忽略黏性项,采用椭圆型角隅函数对Mohr-Coulomb准则进行三维化,建立了适合于无黏性土的三维强度准则,该准则能合理反映峰值内摩擦角随中主应力比的变化特性。以垂直与平行于土体沉积面方向的强度之比引入层状各向异性系数,并根据主应力轴与土体沉积面方向关系修正角隅函数,提出了一个适用于层状各向异性无黏性土的三维强度准则。通过研究其偏平面形状及峰值内摩擦角与中主应力比关系随层状各向异性系数的变化特性,表明该准则描述层状各向异性无黏性土强度的适用性。通过预测两组砂土真三轴试验结果,进一步地证实所提出强度准则的合理性。
By neglecting the cohesion term and using an elliptical shape function,a 3D Mohr-Coulomb strength criterion was proposed to describe the strength of cohesionless soils.The proposed criterion predicts the dependency of the peak friction angle on the intermediate principal stress ratio well.According to the direction of deposition and the major principal stress,a term,which includes a layered-anisotropic parameter representing the ratio of soil strength perpendicular and parallel to the sediment,was added into the shape function,then,a simplified strength criterion for layered-anisotropic cohesionless soils is proposed.The suitability of the criterion was tested by studying the influence of layered-anisotropic parameter on the shape of deviatoric plane and the relationship between the peak friction angle and the intermediate principal stress ratio.By comparing with the experimental results of true triaxial tests on sands,the proposed strength criterion was validated to predict the strength of layered-anisotropic soils.