【作者】 李阳； 许见超； 郭全全； 陈圣刚； 叶英华；

【Author】 LI Yang;XU Jian-chao;GUO Quan-quan;CHEN Sheng-gang;YE Ying-hua;Department of Civil Engineering,Beihang University;State Key Laboratory of Subtropical Building Science,South China University of Technology;

【机构】 北京航空航天大学土木工程系； 华南理工大学亚热带建筑科学国家重点实验室；

【摘要】 混凝土U型薄壁梁在城市轨道高架桥中应用日益广泛,而其受扭性能研究相对滞后。本文基于Vlasov开口薄壁构件扭转理论和初参数法,分析了边界约束条件和跨高比对U型薄壁梁纯扭性能的影响。分析发现,两端固支与两端简支U型薄壁梁最大内力出现的位置和大小差异很大,在常用跨高比范围内,两端简支梁的最大翘曲弯矩和最大自由扭矩均大于两端固支梁,工程设计中应予以关注。U型薄壁梁只在约束影响长度范围内产生翘曲弯矩和翘曲扭矩,随着跨高比增加,固支和简支U型薄壁梁最大翘曲弯矩逐渐增加并趋于定值,最大自由扭矩增加并趋于总扭矩。另外,本文分析计算了开裂荷载,混凝土U型薄壁纯扭构件在常用跨高比范围内,先出现弯曲裂缝,后出现剪切裂缝。计算的弯曲和剪切开裂扭矩与本项目组完成的U型梁试验结果吻合较好。更多还原

【Abstract】 U-shaped thin-walled RC beams are widely applied in urban railway transit in China, but research reference related to the torsional response of U-shaped beams is extremely rare. By using the Theory of Vlasov and initial parameter method, this paper analyses torsional response of the beams with different boundary constraint conditions and different span-to-height ratio. The place and quantity of maximum internal force of simply supported beams and clamped beams are totally different, the maximum warping moment and maximum circulatory torsion of simply supported beams are larger than clamped beams in common used span-to-height ratio, which should be noticed in using. Warping moment and warping torsion only appear in a certain influential range. With the increase of span-to-height ratio, the maximum warping moment will increase and tend to constant and the maximum circulatory torsion will also increase and tend to total torque. The cracking torques are also calculated in this paper, the flexural cracking appears early and the web shear cracking appears later in common used span-to-height ratio. The calculation results agree with the experimental results.更多还原