论文部分内容阅读
以土的临界状态和边界面塑性理论为基础,引入状态参数,考虑砂土的剪胀特性,提出一个新型三维多重机构边界面模型。模型将复杂的宏观变形行为分解为一个宏观体应变机构和一系列空间分布的虚拟一维微观剪切机构。每个微观剪切机构包含一个微观剪应力–应变关系和一个微观应力–剪胀关系。利用三轴压缩试验中的应力条件,建立典型宏微观参数之间的关系。模型包含13个参数,多数可通过具有明确物理意义的土性参数来确定。通过对砂土三轴压缩试验和空心圆柱扭剪试验结果的数值模拟,表明模型不但能够合理反映在排水或不排水条件下砂土的硬化及软化特性,而且能在不增加任何参数条件下预测应力主轴旋转产生的变形累积特性和应变增量主轴与应力主轴之间的非共轴特性。
Based on the critical state of soil and the plastic theory of boundary surface, the state parameters are introduced, and the dilatancy characteristics of sand are considered. A new interface model of three-dimensional multi-mechanism is proposed. The model decomposes the complex macroscopic deformation behavior into a macroscopic body strain mechanism and a series of spatially distributed virtual one-dimensional microscopic shear mechanism. Each micro-shear mechanism contains a micro-shear stress-strain relationship and a micro-stress-dilatancy relationship. Using the stress conditions in triaxial compression tests, the relationship between typical macro and micro parameters was established. The model contains 13 parameters, most of which can be determined by the soil parameters with a clear physical meaning. Through the numerical simulation of sand triaxial compression test and hollow cylinder torsional shear test, it shows that the model not only can reasonably reflect the hardening and softening characteristics of sand under drainage or undrained conditions, but also can predict without adding any parameters Deformation accumulation characteristics caused by stress spindle rotation and non-coaxial characteristics between stress increment principal axis and stress spindle.