1964日本新瀉地震、1995阪神大地震、2001年東日本大地震發生及2016年的美濃地震時，在震央附近許多地方都發生土壤液化之現象。臺灣西部平原區多屬地質軟弱的沖積地層，且地下水位面較高，而臺灣位於歐亞板塊交界，地震頻繁，在大地震發生時，極有可能發生土壤液化現象。若土堤結構位於砂質地盤、河岸或河堤邊，因受振引致土壤液化與側向滑動，會使土堤產生相當大的損害。 本研究藉由中央大學地工離心機暨振動台進行離心模型試驗，在50倍的人造離心重力場中，模擬現地土層及土堤在受振過程與土壤發生液化後之行為。並同時在離心模型中嘗試以地盤改良工法改善因土壤液化與側潰引致土堤結構的位移行為並比較各工法之成效。本研究採用的改良工法有垂直排水工法、礫石樁工法、降低飽和度工法及減輕載重工法；其中，降低飽和度工法為使用幫浦將氣體打入土壤孔隙中以降低土壤之飽和度，減輕載重工法為使用發泡性聚苯乙烯取代土堤的土壤以降低地盤上的載重。各工法改良之成效是以土層與土堤受振時之加速度歷時、試驗過程土壤中激發的超額孔隙水壓與試驗前後土堤沉陷、側向位移量進行評估。 ;West Taiwan plain is soft alluvium ground with high ground water level. Moreover, Taiwan is located at Circum-Pacific seismic belt, liquefaction usually occurs during large earthquake. For an embankment which is built on the liquefiable ground with gentle slope, the soil liquefaction and lateral spreading due to earthquake would cause significance damage to the embankment. Therefore, it’s very important to understand the failure behavior of lateral spreading for an upper structure on liquefiable gentle slope during shaking. A series of centrifuge shaking table test are designed to test in 50 g acceleration field. The main objective of this research is to discuss the effectiveness of different countermeasures against the embankment settlement and displacement by lateral spreading. The vertical draining system, granular column method, soil de-saturated method and EPS material were applied to the centrifuge models. The embankment settlement and displacement, acceleration and the pore water pressure histories of improved and non-improved models are measured and compared to discuss the effectiveness of the countermeasures.
