Preface |
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ix | |
Acknowledgments |
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xi | |
Authors |
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xvii | |
List of notations |
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xix | |
List of nomenclature |
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xxiii | |
1 Introduction |
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1 | (16) |
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1.1 Role of vegetation in civil engineering |
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1 | (1) |
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1.2 Fundamentals of unsaturated soil mechanics |
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2 | (2) |
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1.3 Energy balance, water, carbon and nutrient cycles in a soil-plant-atmosphere system |
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4 | (7) |
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4 | (1) |
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5 | (2) |
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7 | (1) |
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1.3.4 Photosynthesis and respiration of plants |
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8 | (1) |
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9 | (2) |
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1.4 Water absorption and transportation mechanism of vascular plants |
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11 | (4) |
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1.4.1 Mechanisms of root water uptake |
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12 | (1) |
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1.4.2 Mechanisms of water transport from roots to leaves |
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12 | (2) |
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1.4.3 Repair of xylem cavitation |
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14 | (1) |
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1.5 Structure of the book |
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15 | (2) |
2 Hydrological effects of plant on matric suction |
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17 | (34) |
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17 | (1) |
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2.2 Factors contributing to transpiration-induced suction |
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17 | (19) |
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2.2.1 Atmospherically controlled plant room |
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17 | (3) |
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2.2.2 Effects of soil density on plant growth and induced suction |
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20 | (4) |
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2.2.2.1 Grass characteristics |
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21 | (1) |
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2.2.2.2 Water infiltration rate |
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22 | (1) |
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2.2.2.3 Induced suction distribution |
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22 | (2) |
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2.2.3 Effects of plant density on plant growth and induced suction |
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24 | (9) |
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2.2.3.1 Above-ground plant characteristics |
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24 | (2) |
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2.2.3.2 Below-ground plant characteristics |
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26 | (3) |
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2.2.3.3 Suction induced during evapotranspiration |
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29 | (1) |
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2.2.3.4 Water infiltration rate |
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30 | (1) |
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2.2.3.5 Suction preserved during rainfall |
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31 | (2) |
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2.2.4 Effects of CO2 on plant growth and induced suction |
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33 | (3) |
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2.2.4.1 Plant characteristics |
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34 | (1) |
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2.2.4.2 Induced matric suction |
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35 | (1) |
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2.3 Correlating plant traits with induced soil suction |
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36 | (7) |
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2.3.1 Plant traits and physiological responses |
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37 | (1) |
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2.3.2 Relationships between plant traits and induced suction |
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37 | (6) |
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2.4 Root-induced changes in soil hydraulic properties |
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43 | (6) |
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2.4.1 Water retention curve of vegetated soil |
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43 | (5) |
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2.4.1.1 Soil vegetated with grass |
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43 | (2) |
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2.4.1.2 Soil vegetated with tree |
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45 | (3) |
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2.4.2 Water permeability function |
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48 | (1) |
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49 | (2) |
3 Mechanical effects of plant root reinforcement |
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51 | (20) |
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51 | (1) |
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3.2 Revisiting the power decay law |
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51 | (7) |
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3.2.1 The state of the art |
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51 | (1) |
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3.2.2 Root tensile behaviour of species native to temperate Europe |
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52 | (5) |
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3.2.3 Inter-species variability |
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57 | (1) |
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3.2.4 Strength-diameter relationships |
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57 | (1) |
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3.3 Root tensile behaviour |
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58 | (6) |
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3.3.1 Four plant species native to southern China |
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58 | (2) |
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3.3.2 Root sampling and measurement of root area ratio (RAR) |
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60 | (2) |
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62 | (2) |
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3.4 Effects of fungi on root biomechanics |
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64 | (5) |
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3.4.1 Actions of fungi on cellulose |
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64 | (1) |
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3.4.2 Effects of the AMF colonisation rate on plant biomass |
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64 | (2) |
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3.4.3 Effects of AMF on root biomechanical properties |
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66 | (2) |
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3.4.4 Potential mechanisms |
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68 | (1) |
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69 | (2) |
4 Field studies of plant transpiration effects on ground water flow and slope deformation |
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71 | (34) |
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71 | (1) |
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4.2 Case study 1: Compacted sandy ground at HKUST Eco-Park |
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71 | (14) |
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4.2.1 Plant effects on the infiltration rate |
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71 | (3) |
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4.2.2 Effects of plant variability on the infiltration rate |
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74 | (2) |
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4.2.3 Effects of mixed tree-grass planting on plant growth and soil hydrology |
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76 | (9) |
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4.2.3.1 Observed plant traits |
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77 | (4) |
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4.2.3.2 Effects of tree spacing on saturated water permeability (kJ |
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81 | (1) |
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4.2.3.3 Effects of tree spacing on the transpiration- induced suction response |
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81 | (2) |
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4.2.3.4 Effects of tree spacing on the suction response during rainfall |
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83 | (2) |
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4.3 Case study 2: A cut slope of expansive clay slope in Zaoyang, China |
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85 | (6) |
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4.3.1 Grass effects on infiltration characteristics |
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88 | (1) |
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4.3.2 Grass effects on soil pore-water pressure |
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89 | (2) |
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4.4 Case study 3: A natural saprolitic hillslope in Hong Kong |
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91 | (11) |
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4.4.1 Plant-induced changes in soil hydrology |
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95 | (2) |
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4.4.2 Plant effects on slope hydrological responses |
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97 | (1) |
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4.4.3 Transpiration effects on the stress-deformation characteristic of the slope |
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98 | (8) |
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4.4.3.1 During the rainstorm from 5 to 9 June 2008 |
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98 | (3) |
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4.4.3.2 During the dry season |
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101 | (1) |
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102 | (3) |
5 Theoretical modelling of plant hydrological effects on matric suction and slope stability |
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105 | (22) |
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105 | (1) |
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5.2 Plant transpiration-induced changes in matric suction and slope stability |
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106 | (12) |
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5.2.1 Governing equations |
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106 | (3) |
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5.2.2 Steady-state solutions |
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109 | (4) |
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5.2.3 Transient-state solutions |
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113 | (1) |
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5.2.4 Root architecture effects on soil matric suction |
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114 | (3) |
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5.2.4.1 Effects of root architecture on steady-state PWP |
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114 | (1) |
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5.2.4.2 Effects of root architecture on transient-state PWP |
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115 | (1) |
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5.2.4.3 Effects of root depth |
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116 | (1) |
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5.2.5 Root architecture effects on slope stability |
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117 | (1) |
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5.3 Root-induced changes in soil hydraulic properties |
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118 | (6) |
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5.3.1 Theoretical modelling |
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118 | (3) |
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5.3.2 Plant effects on matric suction |
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121 | (1) |
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5.3.3 Plant effects on slope stability |
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122 | (2) |
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124 | (3) |
6 Effects of plant on slope hydrology, stability and failure mechanisms: Geotechnical centrifuge modelling |
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127 | (32) |
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127 | (4) |
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6.1.1 Fundamental principles of centrifuge modelling |
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127 | (2) |
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6.1.2 The state-of-the-art geotechnical centrifuge at HKUST |
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129 | (1) |
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6.1.3 Centrifuge modelling of the behaviour of vegetated slopes |
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129 | (2) |
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6.2 Mechanical root reinforcement of soil slopes |
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131 | (5) |
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6.2.1 Performance of bare slopes |
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132 | (2) |
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6.2.2 Effects of mechanical root reinforcement on slope stability and failure mechanisms |
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134 | (2) |
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6.2.2.1 Observation of slope failure mode |
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134 | (1) |
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6.2.2.2 Slope stability back-analysis |
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134 | (2) |
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6.3 Artificial roots for modelling both plant hydrological and mechanical effects |
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136 | (6) |
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6.3.1 Design and working principle |
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136 | (2) |
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6.3.2 Performance of the root system |
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138 | (4) |
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6.4 Effects of transpiration on root pull-out resistance |
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142 | (4) |
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6.4.1 Effects of root architecture on the PWP distribution (i.e., matric suction) |
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142 | (2) |
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6.4.2 Effects of transpiration-induced suction on pull-out resistance |
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144 | (2) |
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6.4.3 Effects of root architecture on pull-out resistance 14S |
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6.5 Plant hydro-mechanical effects on slope behaviour |
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146 | (11) |
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6.5.1 Effects of plant root architecture on slope hydrology |
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147 | (5) |
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6.5.1.1 Responses of pore-water pressure during the simulation of transpiration |
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147 | (2) |
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6.5.1.2 Responses of pore-water pressure during rainfall |
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149 | (3) |
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6.5.2 Plant effects on slope stability |
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152 | (3) |
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6.5.3 Effects of root architecture on the failure mechanisms of 60° slopes |
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155 | (2) |
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157 | (2) |
References |
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159 | (16) |
Author index |
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175 | (4) |
Subject index |
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179 | |