Structural Behavior Analysis And Research Of The Girder Of The Low-Pylon Cable-Stayed Bridge With Twin Towers

The low-pylon cable-stayed bridge is a new type of bridge structure system between the girder bridge and the cable-stayed bridge, and it has the advantage of the girder bridge and the cable-stayed bridge, for example, the preferable structural behavior and the economic benefits. In recent years, it is becoming increasingly clear that the low-pylon cable-stayed bridge is of tremendous significance development potential at home and abroad. According to the structure of the low-pylon cable-stayed bridge, its marked characteristic is that the main girder, the stay cable and low pylon work together. The stay cable bears a small part of load, but the main girder bears the most loads, which include bending moment, shearing force and axial force. As a result, the behaviors of the main girder of the low-pylon cable-stayed bridge are more complicated than which of the girder bridges and cable-stayed bridges, and the non-uniform stress is more serious than other bridges. Stress characteristic analysis of the girder of the low-pylon cable-stayed bridge is the key of bridge design, but its research and application was carried out lately that many problems and theories are pressing for solution. At present, the design and construction on the low-pylon cable-stayed bridge is often based on the girder bridge and the cable-stayed bridge because it has not perfect according theory.In this paper, based on the low-pylon cable-stayed bridge Mianxian Han River Bridge and large amounts of data, carrying out the following three areas:First, based on the collection, analysis and summary on the theories and design datas of the low-pylon cable-stayed bridge at home and abroad, the paper provides detailed reports on the modeling course of the low-pylon cable-stayed bridge with the the theory of finite element, and builts the finite element model of the low-pylon cable-stayed bridge with twin towers by using the finite element analysis software MIDAS/CIVIL.Second, based on some computing results of the finite element model, the paper provides contrast analysis and discussion on the structural behavior of the girder of the low-pylon cable-stayed bridge with twin towers in the most cantilever stage and the builted bridge stage, summarizes the distribution laws and characteristics of the internal force and stress of the main girder in the two stages, then suggest the appropriate measures which make the girder behavior more uniform and reasonable.Finally, the paper summarizes the computing results of the main girder of the finite element model under the main loads, analysises the laws and characteristics of the internal force and stress of the main girder in the main loads, discusses the most unfavorable load and the influence under these main loads, in the end, finds the relevant conclusion which can provide some references for the design, calculation and construction of the low-pylon cable-stayed bridge with twin towers.