Vibrohammers used to steel sheet piles driving, making sheet pile walls, including water-tight ones. Using such vibrohammers , the steel pipes can be driven, which further are filled with concrete or ballast making piles. Depth vibrators are used to create by vibration underground cavities that are filled with concrete thus forming underground structures.
IMPACT DRIVING METHODS
Impact driving methods are used for driving steel pipes or reinforced concrete piles. Both diesel and hydraulic hammers can be used. Different weight hammers can be used with various basic models of RTG machines to drive different lengths piles. A data recording system that records the number of hammer strikes, impact force and power consumption, can be equipped in the RTG machines. This allows each pile to provide an installation report.
Pressing method can be used where a steel sheet pile or wall must be erected, especially in the cases where vibrohammers or impact hammers cannot be applied. Using press-system, U and Z-profile sheet piles can be pressed without any noise and vibrations. RTG Hydro-press equipment has flexible modular structure, therefore can be applied for different size and profile steel sheet pile pressing in.
Using different exchangeable fittings, various drilling methods can be applied in RTG machines, such as:
- FoW(Fron of Wall) method or drilling with double drilling head. When using this method, a casing and auger rotate in opposite directions thus allowing performing holes very close to the buildings.
- A Continuous Flight Auger (CFA) drilling method.When performing piles under this method, an auger drills in to ground and when extracting the auger concrete pumping in free place through tube in auger.
- Kelly drilling method,used to perform big-diameter and high-depth drillings. The so-called Kelly bars and Kelly winch with working tools – auger or bucket – are used to employ this method.
- A Full Displacement Process (FDP) method, i.e. performing drilling while at the same time compacting the ground, is used in for average diameter piles production, when special equipment is screwed in the ground and thus the ground is compacted without displacing it to the surface. Upon reaching a desired depth, concrete is pumped to the hollow to fill the cavity.
SOIL MIXING METHODS
In favourable geological conditions, piles on-site can be formed by mixing soil with cement slurry. Special equipment is used for the mixing: cement grout is injected to the mixed soil. Single, duplex and triplex system or special cutters can be used for ground mixing. For this methods drilling rig and rotary head must have power to rotate mixing tools with high speed (50-60 rpm) .