基于动载试验的变截面桥梁静载试验结果预测方法研究

为了解决既有桥梁荷载试验成本高、对交通影响大以及容易对桥梁结构造成损伤等诸多问题,提出基于廉价安全的动载试验数据,利用响应面方法对既有桥梁的实际刚度进行智能分析预测,从而达到高精度预测既有桥梁静载试验结果的目的。为实现上述目标,选取典型连续变截面刚构桥作为研究对象,尝试将桥梁主梁变截面参数化,对桥梁关键设计参数进行敏感性分析,并且建立Kriging响应面模型,实现对有限元模型的高精度修正。研究结果表明:基于Kriging模型的有限元模型修正方法能够利用桥梁动载测试结果对初始设计参数进行修正,并进一步预测静载试验结果;该方法成本低廉,对交通影响小且安全性高,这将节省大量的桥梁静载试验费用,同时能够对桥梁的静力行为进行全方面有效的分析和预测。研究结果可为既有桥梁工程的管养维护决策提供新的思路。

Prediction Method of Static Load Test Results of Variable Section Bridge Based on Dynamic Load Test Data

To solve the problems of the high cost of the existing bridge load tests,the significant impact on the traffic flow,and the easy damage to the bridge structure.Proposed based on cheap and safe dynamic load test data,a response surface method is used to intelligently analyze and predict the actual stiffness of existing bridges to achieve a high-precision prediction of existing bridges'static load test results.In order to achieve this goals,the main girder section of the variable-section bridge is parameterized,the sensitivity analysis of the key design parameters of the bridge is carried out,and the Kriging response surface model is established to realize the high-precision correction of the finite element model.This paper takes a typical variable-section 3-span continuous rigid frame bridge as the research object.The research results showed that the finite element model correction method based on the Kriging model can use the bridge dynamic load test results to correct the initial design parameters and further predict the bridge static load test results.This method is cheaper,has a lesser impact on the traffic,and has higher safety,which saves on a lot of bridge static load test costs.At the same time,it can carry out comprehensive and effective analysis and mechanical performance prediction for the static performance of the bridge.The research results can provide a novel method for the maintenance and maintenance of existing bridges.