Detection And Evaluation Of Load Bearing Capacity Of Prestressed Concrete Box Girder In Active Service

There are many prestressed bridges in our country appear diseases and defects, part of the bridge has reached the design life of serving and even overrun, there is a big security risk, cannot meet the needs of the development of traffic.Demolition and reconstruction will spend a large sum of money, so both the bridge detection and evaluation is of great importance.This paper discusses current situation of domestic and foreign common defects and diseases of prestressed bridge, at the same time, to study the bridge detection and evaluation of a detailed description at home and abroad, the purpose and importance of the detection and evaluation of active bridge. The evaluation process and main evaluation methods of bridge carrying capacity are analyzed in detail, and the advantages and disadvantages of different methods are compared and analyzed. Existing Bridges and the current detection means and methods are summarized, including visual inspection, the local non-destructive testing and the purpose and content of the load test, and the bridge of dynamic and static load test of the principles discussed.A case study of a prestressed concrete continuous girder bridge in service, characterized by continuous beams of the bridge number is large, currently belong to the rare. Appearance using three methods including the on-site inspections, he bridge caculations, and load test on bearing capacity of the bridge for test and evaluation.The on-site inspections main is through experienced technicians on old bridge for full of detection, according to site survey was informed that bridge exists of various disease,through qualitative and quantitative detection resultson bridge status for classification and score; bridge caculationsare based on the existing bridge design specifications as the basis, based on the investigation of bridge by Midas Civil modeling and computational analysis, so as to determine the bearing capacity of bridge; load test method is simple in appearance after the investigation and determination of test cross, through the finite element software to calculate the loading condition and the wheel, then to the bridge Test of load is applied, the measured test data can directly reflect the bridge actual working state, so as to realize the detection and evaluation of bridge. Three methods concluded for the bridge carrying capacity can meet the operational requirements and demonstrates the practical feasibility of the existing evaluation methods, but also for the detection and evaluation of the other bridge analysis provide a reference.