非线性理论在土体结构性研究中的应用

The application of nonlinear theory in the soil constitutive

【目的】分析可变性和可稳性在土体结构性演化过程中发挥的作用。【方法】运用分岔理论构建可变性和可稳性引发应变的演化模型,并对陕西省杨凌地区土样进行侧限压缩试验,分别测试原状土、饱和土和重塑土的应变曲线,计算杨凌地区黄土平衡态迁移过程。【结果】土体结构性系统共有4种平衡态;陕西杨凌黄土土体结构性系统平衡态迁移过程表现为,随着荷载的增大,系统以非周期的曲线或直线运动的形式远离平衡态A,由于可稳性和可变性之间的竞争力存在悬殊,且可变性具有较强的竞争力,系统远离平衡态D和C,最终向平衡态B演化。【结论】可变性和可稳性之间竞争力的强弱决定土体结构性演化过程的走势。

【Objective】 This paper analysed the variability and stability in the soil constitutive evolution processes.【Method】 Using bifurcation theory,the research constructed variability causing strain and stability causing strain evolution model.Based on the compression test of loess samples from Yangling region of Shaanxi province,the paper tested intact specimen,saturation specimen and remolding specimen strain curve separately,and calculated Yangling loess equilibrium migration process.【Result】 The soil structural system has four kinds of equilibrium.The equilibrium migration process of Yangling loess is of non-cycle curve or linear motion far away from equilibrium A.As there exists great gap between the competitiveness of stability and variability,and variability has strong competitiveness,the system is far away from equilibrium D and C,and finally evolves to the equilibrium B.【Conclusion】 The final state of the soil constitutive evolution depends on the strength of the competition between variability and stability.