Referring to the investment orientation and reducing the housing crisis by establishing residential complexes in mountainous areas adjacent to the city and expanding the city’s area to control population growth. This research focused on studying structural cracks that appeared in several residential units of the Garden City complex in Kirkuk, which were attributed to soil subsidence and swelling problems. The study collected data at five locations within a residential complex in Kirkuk City. Utilized the Inverse Distance Weighted (IDW) method for the examination of the ratio of clay to silt, and also the physical attributes of swelling, liquid limit (LL), void ratio (e) and compression index (Cc). Also, the study examined the chemical characteristics of total free calcium carbonate content (CaCO₃, %) and total gypsum content (GYP, %). The study used single-regression and multiple-regression models for the interpolation of the plasticity index (PI) and soil attributes. The creation of the digital map sets was for examining the physical and chemical residential compound characteristics in Kirkuk City. PI values can be predicted with greater accuracy by considering integrated physical and chemical soil qualities than g just on chemical or physical factors. PI and physical soil components exhibit a range of both beneficial and detrimental connections. The changes of plasticity index (PI) in connection to physical soil qualities exhibited positive relationships with liquid index (LI), LL, swelling potential, Cc, rebound index (Cr), and e, while PI variations and chemical soil values are positively correlated such as sulfate (SO₃%), gypsum (GYP%), and chloride (Cl%). Linear multiple regression models (LMRM) of physical and combined physical-chemical soil variables reliably PI index values, exhibiting high R² value ranges (between 0.072 and 0.018). Elevated clay content, high liquid limit, and swelling signify expansive soils that present hazards for foundations and infrastructure. Minimal silt content: little impact on permeability or erosion. The void ratio (e): Elevated values (0.9+) indicate loose, compressible soils that require stabilization.
