Abstract:To investigate the turbulence-sand particle movement characteristics of the flow fields of a railway cutting in wind-blown sand areas and to optimize structural parameters for the protective measures, the numerical simulation analysis of the flow field with a railway cutting was carried out. Based on the Euler-Lagrange framework, the three-dimensional turbulent flow model of LES-DPM was established, and the characteristics of wind-sand flow and the movement of sand particles in the aeolian landform were studied. Two types of the protective measures were designed according to the characteristics of wind-sand movement, At the same time, the optimal design parameters of sand protection measures are obtained by comparing the flow field characteristics and sand prevention effects at different distances and different arrangements. The results show that a large number of small-scale horseshoe vortices appear in the cutting due to the concave structure, and most of the low broken velocity vortices near the rail, the turbulence structure is complex. The wind-velocity near the rail is less than 3.6 m/s, the moving particles is easily affected by the reverse pressure gradient and turbulence to settle into the cutting. The risk of sand burial is significantly increased. Therefore, it has been determined that the most effective protection can be achieved by placing a 2 m high retaining wall on the windward side at a distance of 20 m from the cutting. Most of the particles are trapped in front of the retaining wall, while those that manage to pass through settle in the backflow area behind it, with a particle size less than 0.125 mm. It has been observed that the utilization of a double-row sand retaining wall (2 m/3 m) can further expand the range of low-velocity reflux area and decrease the number of particles entering into the excavation, thereby enhancing its protective efficacy.