植生木樁穩定邊坡效果之觀測試驗

Study on Effectiveness of Vegetative Stakes for Slope Stabilization

陸象豫(Shiang-Yue Lu)

《中華水土保持學報》 18卷1期 (1987/05) Pp. 59-68

https://doi.org/10.29417/JCSWC.198705_18(1).0006

摘要

本試驗之目的在探討於道路上邊坡打樁之可行性；計進行不同打樁深度成活率比較試驗、木樁劈裂後不同處理試驗、木樁根系增加抗剪強度效能及抵抗拉力強度測定試驗，常用植生木椿生長情形觀測等項目。供試種爲九芎、水柳、榕樹等三種。試驗結果獲知除榕樹外，九芎、水柳均可生長於含石量甚高之上邊坡試區。不同打樁深度成活率比較試驗顯示打入越深成活率越高，然而水柳、榕樹在各種打椿深度下之成活率差異均未達5％顯著水準。木樁強行打入發生劈裂後，以鋸掉劈裂端之處理方式最能維持原有之成活率，且最省工。打樁四個半月後所測得帶根系之土壤樣品之最大抗剪強度分別爲：水柳0.440 Kg/cm^2、九芎0.335 Kg/cm^2、榕樹0.294 Kg/cm^2，而原土壤之最大抗剪強度爲0.250 Kg/cm^2，證實木樁生根後能增加土壤之抗剪強度。木椿抵抗拉力強度試驗測得根系健全後，平行坡面橫拉之抵抗力可達40 kg以上，顯示木樁有足夠之能力抵抗由坡面上方滑落石塊之衝擊。本試驗並測知，打樁後水柳約15天，九芎約20天，榕樹約35天卽開始萌芽；九芎約50天，水柳約70天，榕樹約110天後卽可長出根系。

並列摘要

The purpose of this experiment is to test whether vegetative stakes can stabilize cut-bank of road or not. The plant species chosen for this experiment are wildly growth in Taiwan area, they are Water Willow, Subcostate Crape Myntle, and Marabutan. The results obtained are summarized as follow: 1. Besides Marabutan, the other two plants can grow well in the rocky cut-bank of the road. 2. Survival percentage of vegetative stakes is related to the striking depth, but the difference of each treatment have not exceed 5% level of significance. 3. When vegetative stakes cleaved, the most suitable treatment which can maintain survival percentage is sawing the cleaved part off. 4. The maximum shear strength for each sample containing roots which growing 4.5 months are as follow: Water Willow 0.440 kg/cm^2 Subcostate Crape Myrtle 0.335 kg/cm^2 Marabutan 0.294 kg/cm^2 shear strength of sample contain no roots is 0.250 kg/cm^2. After roots growing well enough, vegetative stakes can resist the force of 40kg from lateral pulling. 5. The time for sprouting after striking (planted) is as follow: Water Willow 15 days Wubcostate Crape Myrtle 20 days. Marabutan 35 days and the time for the first root growing is as follow: Water Willow 50 days Wubcostate Crape Myrtle 70 days Marabutan 110 days.