Analysis on the effect of freeze-thaw on landslide prevention projects in seasonal frozen soil area

The planned route of the Sichuan-Tibet railway passes through the frozen soil on the eastern edge of the Qinghai-Tibet Plateau. The freezing-thawing environment is relatively complicated. More than 25 typical cases of landslide control projects along G317 and G318 in western Sichuan and Qamdo areas were investigated. The failure modes and force mechanisms of the projects under freeze-thaw conditions were summarized. The calculation method of horizontal frost heave force was discussed. The effects of horizontal frost heave retaining walls and drainage ditches were explored. The calculation results show that the horizontal frost heave force is much larger than the active earth pressure. The effects of frost heave and thawing on anchor cable engineering are clarified. It is considered that the effect of open frost heave on control engineering is greater than that of closed frost heave. Methods of material antifreeze grade and measures to reduce freeze-thaw effect were proposed. It can be used as a reference for landslide management projects along the Sichuan-Tibet railway.