17:15 〜 19:15
[HDS07-P14] Study on the Shallow Soil Erosion Characteristics of Vegetated Slopes and Their Effect on Slope Stability
キーワード：rainfall simulation test, root biomechanics, slope stability
Taiwan, situated at the Eurasian and the Philippine Sea Plate boundary, features a fragile, mountainous terrain. According to the Rural Development and Soil and Water Conservation Agency, Taiwan's sloping land accounts for 74% of its total area. Seasonal rains from the spring monsoon and intense summer typhoons bring high-intensity rainfall, with the average annual rainfall over the past decade reaching approximately 2,500 mm.
This study selected Formosan alder (Alnus formosana (Burkill ex Forbes & Hemsl.) Makino) and Silver grass (Miscanthus floridulus (Labill.) Warb. ex K. Schum. & Lauterb.) as study materials to conduct erosion tests under varying rainfall intensities and slopes to assess their erosion resistance and explore the soil mechanical performance of root-containing soils.
The results of the rainfall simulation test showed that erosion volumes for vegetated samples were significantly lower than those for bare soil samples, with vegetation cover and slope identified as the primary factors affecting erosion volume.
Shear test results showed that Formosan alder could withstand a maximum shear force of approximately 1.63 kN, Silver grass a maximum of 0.98 kN, and bare soil 0.3 kN. Formosan alder and Silver grass exhibited significantly higher shear values than bare soil, with notable differences in the maximum shear resistance among the three. Soil cohesion and internal friction angles of root-containing soil in both test species were greater than those of bare soil, indicating that vegetation roots enhance effective soil cohesion.
The pull-out test results showed that the maximum average pull-out resistance was 0.52 kN for Formosan alder and 0.24 kN for Silver grass, with significant differences in average pull-out resistance between the two species. Single-root tensile test results indicated a positive correlation between root diameter and single-root tensile force, while tensile strength and Young's modulus negatively correlated with root diameter.
This study selected Formosan alder (Alnus formosana (Burkill ex Forbes & Hemsl.) Makino) and Silver grass (Miscanthus floridulus (Labill.) Warb. ex K. Schum. & Lauterb.) as study materials to conduct erosion tests under varying rainfall intensities and slopes to assess their erosion resistance and explore the soil mechanical performance of root-containing soils.
The results of the rainfall simulation test showed that erosion volumes for vegetated samples were significantly lower than those for bare soil samples, with vegetation cover and slope identified as the primary factors affecting erosion volume.
Shear test results showed that Formosan alder could withstand a maximum shear force of approximately 1.63 kN, Silver grass a maximum of 0.98 kN, and bare soil 0.3 kN. Formosan alder and Silver grass exhibited significantly higher shear values than bare soil, with notable differences in the maximum shear resistance among the three. Soil cohesion and internal friction angles of root-containing soil in both test species were greater than those of bare soil, indicating that vegetation roots enhance effective soil cohesion.
The pull-out test results showed that the maximum average pull-out resistance was 0.52 kN for Formosan alder and 0.24 kN for Silver grass, with significant differences in average pull-out resistance between the two species. Single-root tensile test results indicated a positive correlation between root diameter and single-root tensile force, while tensile strength and Young's modulus negatively correlated with root diameter.