Influence of Configuration of Vegetation on the Stability of Slopes
| Autor: | Yi-Fan Lai, 賴羿帆 |
|---|---|
| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 99 As one of the nature’s most important methods in maintaining slope stability, vegetation in bare slopes as a result of landslide and recovery stability analysis have become important issues in maintaining slope stability. However, one must find out which kind of vegetation configuration is most effective in the defense against shallow slope failure. In this study, PLAXIS 3D was used for numerical simulation with tap root systems individually placed on upper, mid and lower slope in the investigation of impacts brought by the rainfall on slope displacement and mechanical mechanisms; in addition, the effects of different vegetation configurations on slope stability were also analyzed by this study. From the analysis, the presence of vegetation can increase overall slope stability with slope surface soil of the neighboring root systems bounded or restricted by the root system before an arch is formed to weaken of soil displacement. As the arch’s retaining effect increased, the distance between the root systems shortened while as the distance between root system increased, the effects of vegetation on slope safety were limited. As the distance between vegetation reached over 6m, the degree of increase in safety factor also gradually settled at a fixed value with less than 2% safety factor difference shown between the vegetations. The tree weight has slight effect on the safety factor of the vegetated slope. When vegetation was placed on top of potential failure, its weight enhanced slope sliding power, resulting in the decrease of safety factor whereas when the vegetation was placed below potential failure, the weight of the trees served as a foundation weight and indirectly increased slope stability. Slope can provide better slope sliding control in overall forestation than upper, mid, and lower slope forestation alone. Compared to slopes without root systems, safety factor in single-row vegetation can only reach up to 20% maximum whereas a 68.5% increase in safety factor was seen in overall forestation. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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