Study on Instability Process of Slag Landfills: Example of the Subgrade Landslide on Fuxin Nanhuan Road in Liaoning, China

The management and knowledge of landfills are generally inadequate and could lead to significant catastrophes. This is particularly concerning for solid waste landfills due to their large size and potential to threaten nearby structures and residents in the event of landslides. In this paper, we investigated a backfill landslide induced by road construction in a coal mine slag landfill. Our analysis of satellite images and field surveys revealed that the alteration of the mounding morphology at the slope's crest by construction triggered the landslide. We established an engineering geological model of the main sliding plane and utilized the discrete-element program MatDEM to reproduce the landslide's development and predict its final accumulation pattern and impact range. Our study highlights the potential dangers of engineering construction carried out on relatively stable solid landfills. The combined in situ and numerical analysis research methods employed in this study can provide important references for risk assessment and treatment measures.