顶板横向预应力钢束对箱梁横向计算结果的影响

Effect of Lateral Prestressing Tendon in Top Deck on Lateral Calculation Result of Box Beam

研究目的:研究顶板横向预应力钢束对箱梁横向计算结果的影响,给箱梁结构设计提供借鉴和帮助。研究方法:以达成线唐家渡涪江双线特大桥和襄渝线三汇镇渠江三线特大桥预应力混凝土连续箱梁为例,采用M IDAS进行箱梁横向分析计算。研究结果:通过实例分析计算得出,当顶板设置横向预应力钢束时,梁体弯矩方面:顶板、腹板顶部弯矩均明显减小,底板弯矩稍有增大;梁体应力方面:顶板处于受压状态,不出现拉应力,底板拉应力稍有增大。研究结论:合理设置顶板横向预应力钢束是非常有利的。但如果顶板横向宽度不大,且顶板结构高度不受限制时,则不必设置顶板横向预应力钢束。

Research purposes： This paper analyzes the effect of the lateral prestressing tendon in top deck on the lateral calculation result of box beam. It provides certain reference and help to structure design of box beam. Research methods：Taking the Tangjiadu - Fujiang Double - track Railway Bridge in Dazhou - Chengdu Railway and Sanbuizhen-Qujiang Tnline Railway Super Majon Bridge in Xiangfan- Chongqing Railway fo example, this paper researches the lateral analysis and calculation of box beam by using MIDAS. Research results：Through analysis of the examples, this paper provides the results that when the lateral prestressing tendon is set in top deck, the moments of top deck and the top of web would reduce obviously, while the moment of bottom slab would increase slightly, the top deck would be in compression and the tension stress of bottom slap would increase slightly. Research conclusions：This paper concludes that it is beneficial to set the lateral prestressing tendon rationally in top deck. But if the lateral width of the top deck is not too wide and the height of the top deck is not restricted, the lateral prestressing tendon in top deck need not be set.