To address the technical challenges in widening existing embankment due to terrain constraints, a new composite supporting structure termed as adjacent composite pile-sheet wall (ACPSW) is proposed, i.e., the new pile-sheet walls are installed side-by-side in the middle of the old pile-sheet walls. Based on the Lanzhou Hub project of Zhongwei to Lanzhou Railway, this paper investigates the pile horizontal deformation, pile bending moment, soil pressure behind the pile and sheet, as well as load-sharing ratio between the old and new pile of ACPSW at different construction stages through field tests and numerical simulations. The results obtained from the field tests were compared with that obtained from the numerical simulation to validate the reliability of the numerical model. Moreover, a serviceability assessment on old pile of ACPSW is also conducted. The results indicate that the new pile-sheet wall and the old pile-sheet wall can deform synergistically and bear the external loads together under new widening embankment loads and train loads, and the load-sharing ratio between old and new pile is 0.62:1.0. The research results can provide a reference for the design and construction of existing line reconstruction and new projects adjacent to existing lines.

Slow-moving landslides, characterized by sustained destructive potential, are widely distributed in northwest China. However, research on the damage mechanisms of masonry buildings caused by slow-moving landslide-induced surface deformation is significantly lacking, which severely restricts the physical vulnerability assessment of masonry structures and the quantitative risk evaluation of slow-moving landslides. Through field investigations, CDEM numerical simulations, and statistical analyses, this study reveals the cooperative deformation characteristics and progressive failure mechanisms of masonry buildings subjected to ground cracks in slow-moving landslides, and establishes physical vulnerability curves for four distinct ground crack scenarios. The key findings indicate that masonry buildings affected by slow-moving landslides primarily exhibit transverse wall cracking and longitudinal wall inclination due to ground crack propagation. As crack propagation continues, the first-floor walls exhibit significantly higher Mises stresses compared to those on the second floor. Wall inclination rates demonstrate a distinct threshold effect during crack propagation: below the threshold, inclination increases linearly with crack displacement, while above the threshold, it exhibits exponential growth. Under identical crack displacement conditions, wall inclination rates decrease in the following order: horizontal tension, combined tension, settlement, and combined uplift scenarios. The differential effects of these scenarios on wall inclination become more pronounced with increasing crack displacement. Weibull functions were employed to fit vulnerability curves for masonry structures under four ground crack scenarios, revealing displacement thresholds of 22 cm, 26 cm, 27 cm, and 37 cm for complete structural vulnerability (V = 1) in each respective scenario. These findings provide valuable insights for vulnerability prediction and emergency rapid assessment of buildings subjected to slow-moving landslides across various disaster scenarios.