Kerman and its surrounding towns consist of a flat alluvial plain of fine silt and clay materials. In morphological aspects, these sediments have a very gentle slope with the main infrastructure of the city built on them. Generally, the structure of undisturbed soils is developed over time due to the influence of environmental factors. Geological factors in the Kerman fine-grained alluviums have caused the formation of some structures after their deposition. In this research, in order to investigate the soil structure and determine the collapsibility index, 40 samples were collected from different parts of the city. Next, the engineering properties of Kerman’s soil (e.g., mineralogy and collapsibility), development of soil structure, and sensitivity of the soil structure were studied. To determine the sensitivity and structural coefficient of these soils, Schmertmann’s criteria and Liu and Carter’s model were applied, respectively. Moreover, scanning electron microscopy (SEM) images and energy-dispersive X-ray spectroscopy (EDS) method were used to study Kerman’s deposits. Mineralogy results of Kerman’s plain soils reveal that there are minerals such as illite, chlorite, smectite, and calcite in these deposits. The SEM images confirmed the consolidated and compressed structure of the soil grains in most of the samples. Furthermore, the results showed that the soils of Kerman were often compressed and over-consolidated. The collapsibility index showed a quite direct relationship with the structure development, as the collapsibility was low in the samples with low destructuring coefficient while it was high in the samples that had a structure.

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