Experimental Research Of Model On Qin Cable-stayed Bridge

Qin Bridge, combined with appreciation and practicability, has enjoyed favour among people because of its graceful shape. It is a steel-concrete hybrid beam cable stayed bridge, with curve tower and single back stay cable. Qin Bridge also is complex in design due to its special shape and frame, so many problems need to be settled, such as static analysis, dynamic property, stress distribution of tower, its anchorage zone and bonding pad's, and so on. It is necessary not only to analyze the structure by FEM but also to do a model test to examine.In order to solve these problems, a systematic model test is done. This test has three main parts: making the whole model, doing the static test and dynamic test of the whole model, doing local photoelasticity experimentation.First, based on similar theory and Qin Bridge's characters, the whole model is made. As the model is designed, the steel box beam is equivalent to concrete beam according to area and moment of inertia. In order to meet the demand of dynamical experimentation, balance weight is done on tower and beam.Static test is done to the whole model. The loading behaviour is determined under the condition of ensuring the load test efficiency. According to the results of comparison between the testing value and the theoretical value at the control section, the theoretical analysis is exact, and the whole model accords with similar qualification. Thus, we can go on the dynamic test.In dynamic test, the main aim is acquiring Qin Bridge's dynamic character such as natural vibration frequencies, mode damp, oscillating modes. White noise power is used to motivate the model. By the analysis with transfer function, mode parameter is got. The results from test tally with the ones from theory.Photoelasticity experimentation is done on the tower and the bounding pad of tower and beam. Making use of photoelasticity stress analysis method, the stress distribution is explored. It is valuable to optimize the design and adjust calculation.Above work offers favorable gist for design scheme.