Research on the evolution mechanisms and prevention countermeasures behind a large-scale landslide in complicated-geological-structure red beds.

Red beds are a general term for rock series with a primarily red color. In red beds, known as slippery strata, a heavy rainfall event can trigger a large number of landslides, and large-scale landslides are easy to breed in red beds with complex geological structures. Such landslides are highly destructive, cause significant losses, incur high remediation costs, and are prone to recurrent activity triggered by external factors, making them difficult to eradicate. This study takes the Leidashi landslide in a geological complex red bed as an example. Through landslide investigation, the geological environmental conditions conducive to disaster formation were thoroughly examined. Through numerical simulation analysis, rainfall-induced landslide-triggering mechanisms were summarized. By comprehensively analyzing the mechanisms of two major sliding events caused by rainfall and limitations of the first landslide mitigation project, evolutionary mechanisems of the landslide were proposed and applied to guide restoration and mitigation engineering practices, achieving effective anti-sliding results. Moreover, this study proposes a landslide control philosophy that integrates the general characteristics of red-bed landslides with the specific features of individual cases, employs a developmental perspective to analyze failure patterns and evolution mechanisms, and applies this understanding to guide engineering practices-providing a reference for preventing and mitigating such landslides.