Study on Mechanical Behavior of Steel-concrete Composite Segment for a V-shaped Pier Rigid-frame and CFST Arch Combined Bridge
|School||Central South University|
|Keywords||V-shaped pier rigid-frame and arch combined bridge steel-concrete composite segment local analysis improvement measures|
Abstract:LTG Bridge is a long-span V-shaped pier rigid-frame and arch combined bridge, and its span composition is (2×30+80+2×30) m.The bridge has four steel-concrete composite segments, which are symmetrical.The structure and force situation of steel-concrete composite segments are complex, in the analysis of the whole bridge,it is difficult to take structure details into consideration. Based on global finite element analysis of this bridge, the paper researched the mechanical behaviors and improvement measures of two steel-concrete composite segments by local finite element analysis method. The major work and results are as follows:1. Based on global finite element analysis,the two composite segments were chosen to be performed local stress analyses, and the calculation method of the local analysis was analyzed, finite element simulation method of the local model were determined, and the local finite element models of two composite segments were established.2. Local finite element analysis of the mechanical behaviors were done to two steel-concrete composite segment. The results show that the mechanical behavior of two steel-concrete composite segments is good and the force transmissions of the steel-concrete composite segment and its bilateral steel box girders are smooth. The stress level of most regions is not high, but the small regional tensile stress exceeds standard value of tensile strength.3. Research was completed on the effects of the inclined leg1angle, layout of pre-stress and construction scheme on the mechanical behavior of steel-concrete composite segment. The proper value of the inclined leg I angle is given. If the bridge adopt improved layout scheme of pre-stress, and the construction scheme:first constructing beam and then the arch, and the main span steel box girders is closed at high temperature, then the mechanical behavior of steel-concrete composite segments can be improved.The research results provide basis for the steel-concrete composite segment design of LTG Bridge, and in the meantime give some references to the design of other similar structures.There are93graphs,11tables and47references in this paper.