Effect of non-plastic marine silt on physical and mechanical properties of Konarak carbonate sand

• Published in: Bulletin of engineering geology and the environment 2024-05, Vol.83 (5), p.161, Article 161
• Main Authors: Salehzadeh, Hossein, Heshmati R., Ali Akbar, Karimabadi, Amin
• Format: Article
• Language: English
• Subjects: Carbonate sand; Carbonates; Compression; Compression tests; Compressive strength; Density; Earth and Environmental Science; Earth Sciences; Foundations; Geoecology/Natural Processes; Geoengineering; Geotechnical Engineering & Applied Earth Sciences; Grains; Hydraulics; Load; Mechanical properties; Mixtures; Nature Conservation; Original Paper; Physical properties; Relative density; Sand; Sand & gravel; Sediments; Shear strength; Silt; Specific gravity; Triaxial compression tests; Void ratio
• ISSN: 1435-9529; 1435-9537
• DOI: 10.1007/s10064-024-03650-9

In this work, the physical and mechanical properties of Konarak carbonate sand located in the southeast of Iran at the shore of the Gulf of Oman (Makran) and the effect of marine silt on these properties were evaluated. To this aim, the basic index tests, 1D compression, and triaxial compression tests, along with simulating different field conditions, were conducted on Konarak carbonate sand-silt mixture, considering the wide range of variations in marine silt. Based on the results, Konarak carbonate sand showed a great dilation tendency under monotonic shear in undrained conditions, due to the special shape of the grains, their resistance to breakage, and their relatively lower extreme void ratios compared with other carbonate sands. Further, the influence of marine silt on the properties of that carbonate sand relies on the silt content (SC) and the mixture relative density. In this respect, adding 10% silt to sand (SC = 10%) can decrease the undrained strength in loose and medium conditions, although fewer changes are observed in undrained strength in dense and very dense conditions. Moreover, increasing silt content up to SC = 20% increases the supporting role of silt particles for sand grains and raises the strength in all states of the relative density. The behavior tends toward the pure silt sample (i.e., reduced strength and increased tendency to compression) as the threshold silt content (SC th ) is exceeded. Below the threshold, however, the use of the equivalent intergranular void ratio parameter could eliminate the dependence of the test results on the SC.