Monitoring And Simulation Analysis Of The Pre-stressed Structure During The Construction And Service Period

The prestressed concrete structure has become the development trend of construction.Parabola form layout is always used in the prestressed reinforcement, but the four section parabola is still in the exploration in the large-span prestressed concrete structures.In addition, the prestressing loss will directly affect the prestress and the performance of the prestressed structure.The Structures are vulnerable to damage with the long-term static load and live load,its corresponding bearing capacity and stiffness will reduce with the increase of time.This will not only affect the normal operation of buildings, but also shorten the service life of buildings and the safety of the buildings. Therefore, the construction monitoring and health monitoring is necessary for the large public buildings.Evaluate health status of the building, and make corresponding engineering decision-making for the buildings,and then to warn and alarm the buildings for implementation of maintenance, repairing and reinforcement them.The project of planning exhibition hall,exhibition hall and the public museum of Fuxin has part of the prestressed structure. It needs to study the part of prestress engineering of this structure.Specifically including the followings:(1) It studys the loss of the prestressed concrete structures during construction and service time theoretically, especially the loss of post-tensioned method.And then calculate the loss of bonded post-tensioned prestressed concrete beam about this project.(2) In construction stage, theoretical calculation and field measurement was taken to test of prestressed tensioning construction quality of the girder which was four section parabola distributed in the project.Finite element software was taken to simulate inverted camber.Compare the simulated value, the theoretical value and monitoringto verify the feasibility of finite element software to simulate the prestressed structure.(3) In service stage, it takes finite element software to simulate the different loss of prestress to analyze the impact of the loss to the deflection of beam and other part of the structure.Based on this method, it can determine the role of each beam.This is regarded as the standard of health monitoring.(4) Through embeding the sensors under the anchor, stress under the prestressed beams can be acquired, then the datas is collected through a data acquisition system.Based on the results of numerical simulation, when the beams' stress change, corresponding measures would be taken to achieve the function of real-time monitoring, early warning and recording.