大跨径PC梁桥参数敏感性分析与识别

Analysis and Identification of Parameter Sensitivity for Long-span PC Beam Bridge

摘要:

为研究大跨径PC梁桥在悬臂施工过程中，不同设计参数对主梁线形和受力状态的影响，进而实现关键参数的识别，以南昌西二环某4跨连续梁桥施工工程为依托，基于MIDAS Civil软件建立的有限元模型和现场监测监控数据，采用正交设计理论和误差识别方法，对影响主梁线形和受力状态的参数进行敏感性分析。结果表明：当以主梁线形作为控制目标时，应将混凝土容重、混凝土弹性模量和预应力设为主要设计参数，环境相对湿度设为次要设计参数；当以主梁截面应力作为控制目标时，应将预应力和混凝土容重设为主要设计参数，环境相对湿度设为次要设计参数。据此结论指导实际施工后，取得了良好效果。

Abstract:

To study the influence of different design parameters on the main beam alignment and stress state of large-span PC beam bridge in the process of cantilever construction, and to achieve the identification of key parameters, relying on the construction of a four-span continuous beam bridge in West Ring II of Nanchang, and based on a finite element model established by Midas Civil software and the field monitoring and inspecting data, the orthogonal design theory and error identification method are adopted to carry out a sensitivity analysis on the parameters affecting the main girder alignment and stress state. The results indicate that when the main beam alignment is as the control objective, the concrete unit weight, concrete elastic modulus and pre-stress should be set as the main design parameters, and the environmental relative humidity is set as the secondary design parameter. When the main beam section stress is as the control objective, the pre-stress and concrete unit weight should be set as the main design parameters, and the environmental relative humidity is set as the secondary design parameter. Hereby, this good effect is achieved after the conclusion guides the actual construction.