Slope stability of forested slopes considering effect of tree root and steel bar reinforcement (特集:地すべりと植生)
Slope stability of forested slopes considering effect of tree root and steel bar reinforcement (特集:地すべりと植生)
复制标题
考虑树根和钢筋加固作用的森林边坡的边坡稳定性（专题：滑坡和植被）
DOI：
10.3313/jls.41.3_264
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
K. Shiraki
中科院分区：
文献类型：
--
作者：
Q. M. Nghiem;Hiroyuki Nakamura;K. Shiraki
树根穿过上部土层进入基岩，增加了土体的抗剪强度，使边坡更加稳定。根系加固对土体强度的影响已通过机理和经验研究得到了很好的研究，但很少有研究探讨树木根系与钢筋结合对边坡稳定性的影响。另外，以往的研究大多没有考虑边坡位移对树根和钢筋加固效果的影响，本文根据树根的实际分布情况，提出了考虑树根加固作用的边坡稳定性分析方法。边坡位移越大，树根的加固作用越大。当边坡稳定后，边坡的阻力和位移逐渐增大。由于某些原因（外部负载，更多的降雨。等），如果边坡再次变得不稳定，滑坡过程重复，直到Fs=1。树木根系起到了加固材料的作用，提高了边坡的安全系数，Fs≥1。然而，森林边坡的目标安全系数（也称为设计安全系数Fds）必须等于或大于一个标准值（如Fds= 1.2）。Fds的大小取决于斜率的重要性。因此，即使边坡有树根加固，我们也需要额外的加固。边坡加固的方法很多。在本文中，选择钢筋的原因有两个：1）钢筋具有相同的行为作为根在滑坡; 2）钢筋是很少的方法，可以维持植被在边坡上。应用Nghiem等提出的斜根模型，(2001，2003），提出了根纤维与钢筋联合加固边坡的设计方法。
A tree root crossing through upper soil layer into bedrock increases shear strength of soil and renders the slope more stable. The effect of root reinforcement on soil strength has been well researched through the mechanistic and empirical studies, but yet few studies have examined how tree roots in combination with steel bar influence slope stability. Further, most of previous research lacked consideration of effect of slope displacement on the reinforcement of tree roots and steel bars.By using actual distribution of tree root, an analysis of slope stability considering tree root reinforcement as a function of groundwater level and slope displacement will be proposed. Larger displacement of slope results in greater reinforcement of tree root. The resisting force and displacemen increase until the slope becomes stable. For some reasons (external load, more rainfall. etc), if the slope became unstable again, the process of landslide repeats until Fs=1. Tree root functions like reinforcement material and improves factor of safety of forested slope, Fs≥1. However, target factor of safety (also called design factor of safety Fds) of a forested slope must be equal to or higher than a standard value (such as Fds= 1.2 in this paper). Magnitude of Fds depends on the importance of slope. Thus, we need extra reinforcement even if the slope has tree root reinforcement. There are many methods to reinforce slope. In this paper, steel bar is chosen for two reasons: 1) steel bar has the same behavior as a root in a landslide; 2) steel bar is one of very few methods that can sustain the vegetation on slope. By applying model of inclined root proposed by Nghiem et al.(2001, 2003), a design method is presented for root fibers reinforcing slope in combination with steel bars.