Dynamic Analysis of MICP-Stabilized Soil and Liquefiable Soil With Varying Salinity Levels

This study investigates the liquefaction potential of soils at Yogyakarta International Airport (YIA), a high-risk seismic zone, and evaluates the efficiency of carbonate precipitation driven by microbial activity (MICP) stabilization under varying salinity situations. The purposes include understanding the dynamic response of natural and MICP-treated soils to seismic loads and assessing the role of salinity in soil behavior. Triaxial cyclic testing was conducted on remolded soil samples at a very loose density (Dr = 10%) to simulate field situations, using Bacillus Safensis. Microbes and a biocementing procedure enhanced with 35% fly ash. Salinity levels of 0%, 1%, 2%, and 3.4% were tested by curing for 28 days. The outcomes reveal that untreated soils liquefied inside of 4–6 cycles at ru = 0.8 for 0%, 2%, and 3.4% salinity. In contrast, 1% salinity delayed liquefaction to 14 cycles, thereby enhancing soil resistance. MICP-treated soils showed enhanced stiffness, decreased compressive strain, and extended resistance to liquefaction under dynamic loads. SEM and XRD analyses verified CaCO3 deposition, particle bonding, and decreased pore space. The novelty lies in demonstrating the significant role of salinity in enhancing the MICP procedure and improving soil stability, providing a sustainable solution for mitigating liquefaction risks in saline coastal regions.