摘要
无索区长度对独塔斜拉桥结构性能影响显著,钢-混凝土混合梁斜拉桥由于主、边跨刚度和自重集度变化大,无索区长度的选取更加重要。以某独塔混合梁斜拉桥为背景,分析和比较无索区长度对斜拉桥结构刚度、斜拉索索力和主梁内力状态的影响。采用等代梁思路定性分析无索区长度对主梁活载挠度的影响。计算表明,无索区长度约为0.2倍主跨跨径时,斜拉索对主梁支承效率最高。计算分析了无索区长度对斜拉索索力的影响,结果表明无索区长度增加使背索和主跨端部拉索索力有较大增加。从主梁应力状态分布均匀的角度推导了无索区长度限值估算公式,实例验证该公式具有设计指导意义。
The non-cable-stayed length,which is a unique parameter for a cable-stayed bridge with a single pylon,has significant influence on structural behaviors.Based on a cable-stayed bridge,analyses and comparisons have been performed to measure the effects of the non-cable-stayed length on structural rigidity,stress distributions of girder,and cable forces.An equivalent beam method was adopted to analyze the effect of the non-cable-stayed length on the girder deflection.The precise calculation indicates that the girder is most efficiently supported when the non-cable-stayed length equals 0.2 times the length of main span.Results indicate that the augment of the non-cable-stayed length has negative effect on cables at the end of both the side span and the main span.A formula has been derived to estimate the limit length of non-cable-stayed area in terms of stress distribution along the girder.
出处
《结构工程师》
北大核心
2013年第6期44-48,共5页
Structural Engineers
关键词
无索区
独塔
混合梁
斜拉桥
设计
non-cable-stayed area
hybrid girder
single pylon
cable-stayed bridge
design