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Drucker-Prager(以下简称D-P)屈服准则因其形式简单、物理意义明确而得到广泛的应用,然而经过多年的应用和研究,其缺点逐渐显现出来,如拉剪区偏大、不具有应力角效应等,针对这些不足,提出了修正的D-P屈服准则。在拉剪区用圆球面和横截面的组合方式代替原来的圆锥面,从而不改变D-P屈服准则压剪区的形式,在考虑岩石实际的拉伸强度的同时,也满足该屈服准则经过单轴抗拉强度点的条件;为考虑岩石在三轴压缩和三轴拉伸状态下不同的强度特性,即应力角效应,引入了一种角隅模型;为保证屈服准则始终通过岩石的单轴抗压强度点,建议了一种材料参数k值的取值方法。为验证屈服准则修正后的适用性和正确性,将修正屈服准则与真三轴试验结果进行了拟合,同时与Mohr-Coulomb(以下简称M-C)准则进行对比,结果表明,修正屈服准则可以很好地描述试验现象,且比M-C准则更接近真实结果。
Drucker-Prager (hereinafter referred to as DP) yield criterion has been widely used due to its simple form and clear physical meaning. However, after many years of application and research, its disadvantages have gradually emerged. For example, the tensile shear zone is too large and does not have stress angle effect For these shortcomings, a modified DP yield criterion is proposed. In the shear zone, the combination of the spherical surface and the cross section is used instead of the original conical surface so as to not change the form of the compression yield zone of the DP yield criterion. While considering the actual tensile strength of the rock, the yield criterion is also satisfied. In order to consider the different strength characteristics of rock under triaxial compression and triaxial tension, that is, stress angle effect, a corner model is introduced. In order to ensure that the yield criterion always passes through the rock’s uniaxial resistance Pressure intensity point, proposed a value of k material value of the method of value. In order to verify the applicability and correctness of the revised yield criterion, the revised yield criterion was fitted with the true triaxial test results and compared with the Mohr-Coulomb (MC) criterion. The results show that the modified yield criterion can be very good Describe the test well, and closer to the true result than the MC criterion.