关键词: 堆石料大量的大型三轴剪切试验结果表明, 其轴向应变与径向应变关系并不完全符合双曲线关系, 而是可以分成两段, 依次用双曲线关系和直线关系来拟合, 提出了一个计算两段关系拐点处径向应变的公式, 对Duncan-Chang模型中泊松比的计算进行了修正。根据堆石料应力-应变关系试验结果, 提出了一个用8参数拟合其应力-应变关系和体变关系的拟合方法, 并将通过此方法得到的计算结果与试验结果进行对比, 验证了拟合方法的精度。

Abstract:

Many large-scale shear experiments show the whole relationship between the axial strain and the radial strain of rockfills is not of hyperbola as Duncan-Chang model presumed. According to the test result, the above curve can be divided into two parts, depicted by the hyperbola and the line in turn. Moreover, an equation used to calculate the radial strain of the inflexion with the confining pressure is proposed. Then the computation of Poisson’s ratio in Duncan-Chang model is modified. Analysing the characteristics of experiment results, a fitting method using eight parameters to model the stress-strain and the volumetric strain curves is established. And by comparing the calculated results from this method and Duncan-Chang model with those original test data, the precision of proposed fitting method is validated.

Key words: fitting, hyperbola, inflexion, stress, strain