模拟岩质边坡条件下11种护坡植物单根抗拉特性研究

Study on single root tensile properties of 11 kinds of slope protection plants under simulated rock slope conditions

摘要:

【目的】 筛选岩质坡面条件下具备优良单根抗拉性能的植物，为植被修复中植物种类选择及配置提供基础力学数据。【方法】 模拟45°岩质边坡条件，以11种常用护坡植物（沙打旺、紫花苜蓿、胡枝子、马棘、紫穗槐、柠条、荆条、盐肤木、欧李、黄刺玫、酸枣）为研究对象，通过拉拔试验结合单因素方差分析探究11种护坡植物单根抗拉特性种间差异，通过回归分析得出植物根系抗拉特性指标与根径的相关关系。【结果】 1）11种植物单根平均抗拉力表现为：荆条＞酸枣＞柠条＞马棘＞紫花苜蓿＞紫穗槐 ＞黄刺玫＞胡枝子＞欧李＞沙打旺＞盐肤木；单根平均抗拉强度表现为：荆条＞柠条＞马棘＞紫穗槐 ＞黄刺玫＞紫花苜蓿＞酸枣＞欧李＞沙打旺＞胡枝子＞盐肤木；单根平均极限延伸率表现为：紫穗槐 ＞欧李＞柠条＞马棘＞荆条＞紫花苜蓿＞酸枣＞沙打旺＞胡枝子＞黄刺玫＞盐肤木。4个径级的比较中，柠条在径级Ⅰ和Ⅱ与荆条在径级Ⅲ和Ⅳ的单根抗拉力、抗拉强度与极限延伸率表现均较高，盐肤木单根抗拉力、抗拉强度与极限延伸率均较小。2）11种植物单根抗拉力与根径均呈正相关的幂函数关系；抗拉强度方面，胡枝子与盐肤木根系抗拉强度与根径呈负相关的指数函数关系，除荆条与酸枣无显著相关关系，其余植物表现为负相关的幂函数关系；极限延伸率方面：欧李、荆条与酸枣拟合曲线为负相关的幂函数，黄刺玫、柠条与紫花苜蓿呈正相关指数函数关系，其余5种植物无明显的函数关系。 【结论】 在岩质坡面的立地条件下，综合具备高单根抗拉力、抗拉强度与极限延伸率的荆条与柠条为护坡最优选择植物。

Abstract:

【Objective】 The purpose of this experiment is to screen out plants with excellent single root tensile properties under rock slope conditions，and to provide a theoretical basis for the selection and configuration of plant species in vegetation restoration.【Method】 In order to provide a theoretical basis for slope vegetation restoration，the 45°slope was simulated，and 11 kinds of commonly used ecological restoration plants（Astragalus adsurgens，Medi- cago Sativa，Lespedeza bicolor，Indigofera pseudotinctoria，Amorpha fruticosa，Caragana korshinskii，Vitex ne- gundo，Rhus chinensis，Cerasus humilis，Rosa xanthina，Ziziphus jujuba）were selected through data query and investigation as the research objects to explore their single root mechanical properties. The difference of single root tensile properties of 11 kinds of slope protection plants was explored by pull-out test combined with one-way analysis of variance. The correlation between root tensile strength，root elongation and root diameter was analyzed by regression analysis.【Result】 1）The order of average tensile force of single root of 11 plants was as follows：Vitex negundo＞ Ziziphus jujuba＞Caragana korshinskii＞Echinops latifolia＞Medicago sativa＞Amorpha fruticosa＞Rosa xanthina ＞Lespedeza bicolor＞Cerasus humilis＞Astragalus adsurgens＞Rhus chinensis. The order of average tensile strength of single root was as follows：Vitex negundo＞Caragana korshinskii＞Echinops latifolia＞Amorpha fruticosa＞Rosa xanthina＞Medicago sativa＞Zizyphus jujuba＞Cerasus humilis＞Astragalus adsurgens＞Lespedeza bicolor＞Rhus chinensis. The order of average ultimate elongation of single root was as follows：Amorpha fruticosa＞Cerasus humilis ＞Caragana korshinskii＞Echinops＞Vitex negundo＞Medicago sativa＞Zizyphus jujuba＞Astragalus adsurgens＞ Lespedeza bicolor＞Rosa xanthina＞Rhus chinensis. In the comparison of the four diameter classes，the single root tensile force，tensile strength and ultimate elongation of Caragana korshinskii in diameter classes I and II and Vitex negundo in diameter classes III and IV were higher，and the single root tensile force，tensile strength and ultimate elongation of Rhus chinensis were smaller；2）There was a positive correlation power function relationship between the single root tensile force and root diameter of 11 plants. Except that there was no significant correlation between root tensile strength and root diameter of Vitex negundo and Ziziphus jujuba（P＞0. 05），the root tensile strength of Lespedeza bicolor and Rhus chinensis decreased exponentially with the increase of root diameter，and the correlation between root tensile strength and root diameter of other plants showed a negative correlation power function. In terms of ultimate elongation：The fitting curves of Cerasus humilis，Vitex negundo and Zizyphus jujubawere negatively correlated power functions. The ultimate elongation of Rosa xanthina，Caragana korshinskii and Medicago sativa roots was positively correlated exponential function distribution. There was no obvious functional relationship between the ultimate elongation and root diameter of Lespedeza bicolor，Rhus chinensis，Hippophae rhamnoides，Amorpha fruti- cosa and Astragalus adsurgens.【Conclusion】 Under the site conditions of rock slope，Vitex negundo and Caragana korshinskii with high single root tensile force，tensile strength and ultimate elongation are the optimal selection plants for slope protection，and Rhus chinensis is not recommended.