It is of great interest to describe and quantify the evolution of microstructure for a better understanding of rock deformation processes. In this study, 2D microstructure images of salt rock are analyzed at several stages of consolidation tests and cyclic compression tests to quantify the evolution of the magnitude and orientation of solidity, coordination, local solid volume fraction, and crack volume. In both the consolidation and the cyclic compression tests, the deformation of aggregates achieved by grain rearrangement is greater than that achieved by the deformation of an individual grain. In the consolidation test, the aggregates are rearranged into horizontal layers of coordinated grains, the orientation distribution of grain indentations is quasi-uniform, and the size of the pores reduces and becomes more uniformly distributed. As a result, salt rock microstructure becomes more homogeneous. The increase in local solid volume fraction in the lateral direction is correlated with an increase in the oedometer modulus. In the cyclic compression tests, grain-to-grain contact areas decrease due to the redistribution of grains and the propagation of intergranular cracks. Aggregates are reorganized into columns of coordinated grains. Intergranular opening-mode cracks tend to develop in the axial direction, while intergranular shear-mode cracks propagate preferentially in the lateral direction. The lateral components of the fabric tensors of coordination and local solid volume fraction decrease, which result in an increase in the Poisson’s ratio. The fabric descriptors used in this work allow a better quantification and understanding of halite deformation processes and can be used in other types of rocks encountering similar deformation mechanisms.

为了更好地了解岩石变形过程，描述和量化微观结构的演化非常有趣。在这项研究中，在固结测试和循环压缩测试的多个阶段分析了盐岩的二维微观结构图像，以量化固体的大小和方向，配位，局部固体体积分数和裂缝体积的演变。在固结和循环压缩试验中，通过晶粒重排实现的聚集体变形都大于通过单个晶粒的变形实现的聚集体变形。在固结试验中，聚集体被重新排列成协调晶粒的水平层，晶粒压痕的取向分布是准均匀的，并且孔的尺寸减小并且变得更均匀地分布。结果，盐岩的微观结构变得更加均匀。横向上局部固体体积分数的增加与里程表模数的增加相关。在循环压缩试验中，由于晶粒的重新分布和晶间裂纹的传播，晶粒间的接触面积减小。骨料被重新组织成协调颗粒的列。晶间开模裂纹倾向于在轴向方向上发展，而晶间剪切模裂纹则优先在横向方向上扩展。织物张量的配位数和局部固体体积分数的侧向分量减少，这导致泊松比增加。