Correction Based On The Static And Dynamic Finite Element Model Of The Existing Reinforced Concrete Arch Bridge Carrying Capacity Assessment

Bridge is the important transport facility which is related to the national economy and people's livelihood. In order to protect the safety of transport facilities and make advantage of existing resources, assessments of the bridge should be made to get the real working states of the structure which include the injury situation, current carrying capacity, and even residual life of the bridge. This paper presents a method of assessing carrying capacity of the bridge which is based on the finite element model (FEM) updating through the static and dynamic test data. The method is applied to an existing reinforced concrete arch bridge. It proves that this method can not only assess the carrying capacity of the bridge, but also predict and analyze the future carrying capacity of the bridge. Therefore, it is worthy to be widely used.In this paper, the bridge, located in Heng Yang, Hu Nan Province, is evaluated using the method of FEM updating with the static and dynamic test data. The main contents of this article are:1. Static load test and ambient vibration test were executed. In the static load test, displacements of the measurement points which were located on the tied beams, ribs, bridge deck, etc were measured in three test cases. In the ambient vibration test, the dynamic characteristics of the bridge and the tension force of the cables under constant load were measured. An analysis was carried out between the test data and calculated data of the FEM.2. The parameters which affect mechanical properties of the bridge are selected, such as elastic modulus, density, boundary, etc. Then parameter sensitivity analysis is performed. At last, the sensitive parameters are selected to be modified.3. The objective function is established based on residuals of indexes, such as frequency and displacement etc, between data of the FEM and situ test. Weighted combination of objective function method and least squares objective function method are selected to update the FEM of bridge. Then the FEM which can reflect the current conditions of the bridge is obtained.4. Based on the FEM above, safety assessment factor is calculated in the dead load case and live load case, and safety performance of bridge is verified. Via area reduction of suspender cable and analysis of overload, study on structure response was performed and future carrying capacity of the bridge was predicted under the condition of structural injure and overload.