常规的均匀网格状配筋承台冲切承载力的计算

目前,相比于承台冲切破坏的空间桁架受力机理研究,承台冲切承载力计算的研究尚显薄弱。采用非线性有限元的电算分析,结合逐次多元最小二乘法的数学推导,得出常规的均匀网格状配筋承台冲切承载力的空间桁架理论表达式。通过对76个桩数有异、布桩形式多变,在国内外文献上公开发表的试验数据的验证,以及与ACI318-05规范中的临界截面应力法、美国CRSI手册方法、中国JGJ94—94与GB50007—2002规范方法的对比计算分析表明:所得公式普遍适用于常规的按均匀网格状布筋承台的冲切承载力计算。

Calculation of the punching shear bearing capacity of pile caps with ordinary uniform grid reinforcement

Based on a study on the spatial strut-and-tie bearing mechanism of pile caps,nonlinear finite element analyses are conducted,and combining with a gradual least square method for multiple variables,theoretical formulae are derived for the punching shear bearing capacity of pile caps with ordinary uniform grid reinforcement.Verification study with the published test data of 76 in the literature,including the critical section stress method of the ACI318-05 code,the American CRSI handbook method,the Chinese code JGJ94-94 and GB50007-2002 methods,indicates that the proposed method is suitable for the calculation of the punching shear bearing capacity of pile caps with ordinary uniform grid reinforcement.