Research On Persistent Stress Monitoring And Early Warning System Of The Mi River Bridge Of National Road309

Since the founding of the P.R. China and in particular adapting the policy of reform and opening up, China road and bridge construction industry has made considerable progress with the development of the cause of all walks of socialism construction. Among all kinds of bridges China constructed, the concrete structure account for more than85%and the prestressing force concrete structures more than80%. Decades of burden, most of the structures began to appear the phenomenon of "aging" and crack occurred on some wide span prestressing force concrete bridges which worth our particular attention to the loss of stress.Focusing on the loss of prestressing force, this paper mainly stresses multi-point shear stress releasing method and the warning changes in monitoring bridge stress-strain changes, in order to be able to provide some reference of experiments, to play a reference role in measuring and monitoring of existing prestressing force of concrete structures and the assessment of the carrying capacity of the existing bridge structureThis paper concludes in detail the loss and survey of stress by using porous stress release method, test method of Acoustoelastic Effect under the anchor, overall vibration method and so on. And draw targeted early warning system based on the analysis and sorting of known data in order that it can provide the basis of realistic data for the management, control and maintenance of bridge.In addition, the research can be used not only for existing prestressing concrete bridge in service, also for other prestresseing concrete structures. The21st century is the century of development of infrastructure, meanwhile is also a century of widely use of prestressing force concrete structure. Therefore, the needs of research and the prospects of application of this subject are very considerable.