臺灣位於環太平洋地震帶上，頻繁的板塊運動引發多次地震。地震產生斷層錯動、地層液化與邊坡滑動等。而斷層錯動會使地表產生永久變位，亦會對土木結構物造成嚴重破壞。而臺灣人口密集，一旦發生地震，對於人民安全及經濟財產，將會造成很大的危害。所以對於地震伴隨的地表變形與破裂，及對地表或地下結構物的影響是值得研究的議題。 本研究在80g的試驗條件下，利用離心模型試驗模擬逆斷層錯動的行為，逆斷層傾角為 60o，模型覆土層高度為20公分，錯動量為5公分。覆土層材料採用砂土，以瞭解逆斷層錯動時，有無淺基礎對近地表變形之影響範圍及變形特性。 試驗結果顯示，逆斷層錯動時，在不同離心重力場下，地表高程劇烈變化影響範圍約等於覆土層厚度。試體置於較高的離心重力場時，所發生之剪裂帶範圍會比較窄。淺基礎載重作用，會使原本在自由場下之逆斷層斷層跡偏移，而偏移形式與基礎的放置位置及基礎接觸應力地大小有關。淺基礎會因逆斷層錯動旋轉及位移，其旋轉量及位移量與基礎放置位置有關。 Taiwan's geographical location is in the Circum-Pacific seismic zone where earthquakes frequently occurred. Earthquakes would cause the fault rupture, liquefaction, and slope instability. The fault rupture will affect the terrain with permanent deformation and destroy structures seriously. If the earthquakes happen to Taiwan, it will damage the safety of public and cause large economical loss. It’s worth noting to consider the surface deformation patterns and the fault rupture traces induced by huge earthquakes. In this research use of the centrifuge model simulates the reverse faulting at the accelerations of 1g, 40g and 80g and the dip slip angle of reverse fault is 60o. The thickness of overburden soil is 20 cm, the maximum vertical throw is 5 cm in model scale. The tested material is quartz sand. The surface deformation profiles and the subsurface rupture traces induced by reverse faulting were observed and compared for the ground with or without a shallow foundation rested on. The test results show that the extent of the surface deformation after reverse faulting is about equal to the thickness of overburden soil at the tested g-levels. The width of shear band is narrower when tested in the acceleration of 80g. The existence of shallow foundation rested on the ground surface would greatly alter the fault rupture trace from that observed in the free field. The magnitude of bearing pressure and the location of shallow foundation are the major factors to change the surface deformation profiles, the fault rupture traces of subsoil, and displacements and rotations of foundation.
