近年來，國際上之營建設計潮流趨勢逐漸朝性能設計邁進，國內以適當數值工具進行性能設計之研究仍處萌芽階段，而EQWEAP(Earthquake Wave Equation Analysis for Piles)之發展行之有年，本研究即以EQWEAP一維波動方程分析和二維、三維有限元素分析樁基礎之受震行為做一比較，將不同數值工具之分析結果及其適用性做一說明。EQWEAP為以集中質塊法模擬自由場反應結果，將其做為前置解進行後續一維波動方程模擬樁基礎受震反應。有限元素分析則包含兩部分，二維與三維分析，分別以荷蘭Delft University of Technology所開發的PLAXIS與由韓國MIDAS IT所開發的MIDAS/GTS 為工具進行樁基礎受震反應分析。 本研究以大台北地區之橋梁樁基礎為數值模型案例(地層深40m和70m，樁徑2m，樁長30m和60m)，考慮鄰近地震觀測站加速度紀錄，並以台北盆地地震危害度曲線(seismic hazard curve) 為主，藉建築耐震設計規範所訂的30年、475年、2500年再現週期所對應的最大地表加速度0.12g、0.29g、0.51g為主進行分析，討論線性樁配合均質線性土壤、非線性土壤與實際案例(分層土壤)分析，地震輸入維度對於樁基礎分析時之影響。 研究成果顯示1.在地盤和地貌構造相對單純的情況下，二維和三維有限元素分析結果均和一維分析相似2.考慮土壤非線性行為後，波動方程和有限元素分析結果亦相似，3. 無論地震力的改變為何，一維波動方程分析與二維和三維有限元素結果皆相當接近4.相對簡單的地質構造下，根據三維有限元素分析結果，單向度水平地震反應不易受其他向度地震反應影響。由此可說明單向度配合一維分析可有效模擬樁基礎行為，分析時間亦以一維波動方程較短，內力影響輸出最為完整，利於樁基礎耐震性能之研究。 In recent years, the geotechnical design is gradually moving towards Performance-Based Design (PBD). The study on seismic PBD of pile foundation is still at an early stage in Taiwan while an available tool EQWEAP (Earthquake Wave Equation Analysis for Piles) has been introduced for many years. In this study, the one-dimensional EQWEAP analysis is compared to two-dimensional and three-dimensional finite element analysis using PLAXIS and Midas/GTS programs in order to understand the reliability of the EQWEAP analysis for applications. Numerical model of a typical bridge pile foundation located in Sinjuang District of New Taipei City area is considered. The thickness of the ground site is assumed as 40m and 70m, respectively. A 3 by 3 pile foundation is considered with each pile diameter 2m, pile length 30m and 60m at different ground sites. Acceleration time records at the nearby seismic stations were obtained and calibrated to 30, 475 and 2500 years considering the seismic design specifications in Taiwan. The corresponding peak ground accelerations are 0.12g, 0.29g and 0.51g respectively. Discussions were made mainly based on observations of linear pile behaviors with the changes of soils to linear and non-linear one(s). Furthermore, the effects of multi-dimension of the seismic accelerations were also investigated. The observations are summarized as follows: (1) For sites with relatively simple geological and geographical conditions, the solutions from 1D and 2- or 3D are very similar. (2) With proper control of the nonlinear soil modeling, the solutions from wave equation and finite element analysis are found similar. (3) No matter how the seismic force changes, the solutions from these analyses are compatible to each other. (4) According to the results of three-dimensional finite element analysis, how many degrees of the input used in the seismic analysis is not that sensitive. Therefore one can always use 1D analysis to obtain rational results. EQWEAP thus can be used to simulate seismic behaviors of the piles for PBD study due to its fast and effective computations.