本研究為期三年，第一年探討根系對土壤剪力強度增量之影響。今年度計畫內容擬以理論及實驗方式二方面來進行含根土壤剪力強度增量之研究。相關研究顯示，含有植生根系補強的土壤會增加土壤的凝聚性和剪力強度，當穿過滑動面的根系貫入深度越深，則對於增加土壤剪力強度的功能越大，因此，研究將由直剪實驗所得資料經由分析及處理後，得到植物根系在不同位移下與土壤剪力強度增量之關係，另由根之直接拉力及握裹實驗，尋求根之抗拉應力及根與土壤間之握裹應力，探討植生根系之長度、斷裂強度及彈性係數與根直徑間之關係，並提出各關係式之使用參數。最後將以根系力學理論為基礎，再考慮根之彈性變形、根與土壤間之握裹應力及根之斷裂強度等因素，建立分析模型。研究中並模擬不同剪力帶厚度，尋求剪力帶厚度改變對植根土壤之側向位移與土壤剪力強度增量關係之影響。 In this year period, extend the fruitful results in last year, theoretical analysis and experimental work will be continue. The capability of root in increasing the shear strength of soil mass has been investigated and verified in the previous studies. The slope stability can be enhanced due to the root system permeated through the shear zone and deeply anchored into the potential slip plane. By means of the experimental data analysis, the variation of root reinforcement with shear displacement could be obtained. On the other hand, the ultimate tensile strength of root and the tangential strength between root and soil were measured by direct pull-out and bonding tests. Relation of Young’s modulus, tensile strength and root length to root diameter was discussed, then the parameters for each species were proposed. The analytical model based on the soil-root mechanical behavior, which respond to the loading by root stretching, root slipping, and root breaking, was established. The relationships of lateral displacement and shear strength increment of soil with various thickness of shear zone were investigated in the research as well. 研究期間 : 9808 ~ 9907
