摘要
影響土壤最大剪力模數的因素包括試體密度、平均有效應力、細粒料含量、塑性和過壓密比等。本研究是利用剪力波元件探討砂和黏土混合土壤的動態特性，試體材料為石英砂依高嶺土含量不同而配置為20%高嶺土及40%高嶺土含量之混合土樣。主要以濕搗法的方式將試體控制在夯實曲線的OMC初始狀態下重模並以不同的有效應力來進行壓密，除此之外，還針對20%高嶺土混合土樣探討OMC、乾側及濕側之初始狀態對於最大剪力模數之影響。 根據試驗結果可發現最大剪力模數會隨著有效應力的增加而上升，無論20%或40%混合土壤皆有一樣的趨勢。隨著土壤塑性指數的不同，過壓密比影響最大剪力模數的程度也會不同，當塑性指數較低時，過壓密比幾乎對最大剪力模數沒有影響；當塑性指數較高時，最大剪力模數隨著過壓密比增加而上升。 本研究除了利用實驗結果外，前人研究的實驗數據結果也被列入並探討前人建立之最大剪力模數經驗公式的適用性，分析各經驗公式在不同大小的參數下，例如最大剪力模數、孔隙比、平均有效應力、細粒料含量和塑性指數等等，所得預測值和實驗求得值之間的殘差量，藉此可進一步了解各經驗公式可能分別適用在不同參數下的各個範圍，如此，可供後人在進行土壤動態分析時，需要利用到土壤最大剪力模數的情況下，針對分析之土壤基本參數選擇更適用之經驗公式來求得更符合現實之土壤最大剪力模數。除此之外，嘗試利用混合土壤的參數及最大剪力模數結果來建立一條經驗公式，希望更能適用於混合土壤的範圍。
並列摘要
Maximum shear modulus of soil is an important dynamic soil property which can be affected by many factors, such as relative density, mean effective stress, plasticity index, fines content, over-consolidation ratio, etc. In this research, a series of bender element tests are performed to estimate the shear wave velocities and hence the maximum shear moduli of soil mixtures. There are two soil mixtures considered in this study. They are soil mixtures composed of 20% Kaolin clay with 80% Silica sand and 40% Kaolin clay with 60% Silica sand. In addition, effect of consolidation stress and plasticity index on maximum shear modulus is explored in this study. Based on the laboratory results, maximum shear moduli of soil mixtures are found to be increasing with increasing consolidation stress. On the other hand, the impact of over-consolidation ratio on maximum shear modulus is different for different values of plasticity index. When plasticity index is low, the influence of over-consolidation on maximum shear modulus is little. However, when plasticity index is high, maximum shear modulus would increase with increasing over-consolidation ratio. In this research, performance of empirical models of maximum shear modulus, which are previously developed by other researchers, is studied. Using the laboratory data from current study and those from other researchers, differences between the data and predictions (from empirical models) are evaluated. In addition, a linear regression model is developed in this study to correlate the maximum shear modulus of soil mixtures with other soil parameters.
參考文獻
延伸閱讀
- 林冠宏（2016）。無凝聚性土壤參數間之轉換及其相關性探討〔碩士論文，國立臺灣大學〕。華藝線上圖書館。https://doi.org/10.6342/NTU201601230
- 陳怡睿、謝舜傑、陳沛靖（2011）。土壤液化敏感區土地開發適宜性之研究。建築學報，(76_S)，131-150。https://doi.org/10.6377/JA.201106.0013
- 李堯夫（2007）。土壤採樣佈點程序合理化之研究〔碩士論文，國立中央大學〕。華藝線上圖書館。https://www.airitilibrary.com/Article/Detail?DocID=U0031-0207200917350479
- 楊逸楨（2007）。Characteristics of organic contaminants adsorption on mineral surface of soil〔碩士論文，國立中央大學〕。華藝線上圖書館。https://www.airitilibrary.com/Article/Detail?DocID=U0031-0207200917350777
- 黃漢誠、楊欣常、馬國宸、陳主惠、譚義績（2001）。Theoretical and Experimental Studies of Soil Moisture Hysteresis Phenomenon。台灣水利，49(2)，30-45。https://www.airitilibrary.com/Article/Detail?DocID=P20220602001-200106-202211030015-202211030015-30-45