桃園台地紅土入滲行為之探討

Study of Infiltration Behavior in Taoyuan Laterite Terrance

李昆性(Kuen-Shing Lee)

指導教授 ： 張德鑫

中原大學/工學院/土木工程研究所/碩士(2004年)

https://doi.org/10.6840/cycu200400007

摘要

摘要
近年來許多紅土台地常發生邊坡崩塌或其他災害，除受紅土台地本身地形和土質特性影響外，環顧這些災害發生的原因，可以發現其共通的原因為降雨沖刷或入滲所致。因此本研究將探討桃園地區紅土之降雨入滲行為及降雨和未飽和層含水量變化之關係。
在探討未飽和層之水份傳輸行為時，飽和水力傳導係數為重要參數，本研究採用現地採樣配合實驗室試驗的方式，求得其值約為3cm/hr，與相關文獻比較尚在合理範圍內。其次本研究利用Van Genuchten之經驗式配合相關參數值建立水土保持曲線和未飽和層之水力傳導係數，並以數值模擬之方法配合現地觀測資料驗證上述各項參數之正確性。
本研究由現地氣象及土壤含水量資料的分析發現，單日降雨量未足0.5mm或連續降雨量未達2.1mm以上，對於10cm深土層之含水量變化影響不大；當連續降雨量達到5mm以上時，才可能使20cm土層之含水量產生變化。在數值模擬中，由於未考慮降雨初期之毛管作用及土壤裂縫所產生之入滲現象，因此在降雨初期含水量變化之模擬有時間稽延產生。

關鍵字

none

並列摘要

Abstract
The slope collapse or other disasters occur frequently in many regions of laterite in these years. According to these reasons for diseases occurring except that affected by topography of laterite tableland and soil characteristics, we can find that the common reason is rainfall flush or infiltration. Thus, the research will study the infiltration behavior in Taoyuan laterite and the changing of moisture between rainfall and unsaturated layer.
When study of delivering the behavior of water in unsaturated layer, the saturated hydraulic conductivity is an important parameter. The research adopts the ways of sampling on the ground and matching with the laboratory test, and we can find that the value is about 3cm/hr. The value is inside the reasonable range, which compares with the site data. Next, the research uses the formula of Van Genuchten and matches with parameter value to establishment soil water characteristic curves and unsaturated hydraulic conductivity. In addition, it uses the way of numerical simulation and matches with the data of observation on the ground to prove the accuracy of above parameters.
The research finds that the amount of rainfall a day is under 0.5mm or continuous rainfall is less than 2.1mm through the analysis of meteorology on the ground and the data of soil moisture, and it doesn’t affect on the moisture of 10cm deep soil layer. When the continuous rainfall is above 5mm, the moisture of 20cm soil layer may change. In numerical simulation, the simulation of the moisture changing during the beginning of rainfall will delay, because we didn’t consider the capillary effect and the infiltration of soil cracks.

並列關鍵字

none

參考文獻

12.曾琮愷 (2002)，「隧道開挖滲流現象之模擬」，私立中原大學土木工程學系研究所碩士論文。

14.郭麗娥 (2003)，「未飽和紅土水力傳導係數之研究」，私立中原大學土木工程學系研究所碩士論文。

13.張德鑫、蔡西銘、鄭正隆、李昆性、郭麗娥 (2002)，「降雨滲流現象對邊坡穩定之時變分析」，行政院農委會水土保持局科技計畫。

17.Richard, L.A. (1931), “Capillary Conduction of Liquids through Porous Medium’’, Physics, Vol.1, pp.318~333.

19.Ferguson, H., and Gardner, W.H. (1955), “Water Content Measurement in Soil Columns by Gamma Ray Absorption’’, Soil Sci. Soc. Am. Proc., Vol.26, pp.11~14.