由于页岩的结构差异，页岩的物理和机械性能会受到粘土矿物类型的极大影响。富含高岭石的样品比富含绿土的样品具有更高的孔隙率和渗透率。我们的样品的静态和动态线性可压缩性通常随围压而降低，并表现出明显的各向异性。加载过程中的静态可压缩性大于动态可压缩性；然而，由于样品在早期卸载阶段的弹性响应，静态可压缩性并不总是大于其等效动态可压缩性。基于裂缝状孔隙的存在的损伤参数被用来解释所观察到的非线性弹性行为，而弹性特性的滞后可以部分地解释加载和卸载之间的损伤参数的差异。由于样品在早期卸载阶段的弹性响应，静态可压缩性并不总是大于其等效动态可压缩性。基于裂缝状孔隙的存在的损伤参数被用来解释所观察到的非线性弹性行为，而弹性特性的滞后可以部分地解释加载和卸载之间的损伤参数的差异。由于样品在早期卸载阶段的弹性响应，静态可压缩性并不总是大于其等效动态可压缩性。基于裂缝状孔隙的存在的损伤参数被用来解释所观察到的非线性弹性行为，而弹性特性的滞后可以部分地解释加载和卸载之间的损伤参数的差异。