混凝土板及基础抗冲切设计计算截面的取法  

Control Section for Calculation of Punching Resistance in Concrete Slabs and Footings

作　　者：周朝阳[1] 张赛赛[1] 刘澍[1] 

机构地区：[1]中南大学土木建筑学院,湖南长沙410075

出　　处：《中南大学学报（自然科学版）》2005年第1期144-148,共5页Journal of Central South University:Science and Technology

基　　金：湖南省自然科学基金资助项目(97JJY2035);湖南省建设科技计划项目(9701-005)

摘　　要：阐释了混凝土板及基础抗冲切设计中计算截面的物理含义;基于现有试验资料,对中、美、加、澳、新、英、德、日等国主要规范以及CEB MC90和EC2等国际标准的取法从研究历史、力学机理和拟合精度等方面进行分析和讨论,提出了评价方法,指出了存在的问题。研究结果表明:平板的冲切抗力计算截面以离柱边 h0 处为最佳,而对柱下独立基础,该截面以距柱边0.5h0 处较为适宜;中、美等国规范取计算周长形状与柱周长相似,其计算结果与试验结果不符。考虑到柱截面形状对抗冲切能力的影响,提出了按面积相等和周长相等的折中方案在矩形柱和圆柱之间进行等效代换的做法,改进和完善了现行规范的抗冲切设计方法。The physical implication of control section for calculation of punching resistance in reinforced concrete slabs and footings was expounded. Based on the existing test data, the definitions by various codes at home and abroad such as CEB MC90 and EC2 are evaluated and discussed from the viewpoints of history, mechanics and accuracy. Meanwhile, the methodology of evaluation was proposed and the defects in those definitions were pointed out. The results show that the control perimeter h0 away from the periphery of column is the best choice for punching capacity prediction of flat plates and 0.5 h0 is appropriate for that of column footings. The Chinese and American codes take the control perimeter affine in shape to the circumference of column connected, leading to a tendency reverse to the test fact. In order to account for the shape effect of column section, a rational treatment is suggested which equivalently transforms between cases with circular and rectangular column by averaging between the two expressions of equalizing respectively perimeters and areas of the columns with different shapes. These conclusions are helpful for improvement of current code approaches to punching shear design.

关 键 词：冲切 计算截面 无梁楼盖 柱下基础 

分 类 号：TU375[建筑科学—结构工程]