地工合成材料應用於加勁擋土牆之碳排放分析

Abstract

本研針對國內自產之地工合成材料種類及其功能進行調查，並針對部分RC與加勁擋土牆使用材料進行CO2排放計算，用以計算分析加勁與傳統RC擋土牆在CO2排放與建造成本上的差異。本研究主要成果如下分述如下。 加勁擋土牆結構體高度15m以下，建造成本約為6000至8000元/m2，結構體高度15m以上建造成本約為8000至10000元/m2，若擋土牆高度越高，格網埋入深度較深建造成本可能高達10000至13000元/m2，反之擋土牆高度越低，功能需求越單純其建造成本可能降至4000至6000元/m2，擋土牆結構體3m高以下加勁與RC建造成本無明顯差異，3m高以上加勁擋土牆建造成本優於RC土擋土牆。 有關擋土牆的CO2排放以本研究中5至8m高的擋土牆為例，加勁擋土牆CO2排放約為20kg/m^2，RC擋土牆CO2排放約為加勁擋土牆的10至40倍，使用加勁擋土牆取代RC擋土牆可大量減少CO2排放，本研究更建立以「建造成本」與「CO2排放」兩項數據之二次回歸曲線可用以預測加勁擋土牆的CO2排放，回歸方程式為y=0.0038x-1.864，相關係數為0.858，此後可以「建造成本」進行加勁擋土牆CO2排放的預測。 根據本研究數據指出，加勁擋土牆可以透過植生的方式吸收建築材料所生之二氧化碳，而其所耗費的時間，如加勁擋土牆結構高度在15m以下需2-5年、15m以上需5-8年，可將建築使用材料所產生的CO2排放完全回收，達到零CO2排放。 以加勁擋土牆取代RC擋土牆，不僅有更經濟的建造成本，更可大量減少CO2排放，且於加勁擋土牆使用年限內更可透過坡面的植生，將建造使用之材料產生的CO2排放回收，達到零CO2排放。

The thesis,via investigation of the types and functions of Geosynthetics Materials, focuses on analysis of comparison between RC Retaining Walls and Reinforcement Retaining Walls in two ways: the first is CO2 deterioration,and the second is Cost. Through the research,the main result of the study is following. When the height of Reinforcement Retaining Walls is lower than 15cm, the cost of its construction will be 6000 to 8000 dollars per m2 approximately.However,when the height of it is higher than 15cm, the cost of it will come to 8000 to 10000 dollars per m2 approximately.Besides,the higher the Reinforcement Retaining Walls is, the more deeply the Geogrid will crave,and the cost of its construction will be 10000 to 13000 dollars per m2;albeit,the lower it is,the shallower Geogrid will crave,and cost of it will be 4000 to 6000 dollars per m2 due to simple requirement of function.Additionally,with comparison with Reinforcement Retaining Walls and RC Retaining Walls, the cost of the former will be cheaper than that of the latter when the structure of the former is higher than 3m. With regard to the CO2 deterioration of Retaining Walls,the amount of Reinforcement Retaining Walls is 20 kg/m^2;albeit,the amount of Reinforcement Retaining Walls is 10 to 40 times size of it. Therefore,it is clear that use of Reinforcement Retaining Walls can reduce the amount of emission of CO2.In addition,for estimation of CO2 emission from the respect of construction cost,the thesis create Quadratic regression curve (y=0.0038x-1.864) to estimate the amount of emission of CO2,which R2 is 0.858. According to the survey of the thesis, in order to recycle the emission of CO2 caused by the materials,Reinforcement Retaining Walls which is vegetated is recommended. The time it takes to achieve the goal depends on the height of its structure: it would take 2 to 5 years if the height is lower than 15 meters;on the contrary,if the height is higher than 15 meters,5 to 8 years were required. Finally,under the series of research,in lieu of its economical respect, reduction of emission of CO2,and recycle of CO2 via vegetation on the surface,it is my conclusion that the use of Reinforcement Retaining Walls is suggested to achieve the goals mentioned above.