<p>Many geotechnical engineering problems involve combining two or more independent physical processes as a coupled solution of seepage, volume change and shear strength. For any physical process being modeled, it is desirous to be able to compute any of the volume-mass soil properties. When the volume-mass soil properties are combined with the stress state of the soil, the result is a volume-mass constitutive relationship. Three volume-mass constitutive relationships (i.e., void ratio, water content and degree of saturation) are generally viewed as being the most fundamental; however, only two of the relations are independent. The unsaturated soil properties associated with seepage, volume change and shear strength problems are also related to the volume-mass soil properties. While the unsaturated soil properties are often estimated as simply being a function of the soil-water characteristic curve, it is more accurate to define the properties in a more rigorous manner in terms of the volume-mass soil properties. The advancement of computing capabilities means that it is quite easy to formulate constitutive relations for shear strength and permeability, for example, in terms of all volume-mass properties of the unsaturated soil.</p><p>The objectives of this dissertation include: i) the development of volume-mass constitutive models for unsaturated soils; ii) the further study and verification of the volume-mass constitutive behavior of unsaturated soils; and iii) the development of techniques for visualization of volume-mass constitutive surfaces for unsaturated soils. To achieve these objectives, the present research study was conducted from both theoretical and experimental bases.</p><p>The theoretical program commenced with a comprehensive literature review of the volume-mass constitutive relationships for unsaturated soils. A new, more rigorous volume-mass constitutive model was then proposed. Appropriate terminology was introduced for the development of the model, followed by an outline of the assumptions used and the mathematical derivation. The proposed model requires conventionally obtainable soil properties for its calibration. The model is capable of predicting both the void ratio and water content constitutive relationships for various unsaturated soils, taking into account elastic and plastic volume changes. Various stress paths can be simulated and hysteresis associated with the soil-water characteristic curve can be taken into account. </p><p>Two closed-form equations for the volume-mass constitutive relationships were derived. A computer software program was written based on the theory of the proposed volume-mass constitutive model. Techniques for the visualization of the volume-mass constitutive surfaces were then presented. An experimental program was conducted in the laboratory. The experimental program involved the verification of a new testing apparatus. Several soils were selected for testing purposes and appropriate testing procedures were established (i.e., soil specimens were initially slurry). The testing stress paths followed in the experimental program were different from most research programs conducted in the past and reported in the research literature. Conclusions regarding the compressibility, stress path dependency, and hysteretic nature of the soil-water characteristic curve of an unsaturated soil were presented.</p><p>A considerable number of test results (i.e., from both the experimental program and the research literature) were used in the verification of the new volume-mass constitutive model. This model has proven to be effective in predicting both collapse and expansion of a soil. The volume-mass constitutive model appears to predict behaviour in a satisfactory manner for a wide range of soils; however, the predictions appear to be superior for certain soils. In all cases the volume-mass predictions of the model appear to be satisfactory for geotechnical engineering practice.

<p>Many geotechnical engineering problems involve combining two or more independent physical processes as a coupled solution of seepage, volume change and shear strength. For any physical process being modeled, it is desirous to be able to compute any of the volume-mass soil properties. When the volume-mass soil properties are combined with the stress state of the soil, the result is a volume-mass constitutive relationship. Three volume-mass constitutive relationships (i.e., void ratio, water content and degree of saturation) are generally viewed as being the most fundamental; however, only two of the relations are independent. The unsaturated soil properties associated with seepage, volume change and shear strength problems are also related to the volume-mass soil properties. While the unsaturated soil properties are often estimated as simply being a function of the soil-water characteristic curve, it is more accurate to define the properties in a more rigorous manner in terms of the volume-mass soil properties. The advancement of computing capabilities means that it is quite easy to formulate constitutive relations for shear strength and permeability, for example, in terms of all volume-mass properties of the unsaturated soil.</p><p>The objectives of this dissertation include: i) the development of volume-mass constitutive models for unsaturated soils; ii) the further study and verification of the volume-mass constitutive behavior of unsaturated soils; and iii) the development of techniques for visualization of volume-mass constitutive surfaces for unsaturated soils. To achieve these objectives, the present research study was conducted from both theoretical and experimental bases.</p><p>The theoretical program commenced with a comprehensive literature review of the volume-mass constitutive relationships for unsaturated soils. A new, more rigorous volume-mass constitutive model was then proposed. Appropriate terminology was introduced for the development of the model, followed by an outline of the assumptions used and the mathematical derivation. The proposed model requires conventionally obtainable soil properties for its calibration. The model is capable of predicting both the void ratio and water content constitutive relationships for various unsaturated soils, taking into account elastic and plastic volume changes. Various stress paths can be simulated and hysteresis associated with the soil-water characteristic curve can be taken into account. </p><p>Two closed-form equations for the volume-mass constitutive relationships were derived. A computer software program was written based on the theory of the proposed volume-mass constitutive model. Techniques for the visualization of the volume-mass constitutive surfaces were then presented. An experimental program was conducted in the laboratory. The experimental program involved the verification of a new testing apparatus. Several soils were selected for testing purposes and appropriate testing procedures were established (i.e., soil specimens were initially slurry). The testing stress paths followed in the experimental program were different from most research programs conducted in the past and reported in the research literature. Conclusions regarding the compressibility, stress path dependency, and hysteretic nature of the soil-water characteristic curve of an unsaturated soil were presented.</p><p>A considerable number of test results (i.e., from both the experimental program and the research literature) were used in the verification of the new volume-mass constitutive model. This model has proven to be effective in predicting both collapse and expansion of a soil. The volume-mass constitutive model appears to predict behaviour in a satisfactory manner for a wide range of soils; however, the predictions appear to be superior for certain soils. In all cases the volume-mass predictions of the model appear to be satisfactory for geotechnical engineering practice.

IC設計公司的間接成本高，須追求規模經濟，但對物聯網這種少量多樣的應用又有厚望。因此多會謹慎投入，怕投入如流水，又怕咬不到餅。 面對整體龐大的物聯網產業，歐美大廠運用優勢，嘗試建立特有的生態圈將各方納入。案例IC設計公司的規模很難和歐美大廠對作，但也有其優勢，不過原規模經濟的商業模式不再適用。 IC複雜使其位居重要位置，而案例IC設計公司擁有許多優秀工程人才，再加上成熟產品線廣，且和物聯網關聯，都是優勢資源。但做的是B2B生意，接觸不到終端市場，而新IC開發時間長，導致對終端需求掌握度低，且現有工程師數量是無法支援有多樣需求的微型物聯網業者，這些就是劣勢資源。 如案例IC設計公司將微型物聯網業者及獨立工作者拉到平台上，提供工作者自主工作機會，同時滿足物聯網業者不足的支援人力。案例IC設計公司須貢獻包含工作者的訓練與認證、協助物聯網業者找到符合的工作者、設計專案流程管理機制同時確保工作者收得到價金。如此解決了對微型物聯網業者支援不夠的問題，還可藉由平台獲取最真確的需求資訊，又解決另一困境。 三方都有得且無太多風險，可行性確認。用波特的五力分析，案例IC設計公司導入新商業模式有相當優勢，早投入更可建立先行者優勢。