弹性索参数对三塔悬索桥抗震性能影响研究

以一座三塔悬索桥为分析对象,采用有限元仿真分析法,研究了中塔、主梁间设置弹性索对该桥抗震性能的影响。针对不同弹性索参数,比较了结构主要构件和部位的内力及位移的地震响应结果。分析结果表明,选用合适的弹性索刚度时,可以显著减小主梁位移、主塔位移和中塔与主梁间的相对位移,减小边塔底内力,而中塔底内力增加很小。弹性索不是耗能装置,只能改变惯性力的传递途径,使结构体系惯性力分配更加合理。

Effects of elastic cables parameters on anti-seismic performance of three-tower suspension bridge

Based on the three - tower suspension bridge, the effect of elastic cable parameters on anti - seismic performance are compared by using finite element method. In the longitudinal direction, e- lastic cables are set between the middle tower and the main girder to restrict the longitudinal relative displacement. Different parameters of elastic cables are employed to compare and analyze the bridge response results in terms of the internal forces of the tower bottom and displacement of the girder end. The analysis results showed that the reasonable stiffness of elastic cables can obviously decrease the displacement of girder end, the top displacement of towers and the relative displacement between the middle tower and main girder. Meanwhile, it also can decrease the internal forces of the side tower bottom, but slightly increase the internal forces of the middle tower bottom. Elastic cables are intro- duced mainly to provide structural system with elastic stiffness other than energy dissipation. Distribu- tion inertial forces of the structural system are more reasonable by changing the transform path of iner- tia forces.