The Failure Criterion and Time‐Dependent Protective Effects of Sand Barriers in Strong Wind‐Blown Sand Environments

This study investigates the failure mechanisms and the protective effects of sand barriers influenced by changes in topography. To achieve this, a series of wind tunnel experiments were conducted to simulate the full operation cycle of commonly used sand barriers. Three distinct growth modes of sand accumulation around sand barriers were identified: double peak mode, single peak mode, and single peak mode with quick failure. The results of the wind field revealed that sand accumulation is typically induced by three factors: bleed wind, backward wind, and reestablishment wind. Moreover, the final shape of sand accumulation body is controlled by the effective protection zone. Two failure regimes of sand barriers were identified as well: rapid failure in high winds and gradual failure in lower winds. To quantify the protective effects of sand barriers, this study proposes four empirical functions: maximum protection area ( S w ), initial sand‐control efficiency ( η 0 ), sand‐control efficiency ( η ), and effective protection time ( T ). Our findings indicate that the wind speed, the structure of sand barriers, and the accumulation body determine the protective effect of sand barriers. Specifically, higher wind speeds, increased porosity, lower barriers, and a larger accumulation body tend to diminish the protection performance of the sand barrier. The results have shown that sand barriers with a porosity higher than 50% have a poor sand‐control effect when wind speeds exceed 16 m·s −1 . The predictions for sand‐control efficiency and the effective time of barriers align well with measured values, exhibiting relative errors of less than 5.9% and 4.2%, respectively. Based on these findings, this study recommends using the higher barriers with lower porosity ( p = 30%) in areas prone to strong wind‐blown sand, with the height of sand barriers determined by the four empirical functions mentioned above. Notably, sand barriers with 30% porosity achieve the longest deposition distance and lifespan.