摘要
为研究城市轻轨预应力钢-混凝土组合梁在长期荷载作用下的受力性能,按照截面刚度和应力相似的原则,设计4根钢-混凝土组合梁模型,进行为期2年的堆载试验,重点考察持续荷载下有效预应力大小和混凝土种类对组合梁跨中变形和截面应力的影响。结果表明:预应力钢-混凝土组合梁的下挠随时间不断增加,但增加的速率有所减缓;在2年持续荷载作用下,PCB-1～PCB-3和CB-1的附加变形分别为3.910mm、3.667mm、2.456mm和4.370mm,可见施加预应力对组合梁的附加跨中变形有较大的影响,且有效预应力越大,附加跨中变形越小,采用高性能混凝土可以明显减小组合梁的附加跨中变形。最后,对城市轻轨预应力钢-混凝土组合梁长期变形的计算方法进行探讨。
Abstract： Based on the equivalent principle of stress and cross-section stiffness, 4 model steel-concrete composite beams for urban light rails were designed and the long-term behaviors were tested under sustained loads of two years to study their long-term load-bearing performance. The research primarily focuses on the stress and deflection at mid-span sections of composite beams with different effective stress and concrete types. The test results show that the deflection of composite beams for urban light rails increased continuously at sustained loads for two years with the rate decreasing. The additional deflections of the PCB-I, PCB-2, PCB-3 and CB-I were 3. 910ram, 3. 667mm, 2. 456mm and 4. 370ram, respectively. It indicated that the additional deflection decreased in higher effective prestressing and high performance concrete used for the concrete slabs. In the end, the calculation methods for long-term deflection of prestressed steel- concrete composite beams for urban light rails are discussed.
出处
《土木工程学报》
EI
CSCD
北大核心
2013年第3期110-118,共9页
China Civil Engineering Journal
基金
国家自然科学基金(50978193)
交通部西部交通建设科技项目(200631882244)
建设部科技项目(2008-K2-21)
上海市科学技术委员会科研计划项目课题(09231200400)
关键词
城市轻轨预应力钢-混凝土组合梁
长期性能
持续荷载试验
跨中变形
计算方法
Keywords： prestressed steel-concrete composite beam for urban light rail
long-term behavior
experiment undersustained load
deflection at mid-span
calculation method
