Threshold Analysis Of Curved ?-Girder For Curved Cable-Stayed Bridge

Curved cable-stayed bridge is the kind of indeterminate spatial cable-supporting structure, whose girder presents obvious characteristics of curved girder bridge, so the force situation of curved cable-stayed bridge is very complex with an apparent spatial characteristic. The curved cable-stayed bridge will inevitably perform the bending-torsion coupling effect because of curvature. When the curvature of curved cable-stayed bridge is small, the bending-torsion coupling effect of the main girder is not obvious and its mechanical behavior performs like the straight cable-stayed bridge with the same span.Under this situation, the bending-torsion coupling effect can be ignored and the structure can be designed as the straight cable-stayed bridge. When the curvature of curved cable-stayed bridge is big, the bending-torsion coupling effect is notable, and then the phenomenon of bearing disengaging or excessive torque may appear, at this time the structure cannot be designed in accordance with straight cable-stayed bridge. With the project of Africa and Congo Brazzaville Binhe curved cable-stayed bridge taken as background, through the numerical simulation and calculation by using the professional finite element software of Midas/Civil, the research of the threshold of curved cable-stayed bridge is conducted. The main work includes:1. Based on the structural analysis theories of curved bridge and cable-stayed bridge,the computational theory and analysis methods of curved cable-stayed bridge are summarized.2. By analyzing the sensitivity of static indices to the curvature radius or the arc length,the evaluation indices for the threshold of curved cable-stayed bridge are determined.3. The thresholds of the curved cable-stayed bridge are calculated, including the upper threshold when the curved cable-stayed bridge can be designed as the straight cable-stayed bridge and the lower threshold when the structure cannot be completely designed as the straight cable-stayed bridge. What's more, the influence of the perturbation of uncertain parameters on the thresholds of curved cable-stayed bridge is analyzed.4. The thresholds of curved cable-stayed bridge with the different arc lengths and tower heights are calculated, and the relation curve and formula between the threshold and arc length or tower height are given.