Abstract: Vertical sand barrier is a kind of valuable sand preventing engineering that combines blocking and conducting sands. When sand barrier plays its function, it was pressed greatly by wind. It is neccessory to analyze the stress on sand barrier for determining effective structure coefficients. The paper referred the bridge design experience for wind speed sampling as well as wind force transformed from wind velocity when analyzed the pillar's stress. Sand barrier's pattern, t he height of wind force, terrain and geography factors etc. are considered for c alculation according with the actual condition. Wind pressure was passed to pillars through crossing branch and main bone of the verticle sand barrier. Stresses on pillar include gravitation, wind force, active earth pressure and passive earth pressure. Pillar's gravitation is neglective by being considered as light timber. Pillar's diameter is usually 5~10 cm, which can not be cut by wind force. So the strength of pillar itself is not considered. The calculation of stress that sand barrier's pillar bear follows the steps:Firstly, the wind force strength was calculated with relative formula between it and wind speed. Secondly, wind load s trength on sand barrier was obtained by the wind force strength multipling coefficients of barrier's pattern, wind force height, terrain and geography facto rs. Lastly, wind load strength multiplied by sand barrier's area and porosity is the stress. When calculating the pillar's embedded depth the paper referred the method of calculating rigid pillar popularily used at present. The load acted on barrier from over sand surface was transformed into the outer load at sand surf ace according to mechanics, and sand body was regarded as homogeneous elastic body to calculate lateral stress on pillar. Only the lateral stress on sand body from pillar is not larger than the allowable stress of sand body, can't the sand body be broken. Sand stress is related with pillar's depth, so the minimum embedded depth of pillar can be determined by calculating the maximum lateral stress at different pillar's depths before sand body is broken.

Key words: Vertical sand obstacle, Stress, Calculation