三塔悬索桥适应性及主缆抗滑移技术探讨

Study of Adaptability and Main Cable Slip Resistance Technique of Three-Tower Suspension Bridge

以泰州长江公路大桥等3座悬索桥为背景,分析三塔悬索桥的适应性,并对该桥式的中塔选型、主缆与鞍槽间的抗滑移安全系数及整体刚度的取值进行研究。研究表明:三塔悬索桥得以实施的技术突破关键是中塔采用合理的纵向抗弯刚度;主缆与鞍槽间的摩擦系数取0.20较为合适,建议主缆与鞍槽之间的抗滑移安全系数不小于1.65;泰州长江公路大桥在不计冲击力的汽车荷载作用下,加劲梁最大竖向挠度为4.337 m(向下),挠跨比为1/249,取用该挠跨比是对悬索桥整体刚度的尝试与实践;该桥主缆与鞍槽间摩擦系数若取用0.2,可进一步提高桥梁的总体刚度。

Three suspension bridges including Taizhou Changjiang River Highway Bridge are cited as examples.The adaptability of the three-tower suspension bridge is analyzed and the type selection of the intermediate tower,slip resistance safety coefficients between main cables and saddle troughs and global rigidity value of the bridge are studied.The results of the study reveal that the key to the technical breakthrough of applying the three-tower suspension bridge is the determination of rational longitudinal bending rigidity of the intermediate tower,the friction coefficient of 0.20 to be adopted between the main cables and saddle troughs is appropriate and it is proposed that the slip resistance safety coefficients between the cables and troughs should not be less than 1.65.As for the Taizhou Changjiang River Highway Bridge,the maximum vertical deflection of its stiffening girder due to the vehicle load that does not take into account of impact is 4.337 m（downward）,the deflection-to-span ratio is 1/249 and the selected deflection-to-span ratio is a trial and practice of the global rigidity of the three-tower suspension bridge.If the friction coefficient of the Taizhou Bridge is taken as 0.2,the global rigidity can be further enhanced.