金沙江干热河谷乡土草本植物根系提高土体抗剪强度及其模型预测

发布时间：2018-09-07 06:52

【摘要】：开展金沙江干热河谷乡土草本植物根系提高土体抗剪强度及预测的研究,为该地区生态恢复、边坡防护、水土流失防治等生态工程中植物选择及其固土能力的计算提供依据。采用原位剪切试验测定扭黄茅(Heteropogon contortus)、莎草(Eulaliopsis binata)、芸香草(Cymbopogon distans)、旱茅(Schizachyrium delavayi(Hack.)Bor)等4种乡土草本植物根系及素土的抗剪切强度;用根系拉力计和电子卡尺测定根系的抗拉强度和直径;用Wu和Waldron垂直根模型(WWM)及纤维束根增强模型(FBM)对根系提高土体抗剪能力进行预测。结果表明:1)4种植物根系直径约80%分布在0.1~1 mm的范围内,扭黄茅、莎草、旱茅根系的直径和抗拉强度之间成负幂函数关系,芸香草两者间没有相关性。2)扭黄茅、莎草、旱茅、芸香草的根系可将土体的抗剪强度分别提高20.7%、85.3%、84.4%、16.1%。3)用WWM模型预测扭黄茅、旱茅、莎草的提高土体抗剪能力,其预测值是实测值的3.59~10.83倍;用FBM模型的预测值是实测值的1.24~2.62倍。旱茅、莎草根系提高土体抗剪强度的能力强于扭黄茅和芸香草,在干热河谷的生态工程中可优先选用;对根系提高土体抗剪强度的预测,FBM模型要优于WWM模型。
[Abstract]:The study on improving soil shear strength and prediction of native herbaceous roots in Jinsha River dry-hot valley was carried out to provide basis for plant selection and soil consolidation ability calculation in ecological engineering such as ecological restoration, slope protection, soil erosion control and so on. Heteropogon contortus and Eulaliops were determined by in-situ shear test. The shear strength of roots and plain soils of four native herbs, namely, is binata, Cymbopogon distans and Schizachyrium delavayi (Hack.) Bor, was measured by root tension meter and electronic caliper, and the tensile strength and diameter of roots were measured by Wu and Waldron vertical root model (WWM) and fibrous bundle root enhancement model (FBM). The results showed that: 1) The root diameters of the four plants ranged from 0.1 mm to 1 mm, and there was a negative power function relationship between the root diameters and tensile strength. There was no correlation between them. 7%, 85.3%, 84.4%, 16.1%. 3) WWM model was used to predict the improvement of soil shear resistance, the predicted value was 3.59-10.83 times of the measured value; the predicted value of FBM model was 1.24-2.62 times of the measured value. The FBM model is superior to the WWM model in predicting the soil shear strength.
【作者单位】：云南农业大学水利学院国土资源科学技术工程研究中心;河海大学水利水电学院;云南农业大学农学与生物技术学院;
【基金】：国土资源部国家公益性行业科研专项课题“立体特征突显区域土地整治技术与建设模式研究”(201511003-3)
【分类号】：S157.43

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