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| Research on the Dynamic Resj3〇nse of Sand Flow and Railway Culvert |
| LI Kai - chong , SHI Long , ZHANG Fang , JIANG Fu - qiang |
| (Northwest Research Institute Co. Ltd of CREC，Lanzhou，Gansu 730000，China) |
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Abstract Research purposes ： In the wind sand disaster areas，when air - sand flow passes through the railway culvert， afected by the boundary effect and narrow^ tube acceleration effect，the obvious disturbance of airflow^ appears，and sand will be carried or deposited around the culvert. The accumulation of wind - blown sand in culvert will influence the normal operation of the train. Aiming at the above problem，this paper studied particularly the formation mechanism of wind sand disaster in culvert by using numerical simulation and field test which provides some theoretical basis for disease treatment and railway design.
Research conclusions:(1) The local high - speed vortex area at inlet of culvert is fomed，when the air flow passes through the railway culvert. Wind speed gradually decreases with the marching of airflow in culvert, but the value is still slightly higher than the outside wind speed. (2) Due to the affection of accelerating effect，vertical gradient difference will be amplified，and stratification phenomena of speed will appeared. (3) Wind speed decreases gradually，and a large amount of sand fall when wind - sand flow moves along the diversion dike. (4 ) The curves of wind speed are arch shapes, which are affected by architectural form. The phenomenon of wind - blown sand appears at the both sides of culvert portal，which are the lowspeed areas of air flow. (5) The research result provides a certain theory support for
wind sand disaster prevention of culvert along the railway line.
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Received: 06 July 2015
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2015, Vol. 32 
