Tianxingzhou Rail-cum-yangtze River Bridge In Wuhan Space Geometric Nonlinear Finite Element Simulation

The main bridge of Wuhan TianXing-zhou highway/railway Yangtze River bridge is a double-tower, three cable planes, three main trusses cable-stayed bridge with span arrangement (98+196+504+196+98) m.The expansion longitudinal beams are designed in every two panels and slots are designed in the concrete deck over the expansion longitudinal beams.The bridge is the first steel-concrete composite cable-stayed through bridge with ballasted deck and is the key project of Wuhan-Guangzhou Passenger Transport Railway.The finite element computing method and the mechanical behavior of Wuhan Tian Xing-zhou highway/railway Yangtze River bridge were studied systemically. Main work of this paper is as follows:1. The main influence factors of geometric nonlinearity of long-span cable-stayed bridge were analyzed, including cable stay sag effect, beam-column effect and big displacement effect, and the corresponding methods were proposed.2. Geometric nonlinear space finite element models of Tian Xing-zhou highway/ railway Yangtze River bridge were established. The deflections and stresses of various members of the bridge under the dead load and the live load were studied. The results show that the rigidity is high and the stress is reasonable.3. The influence of seasonal temperature difference and sunlight-induced temperature difference to the mechanical behavior was studied. The results show that there exists large stresses at the transverse beam crunodes closing with the main span midspan on the effect of the temperature increase or decrease. But combined the above stresses with the stresses under the first dead load, the second dead load and the live load, the total stresses are less than 200MPa.4. Stresses redistribution produced by creep on the concrete of steel-concrete composite railway bridge deck were studied. The results show that stresses in concrete slab become smaller and the stresses in steel beams become larger. The stresses in concrete slab and steel beams are still smaller than the ordainment in criterion after stresses redistribution.The research results in this paper provide references for the design of Wuhan TianXing-zhou highway/railway Yangtze River bridge, the basic ideas and methods can be applied to the analysis of other big and complex steel-concrete composite structure cable-stayed bridge as well.