采用风速概率密度函数和风向频度的乘积表示联合概率密度函数,用极大似然法和概率曲线相关系数法相结合的逐步迭代估计法估计杭州湾跨海大桥桥位处桥面高度各风向的有效最优概率分布类型及参数;利用已建立的风-汽车-桥梁系统安全性分析框架计算得到各个方向下车辆发生事故的临界风速;为了确定桥面局部风环境的状况,在同济大学TJ-3风洞中进行了杭州湾跨海大桥桥面风环境风洞试验研究,并引入等效桥面风速和影响系数以考虑桥梁结构绕流和附属构造物对行车高度处风速的影响;最后,对杭州湾跨海大桥的行车安全进行了基于风速风向的概率性分析,并研究了增设风障对行车安全的影响。结果表明:增设风障是一种非常有效的提高安全行车概率的方法;杭州湾跨海大桥全桥采用70%透风率的风障完全可以满足车辆安全行驶的要求。
Joint probability density f probability density function and wind d distribution types and parameters at th unction was exp irection frequency ressed by the product of wind speed firstly. Effective and optimal probability e height of bridge deck at every wind direction of the site of Hangzhou Bay Sea-crossing Bridge were estimated by the iterated-gradually estimative algorithm which combined the maximum likelihood method with the method of probability plot correlation coefficient. The established safety analysis framework of wind-vehicle-bridge coupling vibration system was used to predict the critical driving safety wind speeds at every wind direction. In order to determine the local wind environment above bridge deck, the wind tunnel testing was carried out in TJ-3 Wind Tunnel of Tongji University. The equivalent wind speed and influential coefficient were introduced to consider the influence of the flow around the bridge deck and the accessory structures on wind velocity. Finally, probability analysis for driving safety of Hangzhou Bay Sea-crossing Bridge based on wind speed and wind direction was carried out. The Influence of installment of wind barrier on driving safety was studied. Result shows that the installment of wind barriers is an effective method of improving driving safety probability. For Hangzhou Bay Sea-crossing Bridge, while adopting wind barrier with 70% of ventilation ratio in its total length, the vehicle driving safety problem can be solved completely.