基于离散元法的纤维改良黄土力学性能研究

Study on mechanical properties of fiber-modified loess based on discrete element method

为进一步探究纤维对改良黄土力学特性的影响,本文以改良黄土为研究对象,基于离散元方法模拟了改良黄土直剪试验,研究了纤维长度以及纤维掺入比等对纤维改良黄土力学特性的影响。研究结果表明:加入聚丙烯纤维后,纤维改良黄土的粘聚力提升了将近两倍,内摩擦角增加了约10°,说明聚丙烯纤维可以有效提升黄土的物理力学特性。随着纤维掺入比从0.05%增加到0.20%,内摩擦角增加了不足5°,而粘聚力增加了30kPa,说明纤维掺入比对粘聚力有较大的影响。模拟结果还表明,纤维长度对改良黄土的力学性能影响不明显。该研究成果对工程实践中黄土地基承载力不足问题的防治和改善具有指导意义。

To further investigate the effects of fiber on the mechanical properties of the improved loess,the direct shear tests of fiber-modified loess are simulated based on the discrete element method,and the effects of fiber length and fiber incorporation ratio on the mechanical properties of fiber-modified loess are researched.The study results show that the cohesive force of the fiber-modified loess increases nearly twice as much after adding polypropylene fiber,and the internal friction angle increases about 10°.These show that polypropylene fiber can effectively improve mechanical properties of loess.As the fiber incorporation ratio increases from 0.05%to 0.20%,the internal friction angle increases less than 5°and the cohesive force increases 30kPa,which show that the fiber incorporation ratio has a greater influence on the cohesive force.The simulation results also show that the fiber length has no obvious effect on the mechnical properties of loess.The study results are of guiding significance to the improvement of insufficient bearing capacity of loess foundation in engineering practice.