Research On Construction Monitoring Of Prestressed Concrete Continuous Rigid Frame Bridge With Y Pier

Continuous rigid frame bridge with Y type pier is novel and attractive. It canreduce pier top negative bending moment, reduce the beam height, shorten the span,etc.on ordinary continuous rigid frame bridge. Then its complicated structure form ofbridge construction put forward higher request. At present, the construction methods,construction monitoring of theoretical researches and engineering applications ofcontinuous rigid frame bridge with Y type pier are less. The widely used twicepre-stressed anchorage research still focuses on short-term stress performance andshort-term pre-stress loss. Its long-term pre-stress loss is a complex problem that hasnot been solved. This paper based on the Laodaohe Bridge on North Road of Wanjiali.We detailed studied the construction and monitoring and long-term prestress loss intwice pre-stressed anchorage.Firstly, completed the full-bridge finite element process simulation analysis, andthen tested in the construction process of the main beam deflection, control sectionstress and other parameters, and the results were compared with the theoreticalcalculation, assessment and correction by comparing the results of the construction.The bridge has demi complete closured currently, the results show that the monitoringis effective.Departure from Y type pier of Laodaohe bridge construction difficulties and focu s,systematically introduced a system of Y pier construction key technology, mainlyincludes the external brace in the support system and concrete block castingtechnology, and summed up the benefits of these technologies. Through to the Y pierof the whole construction process stress analysis, scientific guiding Y pierconstruction, and better achieve the Y pier cracking control and linear control.In order to research the short-term and long-term loss of prestress of the twicepre-stressed and low retracting strand anchorage system, the tensioning process of fivevertical prestressing tendons on laodao river bridge was tested, and three of them wasdone long-term observations on effective prestress. According to the time-step method,and based on axial compression column calculation model, the vertical prestressinglosses theoretical value of the test tendons was calculated. The results show that, themeasured value of prestress loss is less than the calculated value, indicated that the testvertical prestressing tendons with the twice pre-stressed and low retracting strand anchorage have fine long-term performance.Through the construction monitoring, cracking control of the Y-shaped pier andobservation of vertical prestressing, the author analyzed and su mmarized a set of keytechnology about the construction of prestressed concrete rigid frame bridge withY-shaped pier. Provided some valuable research and thinking from the view ofengineering practice.