土石粗粒料的强度和变形特性的试验研究

TESTING STUDY ON CHARACTERISTICS OF STRENGTH AND DEFORMATION FOR COARSE MATERIALS

根据大坝应力路径,对粗粒料进行等应力比和等应力比增量等于常数的三轴剪切试验,得出了相应的应力–应变关系式和规律;根据粗粒料的试验强度曲线特征,提出用幂次型函数表述粗粒料的抗剪强度,并以此为屈服准则,结合弹塑性理论建立了粗粒料的弹塑性本构模型,该模型可以用一个统一的表达式表述,该模型概念清晰、模型参数较少;同时推导出粗粒料的弹塑性矩阵;通过试验验证模型计算得到的粗粒料应力–应变关系曲线和实测结果吻合较好。

Based on the stress path of dam, the triaxial tests of coarse materials are carried out with constant ratios of the principal stresses and the stress increments to obtain the corresponding stress-strain relationship of course materials. According to the strength characteristics of coarse materials, a function is determined to describe the yield criterion of coarse materials. Based on this yield criterion and elasto-plastic theory, an elasto-plastic constitutive model for coarse materials is established. It can be expressed in invariants with clear concept, no odd dots and less parameters. In order to apply it to finite element method, the elasto-plastic matrix is deduced. It is shown that the stress-strain relations hip of coarse materials is in good agreement with experimental data.