A comparative study of environmental and economic assessment of vegetation-based slope stabilization with conventional methods

Abstract

The heavy rainfall induced by global warming has increased the risk of landslides. Eco-friendly approaches, such as employing vegetation, prove effective in satisfying the requirements of both engineering and environmental considerations in slope engineering. The research aims to comprehensively assess and compare the environmental, economic, and slope stability of new stabilization methods, including vegetation cover, in comparison to conventional approaches such as anchorage and nailing. The research initially explored the stability of slopes in various geometries, identifying areas prone to slope failure. Subsequently, slope stabilization designs were implemented using three methods: vegetation, nailing, and anchoring. To enable a comprehensive comparison from environmental and economic perspectives, both life cycle assessment and life cost assessment were conducted. According to the results, employing vegetation proves effective in stabilizing slopes at lower heights, particularly up to 8 m, leading to a negative carbon emission attributed to photosynthesis, reaching up to -249 kg CO₂. In the mid-angle range (30°≤ θ ≤ 60°), anchoring emits less carbon dioxide than nailing due to fewer elements. As the slope angle is increased, the nailing method becomes preferable to the anchoring method due to its use of materials and equipment with lower carbon emissions. During slope stabilization through nailing and anchoring, cement and steel emerge as the primary contributors to carbon emissions. Vegetation stands out as the most cost-effective slope stabilization option, with costs potentially reduced by 250% compared to conventional methods. Based on this research, vegetation emerges as an eco-friendly and cost-effective alternative for slope stabilization in particular conditions where plants effectively ensure stability. Decisions regarding the use of anchoring or nailing can be made based on environmental and economic aspects, considering the slope geometry.

Keywords: Anchored slope; Bioengineered slope; Life cycle assessment; Life cycle cost; Nailed slope; Slope stability.