Analysis Of Transverse Stiffness And Durability For Reinforced Concrete Box Arch Bridge With Cable-hoisting Method

Since the 1970s, a great deal of reinforced concrete arch bridges with box section have been constructed by cable-hoisting mothed in our country. To some extent it promotes the increasment of arch bridge's span. However, some reinforced concrete box arch bridges by cable-hoisting method show up gradually structural defects in several decade's operation, and expose deficiencies such as weak transverse stiffness of arch ring and structural durability. Based on the actualities together with the strengthening project of the Qiuxi River Bridge located in Chendu-Chongqing expressway, the issues of transverse stiffness and durability about reinforced concrete box arch bridge by cable-hoisting method are studied elaborately in this thesis. The study contents are mainly as follows.1. Taking natural vibration frequency of arch bridge as an evaluation index for the transverse stiffness, the thesis analyses and discusses the essential theory of the arch's natural vibration characteristics, and introduces the basic principle of the finite element method.2. A 3-D finite element model is built on the base of design drawings of the Qiuxi River Bridge with ANSYS, and the natural vibration frequencies and modes are figured out. The effect of natural vibration frequency under different transverse stiffness is simulated by changing the transverse link stiffness of filled concrete between arch box or rib.3. Fuzzy comprehensive evaluation method is introduced into the analysis of bridge's durability, and the weights are reckoned by the analytical hierarchy process. Moreover, the method is applied to the analysis of durability of the Qiuxi River Bridge.