植物根系对红粘土边坡的加固效应研究
发布时间：2019-07-01 15:07
【摘要】：用传统的刚性防护措施对红粘土边坡加固存在诸多问题,如结构物易损坏、破坏周边生态环境、阳光照射后眩光等,使用边坡生态防护这种新型防护方法可以有效避免这些问题,它不但能够增强边坡的稳定性,防止滑坡、泥石流等灾害发生,减少水土流失,还能保护、恢复边坡周边的生态环境,改善局部微气候。本文基于植物根系的加筋理论和锚固理论,结合植物根系形态及分布特点,借助室内直剪试验和有限元数值仿真模拟对植物根系加固红粘土边坡的加筋和锚固效应展开分析研究,分析探讨了红粘土在不同含水率情况下抗剪强度随含根量变化的规律,对影响木本植物根系锚固作用的因素进行有限元分析并通过正交试验分析探讨了单根长度、单根距坡底水平距离、单根与水平向夹角这几个关键因素对边坡稳定性的影响,得出以下主要研究结论:(1)通过一系列土力学试验研究了红粘土的基本物理特性,通过快剪试验分析研究了安徽皖南地区红粘土在不同含水率下的抗剪强度。制备根—土复合体剪切试样,采用室内直剪试验研究分析了含水率、含根量变化对根—土复合体抗剪强度的影响规律。(2)采用MATLAB软件对根—土复合体直剪试验数据进行曲面拟合,得出了粘聚力增加值随含水率、含根量变化的二元二次拟合方程。(3)有限元分析结果显示边坡稳定性排列顺序为:木本植物根系作用边坡草本植物根系作用边坡原始边坡。从边坡稳定系数上看木本植物的固坡效果要强于草本植物,且草本植物在限制边坡水平位移方面要弱于木本植物。(4)通过分析不同工况下的有限元模型,发现主直根型木本植物的根系发挥锚固作用时,主直根起到主要作用,侧根系起到辅助作用;发现将根系布置在边坡底部时固坡效果最好,布置在边坡上部时效果最差,且根系布置水平间距不宜小于2.5m;发现在坡高小于等于15m且坡度缓于1:0.75的边坡上采用具有主直根型根系的木本植物进行防护效果较好。(5)正交试验结果显示,影响边坡稳定性的因素主次排列顺序为:单根距坡底水平距离㧐单根长度㧐单根与水平向夹角。试验得出了单根锚固的较优取值水平,即单根长度为4m,单根距坡底水平距离为0m,单根与水平向夹角为45°。
[Abstract]:There are many problems in strengthening red clay slope with traditional rigid protection measures, such as easy damage of structure, damage of surrounding ecological environment, glare after sunlight irradiation, etc. These problems can be effectively avoided by using slope ecological protection, which can not only enhance the stability of slope, prevent landslide, debris flow and other disasters, reduce soil and water loss, but also protect and restore the ecological environment around the slope. Improve the local microclimate. In this paper, based on the reinforcement theory and anchoring theory of plant roots, combined with the morphology and distribution characteristics of plant roots, the reinforcement and anchoring effects of red clay slope strengthened by plant roots were analyzed and studied by means of laboratory direct shear test and finite element numerical simulation, and the variation of shear strength with root content under different water content was analyzed and discussed. The factors affecting root anchoring of woody plants were analyzed by finite element method, and the effects of single root length, horizontal distance from single root to the bottom of slope, angle between single root and horizontal direction on slope stability were discussed by orthogonal test. The main conclusions are as follows: (1) the basic physical properties of red clay were studied by a series of soil mechanics tests. The shear strength of red clay in southern Anhui Province under different moisture content was studied by fast shear test. The shear samples of root-soil complex were prepared. The effects of moisture content and root content on the shear strength of root-soil complex were studied and analyzed by laboratory direct shear test. (2) the surface fitting of root-soil complex direct shear test data was carried out by MATLAB software, and the increasing value of cohesion with water content was obtained. The binary quadratic fitting equation of root content change. (3) the results of finite element analysis show that the order of slope stability is as follows: woody plant root acting on slope herbaceous root acting on slope original slope. From the point of view of slope stability coefficient, the slope fixation effect of woody plants is stronger than that of herbaceous plants, and the horizontal displacement of woody plants is weaker than that of woody plants. (4) by analyzing the finite element model under different working conditions, it is found that the main straight roots play a major role and the lateral roots play an auxiliary role when the roots of the main straight roots play an anchoring role. It is found that the effect of fixing slope is the best when the root is arranged at the bottom of the slope, and the effect is the worst when the root is arranged in the upper part of the slope, and the horizontal spacing of the root arrangement should not be less than 2.5m. It is found that the protective effect of woody plants with main and straight root roots is better on the slope with slope height less than or equal to 15 m and the slope is slower than 1 鈮，
本文编号：2508588
[Abstract]:There are many problems in strengthening red clay slope with traditional rigid protection measures, such as easy damage of structure, damage of surrounding ecological environment, glare after sunlight irradiation, etc. These problems can be effectively avoided by using slope ecological protection, which can not only enhance the stability of slope, prevent landslide, debris flow and other disasters, reduce soil and water loss, but also protect and restore the ecological environment around the slope. Improve the local microclimate. In this paper, based on the reinforcement theory and anchoring theory of plant roots, combined with the morphology and distribution characteristics of plant roots, the reinforcement and anchoring effects of red clay slope strengthened by plant roots were analyzed and studied by means of laboratory direct shear test and finite element numerical simulation, and the variation of shear strength with root content under different water content was analyzed and discussed. The factors affecting root anchoring of woody plants were analyzed by finite element method, and the effects of single root length, horizontal distance from single root to the bottom of slope, angle between single root and horizontal direction on slope stability were discussed by orthogonal test. The main conclusions are as follows: (1) the basic physical properties of red clay were studied by a series of soil mechanics tests. The shear strength of red clay in southern Anhui Province under different moisture content was studied by fast shear test. The shear samples of root-soil complex were prepared. The effects of moisture content and root content on the shear strength of root-soil complex were studied and analyzed by laboratory direct shear test. (2) the surface fitting of root-soil complex direct shear test data was carried out by MATLAB software, and the increasing value of cohesion with water content was obtained. The binary quadratic fitting equation of root content change. (3) the results of finite element analysis show that the order of slope stability is as follows: woody plant root acting on slope herbaceous root acting on slope original slope. From the point of view of slope stability coefficient, the slope fixation effect of woody plants is stronger than that of herbaceous plants, and the horizontal displacement of woody plants is weaker than that of woody plants. (4) by analyzing the finite element model under different working conditions, it is found that the main straight roots play a major role and the lateral roots play an auxiliary role when the roots of the main straight roots play an anchoring role. It is found that the effect of fixing slope is the best when the root is arranged at the bottom of the slope, and the effect is the worst when the root is arranged in the upper part of the slope, and the horizontal spacing of the root arrangement should not be less than 2.5m. It is found that the protective effect of woody plants with main and straight root roots is better on the slope with slope height less than or equal to 15 m and the slope is slower than 1 鈮，
本文编号：2508588
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