Study On The Steel Truss Arch Applied In The Construction Of Large-Span Arch Bridge

In China Road and Bridge Series, the arch bridge has become the longest history, strong competition form of a bridge, as an old bridge type it has characteristic technical superiority such as large span capacity, high loading capacity, economical cost, less cost on maintenance, and beautiful shape. In recent years, as the rapid development of traffic in China, the need to build large-span bridges to cross rivers become more. Bridge Construction Control is not only an important part of the bridge construction technology, but also the relatively difficulty part of implementation. And the construction process control of long-span bridge, is an important part of state to ensure construction quality and safety, is the important measures to ensure that the bridge with the design requirements.In this paper, in the engineering background of Tongda bridge of Guizhou province, we have adopted a new method named "steel truss arch technology" in the construction of the main arch rib in the large-span reinforced concrete arch bridge which based on a Summary of various construction methods. Our specific work as the following aspects:1 .The method of jacks and cables is a new way in construction without support setting. This paper described the details and attention of the steel truss arch closure used the way .Practice has proved that the construction method is safe, reliable, has a high-precision, and the cantilever assembly of the time is short. It can better solve the problems encountered in the construction without support setting of the long-span arch bridge. And this thesis provides experiences for construction of similar multi-section arch bridges with long span.2.Through the arch centering preloading in the water load test to eliminate the non-elastic deformation of the arch centering, the paper analysed the data and compared the measured value of the deflection and stress value with theoretical value. Test results has a forecasting and guiding role of theory to the problems on concrete pouring process of the main arch ring.Arch load test data show that the steel truss arch of Tongda bridge has assembled accurate, better integrity, and its carrying capacity meet the Arch box concrete pouring needs. This proved the main arch pouring on the steel truss arch is safe and feasible.3.Calculation of stayed-buckle cable force use a elastic-rigid support mothod.This paper deduced the basic principles of elastic-rigid support mothod, then compared and analysed with the finite element method.The two methods can be the close result. Using this method can solve the cable force calculation proplem of the use of jacks and cables in bridge control simply and reliably. It can present the Precamber in the calculation of the cable force, not only can improve the accuracy also can avoid repeated calculations save time.