环境温度对连续箱梁刚构桥相对小波熵指标的影响研究

摘要

以一座高速公路预应力混凝土连续箱梁刚构桥为工程背景，结合健康监测系统的长期测试数据，研究环境温度对相对箱梁桥小波熵指标 SWT的影响规律。首先，介绍了环境激励下桥梁结构相对小波熵指标的计算方法。其次，利用实时监测数据，分析得到了箱梁桥各截面的实测相对小波熵指标日变化和年变化规律。最后，基于逐步最优线性回归分析方法建立了相对小波熵指标与温度时、空间分布的多元线性回归模型，并提出了相对小波熵指标的温度修正模型。结果表明，所建立多元线性回归模型具有较好的拟合和预测精度，通过温度修正可以有效地剔除环境温度变化对预应力混凝土箱梁桥相对小波熵指标的影响，使其有效地应用于桥梁的损伤识别。%In order to obtain influence laws of environmental temperature on the relative wavelet entropy index SWT, the related study based on health monitoring system of a prestressed concrete continuous rigid-frame bridge with box sections was conducted.Firstly,the calculation method of the relative wavelet entropy index for bridge structures under environment excitation was introduced.Secondly,the daily and annual varying rules of the relative wavelet entropy index of each box section of the bridge were analyzed and obtained based on the real-time monitoring data.Finally,by using the gradually optimal linear regression analysis method,the multivariate linear regression model for the relative wavelet entropy index considering time and spatial distribution of temperature was developed,and the temperature correctional model for the relative wavelet entropy index was proposed.Results showed that the multivariate linear regression model has a better fitting accuracy and a relatively high prediction precision;the effects of environmental temperature on the relative wavelet entropy index can be eliminated effectively with the temperature correctional model to make the relative wavelet entripy index be used in bridges'damage identification effectively.