Flexible protection structures have been increasingly applied in avalanche mitigation projects in high-altitude mountainous regions due to their deformation energy-absorption capabilities. However, systematic understanding of their mechanical response and interception mechanisms under varying slope gradients and mesh aperture conditions remains limited. This study investigates the influence of slope gradient and mesh aperture on the interaction between avalanche granular flow and flexible protection nets, focusing on high-altitude avalanche-prone areas in Xinjiang. Field surveys and chute experiments were conducted to examine these factors. Results indicate that the avalanche impact process can be divided into four stages: initial contact accumulation, deflection energy absorption, ultimate response, and stable accumulation. As slope steepness increases, avalanche sliding momentum significantly intensifies. The protective structure's response shifts from quasi-static load-bearing dominated by accumulation to impact-dominated behavior, manifested by increased peak tensile forces and upward displacement of the primary stress zone. Mesh aperture regulates interception efficiency through a trade-off between geometric screening and momentum dissipation, with medium apertures exhibiting superior comprehensive performance. Interception rates display pronounced nonlinear characteristics; this study establishes a power-law prediction model (R²=0.951) for interception rates based on slope-aperture coupling. These findings provide a basis for designing flexible avalanche protection structures in steep mountainous terrain.

Avalanche,Flexible Protection Nets,Slope Gradient,Mesh Aperture,Interception Rate