植物根系倾角对土体抗剪强度影响试验研究

发布时间：2018-03-30 00:06

  本文选题：浅层滑坡　切入点：生态护坡　出处：《工程科学与技术》2017年S1期

【摘要】：植物是天然的工程师,拥有防止浅层滑坡和地表侵蚀的潜能,并具备低投入、低养护、绿色环保和生态平衡等优点。植被护坡技术在西南地区浅层滑坡的预防及治理中有着广泛的应用前景,因此深入了解植被护坡机理具有重要的工程意义。影响植被护坡效应的因素有很多,根-土体系的协同作用机制是当前研究的重点。由于根系的分布模式及倾角不同,根-土体系的强度和变形会有较大差异,因此采用人工根系(草根和灌木根)制备试样并设定根系与剪切面的夹角α值为变量,对比不同试样的强度和变形差异。通过直剪试验研究草本根系倾角对土体抗剪强度的影响,通过三轴剪切试验研究灌木根系倾角对土体抗剪强度的影响。试验结果表明:含根系土样的峰值强度及残余强度均明显高于素土,具有τ_(p素土)τ_(p90°)τ_(p45°)τ_(p135°)的规律;直剪试验中在α值等于135°时土样抗剪强度最高且表现出应变硬化,其余含根系试样应变软化特征均得到不同程度的抑制;三轴试验中当α值为135°时根系对土体抗剪强度的提高最为明显,其残余强度也最大,其余含根系试样抗剪强度也有不同程度提高。恰当的植物根系倾角能够加强根-土体系的协同作用,从而提高土体抗剪强度。同时由于根-土体系表现出延性破坏的特征,从而保证了土坡安全。研究结果可应用于生态护坡实践。
[Abstract]:Plants are natural engineers, have the potential to prevent shallow landslides and surface erosion, and have low input, low conservation, The technology of vegetation slope protection has a broad application prospect in the prevention and treatment of shallow landslides in southwest China. Therefore, it is of great engineering significance to understand the mechanism of vegetation slope protection. There are many factors that affect the slope protection effect of vegetation. The cooperative mechanism of root-soil system is the focus of current research. The strength and deformation of root-soil system will vary greatly. Therefore, artificial root system (grass root and shrub root) is used to prepare samples and the angle 伪 between root and shearing surface is set as variable. The effect of root inclination angle of herbaceous on shear strength of soil was studied by direct shear test. The effect of shrub root inclination on the shear strength of soil was studied by triaxial shear test. The results showed that the peak strength and residual strength of soil samples containing roots were obviously higher than that of plain soil, and had the regularity of 蟿 _ T _ P _ 90 掳) 蟿 _ T _ (45 掳) 蟿 T _ (135 掳)). In direct shear test, when 伪 = 135 掳, the shear strength of soil samples was the highest and showed strain hardening, and the strain softening characteristics of other root samples were inhibited to varying degrees. In triaxial test, when 伪 value is 135 掳, the root system has the most obvious increase in shear strength of soil, and its residual strength is also the largest. The shear strength of other root samples was also increased to some extent. Proper plant root inclination could enhance the synergistic effect of root-soil system, thus enhancing the shear strength of soil. At the same time, the root-soil system showed the characteristics of ductile failure. The research results can be applied to ecological slope protection practice.
【作者单位】： 四川大学水利水电学院水力学与山区河流开发保护国家重点实验室;南京水利科学研究院水利部土石坝破坏机理与防控技术重点实验室;深圳市益田集团股份有限公司;
【基金】：国家自然科学基金资助项目(51579167) 水利部行业专项资助项目(201301022);水利部土石坝破坏机理与防控技术重点实验室开放基金项目资助(YK915003)
【分类号】：Q948;TU411.7
，

本文编号：1683458