黄土单向固结试验微观非连续变形分析

摘要

Mechanical behavior of loess is controlled by overhead structure of skeleton particle, and microstructure of loess could reveal its mechanical behavior by Discontinuous Deformation Analysis(DDA).In order to simulate the characteristics of consolidation of microscopic loess, we carried out test on undisturbed L5(Q2) loess specimens from southern Jingyang plateau of Shaanxi province, and measured the physical and mechanical parameters of loess.Then we obtained microstructure image and particle morphology of the specimens by using optical microscope and image processing software.On this basis, we established soil microstructure model and simulated the compression deformation under load of 1.0, 12.5, 25.0, 50.0, 100.0, 200.0, 100.0 kPa, respectively.Finally, we obtained microstructure image and compression curve of the model in the compression process, which are close to the results of indoor test.Results show that DDA is feasible for simulating the characteristics of the microscopic deformation of loess and this paper provides an idea for analyzing the microscopic physical and mechanical properties of loess.%黄土骨架颗粒的架空结构体系控制着其主要力学行为,应用非连续变形分析方法可从微观揭示其力学行为的本质.采取陕西省泾阳南塬的L5(Q2)黄土原状样,进行各种土力学试验,测定其物理力学性质参数;采用光学显微镜和图像处理软件得到土样的微观结构图像,描绘颗粒形态,建立该土样的非连续变形分析微观结构模型,并模拟了土样在1.0,12.5,25.0,50.0,100.0,200.0,400.0 kPa荷载作用下的压缩变形.结果得到:土样在压缩过程中,微观结构变化图像及压缩曲线和室内固结试验结果较为接近,说明采用非连续变形分析方法模拟黄土的微观变形特性是可行的.研究结果为分析黄土的微观物理力学性质提供了一种思路.