Numerical analysis of wind speed variation under awning boards covering embankment side slopes

To protect the permafrost under the embankment from thawing and to ensure the safety and smoothness of the road, the use of shading boards (awnings) was one of the main measures applied along the side slopes of the Qinghai–Tibet Highway, the Qinghai–Tibet Railway and the Qingkang–Highway embankments. Aside from the shading effect acting against solar irradiation such constructions may also help to channel the natural wind flow and thus contribute to the cooling of the embankment and the underlying ground by enhancing the natural wind flow close to the surface. In this study we present results from numerical finite element simulations of the air flow under two different awning designs, with the aim to find an optimal geometry and awning height to be applied in future engineering work. We compare the air flow profiles across and along the awning headroom and investigate the influence of embankment slope inclination on the flow under the awning.

Research highlights► Embankment surface cooling is of high importance for protecting permafrost. ► Awning constructions are an efficient measure to reach this goal. ► We find that an awning head room of 0.5–0.8 m is a good choice. ► The air flow under the awning is asymmetric. ► Side slope inclination of 1:1.5 optimizes wind speed profile under the awning.