STEP Method (Static SCP Method)

Improvement Principle Compaction, Consolidation and Reinforcement
A static SCP method which consolidates the expanded sand pile by generating the injecting force through the inner screw and the twisting shear occurs at the bottoms side of screw. The strength & the improvement effect of the bottom side created Sand Compaction Pile is nearly the same as Land SCP.
Advantages The strength & improvement effectiveness is similar to Land SCP.
The penetration & withdrawal of casing is by the moving force of auger motor, hence the ultra low vibration, low noise work is possible.
The material discharge rate could be increased from the injection of air-tight screw tip.
Disadvantages Construction’s production is low, thus construction cost is slightly higher as compared to Land SCP.
Construction machines are big, hence separate measures are necessary against ultra soft ground.
Applicable Ground Nearly all types of soil e.g, sandy soil, cohesive soil & organic soil etc.
Objectives Prevention of liquefaction & settlement, and act as structural foundation for street etc.
Improvement Effectiveness Cohesive Soil Prevent liquefaction
Reduce settlement
Increase shear strength
Sandy Soil: Promote consolidation
Reduce residual settlement
Increase shear strength
Specification Standard Pile Diameter Ø 700mm
Pile Arrangement
Square; Equilateral triangle; Parallelogram; Rectangular
Pile Spacing 1.3m ~ 3.2m
Improvement Rate 5% ~ 30 %
Penetration Depth Max GL -20m
Penetration Strength Max N-value < 20
Material Crushed stone, Sand, Slug, Recycle material etc.,
Environment Vibration Minimal Ultra Low Vibration
Noise Minimal Low Noise
Ground Displacement Relatively small