基于长期变形监测数据的连续刚构桥预应力损失识别

Prestress loss identification of continuous rigid frame bridge based on long term deformation monitoring data

为掌握在役连续刚构桥结构预应力状态,提出了基于长期变形监测数据对结构真实预应力状态进行评估的新思路,通过有限元分析建立了结构有效预应力衰减引起长期挠度和混凝土收缩、徐变引起长期挠度的相关关系,结合影响矩阵原理建立了基于长期变形监测挠度数据识别结构有效预应力的方程,并进行了验证。同时在对监测数据进行数理统计分析的基础上针对某连续刚构桥进行了实桥损失识别。研究结果表明:与成桥状态相比,目前顶板钢束有效预应力平均损失0.61%,底板钢束有效预应力平均损失0.33%,结构状况良好,可供同类连续刚构桥预应力损失识别参考。

In order to grasp the prestressed state of the existing continuous rigid frame bridge,the new idea of damage assessment of the prestressed state was put forward based on long-term deformation monitoring data. The relationship between long-term deflection and concrete shrinkage creep was established though finite element analysis.Combined with influence matrix,the effective prestress equation based on deflection data identification of health monitoring was established and verified.At the same time,based on statistical analysis of monitoring data,the damages of a continuous rigid frame bridge were identified.The results show that compared with the completed bridge state,the average loss of roof effective prestress was 0.61%and the average loss of bottom plate effective prestress was 0.33%.The structure was in good condition.Thiscan be used as reference for the identification of prestressed loss of similar continuous rigid frame bridge.4tabs,4figs,18 refs.