基于最大熵理论的润扬悬索桥桥址极值风速预测

基于最大熵可靠度理论,提出了润扬大桥悬索桥的桥址极值风速预测方法,从而为润扬大桥悬索桥的风效应可靠度评估提供实际的荷载概率模型.根据桥址实测短期风速风向数据,计算了反映桥址气候特征的日最大风速风向频度函数,并计算了统计的桥址风速风向联合概率密度函数曲面.在此基础上采用最大熵法建立了桥址的风速风向联合概率模型,并对润扬大桥悬索桥50年和100年重现期内的极值风速进行了预测.分析结果表明,采用联合概率模型能够较好地描述润扬大桥悬索桥桥址的良态气候风场模式,并且桥址预测的极值风速小于设计风速,说明润扬悬索桥抗风设计时考虑了较大的安全度.

Prediction of extreme wind speed for Runyang Suspension Bridge spot based on maximum entropy theory

Based on the maximum entropy reliability theory,the method of extreme wind velocity prediction for Runyang Suspension Bridge spot is presented to provide the practical wind load model for the wind-induced structural safety evaluation.Based on the short-time measurement the wind direction frequency of daily largest wind velocity is calculated to reflect the wind climate characteristics of the bridge site and the statistical curved surface of joint probability density function is also presented.The maximum entropy theory is further used to construct the joint probability model considering the joint action of wind speed and direction,and the extreme wind speed during the return periods of 50 and 100 years are further predicted.The analysis results show that the proposed joint probability model can describe the normal climate mode of Runyang Suspension Bridge spot.And the prediction wind velocity is less than the design velocity,which means that a large safety degree is contained in the anti-wind design of the bridge.