Evaluation of the effects of lateral roots on slope stability

Wien

1988

S. 105-115

12 Abb., 4 Lit. Ang.

Unselbständiges Werk

200005040

A conceptual model to express the effect of tree roots on slope stability is presented. The network of lateral roots is expressed with several layers of net, while vertical roots are represented with groupes of short, small piles. Tree stems are expressed as the weight on the piles. The change of the effect of the nets and piles with elapse of tree ages is discussed. To evaluate the effect of lateral roots(nets), the writers made a simulation model of lateral root distributions by employing TR (tree-root) ratio, pipe theory of tree growth and bifuracation ratio of root networks. The result indicates that root area ratio and tensile strength of lateral roots show the lowest value at the middle of two adjacent trees. The tensile strength at this Iowest point increases with tree age until 20th year, keeping the constant ratio afterwards. The 20th year coincides appoxinately with the age of canopy closure and the starting age of the constant value of L(average distance of trees) / D(diamter brest height). This first 20 years also corresponds with the period of high susceptibility to debris slide occurrance.