| 基于离散元方法的根土复合体冻融损伤数值模拟研究 |
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| 引用本文： | 孙渊,李辉,陈智峰,董建鹏,王亚伟.基于离散元方法的根土复合体冻融损伤数值模拟研究[J].科学技术与工程,2023,23(16):7025-7032. |
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| 作者姓名： | 孙渊 李辉 陈智峰 董建鹏 王亚伟 |
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| 作者单位： | 青海大学 土木工程学院 |
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| 基金项目： | 青海省科技厅项目(2020-ZJ-718) |
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| 摘 要： | 为探究在冻融环境条件影响下根系对边坡稳定性所发挥的积极效应，基于离散元方法对冻融循环作用下根土复合体的力学特性进行研究。利用PFC软件，提出一种新的冻融损伤模拟方法，对黄土进行不同冻融循环次数下的模拟。利用此方法，黄土在不同循环次数下无侧限抗压强度的模拟结果和试验结果较为吻合，证明了此方法的可行性。之后建立根系模型，模拟根土复合体的UU三轴试验，并对根土复合体的数值模型进行参数标定。进一步探究根系角度对根土复合体强度的影响效应，并对不同冻融循环次数下根土复合体的强度特性进行数值模拟研究。结果表明：所提出的冻融损伤模拟方法可以较好地模拟黄土在冻融循环作用下的劣化效应；根系的存在会提高土体的强度特性，在相同的冻融循环次数下，根土复合体的强度均高于素土，并且根土复合体的强度会随着冻融循环次数的增加先下降后趋于平缓；当根系倾角为90°时，对土体的强度提高效应最大，并且在冻融循环作用下，强度下降较低。当根系倾角为0°时，对土体的强度提高最小。研究成果为从细观角度探究根土复合体的冻融损伤机理提供了新途径，并且可为寒区生态边坡工程建设提供指导意义。
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| 关 键 词： | 离散元 根土复合体 冻融循环 PFC |
| 收稿时间： | 2022/7/9 0:00:00 |
| 修稿时间： | 2023/3/9 0:00:00 |
Numerical simulation of freeze-thaw damage of root-soil composite based on discrete element method |
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| Sun Yuan,Li Hui,Cheng Zhifeng,Dong Jianpeng,Wang Yawei.Numerical simulation of freeze-thaw damage of root-soil composite based on discrete element method[J].Science Technology and Engineering,2023,23(16):7025-7032. |
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| Authors: | Sun Yuan Li Hui Cheng Zhifeng Dong Jianpeng Wang Yawei |
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| Affiliation: | Qinhai University |
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| Abstract: | Based on the discrete element method, a new simulation method of freeze-thaw damage is proposed to simulate the PFC of loess under different freeze-thaw cycles. Using this method, the simulation results of unconfined compressive strength of loess under different cycles are similar to the experimental results, which proves the feasibility of this method. Then, a root system model is established to simulate the UU triaxial test of the root-soil composite.The parameters of the numerical model of the root-soil composite were calibrated. The effect of root angle on the shear strength of root-soil composite was further explored, and the strength characteristics of root-soil composite under different freeze-thaw cycles were numerically simulated. The results show that:(1) The proposed simulation method of freeze-thaw damage can well simulate the deterioration effect of loess under freeze-thaw cycles. (2) The existence of roots can improve the shear strength of soil. Under the same number of freeze-thaw cycles, the shear strength of root-soil composite was higher than that of plain soil, and the shear strength of root-soil composite decreased first and then tended to be flat with the increase of freeze-thaw cycles.(3) When the root inclination angle is 30 degrees, the effect of soil strength improvement is the largest. When the root inclination angle is 60 degrees, the improvement of soil strength is the smallest. However, when the root inclination angle is 60 degrees, the influence of freeze-thaw cycles on the shear strength of root-soil composite is the smallest. The results provide a new way to explore the mechanism of freeze-thaw damage of root-soil composite from the microscopic point of view.It can also provide guidance for the construction of ecological slope engineering in cold regions. |
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