本文應用Vardoulakis和Harnpattanapanich所開發的方法來解決由表面荷重引起之三維壓密問題。 此方法(我們稱之為L-F法)是建立在Biot的孔隙彈性理論與位移函數在空間與時間轉換域的一般解上。 然而，由於一般解中的指數函數包含有深度 z 以及時間轉換後的變量 "s" ，因此當這兩個變量超出可計算範圍時，會出現數值上的困難。 本研究著重於發展數值技巧以改進L-F法在一些極端情況的使用，包括了：(1) 厚層問題、(2) 多含水/阻水層問題、(3) 極限時間下的壓密行為。 此外，本文也採用有限元素法(FEM)來驗證數值技巧在平面應變與三維下的準確度。 藉由兩種方法的比較，顯示本文提出之數值技巧成功地解決了關於指數函數的問題，同時也突顯出L-F法在效率上的優勢，尤其是對於三維的壓密問題。

This thesis applied the numerical procedure developed by Vardoulakis and Harnpattanapanich to solve three-dimensional consolidation problems caused by surface loading. This procedure (we call it the L-F method) is based on Biot’s poroelastic theory of soils and the general solution of the displacement functions in the transform spatial and time domains. Since the general solutions consist of exponential functions in terms of depth z and the transformed variable "s" of time, difficulties will occur when the components of exponential terms excess the numerical limits. This research focused on improving the L-F method to solve some extreme cases, including (1) thick-layer problems, (2) multi-aquifers/aquitards systems, and (3) limiting time consolidation behaviors. Additionally, finite element models were built to verify the results of our numerical method, and the verification was carried out in both plane-strain and 3D problems. The comparisons show that our numerical techniques successfully solve the difficulties related to exponential terms and the efficiency of the L-F method is better than the finite element method, especially for 3D problems.

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