Abstract
The serious damages to the sand liquefied groud by earthquakes are often reported everywhere in the world.
Now, a preventive method is developed by means of installation of the drainage of excess pour pressure by the use of geosynthetic board drains.
The drain materials are easily transported anywhere to the sites by the roll package. Each of the drain material is inserted into the ground through the mandrel like the general vertical drain method.
For designing the intervals of the drains to be inserted, large scale vibration table experiments and field vibration tests were performed. The effect of this preventive method using geosynthetic board drains against liquefaction was well verified available as the preventive construction method against liquefaction.
