土壤液化對建築物、土石壩、橋梁、港口和地下管線都有很大的影響。許多地震會導致地盤液化，造成大規模性災難與經濟損失。因此，了解土壤液化對於結構物的影響，是一重要課題。利用離心模型試驗來研究地震引致的地盤液化，已被證明，是一有效並具有良好試驗結果之方法。 本研究設計兩種不同樓層數(1與3層樓)之淺基礎建築物模型，利用中大地工離心機於65g離心力場下進行模型試驗，並藉由試體中安裝之加速度計、孔隙水壓計、線性差動可變變壓器(LVDT)、雷射位移計(LDT)及土壓力計，分別量測各項物理量之受震歷時，探討淺基礎建築物於液化地盤上之受震反應。 研究結果顯示:(1) 砂土試體在土壤未達液化狀態時，有明顯加速度振幅放大效應；但當地盤產生液化現象時，液化層會阻隔振波的傳遞，對建築物有振動衰減之效果；(2)建築物越重時，受震後所產生的沉陷量會越大；(3)建築物之沉陷會隨輸入振動的增強而增加，且大部分的沉陷都在震動期間所產生；(4)當施加震動越大時，液化層深度會越深，且土層液化狀態維持時間較長，超額孔隙水壓消散所需的時間也較為長久。(5)地表的緊砂層，減少地表的最大加速度振幅，更能大幅度降低地表沉陷量與建築物沉陷量。 ;The effects of liquefaction on foundations of buildings, bridges and other structures, as well as on ports and buried lifelines, cause large economics losses in many earthquakes.This research is a project for studying post-earthquake settlement and deformation behavior of buildings with shallow foundations in liquefiable ground using dynamic centrifuge tests. In this research, a centrifugal scale-down model was specifically designed and tested at 65g. The model buildings used in the study have two different weights and in the different sand grounds saturated with viscous fluid. Several accelerometers, pore water pressure transducers, linear variable differential transformer (LVDT), laser displacement sensor and earth pressure cells were installed to measure the seismic responses.The measured data included the generation of pore water pressure the ground and the displacement histories of the ground and building during shaking. Based on the model test results, the following conclusions are made: (1) In liquefiable ground, liquefied layer will isolate the vibration that progagate to the buildings. (2) After earthquake shaking, the heavier the building the settlement ,the larger. (3) The settlement of Buildings settlement increase with the increasing of the input vibration. (4) The liquefied depth of sand layer increases with the increasing of input.(5) By setting the dense sand layer on the ground surface can significantly reduce the settlement of ground and building.
