Technologies and Solutions

Static Densification Pile Construction Method: SDP-N Construction Method

The SDP-N Construction Method is an environment-friendly static compaction ground improvement method which achieves densification of the original ground by forming enlarged-diameter compaction piles (enlarged-diameter piles). As features of this method, static penetration of the casing pipe (single-walled pipe) in soft sandy ground is achieved by a rotational penetration system that combines a rotary drive device and a forced penetration device. Discharge and drive-back of the improvement material (sand, crushed stone, recycled crushed stone, other materials) are performed by static energy during formation of ground improvement piles.

A special excavation mechanism, which is the most important feature of the SDP-N Method, breaks up mass of soil directly under the casing pipe during forced penetration of the casing pipe, forcibly conveys the broken-up soil outside of the pipe, and presses the crushed soil into the wall of the pile hole. As a result, an improved compaction effect can be expected in the ground between piles.

Static Densification Pile Construction Method: SDP-N Construction Method


  • Optimum method for ground improvement in urban areas, as vibration and noise are reduced because compaction is performed by static energy.
  • Construction cost savings are possible because surplus soil generated in construction can be used as a pile material to achieve recycling.
  • A wide range of materials can be used as the pile material, from the conventional sand material to cement-stabilized surplus construction soil.
  • An improvement effect equal to that of the conventional method has been confirmed.