Effects of windblown sand damage on desert highway guardrails

Barriers, which are normally used as highway safety instruments, cause adverse sand deposition damage to pavements along desert highways. To select a suitable barrier type for desert highways, this study conducted wind tunnel experiments and field test to measure the velocity field and sediment deposition morphology for different types of barriers. The results indicate that the velocity decreases in the foot of the subgrade, and the smooth air flow is maintained along the pavement. Wind velocity decreases slightly under the W-beam bottom, and the maximum velocity reduction is in the lee of the W-beam barrier. Wind velocity considerably decreases before and after the concrete barrier because of the dense structure of the barrier. Cable barriers slightly disturb the air flow and marginally decrease its velocity. Sediment deposition characteristic measurements demonstrate that for W-beam median barrier, sand is deposited on pavement in the lee of the barrier; further, for both W-beam roadside barrier and median barriers, sand is easy to be deposited in the front and back of the barrier, mainly on the windward pavement. For concrete barriers, considerable amount of sand is deposited in the front and back of the barriers, which induces the serious sand deposition damage on the pavement. The cable barrier causes minimal sand deposition, and it is a recommended structure for the barrier selection of desert highways. Further, small wind incidence angles are also favorable when designing desert highways.