摘要
斜拉桥作为高次超静定结构,其斜拉索力对梁的应力和变形起着决定性作用。按刚性支承连续梁法或零位移法确定的斜拉索力虽可达到梁内弯矩合理分布,但塔底弯矩往往得不到控制,且要达到这一索力状态,随施工方法不同而应有不同的初始张拉力和体系完成后的二次张拉力。本文提出了以斜拉索用量(索力×索长)最小为目标,任一受力阶段的梁、塔内力或位移满足容许值为约束条件来确定最优初始张拉力、二次张拉力以及恒载索力的方法。并通过计算实例论证了本文方法的正确性,通用性和合理性。
The tensioning force in cable stay has s decisive effect upon the stress and strain of the girder in a cable-stayed bridge. Although an appropriate bending-moment distribution in the girder can be established under the tensioning force in the stays determined by rigid supported continuous beam method or nil-displacement method, the bending-moment at the bottom of the pylon can not be effectively controlled. Moreover, the initial tensioning during a balanced cantilever constuction and the subsequent tensioning after the completion of the structure should have varied with different construction process. In this paper, an optimum procedure to determine the initial and subsequent tensioning of stays and stay forces under dead load is presented. The miminum quantity of stays(force x length of stay)is taken as the objective function and the allowable section forces or displacements of the girder or pylon in any construction process as the constraint conditions. The generality, validity and reasona bleness of the procedure are shown by an example.
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
1990年第1期38-48,共11页
China Journal of Highway and Transport
关键词
斜拉桥
最优索力
应力分析
Cable-stayed bridge Tensioning Optimun tensioning force stays fores under dead load
