Abstract: Based on the wind tunnel simulation test of the flow field structure of the sand-blocking fences in Shapotou section of Baotou-Lanzhou Railway, the article evaluates the sand-blocking effectiveness of sand-blocking fences with different weaving structures, in order to provide a basis for the optimization of the structure of biomass sand-blocking fences. The results show that there are obvious velocity zones when the airflow passes through the horizontal and vertical sand-blocking fences. No matter before or after the airflow passes through the sand-blocking fence, the wind speed decreases. However, the comprehensive effectiveness of windbreak and sand prevention brought by the vertical woven branch fences is significantly better than that by horizontal woven branch fences. In addition, the sand-blocking fences, which are vertically woven, have a simple production process, and a wide range of raw materials as well as the length of the branches is unlimited. Therefore, the vertical woven branch fence is more suitable for popularization in the application of sand prevention and control. Although porosity is an important technical parameter in the design of sand-blocking fences, the structure of fences has a direct impact on the sand flow field and is the key factor determining the protective effect on sand activities.

Key words: Baotou-Lanzhou Railway, Shapotou, branch, sand-blocking fence, flow field