Journal of the Korean Geo-Environmental Society ISSN:1598-0820(Print) 2714-1233(Online) 한국지반환경공학회 논문집

In Korea, where the four seasons are distinct and the climate has a strong influence, urban roadside slopes are closely connected to citizens' residential areas, which adds to the importance of keeping them safe. At the same time, aging of the facilities installed along roadside slopes is progressing, leading to revisions in related laws and efforts to unify slope maintenance agencies. Against this backdrop, the need for proactive prevention—eliminating risk factors in advance rather than relying on annually repeated maintenance—has emerged. On flat roads, repeated freeze–thaw cycles lower shear strength. Likewise, in the three-dimensional structure of vertically elevated roadside slopes, it is urgently necessary to identify and remove the causes of shear strength reduction due to freeze–thaw cycles. This study was prompted by the observation in the 2021 Seoul Roadside Slope Condition Survey that roadside slopes repeatedly affected by freeze–thaw cycles exhibit consistent patterns closely related to geographical conditions during winter. Based on this, shear strength test results from 21 sites and limit equilibrium analysis results from 29 sites were selected from existing data. By comparing and analyzing the characteristics of these hazardous roadside slopes, the study demonstrates that in climates with distinct seasons, the shear strength of roadside slopes varies depending on the slope orientation.