牛顿插值法的灰色GM(1,1)模型在桥梁荷载试验中应用

Application of the Grey GM(1,1) Model of Newton Interpolation Method in Bridge Load Test

由于传统的灰色GM(1,1)模型预测精度不高,以牛顿插值法函数对初始序列背景值进行优化提出了改进模型。以武汉市某等截面连续钢箱梁桥现场荷载试验为工程依托,通过分级加载实测挠度与理论计算挠度差值为初始数据列,来预测下一级加载实测挠度。基于牛顿插值法灰色GM(1,1)改进模型与原始模型预测的数据平均相对误差减小了2.4%,预测第六级加载弹性挠度值减小2%。结果表明,基于牛顿插值法对初始序列背景值优化的改进模型在大型桥梁荷载试验中预测下一级实测挠度值的精度高、可靠性好。

Since the prediction accuracy of the traditional gray GM(1,1)model is not high,this paper proposes an improved model to optimize the initial sequence background value by using Newton interpolation function.Based on the field load test of a constant section continuous steel box girder bridge in wuhan city,the measured deflection of the lower level of loading is predicted by using the difference between the measured deflection of graded loading and the calculated deflection as the initial data column.The average relative error between the modified model and the original model based on Newton interpolation gray GM(1,1)was reduced by 2.4%,and the predicted elastic deflection of the sixth stage was reduced by 2%.The results show that the improved model based on the Newton interpolation method to optimize the initial sequence background value is of high accuracy and good reliability in predicting the actual deflection of the next level in the load test of a large bridge.