The Stage Analysis Of Force And Research On Construction Control For Large-cantilevered Prestressed Pier Caps

In recent years,with the continuous development of city construction and traffic volumeincrease sharply,we need the more and the more wide roads to meet citizens’ traveldemand.However, extend road restricted by the side of road building,only through expansionthe viaduct can solve the contradiction space.In the process of the construction of the viaductbridge deck more and more wide,under the premise of not only ensure it has enough traffic onthe bridge widith,but ensure that the bridge has a large space and good line of sight,theconcept of large-cantilevered pier cap arise at the historic moment. Projects related to thelarge-cantilevered prestressed pier caps have never been implemented before in our country.We have less experience about the construction of it.The research in this field need to carryout. Settling the practical problems including structural analysis, design, construction andoperation, giving useful advice on the future application of large-cantilevered pier caps. Aimto improve the overall technical level about the large-cantilevered prestressed pier caps on thestructural analysis, design, construction and operation.Mechanical characteristics, failure patterns and numerical methods of the pier caps havebeen studied respectively. Through analyzing the differences of using3D solid finite elementsand3D beam elements in stress analysis, this paper suggests that3D solid finite elementmodel be used in studying certain structural zones, like the column-cap joints and streamlinedtransition zones of column cross-section. Meanwhile, the non-linear elastic-plastic materialmodel has been proved applicable to the analysis, different anti-cracking methods have beencomparably studied and precisely analyzed the stress conditions of the cap beam on differentconstruction stages. The stress distribution of the beam and variation of stress in constructionhave been mastered in theory, the strength characteristic of large-cantilever pier beam alsobeen studied. The FBG sensorsis has been used in the beams in construction to obey stressdistribution in every construction stages. Furthermore, this paper compares the theoreticalresults with the measured data, proving that it is an effective way to build3D solid FEMmodels with coupled prestressed reinforcement elements, in the analysis of this type of piercaps. Additionally, the use of FBG sensorsis recommended in construction control as aneffective way to enhance stress and strain monitoring in the construction and operation processes.Ideas and proposals from this thesis have been successfully applied to thislarge-cantilever pier beam, solving certain practical problems. The research findings helpimproving levels of finite element analysis, structural design, construction control andoperational management of large-cantilevered pier caps, furthermore providing references forthe implementation of similar projects.