Sand-fixing effect and compound change of nylon checkerboard sand barrier.

Abstract

Grid-based sand-fixing protection barriers have been widely used to solve linear engineering problems in sandy areas. Their placement directly affects the combined change law of wind speed weakening and sand sediment in the sand barrier. It also affects the cost of sand control and the selected structure of the protection system. Therefore, quantifying the effect of different sand barriers is important. We installed nylon mesh checkerboard sand-fixing barriers of three heights and three sizes on the windward side of the highway in the Ulanbuhe Desert, China. By using anemometer and sand collecting instrument, through comparing and observing air flow changes, windproof efficiency, and sand sediment inside the sand barrier, it is found that height had more influence on the protective benefit of a sand barrier than did the mesh specification. The protective effect at the boundary of a sand barrier resulted from compound superposition. The model for calculating a suitable sand barrier protection width was affected by sand-driving wind speed, open field wind speed, sand barrier unit side length, height, and actual protection demand. Sand barriers of 1 × 1m (It is the grid size of the mesh.) at 20-cm height, 1 × 1m and 1.5 × 1.5-m at 30-cm height could be laid over a wide area. Different collocation patterns can be selected according to the dominant wind direction. The results can provide basic data and theoretical support for sand barrier protection system.