本文除了介紹台中港碼頭的破壞案例，將災害調查數據與日本地震災害案例作比較之外，並希望藉由能夠由數值分析軟體FLAC模擬台中港現場災害的破壞模式。並在模擬的過程中探討以FLAC進行動態分析的各項步驟以及相關的影響因素，確立以FLAC進行動態分析的可行性，並提供未來學者欲以FLAC進行動態分析研究的參考。 本研究的成果，在案例研究方面，建立了台中港與神戶港案例模式的比較，從施工方式與現地尺寸、地震規模和地質鑽探記錄去探討兩個不同時空下地震災害的關連性，以提供未來工程設計的參考。另一個最主要目的，更是了解FLAC程式動態分析法的特性與步驟，引進多種分析方法，建立起現地孔隙水壓分布與地表變形模式，並針對膨脹角(Dilation Angle)於沉箱運動行為與孔隙水壓激發特性進行參數分析。 從參數分析的結果發現，具有膨脹角的土壤對於沉箱位移量的發展與孔隙水壓的激發都有明顯抑制的作用；而利用土壤的殘餘強度進行動態分析，對於後線地表變形的模擬是一種較為實用的模擬技巧。從現地孔隙水壓的模擬結果，可以幫助我們對於當地震作用時，沉箱基礎鄰近區域的孔隙水壓上升的分布情況，有更深一層的了解。另外，藉由作用於牆體動態土壓力的觀測，探討利用數值分析軟體(FLAC)之計算結果與傳統理論(M-O法)計算結果之間的準確性。 It has been investigated and evaluated that destructive pattern in Taichung Harbor and the Port and Rokko Island occurred during 1999 Chi-Chi earthquake and 1995 Hyogoken-Nambu earthquake. Destruction phenomenon can be divided into two parts: Lateral displacement, settlement, and inclination induced by the lost of bearing capacity in foundation soil below the caisson; another way, not only serious ground failure but also structure damages will be caused by lateral spreading and settlement of saturated cohesionless soil liquefaction behind the quay wall resulting from strong earthquake. In this thesis, observed lateral displacement and settlement of the ground surface resulting from liquefaction in Taichung Harbor are described and evaluated in terms of the values estimated based on existing methodology. Finally, the outcome of an in-situ survey and the comparison between Taichung Harbor and Kobe Port on permanent deformations behind the quay wall are presented. The numerical tool employed in the present study is FLAC, a two-dimensional explicit finite difference code for modeling soil, rock and structural behavior. The result conducted by static earth pressure analysis concluded that a lateral extension of as much as six times the wall height is required to eliminate the effect of the boundary condition for infinitely extended backfills. In addition, a perfect result compared with classical Coulomb earth pressure analysis theory is shown. By dynamic analysis of caisson quay wall with FLAC, two goals are achieved. One is to understand how to conduct the dynamic analysis in FLAC when pore pressure generation and ground deformation is considered. Another is to verify the ability of FLAC to predict hazard in field model. For the numerical model, comparison between measured and computed model response were made. The result shows that ground deformation simulation is well done by using residual strength method in dynamic analysis. In addition, the displacement of quay wall and the pore pressure generation is greatly induced when dilation angle is increasingly applied in the backfill or foundation soil.
