短时冻区残积土细观破坏过程的离散元模拟

为明确短时冻区残积土体细观破坏规律,以福建省短时冻区典型残积土为例,基于三轴试验数据对不同短时冻融次数下残积土的细观参数进行标定,同时分析围压及冻融次数下残积土细观破坏过程.结果表明:残积土在压缩过程中,逐步呈现出一个菱形区域,最终菱形区域会形成一个剪切面.残积土压缩时破坏过程可分为弹性变形阶段、塑性发展与强度峰值阶段以及峰后破坏三个阶段.残积土的稳定性会因土体周围围压的上升和土体冻融次数的减少而提高,同样也会增加残积土的抗剪强度.

Discrete element simulation of meso failure process of residual soil in short time frozen zone

Taking the typical residual soil in the short freeze area of Fujian Province as an example, this paper is based on the three axis experimental data for the calibration of the microscopic parameters of the residual soil under different short freezing and thawing times, and the analysis of the meso damage process of the residual soil under the confining pressure and the freezing thawing times in order to clarify the failure law of the residual soil in the short freeze area. The results show that the initial stage of residual soil compression is mainly vertical deformation, and later compression is mainly transverse displacement, which gradually presents a rhombic region, and eventually a shear plane will be formed in the rhombic region.The failure process of residual soil under compression can be divided into three stages: elastic deformation stage, plastic development stage and peak strength stage, and post-peak failure stage.With the increase of confining pressure, it is found that there is an obvious shear band in the rhombic soil particles.The stability of residual soil will be improved by the increase of confining pressure around the soil and the decrease of freeze-thaw times, as well as the shear strength of residual soil.