Characterizing clay soils in Diwaniyah, Iraq, is important because differences in mineralogy, salt content, and chemical composition can significantly affect the swelling tendency, strength, compressibility, and overall performance of foundation and subgrade soils for pavements. In this context, this research focuses on the study of chemical properties of the local clay soils along with physical and mineralogical properties. 16 samples of clay soils were collected from four sites (S1-S4) within a depth range of 0-2.0 m. The laboratory tests that were conducted included particle size distribution, Atterberg limits, pH, electrical conductivity, sulfate, chloride, calcium carbonate, organic matter content, soluble salts,major oxides,mineralogical composition, compaction, unconfined compressive strength (UCS), cohesion, friction angle, California Bearing Ratio (CBR), free swell ratio, and compression index. Soil compositions revealed a mean clay percentage of 59.32% and plasticity index of 28.15%, implying moderate-to-highly plastic behavior of soils. Mean pH and conductivity were 7.86 and 6.10 dS/m, respectively, but the high concentration of soluble salts varied chemically. The dominant mineral was quartz at 27.75%, and montmorillonite averaged 18.50%. Results from engineering tests showed a mean value of 179.50 kPa UCS, 5.60% CBR, 43.25% free swell, and 0.32 compression index. Soil composition S3 performed best in terms of engineering performance while S2 exhibited higher salinity and swelling potential along with inferior strength properties. From the above discussion, it is clear that soil chemistry and mineralogy are interrelated with engineering properties of soils, which could be applied in foundation design, paving construction, drainage, and stabilization of soils in Diwaniyah.
Hadi SH, Sada YAA. Study of Swelling Potential Soil in Diwaniya City Based on Previous Empirical Equations. 2022 International Symposium on Multidisciplinary Studies and Innovative Technologies (ISMSIT). IEEE; 2022. p. 417–23.
2.
Khalaf MO, Issa BM. Determining the Physical and Chemical Properties of the Soils in Babylon and Al-Qadisiyyah for Manufacturing Clay Bricks. The Iraqi Geological Journal. 2021;100–16.
3.
Sa’ur RH, Al-Jeznawi D, Alzabeebee S, Bernardo LFA, Keawsawasvong S. Geotechnical and Geophysical Assessment of the Soil Layers of the Missan Combined-Cycle Power Plant Project. CivilEng. 2024;5(3):717–35.
4.
S. Ahmed M, S. Othman B, A. Al-jalabi F. Geotechnical Evaluation of Soil in Taza District, Southeast of Kirkuk, Iraq: Correlation Between Chemical and Some Physical Properties. Iraqi National Journal of Earth Science (INJES). 2026;26(2):196–212.
5.
Azizi Al-Mahanna RH, Sagban Alabadi LA. Study of the Composition and Relative Distribution of Light and Heavy Sand Minerals and the Effects of Weathering on Some Soils from the Middle Euphrates Regions. IOP Conference Series: Earth and Environmental Science. 2025;1487(1):012216.
6.
Khaleel RI, Salim IH, Ali MI. Evaluation of Some Properties Geotechnical Ground Soils for Selected Sites in Samarra City/Iraq. International Journal of Sustainable Development and Planning. 2024;19(5):1755–61.
7.
Roqaya Zahim Khalaf, Mohammed Rashid Abood. Evaluation of Some Geotechnical Properties of the Soil of a Proposed Site for the Construction of Residential Complexes, Northwest of Tikrit City. Iraqi National Journal of Earth Science (INJES). 2025;25(3):19–30.
8.
Al-Taie AJ, Al-Shakarchi YJ, Mohammed AA. INVESTIGATION OF GEOTECHNICAL SPECIFICATIONS OF SAND DUNE SOIL: A CASE STUDY AROUND BAIJI IN IRAQ. IIUM Engineering Journal. 2013;14(2).
9.
Abdulhussein MA. Evaluation of Geotechnical Properties of Soil at Selected Sites in Al-Nasiriya City. Iraqi Journal of Science. 2024;4382–92.
10.
Salih MM, Jawad FW, Al-Ameri AFI, Abdulhameed AA. Geotechnical correlations of soil properties in Hilla City – Iraq. Open Engineering. 2022;12(1):729–42.
11.
Younis SN, Mahmood RA, Alsaad HA. Swelling Potential and Mineralogy of Al-Hartha City Soil in Basrah-Southern Iraq. Iraqi Journal of Science. 2024;2020–30.
12.
Mearek SM, Shadhar AK, Abbood HH. Relation Between Swelling Pressure and Potential Expansion Soil with Atterberg Limits. Wasit Journal of Engineering Sciences. 2022;10(2):12–9.
13.
Haider Abaid AlAmar. Geotechnical and Geochemical Study of Shatt Al-Hilla Banks’ Soil in Babylon Governorate, Middle of Iraq. Iraqi National Journal of Earth Science (INJES). 2025;25(1):222–31.
14.
Al-Ani T. Mineralogy, geochemistry, and ore formation of Nuwaifa bauxite deposit, western desert of Iraq. Arabian Journal of Geosciences. 2017;10(3).
15.
Al Baghdady SNS, Sagban Alabadi LA. Studying and diagnosing the heavy and light sand Minerals for some of the soils in southern and northern Iraq. IOP Conference Series: Earth and Environmental Science. 2021;735(1):012081.
16.
Enad AA, Ahmed SM, Mohammed AK, Mohammed AS. Influence of Feldspar Addition on the Geotechnical Properties of Expansive Soil in Rahhaliya, Iraq. Revue des composites et des matériaux avancés. 2024;34(2):143–8.
17.
AL-Ani SMA, Enad AA, Al-Hadeethi B, Alqurqash A, Hussein HA, Alani MW, et al. Evaluation of Sand Glass Powder to Enhance Some Geotechnical Properties of Expansive Clay Soils. Mathematical Modelling of Engineering Problems. 2025;12(8):2754–60.
18.
Shahad RF, Mohammed RJ, Abdalkadhum AJ, Hussain S, Khallouf A, Almayahi AT. Assessment of soil composition, vegetation, and geochemical properties using GIS tools in Iraq. Innovative Infrastructure Solutions. 2026;11(8).
19.
Mukheef RAAH, Obayes AA, Omran ZA. Study The Suitability of Water Quality For Agricultural Uses In Al- Diwaniyah Governorate in Iraq. Asian Journal of Water, Environment and Pollution. 2022;19(1):87–92.
20.
Jaafar IM, Al-Mosawi WM, Khalf YI, Al-Khalidy AA, Haiwe MA. Preconstruction Site Evaluation Using Electrical Resistivity and Geotechnical Investigations in Al-Qasim District, Babylon Governorate, Iraq. The Iraqi Geological Journal. 2026;139–54.
21.
Prashanth R. Design and Performance Evaluation of a Distributed IoT Framework for Adaptive Smart Environment Management. National Journal of Ubiquitous Computing and Intelligent Environments. 2026;(2):1–11.
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