柳杉不同树龄根系加筋作用对边坡稳定性的影响

Reinforcement Effects of Cryptomeria fortunei Roots of Different Ages on Slope Stability

[目的]在浅层滑坡比较频繁的四川省北川县，开展了不同年龄柳杉根系对边坡稳定性作用的研究。【方法】测定3、6和9a生的柳杉不同深度土壤中根的长度，并计算其垂直消弱系数；测量不同直径根的抗拉力及抗拉强度；将土带回做根土直剪试样的剪切强度，并简单计算边坡的稳定系数。【结果]9a生柳杉根系的8最高，垂直分布较深，3个年龄段根系直径较小时抗拉力及抗拉强度差别很小，当直径超过4mm时差距较明显。9a生的直剪试样cr增加最明显，含水量大时土壤的黏聚力有所降低。现有植被情况下边坡稳定系数较裸坡增加了33．53％～88．93％。【结论】随着柳杉年龄的增长，根系生物量不断增加，其根系加筋作用使边坡稳定性有所提高。

EObjectivel Shallow landslides is relatively frequent in Beichuan county of Sichuan prov- ince. Therefore, our objective was to study the effects of Cryptomeria fortunei roots of different ages on slope stability in this area. [Methodl Determination the length of 3-, 6- and 9-year yearold C. fortunei root in soil within different depths were measured in length, and calculate its vertical weakening coefficient was calculated. The measuring the tensile strength power and strength of root of different diameters and tensile strength of the root were analyzed. The soils were trans ported back to investigate root soil shear specimen shear strength, and a simple calculation to cal culate of factor of slope stability factor. Resultsl value of 9-year-old C. fortunei root was the highest. There were no clear differences in tensile power and strength when root diameter was smaller. However, the differences became significant when the diameter 4 mm. The direct shear specimen cr was the best in 9-year-old C. fortunei. Cohesion was decreased when soil water content was relatively high. The existing vegetation increased stability coefficient by 33.53%- 88.93 %compared to bare slope. EConclusionl Root biomass increased with C. fortunei ages and reinforced role of roots in the slope stability was improved.