Demonstration of the Hard Ground Press-in Method Using New Pile Auger Held in Taiwan

GIKEN LTD. (Head Office: Kochi-shi, President and CEO: Atsushi Ohira) has held a demonstration in Taiwan of the Hard Ground Press-in Method using the flywheel-type new pile auger. The demonstration was conducted in collaboration with AKTIO Corporation (Head Office: Chuo-ku, Tokyo, Chairman and CEO: Mitsuo Konuma), one of the leading construction equipment rental companies, with which GIKEN has a rental business alliance.

Taiwan has a large amount of ground that contains gravel and boulders, and many construction sites remain untouched due to the vibration and noise that occur during construction. The Hard Ground Press-in Method using the flywheel pile auger makes construction possible on extremely hard ground with an SPT-N value (ground hardness) of 600 or more while retaining the advantage of press-in technology of minimising vibration and noise. It also makes stable and speedy excavation possible even when encountering boulders not identified in prior geological investigations.

This construction method will be a groundbreaking solution for Taiwan toward National Resilience against disasters such as earthquakes and extending the lifespan of infrastructure. On the tailwind of this demonstration, which proved the method’s superiority to over 100 local construction workers, we will work with the AKTIO Group to create a method to promote construction and a business model, and help bring about a sustainable society.

Taiwan has a large amount of ground that contains gravel and boulders, and other construction methods generate vibration and noise during excavation, which can have a negative impact on the lives of residents. Other construction methods also generally require excavating the ground with a piling machine, replacing existing ground with sand, and then starting the pouring procedure with a piling machine. In addition to having a large number of steps, it is not possible to use a single machine to excavate the ground and pour sheet piles, which increases construction time and cost.

The Hard Ground Press-in Method
By equipping SILENT PILER^TM with a pile auger, this method employs the “Coring Theory,” a unique coupling of press-in and augering (drilling) functions that enables steel sheet piles to be pressed into hard ground. It enables piles to be installed even into cobblestone and gravel layers or bedrock without losing the superiorities of press-in technology, such as the lack of vibration and noise.
With press-in and augering functions in a single machine, this method eliminates the task of replacing existing ground with sand that other construction methods require. This not only reduces time and cost, but also makes the construction process extremely efficient. Because the level of drilling is minimised, machines remove only a little soil without disturbing the surrounding ground to install completed piles with a high bearing capacity.

Flywheel-type auger
A new pile auger adopts a flywheel mechanism incorporating a weight on the rotating shaft that transmits the power of the hydraulic motor, and further improves pile excavation efficiency compared to conventional pile augers. By increasing torque using the moment of inertia of rotation caused by the weight, it prevents sudden drops in the auger rotation speed encountering hard ground that is difficult to excavate. This allows stable auger rotation to be maintained, improving excavation efficiency. In addition, the strength of the casing and screw shaft has been increased from conventional pile augers, improving energy transmission efficiency. The wear-resistance of the cutting claw, called “bit,” has also been improved.

Demonstrations were held in Taoyuan City, Taiwan on April 22 to 23. A total of four demonstrations were held over two days, with over 100 participants including local construction consultants and prime contractors.
The site had an extremely hard ground with an SPT-N value of 600, with large gravel and boulders mixed in the surface layer, but the Ground Press-in Method using a flywheel-type pile auger allowed for speedy construction while minimising vibration and noise. Participants made comments such as, “I hope this will become more widespread because it will help improve productivity,” and “The method perfectly fits for many construction sites in Taiwan where vibration and noise must be taken into consideration, such as residential areas,” and specific questions and opinions regarding its implementation were also exchanged, providing momentum for the future dissemination activities to the upper-class planning construction work throughout Taiwan.

■Profile of GIKEN Group
GIKEN developed SILENT PILER^TM, the world’s first reaction-based hydraulic pile jacking machine, installing piles without noise or vibration. GIKEN Group now actively promotes its press-in technology worldwide and contributes to the construction industry by proposing and implementing innovative solutions. The innovative press-in technology provides a unique solution and the adoption of this technology has spread to over 40 nations and regions.