植生根系增加土壤抗剪強度之研究

A Study on Soil Resistance Shear Strength Increment of Root System

郭濰榕(Wei-Jung Kuo)

指導教授 ： 張德鑫

中原大學/工學院/土木工程研究所/碩士(2015年)

https://doi.org/10.6840/CYCU.2015.00146

摘要

隨著國內對於生態環境的關注，植生護岸工程已經成為穩定河川堤防的重要方法。基於植生根系力學之研究，植物根系對土壤剪力增量之計算已漸漸明朗化，故本研究參考基樁之拉拔試驗分析，推導一拉拔公式及簡化根系力學之應用。研究中結合理論與現地試驗，進行土壤抗剪強度之研究，並應用於植生護岸之安全評估，而植生材料則選擇柳枝工護岸之力學特性為研究主軸。
現地拉拔試驗場址為台中市筏子溪之柳枝工護岸工程，試驗中除採無含根土樣進行直剪試驗以獲得土壤參數，並於現地進行植物根系拉拔試驗，將試驗所得參數代入推導公式中，可求出植生根系抗剪強度之增量。另外透過水流造成之拖曳力、水流沖擊導致植物彎曲之破壞力學、推導拉拔公式等理論分析，據以評估柳枝工護岸可能造成之破壞情形，以利後續進行相關工程設計及安全性之參考。研究成果顯示柳枝工護岸可達到很高的抗沖蝕強度，也可以確定生態工法-柳枝工能達到與一般傳統施工方式的抗破壞強度。

關鍵字

柳枝工 ； 生態工法 ； 剪力強度

並列摘要

With the growth of concern about ecological and environmental issues in Taiwan, vegetation revetment engineering has become an essential method for stabilizing river embankment project in recent years. Based on researches of roots system mechanics, plant roots system for the calculation of soil shear increments has gradually come to light. This study refers to the pull-out test analysis of foundation piles, then derives a series of pull-out formula and the application of simplified roots system mechanics. Both theoretical concepts and situ test references were integrated to carry out the analysis of soil resistance shear strength, hope it can be applied to assess the safety and applicability of the vegetation revetment. Mechanical properties of the willow works revetment was mainly discussed for the entire study.
Fazi river willow works revetment engineering in Taichung was chosen to be the situ pull-out test address. Two different types of test were conducted here, including direct shear tests on sampling soils and the situ pull-out tests of roots system, to acquire soil parameters using in the following derivation, which aimed to obtain the increments of resistance shear strength of roots system. Furthermore, for the purpose of assessing whether willow works revetment would reach the destruction situation, this study also considered the effect of stream drag force, destruction of the plants bend of mechanics led by water flow, and deriving pull-out formula as well as other theories. The consequence shows that willow works can achieve a high resist invasion strength, also indicates this ecological engineering methods can be achieved the resist destruction strength as same as traditional construction methods.

並列關鍵字

willow works ； ecological engineering methods ； shear strength

參考文獻

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