台灣位處地震頻繁的環太平洋地震帶上，歷史上曾遭遇許多災害性地震，隨之而來的土壤液化問題在近幾年逐漸受到人們關注。本研究使用FLAC2D (version 7.0)有限差分軟體研究台灣液化土層上單棟建築物之受震行為，研究之地盤條件，是以1999年集集地震與2016年美濃地震之液化鑽孔資料規劃一簡化土層，並以PM4Sand砂土模型模擬液化土層；建築物條件，選用台灣常見的鋼筋混凝土五層樓淺基礎建築物進行模擬；輸入震動以1999年集集地震波形進行模擬。本研究共進行十四組數值模擬，內容包含三大變因，分別為地下水位變化、不同基礎型式、淺層地盤改良等，探討於各種情況下之建築物受震液化行為。 研究結果顯示：地下水位下降對建築物抗液化效果顯著；不同基礎形式則因重量與應力影響圈等因素，抗液化效果不佳；淺層地盤改良工法則因為上部結構傾倒彎矩、基礎版接觸應力等因素，使該工法不具抗液化成效，於台灣的適用性存疑。 ;Taiwan is located in the seismically active Pacific Ring of Fire and has experienced numerous catastrophic earthquakes throughout its history. In recent years, the issue of soil liquefaction following these earthquakes has garnered increasing attention. This study employs FLAC2D (version 7.0), a finite difference software, to investigate the seismic behavior of a single building situated on liquefied soil layers in Taiwan. The ground conditions for the study are based on simplified soil layers derived from liquefaction borehole data from the 1999 Chi-Chi Earthquake and the 2016 Meinong Earthquake, using the PM4Sand model to simulate the liquefied soil layers. The building conditions selected for simulation are typical five-story reinforced concrete shallow foundation structures commonly found in Taiwan. The seismic input is based on the waveforms from the 1999 Chi-Chi Earthquake.This study conducts a total of fourteen numerical simulation tests, examining three major variables: changes in groundwater levels, different foundation types, and shallow ground improvement methods. The study aims to explore the liquefaction behavior of buildings under various conditions.
The results indicate that lowering the groundwater level significantly enhances the building′s resistance to liquefaction. However, different foundation types show poor liquefaction resistance due to factors such as weight and stress influence zones. The shallow ground improvement methods, on the other hand, do not demonstrate effective liquefaction resistance due to issues like tilting moments of the superstructure and contact stresses of the foundation plate, raising doubts about their applicability in Taiwan.
