This paper introduces a kind of double-row reed–nylon net combined sand barrier. Using the computational fluid dynamics (CFD) method and the Euler–Euler double-fluid model, the new sand fences’ windproof effect and airflow features are simulated under different porosities and spacings, and the optimal configuration parameters are selected. The new sand fence has better windproof performance and practical significance than double-row reed and double-row nylon net fences. The new sand fences with a porosity of 0.3–0.4 and spacing of 28 H provide a longer protection range and a better wind protection effect. Considering the serious sand damage in China’s Taklamakan Desert, the new fences’ impact on sand buildup is examined. The combined sand fences have powerful sand blocking and accumulation effects, even though there is only a small quantity of sand accumulation on the leeward side of the second row. The sand particles primarily settle between sand fences in the center and rear areas. The combination of sand fences made of different materials combines the advantages of both, improves the construction efficiency and service life, and provides a more economical and efficient sand barrier arrangement for the arrangement of wind and sand-blocking facilities around railroads and highways in desert areas.

This study uses the computational fluid dynamics (CFD) method to investigate the effects of the depth-width ratio of a three-dimensional street valley and wind velocity on the flow field and pollutant spread in street valleys with double-deck elevated bridges. The simulation results indicate that when there is no viaduct, there is only one vortex in the gorge when the depth-width ratio (H/W) is less than 1.5; when it is equal to 1.5, multiple vortices appear. With a double-deck viaduct, the viaduct changes the airflow field and turbulence structure in the valley, creating a primary vortex and multiple secondary vortices. Aiming at the diffusion of pollutants, the changing trend in the horizontal and vertical direction was quantitatively analyzed. The study found that when the aspect ratio increased from 0.8 to 1.5, the CO concentration on the leeward side increased by 40%, and the CO concentration on the windward side increased by four times. When the street width increased from 20 m to 37.5 m, the CO concentration decreased by 30%. The increase in wind speed reduced the CO concentration by 28% on the lee side and 33% on the windward side. This study reveals the general pattern of pollutant dispersion in viaduct-street canyon structures, providing insights into the construction of viaducts.

This paper uses the SPH method to study snow disasters, including the snow flow model of a vertical water diffusion equation and heat balance equation. The advantage of the SPH method is that it can capture particles’ positions, which can be used to track the initial position distribution of hazardous particles. At the same time, a particle modeling method based on pixel value is proposed, which has certain advantages in dealing with the boundary modeling of different materials. In addition, snow disaster prevention and the control of classic embankment and cutting procedures were carried out. The final treatment results showed that the number of snow particles on the subgrade surface was reduced by about 90%. The validity and feasibility of the snow disaster simulation software based on the SPH method are verified by comparison with the experimental results.