Seismic Responses Analysis Of Zhuanghe Construction Bridge

As a new type of bridge, self-anchored cable-stayed suspension bridge has not only someadvantages of traditional cable-stayed suspension bridge, but also has merits of self-anchoredsuspension bridge. It has good structural performance, remarkable technical and economicalbenefit, therefore has been adopted by engineering filed so far. However, there is littleresearch on dynamic behavior for the type of bridge from the documents that have existed.With the engineering background of Zhuanghe Construction Bridge, the dynamiccharacteristic and seismic response of this new structural system are investigated in thisdissertation, the main research work covers the following aspects:(1) Dynamic characteristics of self-anchored cable-stayed suspension bridge mainlyinclude natural vibration frequencies and principal modes, which are the base andprecondition of dynamic response analysis for the kind of this system bridge. Based on FiniteElement Methods, dynamic characteristics of Zhuanghe Construction Bridge are analyzed andcompared with those of earth-anchored cable-stayed suspension bridge with the same spanand structure parameters by using spatial finite element model, some new traits of dynamiccharacteristics for the system bridge are summarized.(2) The standard seismic response spectrum is inputted from longitudinal, transverse andvertical direction respectively. Two kinds of seismic combinational modes, which arelongitudinal vibration plus vertical vibration and transverse plus vertical vibration areconsidered. In order to ensure the precision, the CQC (Complete Quadratic Combination)approach is applied.(3) In the condition of nonlinear uniform, the artificial earthquake wave is inputted fromlongitudinal, transverse and vertical direction respectively. The response time histories ofinternal force and displacement of controlling section such as main beam, tower are analyzedand compared. The effect regulation is discussed in detail.(4) The spectral analysis is linear so the nonlinear factors can not be taken into account.The dynamic properties of Zhuanghe Construction Bridge are calculated also with dynamictime-history analysis considering the nonlinear factors. The earthquake response is gainedaccording to the calculation results of the two methods. (5) The aseismatic behavior of bridge is mainly influenced by the selected structuralsystem. So three structural systems are analyzed and a sort of elastic restriction structuralsystem composed of towers and beams is selected. This paper also analyzes the influence oflongitudinal elastic restriction on dynamic character and seismic response. Besides, effects ondynamic characters due to rigidity of stiffing girder as well as stiffness of tower are studied,and the influence regulations are discussed in detail.These laws can be used as the basis of seismic design of the Zhuanghe ConstructionBridge and is useful for directing seismic response analysis of such kind bridge.