Effects of Seasonal Freezing on Bridge Column–Foundation–Soil Interaction and Their Implications

Several seismic regions around the world experience seasonal freezing that can drastically alter the soil-foundation-structure interaction and structural response under earthquake loads. This paper analytically investigates the effects of seasonal freezing on lateral load response of a bridge column supported by a cast-in-drilled-hole (CIDH) foundation shaft. Accounting for the temperature effects on materials, the analyses were conducted at ambient temperatures of 23° C, −1° C, −7° C, −10° C, and −20° C, and the results obtained at 23° C and −10° C were validated using experimental data. In comparison to the response at 23° C, the response of the column-shaft system in the range of −1° C to −20° C exhibited 40%–188% increase in the effective elastic stiffness, 17%–63% reduction in the lateral displacement capacity, 0.54–0.82 m upward shift in the maximum moment location, 25%–30% increase in the column shear demand, and 25%–80% increase in shear and 19%–68% reduction in the length of the plastic region in the CIDH shaft.