Fragility Analysis of DSM Piles in Mitigating Liquefaction-Induced Deformations in Soil-Tunnel-Superstructure Systems

This study evaluates the seismic performance of soil-tunnel-superstructure systems and examines the effectiveness of deep soil mixing (DSM) piles in mitigating liquefaction-induced deformations in urban environments. Advanced numerical simulations, conducted using the finite element method (FEM) in Midas GTS NX software, were validated against centrifuge test data to ensure accuracy. The UBCSAND and HSsmall constitutive models were employed to simulate liquefiable soil and DSM piles, respectively, while adaptive meshing techniques enhanced computational precision. DSM piles were shown to significantly reduce surface building settlements and tunnel uplift by increasing soil stiffness and redistributing stresses, although localized pore pressure accumulation was observed in untreated zones due to restricted drainage. Fragility curves, developed using incremental dynamic analysis (IDA) with seven real earthquake records, revealed a substantial reduction in the probability of exceeding critical damage states when DSM piles were implemented. This research highlights the importance of multi-valued fragility curves incorporating intensity measures such as PGA, PGV, and PGD to capture the complexities of seismic vulnerability. The findings provide valuable insights into seismic risk mitigation strategies for urban infrastructure, emphasizing the role of DSM piles in enhancing structural resilience against liquefaction-induced damages.

کلیدواژه ها:

Fragility analysis ، Liquefaction mitigation ، Tunnel uplift ، Deep soil mixing (DSM) ، Seismic resilience