道路边坡生态防护力学机理研究
发布时间：2019-04-24 05:46
【摘要】：近年来我国经济发展迅速,全国各地大兴土木,投入的基础设施建设非常大。大量的基础设施建设,对人们生活提供了方便也提高了生活质量,但是对自然界中原有生态环境造成了影响。特别是在山区和丘陵地带建设高速公路、铁路等大型基础设施,无可避免的进行高填深挖,对原有植物和土体结构造成破坏,有的甚至还造成了裸露的边坡。部分人工边坡有存在安全隐患,如坍塌、侵蚀、滑坡等,更严重的还会出现破坏生物链和水土流失等环境问题。传统的工程防护措施比较成熟,能较好地加固人工边坡,但也存在不足,因为传统工程防护完全封闭了植被生长,这对可持续发展以及环境保护不利。相对于传统边坡护坡技术,植被护坡技术有更多的优势,如景观效果好、工程造价低以及服务年限长。边坡生态防护逐步得到了推广运用,在高速公路、水利水电、铁路等工程的坡面防护中广泛运用。在边坡生态防护的研究领域中根系固土力学机理有较广泛的关注,也是研究的热点问题。在国内外已有研究基础之上,本论文以狗牙根和马尼拉草以及长沙本地黏性土组成的根土复合体作为研究对象,依托长沙市科技计划项目“长沙市公路路域生态恢复技术及推广研究”(项目号：K1205028-11)和中南林业科技大学科研究生技创新基金(项目号：CX2013Z41)等开展相关研究,所做的主要工作和取得的主要结论如下：1、在长沙市的市政公路边坡进行现场调研,研究了狗牙根和马尼拉草的生长状况以及根系的分布形态与密度。得出了根系密度随土层深度的增加而减小的规律,并且得出了函数关系。2、通过对不同根密度的根土复合体的直剪试验,得出抗剪强度和含根量的关系,以及提出了两种草本植物根土复合体的黏聚力和内摩擦角与含根量的函数关系,计算结果和实测数据非常吻合,并得到了以下结论：(1)垂直应力影响剪切强度,垂直应力和根土复合体的抗剪强度呈线性关系。随着垂直应力的增大,抗剪强度呈线性增加。(2)根含量影响土体的剪切强度,根土复合体的的抗剪强度随着根数的增加而增强,但随着根数的增加,抗剪强度的增幅逐渐减小。(3)根对土体的内摩擦角的影响不大,但是黏聚力增加明显,这相当于通过根来增加凝聚力从而提高土体的抗剪强度。(4)根土复合体的剪切强度与土的含水量也有关系。含水率越低,抗剪强度越大；在含水率较低时根对土体的抗剪强度有较大提高,即根对土体抗剪切度贡献大。(5)在两种含水率的情况下,狗牙根的根土复合体抗剪强度增幅值大于尼拉根土复合体抗剪强度增幅值。(6)提出了两种草本植物根土复合体的黏聚力和内摩擦角与含根量的函数关系,其中黏聚力与含根量呈对数函数规律变化,内摩擦角与含根量呈线性函数规律变化。3、根据道路的边坡情况,通过瑞典条分法研究了狗牙根和马尼拉草不同根密度的边坡稳定系数,根密度越大其边坡的稳定系数也越大,并且得出了根密度与稳定系数的函数关系。
[Abstract]:In recent years, the economic development of our country has been developing rapidly, and the construction of the infrastructure that has been invested in the whole country is very large. The construction of a large amount of infrastructure has provided a convenient and improved quality of life for people, but has an impact on the ecological environment in the natural world. In particular, a large-scale infrastructure, such as a highway, a railway and the like, is built in a mountain area and a hilly area, so that the high-filling and deep-excavation can be avoided, and the damage to the original plant and the soil body structure is avoided, and the exposed side slope is even caused. Some artificial side slope has potential safety hazard, such as collapse, erosion, landslide, and more serious environmental problems such as biological chain and water and soil loss. The traditional engineering protection measures are relatively mature, can better reinforce the artificial side slope, but also have insufficient, because the traditional engineering protection completely closed the vegetation growth, which is unfavorable to the sustainable development and the environmental protection. Compared with the traditional slope protection technology, the vegetation slope protection technology has more advantages, such as good landscape effect, low engineering cost and long service life. The slope ecological protection has been widely used in the slope protection of the highway, water conservancy and hydropower, railway and other projects. In the research field of slope ecological protection, the mechanism of root-fixing soil mechanics has a wide range of attention, and it is also a hot issue of research. Based on the existing research, this paper takes the root and soil complex of the root of the dog and the grass of manila and the local cohesive soil of Changsha as the research object, and relies on the "Study on the Technology and Promotion of the Ecological Restoration of the Road and Road in Changsha" of the project of Changsha Science and Technology Plan (Project No.: K1205028-11) and the Science and Technology Innovation Fund (Project No.: CX2013Z41) in Central and South Forestry Science and Technology, and other relevant research, the main work and main conclusions are as follows:1. On-site investigation of the municipal highway slope in Changsha, The growth of root and manila grass and the distribution and density of root system were studied. The relationship between the shear strength and the root content is obtained by the direct shear test of the root soil complex with different root density. The cohesion and internal friction angle of the two kinds of herbaceous plant root-soil complex and the function relation of the internal friction angle and the root-containing quantity are proposed, and the calculation results and the measured data are in good agreement, and the following conclusions are obtained: (1) the vertical stress affects the shear strength, The shear strength of the vertical stress and the root-soil complex is linear. With the increase of the vertical stress, the shear strength increases linearly. (2) The root content affects the shear strength of the soil, and the shear strength of the root-soil complex increases with the increase of the number, but with the increase of the number, the increase of the shear strength is gradually reduced. (3) The influence of the root on the internal friction angle of the soil is not small, but the cohesion is obviously increased, which is equivalent to the increase of the cohesion through the root, so as to improve the shear strength of the soil. (4) The shear strength of the root soil complex is also related to the water content of the soil. The lower the water content, the greater the shear strength; when the water content is low, the shear strength of the root to the soil is greatly improved, that is, the root has great contribution to the shear strength of the soil body. (5) In the case of two water content, the shear strength increase of the root-soil composite of the root of the dog is greater than the increase of the shear strength of the composite soil. (6) The cohesion and the internal friction angle and the root-containing function relation of the root-soil complex of the two kinds of herbaceous plants are put forward, in which the cohesive force and the root-containing amount change regularly, the internal friction angle and the root-containing amount are in linear function, and 3, according to the slope of the road, The stability coefficient of the slope with different root density of the root of the dog and the manila grass is studied by the Swedish method. The higher the root density and the stability coefficient of the slope are obtained, and the function relation between the root density and the stability coefficient is obtained.
【学位授予单位】：中南林业科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U417.12
本文编号：2464152
[Abstract]:In recent years, the economic development of our country has been developing rapidly, and the construction of the infrastructure that has been invested in the whole country is very large. The construction of a large amount of infrastructure has provided a convenient and improved quality of life for people, but has an impact on the ecological environment in the natural world. In particular, a large-scale infrastructure, such as a highway, a railway and the like, is built in a mountain area and a hilly area, so that the high-filling and deep-excavation can be avoided, and the damage to the original plant and the soil body structure is avoided, and the exposed side slope is even caused. Some artificial side slope has potential safety hazard, such as collapse, erosion, landslide, and more serious environmental problems such as biological chain and water and soil loss. The traditional engineering protection measures are relatively mature, can better reinforce the artificial side slope, but also have insufficient, because the traditional engineering protection completely closed the vegetation growth, which is unfavorable to the sustainable development and the environmental protection. Compared with the traditional slope protection technology, the vegetation slope protection technology has more advantages, such as good landscape effect, low engineering cost and long service life. The slope ecological protection has been widely used in the slope protection of the highway, water conservancy and hydropower, railway and other projects. In the research field of slope ecological protection, the mechanism of root-fixing soil mechanics has a wide range of attention, and it is also a hot issue of research. Based on the existing research, this paper takes the root and soil complex of the root of the dog and the grass of manila and the local cohesive soil of Changsha as the research object, and relies on the "Study on the Technology and Promotion of the Ecological Restoration of the Road and Road in Changsha" of the project of Changsha Science and Technology Plan (Project No.: K1205028-11) and the Science and Technology Innovation Fund (Project No.: CX2013Z41) in Central and South Forestry Science and Technology, and other relevant research, the main work and main conclusions are as follows:1. On-site investigation of the municipal highway slope in Changsha, The growth of root and manila grass and the distribution and density of root system were studied. The relationship between the shear strength and the root content is obtained by the direct shear test of the root soil complex with different root density. The cohesion and internal friction angle of the two kinds of herbaceous plant root-soil complex and the function relation of the internal friction angle and the root-containing quantity are proposed, and the calculation results and the measured data are in good agreement, and the following conclusions are obtained: (1) the vertical stress affects the shear strength, The shear strength of the vertical stress and the root-soil complex is linear. With the increase of the vertical stress, the shear strength increases linearly. (2) The root content affects the shear strength of the soil, and the shear strength of the root-soil complex increases with the increase of the number, but with the increase of the number, the increase of the shear strength is gradually reduced. (3) The influence of the root on the internal friction angle of the soil is not small, but the cohesion is obviously increased, which is equivalent to the increase of the cohesion through the root, so as to improve the shear strength of the soil. (4) The shear strength of the root soil complex is also related to the water content of the soil. The lower the water content, the greater the shear strength; when the water content is low, the shear strength of the root to the soil is greatly improved, that is, the root has great contribution to the shear strength of the soil body. (5) In the case of two water content, the shear strength increase of the root-soil composite of the root of the dog is greater than the increase of the shear strength of the composite soil. (6) The cohesion and the internal friction angle and the root-containing function relation of the root-soil complex of the two kinds of herbaceous plants are put forward, in which the cohesive force and the root-containing amount change regularly, the internal friction angle and the root-containing amount are in linear function, and 3, according to the slope of the road, The stability coefficient of the slope with different root density of the root of the dog and the manila grass is studied by the Swedish method. The higher the root density and the stability coefficient of the slope are obtained, and the function relation between the root density and the stability coefficient is obtained.
【学位授予单位】：中南林业科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U417.12
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，本文编号：2464152
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