Abstract: 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.

Key words: loess, overhead structure of skeleton particle, consolidation tests, microscopic structure, discontinuous deformation analysis