Anti-slide piles play an important role in landslide control. However, owing to a limitation in the slide–resist design concept, large landslides are difficult to control. Moreover, the displacements of controlled projects are significant. In this paper, we propose an improved anti-slide pile design concept that develops and utilizes the landslide body. On this basis, we also design an arm-stretching-type anti-slide pile structure. We establish formulas for calculating the internal forces of this structure. The results of a case study indicate that the maximum shear force and bending moment of the arm-stretching-type anti-slide pile body were reduced by 43.6% and 25.4%, respectively, compared with those of a conventional single pile. Furthermore, the results of numerical modeling indicate that the arm-stretching-type anti-slide pile could significantly reduce landslide displacement. Thus, the proposed design is expected to solve the problems encountered when using conventional anti-slide piles for landslide control and can thereby become widely applicable in practice.

The anti-slide pile is one of the most used measures in landslide control globally. Following its application, various structures have been developed. In this paper, we analyze the anti-slide pile structure development process and extract two development paths. One path is aimed at improving the applicability. The second path starts from an in-depth study of pile–soil interactions. However, these two paths share a single design concept: The anti-slide pile provides direct resistance to maintain landslide stability, that is, the anti-slide pile and the landslide body are thought to be confrontational sides. We here propose developing and utilizing the landslide body in anti-slide pile design. Accordingly, the confrontation relationship between the anti-slide pile and the landslide body can be changed while shifting away from the view that the landslide body is only a hazard. On this basis, we also design a novel structure: An arm-stretching-type anti-slide pile. The simulation verification results show that this novel structure works well in realizing the proposed design concept. Compared with the commonly used wholly buried pile, the safety factor of the landslide controlled by the novel structure is improved by 43.56%. This study promotes the design concept of anti-slide pile developing from the existing slide–resist single mode to the slide–self-stabilize–resist compound mode.

The stability of a double-row steel sheet pile cofferdam structure under soft ground conditions was investigated in this study, using the temporary cofferdam of the Shenzhen–Zhongshan cross-river channel as the engineering background. The stability of the cofferdam design solution was calculated with a model that incorporates factors such as the coordination of independent pile top displacement, as well as the m-value for backfilled sand and the thrown rock body. The internal force and displacement results of the cofferdam under different working conditions are obtained. And the entire construction process was analyzed using the finite element method. The results indicate that the overall stability and overturning stability of the cofferdam satisfy relevant safety requirements, with minimum safety factors of 1.744 and 1.400, respectively. The maximum displacement of the inner and outer steel sheet piles is 34 mm, the maximum bending moment is 249.30 kN·m, and the maximum shear force is 266.66 kN. The displacements of sheet piles were within an acceptable range, and the internal forces remained below the load capacity of the selected sheet pile type for the design. Based on these findings, the cofferdam structure can be considered safe and satisfying the specified requirements. This work may have instructive value for cofferdam design and construction.