Features

This method involves reversely rotating the outer auger and inner auger and boring the ground. By installing casing to the outer auger and a screw to the inner auger for double digging, civil complaints due to noise and vibration can be reduced. As earth and sand are not compacted in the screw fore end, the excavation rate is high. A high bearing capacity can be secured through observing removed earth and sand or rock pieces with the naked eye and confirming and deciding bearing layers.

Advantage

• Low-noise and low-vibration cause few civil complaints.
• Boring of soft layers, sand and gravel layers and the deposit strata is possible by using a screw and casing.
• Use casing can prevent construction methods from collapsing.
• As the boring of soft rock layers is possible, users can achieve a high bearing capacity.
• As fragments of removed soil can be checked, it is possible to confirm bearing layers.

D.R.A boring process