二維裂縫暫態入滲過程之研究

Transient Infiltration Process of Seepage Flow from Two Dimensional Cracks

周憲德(Hsien-Ter Chou) ； 李伯亨(Bo-Heng Lee) ； 陳主惠(Chu-Hui Chen)

《中國土木水利工程學刊》 20卷4期 (2008/12) Pp. 483-493

https://doi.org/10.6652/JoCICHE.200812_20(4).0003

摘要

本文以理論及實驗分析非飽和土壤中裂縫之暫態入滲形態與特性，並探討依Green-Ampt (G-A)假設所推導之一維及擬二維裂縫暫態入滲公式的適用範圍。裂縫入滲濕鋒由外而內可分為目視乾濕界面、G-A濕鋒及飽和濕鋒等三種，本文分別利用砂箱（細粒料土壤）及Hele-Shaw模型（粗顆粒土壤）進行實驗分析與比較。相較於細顆粒土壤，粗顆粒土壤之重力效應較顯著。入滲初期，濕鋒可分割為A1及A2上、下兩個無因次曲線，且砂箱實驗與Hele-Shaw模式兩者具極佳相似入滲形態，故可利用此曲線關係推求土壤內部之飽和濕鋒形態。本文所提出之裂縫暫態入滲範圍及入滲率可供分析現地裂縫入滲及邊坡穩定之參考。

關鍵字

二維暫態入滲 ； 裂縫 ； Hele-Shaw模式 ； 濕鋒 ； Green-Ampt模式

並列摘要

This study explores the 2-D transient seepage flow from cracks into different porous media, including both coarse material and fine material. The Crack Apparatus of Hele-Shaw Model is chosen to analyze the configuration of wetting front in the coarse material. Due to the effect of gravity on the flow condition, the wetting front in the coarse material is more elongated than that of the fine material. The limited width of wetting front is approaching a constant value in the coarse material. On the other hand, the effect of capillary causes the wetting front in the fine sand expands continuously as time increases. In this paper, a Green-Ampt type of conceptual model is proposed to describe the propagating process of the wetting front in different materials. The time-dependent wetting front and the corresponding wetted area are obtained in this study, which are beneficial for examining the leaky contaminant transport from cracks into different porous media or for the analysis of the slope stability problems.

並列關鍵字

2-D transient seepage flow ； crack ； hele-shaw model ； wetting front ； green-ampt model