Numerical Modeling of Liquefiable Soil Improvement Using Gravel Columns: A Case Study of Isla San Lorenzo, Northern Peru

Araujo W.; Farfán A. · International Conference on Civil, Structural and Transportation Engineering (2026) · DOI: 10.11159/iccste26.184

Resumen

Liquefaction-induced ground damage was observed in the populated area of Isla San Lorenzo (Vichayal, Piura, Peru) following the Mw 6.1 earthquake of July 30, 2021, evidenced by sand boils, ground cracking, and differential settlements. Thi s study evaluates the effectiveness of gravel columns as a soil improvement technique to mitigate liquefaction through two-dimensional numerical modeling using the finite element method. Dynamic analyses were performed with MIDAS GTS NX, considering both natural and improved soil conditions under real seismic loading. Liquefiable sand layers were modeled using the UBCSand constitutive model, allowing simulation of excess pore pressure generation and dissipation during seismic excitation. Model validation was carried out through normalized stress response and pore pressure ratio indicators. Several gravel column configurations were analyzed to assess their influence on liquefaction mitigation performance. Results show a significant improvement in soil behavior, with reductions of up to 31% in maximum pore pressure and 42% in excess pore pressure when gravel columns were implemented. An optimal replacement ratio was identified, achieving up to 52% improvement during the critical phase of the earthquake. The results confirm that gravel columns are an effective mitigation measure against soil liquefaction, with system stiffening identified as the dominant improvement mechani sm. The findings provide technical support for the application of gravel columns in seismic-prone coastal areas with similar geotechnical conditions.

Instituciones: Universidad de Piura