承台冲切破坏空间桁架理论中两个关键问题的探讨

THE DISCUSSION ON TWO CRITICAL PROBLEMS OF SPATIAL STRUT-AND-TIE THEORY ABOUT PUNCHING FAILURE OF PILE CAPS

为加深对承台冲切破坏空间桁架理论的研究,运用文献资料与作者既有研究成果,分析探讨了该理论中的两个关键问题:斜压杆端截面尺寸的取值与斜压杆强度的确定。结果表明:斜压杆端截面面积应小于桩横截面面积,二维、三维斜压杆强度存在数值大小与公式参变量方向维数上的变化,三维斜压杆强度的参变量应是冲跨比与砼强度。

In order to thoroughly study the spatial strut-and-tie theory on the punching failure of pile caps, two critical problems, value about end cross dimension of strut and calculation on strut strength, have been carried out based on the literatures and the research results from author. The results indicate that the end cross area of strut should be smaller than the cross area of pile, that there are difference on the value and dimension number of formula variables between a two-dimensional strut strength and a three-dimensional strut strength, the formula variables of the three-dimensional strut strength should be the ratio of punching-span and concrete strength.