大跨度斜拉桥钢和碳纤维拉索设计安全系数

为了确定合理的大跨度斜拉桥拉索设计安全系数和探索碳纤维拉索在斜拉桥中的适用性，利用考虑非线性影响的计算方法分析了跨度为1 400 m的斜拉桥设计方案的抗风性、结构刚度和强度，以及拉索设计安全系数变化对主梁结构设计的影响，从结构系统安全性要求出发讨论了拉索安全系数的合理范围.以应用碳纤维拉索的桥梁为对象，比较了使用碳纤维拉索的斜拉桥主梁在抗风性、使用性以及结构强度方面与钢索斜拉桥的差异.结果表明，在使用荷载作用下，1.7～2.5的钢索设计安全系数不会影响主梁的设计；当设计安全系数大于2.5时碳纤维索斜拉桥可以达到钢索斜拉桥的结构性能以及安全性能，而碳纤维索的自重仅为钢索的1/10左右

Safety factor for steel and carbon fiber reinforced plastic cables of long-span cable-stayed bridges

The effects of cable safety factor on the wind resistance,stiffness and strength of the girder of a cable-stayed bridge with 1 400 m center span were analyzed with considering the geometry and material nonlinearity in order to determine the reasonable cable safety factor for long-span cable-stayed bridges and investigate the application of carbon fiber reinforced plastic(CFRP) cables.The reasonable safety factor range for steel cables was proposed in view of the structure security.The safety factor of 1.7~2.5 was proved to have no effect on the girder design.The differences in wind resistance,serviceability and structural strength of girders were identified between CFRP cable-stayed bridges and steel cable-stayed bridges.Comparison shows that CFRP cables can be used in long-span cable-stayed bridges and is reliable as steel cables when safety factor exceeds 2.5,while the deadweight of CFRP cable is just 1/10 of that of steel cable.