超大跨度CFRP索斜拉桥的力学性能分析

Mechanical Properties of Super Long-span Cable-stayed Bridges Using CFRP Cables

为了探讨碳纤维材料(CFRP)索在超大跨度斜拉桥中应用的可行性,以1400 m主跨的超大跨度钢拉索斜拉桥设计方案为例,采用拉索的等强度和等轴向刚度方法,拟定了两座等跨径布置CFRP索的方案桥,分别采用结构三维几何非线性方法、子空间迭代法、空气动力稳定性分析方法以及地震响应的反应谱分析方法,对应用钢索和CFRP索的超大跨度斜拉桥的静力特性、动力特性、抗风稳定性以及抗震性能等进行了分析与比较,并从力学性能角度探讨了CFRP索在超大跨度斜拉桥中应用的可行性。结果表明:从力学性能角度而言,超大跨度斜拉桥采用CFRP索是可行的,但是拉索截面尺寸采用等轴向刚度方法确定则更有利。

To understand the applicability of carbon fiber reinforced polymer （CFRP） cables in super long-span cable-stayed bridges, taking a 1 400 m cable-stayed bridge using steel stay cables as an example, two cable-stayed bridges with CFRP stay cables and same span were designed, in which the cable＇ s cross-sectional area was determined by the principles of equivalent cable strength and stiffness. By using the methods of 3D structural geometric nonlinear finite element analysis, subspace iteration method, aerodynamic stability analysis and the seismic response spectral analysis respectively, mechanical properties including the static behavior under service load, dynamic behavior, wind stability and seismic behavior of the bridge using either steel or CFRP cables were investigated and compared, and the mechanical applicability of using CFRP cables in super long-span cable-stayed bridges was discussed. The results shows that viewed from the aspect of mechanical properties, the use of CFRP cables in super long-span cable-stayed bridges is feasible, and determination of the cross-sectional areas of CFRP cables by the principle of equivalent axial stiffness is favorable.