基于裂缝宽度变化的连续刚构桥安全性预警技术

Safety early warning technology of continuous rigid frame bridges based on crack width variation

为了剔除温度变化对连续刚构桥裂缝宽度的影响,提高通过裂缝宽度变化评估桥梁安全性的效率和准确性,以广西境内一座刚构桥为研究对象,分别建立了全桥整体模型和带裂缝梁段精细化模型,根据跨层级模型计算结果研究了温度与裂缝宽度变化之间的关系。结果表明:均匀温度和梯度温度作用均对裂缝宽度变化存在影响,利用修正后考虑混凝土材料特性变化的关系式可以快速确定温度变化导致的裂缝宽度变化值,为桥梁安全性预警提供重要依据。最后,将本文方法应用于某桥工程实例,通过实测数据验证了该方法的准确性。

In order to eliminate the influence of temperature variation on crack width of continuous rigid frame bridges and improve the efficiency and accuracy of evaluating bridge safety through crack width variation,a rigid frame bridge in Guangxi was taken as the research object.The whole bridge model and the refined model of beam segment with cracks were established respectively.The relationship between temperature and crack width variation was studied according to the calculation results of crosslevel model.The results show that both the uniform temperature and the gradient temperature action have an effect on the crack width variation.The modified formula considering the change of concrete material characteristics can be used to quickly determine the crack width variation caused by temperature change,which can provide an important basis for bridge safety early warning.Finally,the proposed method is applied to Luotianle Bridge project,and the accuracy of this method is verified by measured data.