工程開挖裸露地表植生覆蓋對土壤沖蝕之探討

The Effects of Surface Protection On Soil Erosion For Construction Excavation Slopes

林義傑(Yi-Chieh Lin)

指導教授 ： 張子修

朝陽科技大學/理工學院/營建工程系/碩士(2009年)

摘要

摘要
目前整治崩塌裸露地及邊坡穩定，常使用人造被覆材料進行坡面保護工法，本研究透過人工降雨室內實驗，模擬降雨進行土壤沖蝕量，探討植生覆蓋材料單層植生棉毯、稻草蓆與矩形錐立體植生網抑制土壤沖蝕之成效。
經由本研究結果數據顯示三種植生覆蓋材料與對照組（無鋪設）比較，在坡度20°、30°、40°皆能有效防制土壤沖蝕。本研究結果顯現，一般而言覆蓋材料在坡度30度以上是最重要的抗沖蝕條件，尤其坡度增加到40度可明顯降低土壤沖蝕量53％~64％；本實驗結果亦發現植生棉毯和稻草席隨坡度增加其抗沖蝕效率並沒有明顯下降，故可推論可以適用在坡度高且變化大的地區；而矩型錐立體植生網隨坡度增加到40度時其抗沖蝕效率顯著下降，則其抗土壤沖蝕效率不佳，所以在工程實務上應該避免使用在坡度40度之邊坡。

關鍵字

土壤沖蝕 ； 抗沖蝕效率 ； 植生覆蓋

並列摘要

Abstract
In the recent years, man-made materials have been widely used in slope stabilization constructions as a type of surface protection on the exposed soils to mitigate the slope-slide related natural hazards from construction excavations throughout the Taiwan region. A series of controlled rainfall tests were conducted in the laboratory for the research to evaluate the effects of surface protection on soil erosion using 3 selected man-made materials: (1) single layer cotton blanket, (2) straw blanket, and (3) cubic geo-synthetic cloth, which are the most commonly used in practice. The parameters used in the laboratory tests include (1) type of surface protection, (2) rainfall intensity (2.14mm/minute) and duration (3, 6, 9 minutes), and slope angle (20°, 30°, 40°).
Results of the study indicated that surface protection with all 3 materials can reduce soil erosion due to surface run-off compared with that without surface protection for the slope angle from 20°to 40°. The study results also revealed that surface protection using man-made materials is the most influential parameter for slope deeper than 30° to reduce soil erosion due surface run-off. This is more significant for slope of 40° that soil erosion can be reduced 53-64% when compared to that of slope angle 30° when surface protection was installed. Also, when cotton blanket and straw blanket were used, surface protection leaded to no reduction in soil erosion resistance for all slope angles from 20°to 40°. This implies that these two materials are ideal materials for slopes with greater and changing angles for reducing soil erosion. However, the soil erosion resistance using the cubic geo-synthetic cloth became less significantly when the slope angle increased from 30° to 40°. This suggested that cubic geo-synthetic cloth exhibit less effectiveness for reducing soil erosion for slope at greater angles, therefore should be avoided in practical applications where the excavation slope angles are greater than, say 40°.

並列關鍵字

soil erosion ； erosion resistance ； surface protection

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