Development of evaluation techniques of the effect of tree roots on slope stability.

树根对边坡稳定性影响评价技术的发展

• 批准号: 60860014
• 负责人: TSUKAMOTO Yoshinori
• 金额: $ 4.03万
• 依托单位: Tokyo University of Agriculture and Technology.
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research
• 财政年份: 1985
• 资助国家: 日本
• 起止时间: 1985 至 1986
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-60860014/
• 关键词: Forest; Tree root distribution; Surface soil; Similation model; Upper bound theorem; 安全率; 樹木根系; 斜面; 安定評価; 手法開発

1) A conceptual model which express the lateral roots with nets and vertical roots with short piles is represented. The change of the effect tree roots on slope stability is discussed with this model.2) The slope is classified into four types with the subsurface conditions into which vertical roots penetrate. It is pointed out that the slope with the transition layer which restricts tree root growth is affected greately by tree cutting.3) The pipe theory and the bifurcation ratio are employed for making a simulation model to estimate the lateral root network. The lateral roots showed the lowest volume at the middle of two adjacent trees. This lowest volume increased sharply before the tree age of 20. After 20th year, the lateral root volume showed a constant value. Since this 20 years correspond to the high occurrance period of debris slides after tree cutting, the writer presumes that lateral roots affect slope stability.greatly.4)The upper bound theorem is applied to evaluate the effect of lateral roots and vertical roots simultaniously. The result showed that the effect of lateral root becomes greater as the landslide becomes smaller. The effect of vertical roots becomes greater as the surface soil depth gets smaller.5) The relationship between four slope types and the effect of tree roots on slope stability is classified and evaluated with the aid of the upper bound theorem taking into consideration the surface soil depth and the growth restriction of vertical roots.

1)提出了网状横向树根和短桩垂直树根的概念模型。利用该模型讨论了树根对边坡稳定性影响的变化。2)根据垂直树根穿透的地下条件，将边坡分为四种类型。指出有过渡层的坡度受树木采伐的影响较大。3)利用管子理论和分叉率建立模拟模型，对侧根网络进行估算。侧根的体积在相邻两株树的中间最小。这一最低材积在树龄20年前急剧增加，20年后，侧根体积表现出恒定值。由于这20年恰好是采伐后泥石流的高发期，笔者推测侧根对边坡稳定性的影响很大。4)应用上界定理同时评价了侧根和竖根的作用。结果表明，滑坡体越小，侧根的作用越大。5)考虑表层土层深度和垂直根系的生长限制，利用上界定理对4种坡型与树根对边坡稳定性影响的关系进行了分类评价。

项目成果

Yamadera, Kisei: "A proposal of tree seeding in revegetational works" Journal of Japanese of Revegetational works.12(2). 25-35 (1986)

Yamadera, Kisei：“植被工程中植树造林的建议”《日本植被工程杂志》12(2)。

Tsukamoto, Yoshinori: "Hydrogeomorphological characteristics of a zero order basin." Proceedings of the international symposium on erosion and sedimentation of Pacific Rim, Corvallis, Oregon, 1987. (1987)

Tsukamoto，Yoshinori：“零级盆地的水文地貌特征。”

塚本良則: 東京農工大学農学部演習林報告. 23. 65-124 (1987)

冢本吉典：东京农工大学农业研究森林报告。23. 65-124 (1987)

Tsukamoto, Yoshinori: "Evaluation of the effect of tree roots on slope stability." Bulltin of the Experimental Forests, Tokyo University of Agriculture and Technology.23. 65-124 (1987)

Tsukamoto，Yoshinori：“评估树根对边坡稳定性的影响。”

山寺喜成: 緑化工技術. 12(2). 25-35 (1986)

山寺义成：绿化技术 12(2)。