Design And Construction Of The Steel Truss Arch Of Qi Xing Guan Arch Bridge

The key of large-span reinforced concrete arch bridge is the construction method. Full framing method was mainly used in the past. With the technical development of no-bracket method, the application scope of arch bridge is enlarged and the ability of arch bridge is increased in the competition of all different patterns of large-span bridges. In recent years, the main no-bracket methods about arch bridges are the four below: cable hoisting construction , cantilever construction , fabricated cable construction, rotation construction. Afterwards the method of stiff framework and fabricated cable construction are put into practice. On the base of the above methods, we use new method named "steel truss arch technology" in the construction of the main arch rib in the large-span reinforced concrete arch bridge.Based on Qi Xing Guan arch bridge in Guizhou province, this paper is mainly about the computed theory, the stability theory, and FEM theory of arch-bridge. On the foundation of many 1 oad tests, we have finished the theoretical c alculation and load tests about the steel truss arch of the bridge. The following is the detail:First, this paper introduces the arrangement of the steel truss arch and the organization of whole construction, and then optimizes the concreting program of arch section. Second, by two programs designed by Prof Huang cai liang of Dalian University of Technology: PFR and CREEP7, the calculation of internal force and stability analysis has been finished. It can be proved that axis force, bending moment , stress, stability coefficient are less than the data of the criterion permission. At last, the application of the steel truss arch is expanded. It is proved that steel truss arch has the advantage of the structure simplicity, standard size, easy installation, and economical cost, thus the technology can be used in more fields. And taking example for Di Na He arch bridge, the standard rise-to-span ratio of the steel truss arch of Di Na He arch bridge was calculated.Water tank pre-pressing the arch can relieve nonelastic deformation of the steel truss arch. By comparing the data of stress and deflection derived from the test with those from theoretical calculation, necessary suggestions can be given to the process of the whole concretion. The data that from the load test expresses that steel truss arch of the Qi Xing Guan bridge is accurately assembled and has fine integration, and the bearing capacity is enough to satisfy the demand of the concreting of the box shape arch-circle .It is safe and feasible to concrete the main arch-circle by steel arch truss.