Large Span Continuous Prestress Loss Monitoring Research During Sustained Loads

With the adoption of reform and opening-up, the construction of bridges hasdeveloped rapidly in China, which plays an important role in improving people’s livingconditions, optimizing investment climate, and also promoting economic prosperity.Bridges are artificial structures which are built in order to cross any obstacles, such asrivers, lakes, valleys, deep groove etc, and to ensure the continuity of the transportationlines as well. Continuous rigid frame bridge, as a kind of bridge types among manyothers, has combined continuous beams with the mechanical characteristics of T-shapedrigid frame bridge, so that the continuous main beam and pier are consolidated togetherto bear the load. But among the already-built continuous rigid frames, specially theearlier construction, the problem of downwarping with the mid-span still existedubiquitously. The reason, based on our research and common view, is that there is losson the prestress of the prestressed steel of the box girder. Therefore, the explore of lossof presress has become a particularly important issue.This thesis is based on the project through the top plate, web, floor mounted onsteel beam flux sensor and anchor design, by actual measurement to derive a bridgeunder construction and during the operation of prestressing loss data, with04theoreticalcalculation method specification the results are compared in order to identify themechanism and laws of prestress loss, draw some relevant conclusions. Finally, thefinite element software Midas/civil simulated bridge in the long term loss of prestressloads of size, with field instruments and norms calculate the measured data to comparethe data analysis, validation finite element software simulation bridge structureconstruction, steel beams during the operation of the pre-stress damage the effectivenessand feasibility. On the future of such bridge design and construction, with a veryimportant economic and practical significance.