| 摘要 |
PROBLEM TO BE SOLVED: To provide an effective and appropriate structure capable of certainly and easily preventing sand boil when a natural ground which is a liquefaction ground is liquefied.SOLUTION: In a structure for preventing sand boil to a ground surface when a natural ground 1 which is a liquefaction ground is liquefied, a pavement surface 2 consisting of a surface layer 2a and a roadbed layer 2b layered under the surface layer 2a covers the natural ground, and the roadbed layer is formed as a gravel layer having water permeability. At important positions of the pavement surface, groove parts 3, which become water passages formed so deeply that their bottom parts reach the natural ground and introducing excessive gap water from the natural ground to the gravel layer when liquefaction occurs, are provided at prescribed intervals. The groove part is filled with a gravel material 4 such that the gravel material 4 reaches at least a position connected to the gravel layer, with the gravel material 4 allowing excessive gap water to flow from the natural ground into the groove part and preventing sand from flowing into the groove part when liquefaction occurs. |
