Structure Analysis Of Shanxi Large-span Beam Arch Combined Aqueducts Made By Steel Reinforce Concrete

As a key construction, aqueduct plays an essential role in significantly strategic projects which are used for relieving water resource scarcity in north China. Development of construction theory and society needs an objective combination between aqueduct design and bridge design theory. Many aqueducts have become ones of local landscape due to their novel type of structure and grand scale. Steel reinforced concrete is a well-developed building material which possesses higher bearing capacity, ductility and anti-seismic performance, hence, it is widely applied in bridge structure.Based on one certain project of South-to-North Water Diversion Project in Yuncheng city, three girder and arch combination aqueducts with different spans were analyzed in this thesis. Then an overall model of the structure was built by MIDAS and then, the overall performance was analyzed through calculation of space mechanical model. The main conclusions are as following:1、Base on the conceptual design of three kinds of different design parameters:arch axis, rise-span ratio, supporting the layout of simulation analysis, the reasonable parameters for beam arch combination structure was finally determined.2、Analysis of structure model under static load situation proves that arch springing and vault are both significant positions of structure which need to be paid enough attention to in design.3、 Natural vibration and main mode of vibration characters illustrate the weak stiffness out of plane of structure, so the stability out of plane is a highlight problem where measures should be taken to ensure the lateral stability of corresponding construction member.4、Both earthquake response spectrum method and time-history method are employed to evaluate the aqueduct’s dynamic character, and we conclude that structure’s transverse stiffness is lower than the vertical and longitudinal ones; the internal force of structure under coupling earthquake situation would be much more significant than under unidirectional earthquake situation, especially when transverse earthquake and vertical earthquake are combined together.5、 Out-of-plane stability is the key point of large span structure design. pattern brace have higher stability coefficient than’x’pattern; the number of braces plays crucial role in overall stability of beam arch combination aqueduct, however, excess brace members do not do much in improving overall stability of structure.