Investigation of liquefaction potential of Altınova district coast (Ayvalık, Balıkesir)

This study investigates the liquefaction potential of the coastal zone of the Altınova Neighborhood in Ayvalık district, Balıkesir province, and maps this potential using Geographic Information Systems (GIS). This research focuses on the fundamental mechanisms of soil liquefaction, its influencing parameters, and their potential impacts on structures. The analyses were conducted using borehole data obtained from the microzonation report prepared for the zoning plan of the region archived by the Balıkesir Metropolitan Municipality. A total of 101 borehole records, including parameters such as SPT-N values, soil types, groundwater levels, and geographic coordinates, were compiled and integrated into the GIS environment. Various spatial analyses were performed, resulting in the generation of digital elevation models (DEM), contour maps, groundwater level maps, slope maps, liquefaction potential maps, spatial distribution maps of corrected SPT-N values, and safety factor maps at different depths. To assess seismic loading, the maximum earthquake magnitude and peak ground acceleration (PGA) likely to affect the study area were calculated based on nearby fault zones within a 100 km radius. The Havran-Balya fault was identified as the most critical source, with a potential magnitude of Mw=7.3 and an estimated PGA of 0.1758 g in the target area. In the liquefaction potential map, the liquefaction potential index was calculated for the soil profiles at borehole locations. Upon examination of this map, it was observed that 11.8% of the study area had no liquefaction potential. A total of 64.1% of the area exhibits a "low," 20.5% an "intermediate," and 3.6% a "high" liquefaction potential. These findings contribute to a better understanding of local soil behavior under seismic loading and provide a valuable basis for earthquake-resistant urban planning and hazard mitigation strategies in the region.