Research on the influence of micro-pile layout of stability of landslide resistance

Although traditional landslide mitigation measures, such as conventional anti-sliding piles, benefit from relatively mature technology and design principles, they still present disadvantages including high cost, limited applicability in certain environments, and slow construction speed. As a new type of retaining structure, micro-piles have gained widespread recognition in engineering practice due to their unique advantages: rapid installation, flexible layout, minimal workspace requirements, and high load-bearing capacity. However, research on the mechanical behavior and support effects corresponding to different micro-pile configurations remains relatively limited in China. This paper takes a landslide of a resettlement project in Haiyuan County, Gansu Province as the research object, analyzing the safety factor, pile bending moment, and seismic acceleration response at monitoring points to comprehensively assess the influence of micro-pile layout on landslide stability. The research results show that: (1) The arrangement of micro-piles is relatively sensitive to the impact of pile bending moments, while its effect on the overall safety factor and acceleration response is comparatively minor. (2) The quincunx layout enhances load-sharing coordination among the piles, allowing the anti-sliding capacity of each row to be fully mobilized. This integrates the pile group better become a whole, playing a crucial role in preventing landslide reactivation. (3) The optimal arrangement scheme for micro-piles is a quincunx layout and each row of piles is arranged unequally, which facilitates the development of a soil arching effect and promotes composite action between the pile group and the surrounding soil mass. The results of this study provide a theoretical basis for informing the design and construction of micro-piles in landslide mitigation projects.