COUNTERMEASURE FOR SAND LIQUEFACTION: 'GRAVEL DRAINS METHOD'.

The gravel drain method aims to prevent sandy soil from liquefying by constructing gravel piles in the ground to disperse pore water pressure caused when an earthquake occurs. In designing gravel drains, adequate evaluation of the soil constant and the selection of a highly permeable, choke free gravel are important. The authors propose a selection standard after having made experimental studies. A compaction rod type machine for the construction of gravel drain piles causes low levels of vibration and noise and will not disturb the peripheral ground during its use.