基于ANSYS平台,建立3至6塔主跨跨径为1 400m的多塔悬索桥有限元计算模型,研究索塔数对多塔悬索桥静力特性、动力特性和静力稳定性的影响特点,探讨其对多塔悬索桥活载挠度、塔顶纵向位移及主缆抗滑移性能等关键力学问题的影响特征.结果表明:索塔数由3塔增至6塔时,塔根弯矩最大增大240%,主梁弯矩最大增大18%,主缆抗滑移系数最大减小11%,中间塔顶位移减小2%,一阶弹性稳定系数最大下降6.8%,颤振稳定性指数最大增加8.5%;主梁边跨竖向挠度比中间跨小40%左右,且中间跨挠度相近;索塔数对中间索塔受力影响显著.
Finite element computation models were established on the basis of ANSYS platform for multi- tower suspension bridges with 3- to 6-tower and 1 400 m main span. The characteristics of influence of tower quantity on static property, dynamic property and static stability of multi-tower bridge was investi- gated and the characteristics of influence of tower quantity on the key mechanic problems, such as live load deflection of the bridge, longitudinal displacement of towner top, anti-slide performance of main cable were explored. The analysis result showed that, when the tower quantity increased from 3 to 6, the bend moment of tower bottom would increase by 240% at most, the bend moment of beam would increase 18~/6 at most, the anti-slide factor of main cable would decrease 11% at most, the longitudinal displacement of middle tower would decrease 2%, first-order instability factor would decrease by 6.8% at most, flutter stability index would increase by 8. 5% at most. The vertical deflection of main beams of middle spans would be approximately equal to each other and larger than that of side spans by about 40%. Tower quan- tity would significant effect on the force on the middle towers.