Load Identification on an Arch Bridge Based on the Generalized Flexibility Matrix

Health problems of the bridge structure are a hot issue in engineering research currently. Load identification together with damage identification is an important method to diagnose the health status of the bridge. In order to identify different loads on bridges, this paper takes a box arch bridge built with prestressed reinforced concrete in Chongqing as an example and establishes it’s finite element model. The general flexibility matrix is obtained by calculating the response values of each control section separately caused by each unit characteristic load. The maximum bending moment of each control section is acquired by using the time history analysis of Wenchuan Seismic wave, and the equivalent loads are derived from the general flexibility matrix. Results indicate that this method can identify a wide range of basic load types and accurately identify the actual load of the bridge with high precision. Thus the actual operating conditions of bridge can be better reflected and the bridge’s safety condition can be evaluated. Besides, the load evaluation and maintenance of the bridge can be based on this.