Research On The Techniques Of Cable Hoisting For Steel Box Arched Bridge

With the rapid growth of China's economy, more investment has been done on infrastructure, especially the investment on China's highway construction has reached a peak. As it is known, China is a mountainous country with many rivers, among which 69% area is mountains. Due to the geographic location, a lot of difficulty has been brought to theconstruction of the bridges locating in the mountains and above rivers, which both increase the difficulties of construction as well as investment costs. Therefore, more cable hoisting construction method will be used to build the bridge type we need when the river water is relatively rapid or it has some requirements for the navigation. Thus, the advantages of cable hoisting clearly will be shown in these areas during the construction of bridges. So the research on the techiniques of cable hoisting of bridge construction has a very important significance.The thesis describes the development of arch bridges of both at home and abroad, traditional construction methods of the arch bridges and the arch bridges development of cable hoisting construction. Cable hoisting ropes development is discussed mainly in two aspects, which are the application from the hoisting cable theory and practical engineering.The thesis takes Luowen Bridge for instance, and takes Nanning Bridge cable hoisting as the construction technology, which initially identifies each type of cable for Luowen Bridge cable hoisting system. Then arch cable hoisting of the key points of construction technology and tower computational analysis methods are summarized. The key point is to control tower's top horizontal displacement, so as to lessen the bending moment of cable tower and buckle tower. So the horizontal force caused by the arch rib's hoisting and fixing cable's tensioning must be reduced.According to the cable type selection theory, four suspensions will be introduced respectively, which are catenary, parabola, catenary curve and perturbation theory. Meanwhile, based on the theory suspension, the thesis mainly calculates main cable carrying capacity, safety factor, the main cable stress calculation, calculation of the main cable installation; calculating traction and traction traction rope safety factor; the hoisting cable tension, contact stress and calculate wind cable rope safety factor; calculating the safety factor.Tower cable hoisting system is a very important structure, and the security of tower structure will influence the entire construction process. A lot of unnecessary accidents happened in the past during the construction process due to the unreasonable design of the tower. In this thesis, with the aid of finite element software called Midas, a model of finite element analysis is set for the tower construction in the hoisting system. While the stability of the tower and member forces buckle tower system is analyzed and calculated with the Midas system. Through the computational analysis, force within the main tower and buckle tower bars in the specified range, stability also meets regulatory requirements.