摘要
旧建筑改造有时需要在钢筋混凝土梁上开洞穿过管道.本文通过8根腹板开洞钢筋混凝土梁的弯曲试验,对大洞口引起的梁抗剪性能削弱展开研究,以此为开洞梁的体外加固研究奠定基础.研究结果发现,开洞梁的原有桁架抗剪机制受到破坏,抗剪承载力严重降低.洞口上肢承受偏压作用,下肢承受偏拉作用,上、下肢中部均存在反弯点,独立传递剪切荷载.开洞长度越大,此效应越显著.抗剪削弱对洞口高度最敏感,洞口长度次之.多洞口开洞位置靠近时,受力模式较为复杂,中间联系部分作用不可忽略.开洞位置沿梁高方向和梁跨方向偏移均对其受力有影响,但并不显著,加固设计时可针对受力特点针对性的采取措施.
Web openings in reinforced concrete beams occur often in renovation of old buildings to provide a convenient passage for utility ducts. In this work,eight concrete beams with web openings are tested in flexure to investigate the consequent shear weakening,which lays a foundation for further research on external strengthening techniques. Based on the test results,the truss mechanism of shear resistance is damaged greatly by large web opening,and shear capacity of the beams are reduced remarkably. The upper chord member is subjected to eccentric compression,while the lower chord member is subjected to eccentric tension. Both the members have inflection points around the middle point and carry shear loads independently. The longer the opening is,the more distingwished this effect is. The shear weakening is most sensitive to the height of opening followed by the length. Multiple adjacent openings result in complicated load-carrying pattern,and the contribution of intermediate concrete between the openings can not be ignored. Minor influence is observed as the position of opening moves either along beam span or along the beam depth,thus specific measures should be taken in accordance with opening configuration.
出处
《烟台大学学报（自然科学与工程版）》
CAS
2016年第3期210-215,共6页
Journal of Yantai University(Natural Science and Engineering Edition)
基金
山东省自然科学基金资助项目(ZR2013EEQ018)
关键词
钢筋混凝土梁
腹板开洞
抗剪
受弯试验
reinforced concrete beam
web opening
shear resistance
flexural test
