三維暫態土壤水流模式顯式差分解之一致性及穩定性數値結構分析

Abstract

The three dimensional numerical techniques being considered necessarily to analyse the slope stability problems, and that water content being evidently taken the greatest effects on soil strngth, this study was to clarify the numeric method of explicit time with central finite difference scheme for solving the governing equation of water movement in soils under the three dimenional unsteady state conditions. After thorough analysis, in which exponential type of functions for hydraulic conductivity and soil water characteristic curve were incooperated as an example, the consistency of the governing equation was proved and its stability condition was defined. The stability condition is valid only when the gradient of matric potential in a solum is restricted. 三維暫態水份流動模式之數値分析，因三維水份流動之硏究，特別是用於邊坡穩定分析漸受重視而益形重要。本文首先說明該模式之導引，然後配合指數形式之水力導水度函數與水份特性函數之引用，分析顯式中央差分法用於該模式之穩定性、一致性及收斂性。最後獲得一致性、穩定性及收斂性之數値結構，但亦指出其穩定條件有其適用上限。