Friction in different interfaces such as soil-structure in the foundation often plays a crucial role in the design of various geotechnical structures. It includes deep foundations like piles, drilled shafts, retaining walls, sheet piles, and similar structures. Therefore, determining the shear strength parameters at the soil-structure interface is essential for eva‎luating the load transfer between the structure and the soil. In this context, the present research investigates the effective factors of microbially induced calcite precipitation (MICP) as an eco-friendly method, at the soil-concrete interface to improve the soil’s shear strength parameters around the foundation, and consequently, increase the structural resistance of concrete structures in contact with the soil. In this study, considering parameters such as the size of sand particles, the amount of bentonite used, and the cementation volume ratio, the impact of each of these factors on soil shear strength parameters (internal friction angle and cohesion) has been investigated. A laboratory scale direct shear test apparatus with dimensions of 30cm x30cm was used in this research, which allows for the determination of the maximum shear strength of the investigated samples. According to the results of this study, by improving the soil at the soil-concrete interface, it is possible to increase the soil’s internal friction angle up to 61% and also to increase the soil’s cohesion from 1.2 kPa to 90.84 kPa

حميد هاشم الحسيني , هاجر شرع اصفهاني

عليرضا باغبانان

محمود بهنيا , امين ازهري