强风区铁路风沙防治工程最大输沙量与携沙风荷载计算方法

Computational Method for Maximum Sediment Discharge and Sand-Carrying Wind Load in the Prevention and Treatment of Wind Drift Sand for Railway in Strong Wind Area

针对强风区铁路风沙流灾害防治工程,开展最大输沙量和强风携沙风荷载2个最关键工程计算问题的研究。结合现场踏勘资料与测试数据,分析风向、风力和持续时间3个影响因素对最大输沙量矢量合成与计算的控制影响,基于优势强风流理论,归纳给出信风型、季风型和对流型3种典型工程风型的输沙量计算方法,并且为准确采集沙样数据,专门设计出能随主风向自动转动的野外自动风导向积沙仪。基于现场测试数据,根据相似准则与量纲和谐原理,推导强风区携沙风单位体积沙砾颗粒流体平均飞跃速度计算公式,用于强风区携沙风冲击荷载计算,计算结果符合工程实际,满足工程计算要求。

According to the hazard control engineering for wind-sand flow in strong wind area along railway,research was carried out on two most critical calculation problems: the maximum sediment discharge and sand-carrying wind load.Combined with field survey information and test data,the control influence of wind direction,wind power and duration on the vector composition and calculation of the maximum sediment discharge was analyzed.Based on theory of preferred strong wind flow,calculation method was induced for the maximum sediment discharge under three typical wind types,namely,trade wind type,monsoon type and convection type.In order to accurately collect sand sample data,an automatic outdoor sand-taped instrument which could be automatically rotated with the main wind direction was specially designed.Based on field test data,and according to similarity criteria as well as dimension concordant principle,formula was deduced for calculating the average velocity of gravel particle fluid of sand-carrying wind per unit volume in strong wind area,which was used to calculate the impact load of sand-carrying wind in strong wind area.The calculated results agree with engineering practice and thus engineering calculation requirements can be met.