Influence of pre-seismic history on the cyclic response of seasonal frozen silty sand

Abstract

The implementation of the Belt and Road strategy has increased construction activities in regions with seasonally frozen soil, such as the Qinghai–Tibet plateau. Numerous infrastructure systems in the region are built on seasonally frozen soil, rendering them susceptible to high-frequency seismic loads. Previous studies have demonstrated the significant influence of pre-seismic loads on the mechanical responses of soils. However, research on the influence of pre-seismic loads on seasonally frozen soil is limited. Therefore, two groups of cyclic triaxial tests are conducted in this study to investigate the impact of pre-seismic load and freeze-thaw history on the cyclic response of silty sand. Sample reconstitution and freeze-thaw procedures are described in detail. The test results indicate that the cyclic strength of silty sand decreases with the freeze-thaw history, although the influence diminishes with an increase in the number of freeze-thaw cycles. Additionally, a small pre-seismic load enhances the silty-sand strength, regardless of the freeze-thaw history it underwent. The findings of this study offer valuable insights for engineering construction in areas prone to seasonal freezing and earthquakes.