甘肃科学学报

精确掌握大跨钢桁梁桥实测温度与温致应变的关联性,能够对桥梁结构性能劣化进行有效表征。以沪苏通长江公铁大桥天生港专用航道桥为研究背景,基于长期监测数据分析该桥温度场的时空变化规律及其影响因素,采用分段式MARS模型结合太阳辐射效应建立了温度输入与应变输出之间的精确关系模型。研究表明:温度场的时空变化受到多个因素影响,不同位置测定温度与环境温度存在不同的时滞性,与对应的温致应变无明显时滞性;温致应变与构件温度之间呈现较明显非线性正相关性,改进后的分段式MARS模型比传统线性模型具有更高的拟合精度。这种新的相关性分析方法为大跨钢桁梁桥温度效应的精确分析提供了理论依据,并为钢桁梁桥在工程实践中的温度效应控制与优化提供了相应的技术支持。

To accurately understand the relationship between the measured temperature and temperatureinduced strain of large-span steel truss-girder bridges,and to effectively characterize the degradation of bridge structural performance,a study was conducted using the Husutong Bridge's Tian Sheng Port Navigation Bridge as a case.Based on long-term monitoring data,the temporal and spatial variation patterns of the bridge's temperature field and its influencing factors were first analyzed.A precise relationship model between temperature input and strain output was then established using a segmented MARS model,incorporating the effects of solar radiation.The study shows that the temporal and spatial variation of the temperature field is influenced by multiple factors.Different time lags remain between the measured temperature at various locations and the ambient temperature,while there is no significant time lag with the corresponding temperature-induced strain.The temperature-induced strain exhibits a clear nonlinear positive correlation with the component temperature,and the improved segmented MARS model provides higher fitting accuracy compared to traditional linear models.This new correlation analysis method provides a theoretical basis for the precise analysis of temperature effects on large-span steel truss-girder bridges and offers relevant technical support for the control and optimization of temperature effects in engineering practice.