Research On Sivice Condition Monitoring Project Of Long Span Steel Truss Arch Bridge

The steel truss arch bridge is grand and magnificent, there is some merits such as it has a great ability to step across and bearing capacity. This kind of bridge used in the project practice in the overseas has nearly hundreds of years.But as a result of economic level limit, only until the beginning of the 80s it has been used in the project practice in our country. The Chongqing Chaotianmen Bridge in process has a span of 190+552+190m, it is the longest of the steel truss arch bridge in the world, which has been a historical breakthrough in the structure's system. But there is very little literature material about the research of the long span steel truss arch bridge that can be retrieved at present, and people incomprehensibly know about the steel truss arch bridge in the theory and practice. So, it is very necessary to the study of this paper.Based on the engineering background of Chongqing Chaotianmen Bridge, Carrying out analysis and research on state recognition of finished stage, The project of monitoring and evaluation on sivice condition of long span steel truss arch bridge is established, and the state alarm value is raised. The research of this paper work mainly includes:â‘ The analysis of the whole mechanical behavior on finished stage. Firstly, it is calculated that the static properties of the large span steel truss arch bridge by a variety of load cases and critical cases, and find the structure of the monitoring sites. Secondly, the modal analysis of main structure is carried out, it is conclution that the dynamic characteristics of the steel truss arch bridge are greatly affected by dead load, the vertical bridge stiffness and the horizone bridge stiffness. Therefore, the acceleration sensor is must setted.â‘¡The program of state monitoring system is determined. The Principles of the selection of monitoring cotent is complied which combines real-time monitoring and artificial periodic monitoring. The section of real-time monitoring select the important and representative structure.â‘¢It is considered that the loading conditions and the partial drying affect the structure. According to the principles of the state warning, the stress and deflection of the bar and node is researed, and control the safety of operational stage.â‘£Reference to the evaluation method of bridge safety and the latest research and application results, combining to structural characteristics and sensor distributing. The evaluation project of state is determined.