BORED PILES

Vibropile has developed special equipment for forming high quality rock sockets, and has constructed such piles with load capacities as high as 80 MN, through rock strengths as high as 200MPa.

Selection of appropriate tooling and cutting edges is facilitated by the availability of a wide range of tooling and cutting teeth. This is enhanced by our own range of cutting teeth, manufactured to our exclusive design.

Large diameter bored piles are non displacement piles, commonly used where large vertical loads or bending moments must be supported by the foundations.  Small numbers of high capacity bored piles can often provide extensive savings in pile cap costs, when compared with other lower capacity, pile types. These bored piles founded in rock, provide an effective means of minimising foundation settlement and can be installed with little to no vibration. Vibropile has a large range of equipment available for the execution of bored piles ranging from heavy duty, crane attached units to modern all-hydraulic tracked machines capable of drilling holes in soil and rock.

Soil and/or rock is removed using purpose designed drill tools. These include soil and rock augers, drilling buckets, and core barrels, which can reach depths of up to 80 metres and range in diameter from 400mm to in excess of 3 metres.

Various methods to support the sides of the bored piles during construction are available, and are selected in accordance with the type of formation being drilled, the ground water regime encountered, and the environmental constraints on site.

Shaft support methods available include:

• Drilling under water
• Drilling under bentonite
• Drilling under polymer fluids
• Vibrated temporary casing
• Drilled temporary casing
• Oscillated temporary casing
• Permanent liners

The load capacity of bored piles is a function of the installation technique chosen, the geotechnical capacity of the pile, and the structural capacity of the pile shaft. Settlement considerations often limit the capacity of piles socketed into good quality rock. Bored piles become particularly efficient, where resistance to high lateral loads or bending moments is required, such as those induced by wind and earthquake loading. In these circumstances the larger diameters available, combined with heavy steel reinforcement cages if required, provide the required structural strength.

In very high strength rock, bored piles can be constructed using our custom made augers, digging buckets, and roller cutter barrels. These techniques not only allow the drilling of up to 200MPU rock, but also provide an economical resolution, when compared with conventional methods of drilling, to the problems of penetrating difficult rock.