自锚式悬索桥施工控制中的力学特性

研究了自锚式悬索桥施工控制过程中的力学特性,提出并论证了主缆位移的弱相干性原理和吊杆力的相邻影响原理,即张拉吊杆对非张拉点主缆的位移影响很小,可以忽略;对相邻吊杆内力的影响较大,而对于远处吊杆的内力影响较小。当吊杆通过接长杆锚固在加劲梁上,并在加劲梁被张拉离开支架前这两个原理都是适用的。将这两个原理应用于浙江金华康济桥的施工控制中,仅通过3轮张拉吊杆就顺利地实现了体系转换,使主缆的线形、加劲梁的线形、索鞍的顶推量和吊杆力都达到了设计要求。文章所述原理和方法对自锚式悬索桥的施工控制具有普遍的指导意义。

Mechanical Properties of Self-anchored Suspension Bridges in Construction Control

Mechanical properties of self-anchored suspension bridges in construction control were studied in this paper.Weak interference principle of main cable displacements and near influence principle of hanger force are proposed and proved.These principles mean that tensioning a hanger may bring about very small displacements of other hangers,but may change the inner force of near hangers greater than other hangers further away from it.The principles are correct when all the hangers are fastened to the stiffening girder by assistant hangers before the girder was tensioned away from the falsework.The principles were applied in the construction control of Kangji Bridge,so that system transformation was completed only by three times of tensioning.It is easy to meet the demand of designers for the configuration of main cables,profile of stiffening girders,displacements of saddles and hangers force.Principles and methods discussed in this paper can be guidance for the construction control of self-anchored suspension bridges universally.