澳凼第三大桥斜拉桥的动力特性及线性地震反应分析

结合一座澳门澳凼第三大桥斜拉桥的工程设计实例,采用大型有限元分析程序 ANSYS,选取空间BEAM188、BEAM4 及 SHELL63 单元建立动力计算模型,对比研究了主塔墩底在假定固结和考虑桩土共同工作这两种边界约束处理方式下的动力特性。采用反应谱法和时程分析法对该桥进行了线性地震反应分析,讨论了在两种振型组合方法和三组振型数情况下结构地震响应的最大值。在时程分析中,合理地选取三条地震波分别沿桥的纵、横向输入,得出了主梁和中塔的内力、位移分布规律及时程响应。

DYNAMIC ANALYSIS AND LINEAR SEISMIC RESPONSE OF THE THIRD AODANG CABLE-STAYED BRIDGE IN MACAO

An engineering design case about the 3rd Aodang cable-stayed bridge in Macao is investigated, using the finite element analysis program ANSYS. 3-D elements, element BEAM188, element BEAM4 and element SHELL63 are used in the dynamic FEM model. The dynamic characteristic is discussed under two different boundary conditions at the bottom of the bridge tower: The fixed end and the interaction of pile-soil. In addition, a linear seismic response analysis is performed by employing the response spectrum method and the time history analysis method, respectively. Based on two kind of mode combination methods and three group of mode numbers, the maximum seismic response of structure are carried out. The time history analysis is conducted for the cable-stayed bridge subjected to three earthquake ground motions in the longitudinal and transversal bridge direction, respectively. The internal force, displacement and the time history response of the main girder and the mid tower are obtained.