A number of sand boiling occurred in the coast of Tokyo Bay at Great East Japan Earthquake. A series of model tests was conducted to simulate the phenomenon of sand eruption from the crack of pavement. A model sand layer was prepared in the small soil chamber and the surface was covered by an acrylic lid with a slit opening. Water penetrated into the model sand ground from bottom to top. When the hydraulic gradient well exceeded critical hydraulic gradient, sand eruption has started. Liquefaction was generated also by the 1G shaking table test. Furthermore, effects of grain size on the sand eruption were studied using two layer ground of different mean particle size.