基于线性回归的桥梁结构反应预测分析

Prediction analysis of bridge structural response based on linear regression

针对目前大跨度桥梁荷载效率系数取值的不合理,提出在荷载试验时降低荷载效率系数,通过回归分析法计算出结构反应(应力、应变和索力等)与荷载效率系数的一元线性回归方程,对得到的回归方程进行了显著性分析,并通过回归方程预测了结构反应值,最后用该方法预测了实际工程中一座大跨度PC斜拉桥的主梁挠度值及主梁应力值。研究结果表明:分析计算得出的一元线性回归方程高度显著,可作为有效的预测方程;在实例计算中,预测主梁挠度误差约为0.8 cm,预测主梁应变误差为6.5×10-6,预测误差满足工程精度。

Aimed at the problem existed in load efficiency coefficient of long-span bridges, the load efficiency coefficient decreasing is discussed. The linear regression equations of structural response （stress,strain and cable forces） and load efficiency coefficient are obtained by linear regression analysis, and the significance test of the equations is finished. Based on the linear regression equations, the structural response can be predicted. Finally, the main beam deflection and stress of a practical long-span PC bridge are predicted by this method. The research results show that the linear regression equations are highly significant and can predict structural response accurately. A computation example show that the prediction error of main beam deflection is 0.8 cm and the prediction error of main beam stress is 6.5×10^-6 , the error can meet the engineering accuracy requirements. 6 tabs, 4 figs, 10 refs.