摘要
为研究中柱失效后体外预应力钢筋混凝土框架抗连续倒塌性能,设计制作了五榀1/3缩尺单层双跨体外预应力钢筋混凝土框架,通过变换边界条件、体外预应力筋布置形式等参数,开展了体外预应力钢筋混凝土框架受力性能、机制转换、极限承载力及悬链效应的分析研究,测试了荷载、位移、应变、裂缝的发生以及发展状况等。基于试验结果建立了有限元分析模型,对比分析了有限元结果与试验结果。结果表明:体外预应力加固能明显改善框架抗裂性能,在具有可靠的梁端水平约束前提下,框架梁机制下的极限倒塌抗力最大提升70%,悬链机制下的极限倒塌抗力取决于体外索的屈服强度和极限强度;折线布筋形式较水平布筋能提供更大的竖向倒塌抗力,加速机制转换;增加束高及张拉应力值可提升框架梁机制下的极限倒塌抗力;合理的有限元模型能够较为准确的预估框架梁机制下的抗力峰值、机制转换节点及悬链机制下的抗力峰值。
In order to study anti-collapse performance of a RC frame with external pre-stressed tendons after failure of middle column,five 1/3 scale single-story two-span RC frames with external pre-stressed tendons were designed and fabricated.Tests for these RC frame’s mechanical performance,mechanism transformation,ultimate load-bearing capacity and catenary effect were conducted through changing boundary conditions and layout forms of external pre-stressed tendons after failure of middle column.Their loads,displacements,strains,and cracks’initiation and expansion were measured.On the basis of test results,the finite element analysis model was established.The finite element computation results and test ones were compared.The results showed that external pre-stressed reinforcement can obviously improve anti-cracks performance of RC frames;on the premise of beam ends having reliable horizontal constraints,RC frames’ultimate anti-collapse ability under frame beam mechanism can increase up to 70%,while their ultimate anti-collapse ability under catenary mechanism depends on yield strength and ultimate strength of external cable;compared with horizontal reinforcement form,fold line reinforcement one can provide larger vertical anti-collapse ability,and speed up mechanism transformation;increasing beam height and tensile stress value can improve the ultimate anti-collapse ability under frame beam mechanism;reasonable finite element model can be used to more accurately predict peak resistance under frame beam mechanism,and those under catenary mechanism and mechanism transformation node,respectively.
作者
范云蕾
彭一帆
王杰
FAN Yunlei;PENG Yifan;WANG Jie(College of Civil Engineering,Central South University of Forestry and Technology,Changsha 410000,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2019年第23期203-212,共10页
Journal of Vibration and Shock
基金
国家自然科学基金项目青年科学基金(51308556)
关键词
RC框架抗倒塌
体外预应力筋
预应力
加固
梁机制
悬链机制
anti-collapse of RC frame
external pre-stressed tendons
pre-stressed
reinforcement
beam mechanism
catenary mechanism
