Expacker-N method

Low cost and high efficiency liquefaction prevention and ground improvement method

General Description

This is an injection method against liquefaction that rapidly improves ground without affecting existing structures, using a special injection pipe that can discharge injection materials over a wide area at high speed. The rapid improvement is achieved through efficient infiltration and injection of large volume of material.
The “Column permeation grouting” applied in this method, is a specialized method to inject chemical agents from space assured by Geo-bag" attached on grouting tube. "Geo-filter-N", attached between each "geo-bag", prevents collapse of pore walls, and ensures a columnar permeation space.


Liquefaction countermeasure of sandy ground
Earthquake resistance of existing structure
Permanent water stoppage measures

Scope of application

Soil condition of application
Standard applicable ground: Sandy ground Fine fraction content
Limit applicable ground: Sandy ground Fine fraction content around Fc=40%
Improvement depth: Applicable up to approximately 50m (actual performance: 20m)

Main features

Fast development of improved soil pile
Low pressure injection from inner pipe (triple packer) provides 3m diameter of improved pile swiftly.

Efficient work, shorter schedule
Speedy and effective injection spreads wide area and provides high yield improvement.

Securement of clear point for injection
"Soil packer" and hole collapse prevention mat "Geo-filter-N" keeps secure column space for grouting, makes uniform injection.

No effect on surrounding existing structures
High porous durable grout agent makes no effect of ground settlement for surrounding establishments; they can work as usual.

Decrease the number of drill holes
Widening interval of drill holes; decreases the number of drill holes, cut the time and costs.

Suitable for narrow working spaces
Small drilling machine is used for narrow working spaces.