Research On Stability Of Cantilever Casting Construction Of Shatuo Extra Large Arch Bridge

In recent years,cantilevered arch bridges have developed well in southwestern China,and cantilevered construction techniques are also newer construction techniques in arch bridge construction.Most of the existing studies on the stability of cantilevered arch bridges are aimed at spans below 180m,and only part of the cantilever construction stage stability studies have certain limitations.With the increase of the span,the technical difficulties in the construction of the cantilevered arch bridge are numerous and difficult to control,which greatly increases the construction risk of the cantilevered arch bridge.The construction stability is an important guarantee for the entire construction process.The Shatuo Super Large Bridge is the engineering background.The mid-finance civil simulation model of the cable-tower arch was established by midas civil.The work and results are as follows:① According to the characteristics of the cantilever casting construction of the concrete arch bridge,based on the current research results of the construction stability of the reinforced concrete arch bridge,a relevant simulation model was established,and the buckling stability coefficient analysis of the entire process of the cantilever construction was conducted.That is,the multi-point elastic strengthening stage,the stress concentration decreasing stage,and the bare arch recovery stage.For the maximum cantilever construction stage with the lowest construction stability,the Newton-Raphson iterative method is used to solve,and the degree of the influence of geometric nonlinearity on the construction stability at this stage can be obtained.② According For the demolition construction of the main arch after the closure of the main arch,four kinds of cable-stayed demolition schemes were proposed,and each scheme was comprehensively compared with the stress,safety factor of the anchor cable and construction stability.When the demolition plan is a combination of sequential demolition and jump demolition,the internal force and construction stability of the main arch are better.③ Due to the actual construction conditions on site,the problem of asymmetrical erection of hollow slabs in cantilevered arch bridges,different erection schemes were drawn up.Through analysis of its internal force,line shape and stability,alternatives that are similar to the original design can be obtained.The feasibility and economy of symmetrical hollow slab erection.④ Researched the design parameters of arch ribs and towers and the influence of construction load on the construction stability of the structure.It can be obtained that the rigidity of the tower and high temperature construction have a greater impact on the construction stability;The influence of construction stability is relatively small,which provides relevant reference for the design and construction of the cantilevered arch bridge in the future.