On The Architectural Characteristics And The Mechanical Properties Of Half-through CFST Arch Bridges

In recent years, our country economy stability increases and the scientific technology develops quickly, more investment is put into the fundamental facilities, we accomplish a lot of great construction of bridges and a large improvement also be made in bridge construction technology. With the high capacity, strong spanning ability, good seismic behavior and convenience of construction, Concrete-filled steel tubular (CFST) arch bridge develops rapidly and is a quickest-developing structure of bridge, which was built since 1990. With the continuous development and mature of CFST structural theory, CFST arch bridges are developing in the direction of more large-span and more large scale. At the same time, the application area and range are expanding continuously, and the largest span of CFST arch bridges which have been built has exceeded 450m at the present time. With the adaptable of CFST arch bridge's rapid developing, much favorable work has been done about the theory research of CFST arch bridge, but these fall behind its development.In this paper, the structural system, static and dynamic behaviors of half-through CFST arch bridge are made. And this study will offer a theoretical foundation for development of CFST arch bridge design. The specific research mainly included several aspects as follows:(1)According to the classification of the structural system, the stress characteristics and applicability of structural system, rigid-framed tied arch are discussed respectively. At the same time, the stress characteristics of half-through CFST arch bridge are analyzed. The classification and characters of suspender are discussed. Both of the inner force of tie-bar and the transverse structural style of arch rib are analyzed respectively.(2) The buckling safety factor of Maocaojie Bridge in dead load is calculated by using the analytical method of elastic stability. Then, the influencing factors of resistance to overturning are discussed. And the influence of width-span ratio, lateral connections, disposal of suspender, ratio of rise to span and sloping angle to the stability of bridge are analyzed.(3) The natural frequency and natural mode of Maocaojie Bridge are calculated by using ANSYS, and the characters of different modes are analyzed. The influence of volumetric percentage of steel, sloping angle, ratio of rise to span, lateral connections and width-span ratio to natural frequency and natural mode are discussed. At last, the aseismic performances of bridges are analyzed by using the theory of response spectrum.(4)The structural stress features of side-arch in the construction course of long span arch bridges with side-arch-body system are analyzed. At the course of cable-rope-hoisting construction, when the side-arch is used as balancing weight of main arch hoisting part directly, the predominance of structural stress and economical performance of the side arch is explored and discussed. At the same time, the cable-rope-hoisting construction course of Maocaojie bridge is taken as example in this paper, The local stress distribution, the integral stability and the advantage of the side-arch when used as main arch hoisting balancing weight are analyzed, which can supply reference for a kind of bridge that used the side-arch as balance part in the construction course.