A method and apparatus for forming cemented ground support columns is disclosed. Namely, driving mandrels are provided for the efficient construction of incrementally enlarged diameter support columns. For example, the driving mandrel includes a feed tube that has a top portion and an expansion head portion. The expansion head portion further includes an expansion (or compaction) chamber and a flexible tubular egress port. Further, construction methods are provided of using the driving mandrels for the efficient construction of incrementally enlarged diameter support columns.

A method and apparatus for forming cemented ground support columns is disclosed. Namely, driving mandrels are provided for the efficient construction of incrementally enlarged diameter support columns. For example, the driving mandrel includes a feed tube that has a top portion and an expansion head portion. The expansion head portion further includes an expansion (or compaction) chamber and a flexible tubular egress port. Further, construction methods are provided of using the driving mandrels for the efficient construction of incrementally enlarged diameter support columns.

A large diameter single-piece thermoplastic concrete forming tube with axially spaced and integrally formed fully encircling circumferentially continuous radially rigidifying ribs, and method of forming a concrete column employing the tube.

A vibrator assembly comprising a feed pipe that has a longitudinal axis as well as a first end and a second end. The vibrator assembly may further comprise a vibrator unit that is mechanically coupled to the feed pipe, and a filling assembly which extends into the feed pipe at the first end and is designed to pick up material and direct same into the feed pipe. The feed pipe may have at least two separate channels from the first end to the second end and parallel to the longitudinal axis.

A vibrator assembly comprising a feed pipe that has a longitudinal axis as well as a first end and a second end. The vibrator assembly may further comprise a vibrator unit that is mechanically coupled to the feed pipe, and a filling assembly which extends into the feed pipe at the first end and is designed to pick up material and direct same into the feed pipe. The feed pipe may have at least two separate channels from the first end to the second end and parallel to the longitudinal axis.

A drive point for a substantially tubular, in particular hollow cylindrical, driven pile having a pile core through which concrete can be introduced into the driven pile, wherein the drive point can be fitted onto a pile end of the driven pile, wherein at least one first supporting web with a first contact surface for an end face of the pile end is arranged on an inner wall of the drive point, wherein starting from a plane of a first bearing surface the drive point has a cavity which extends at least partially in a driving direction and into which concrete can be introduced through the pile core when the driven pile is fitted, wherein at least one concrete outlet channel is provided which connects the cavity to an upper edge of the drive point.

A concrete forming tube formed from a thermoplastic material and having a first end, a second end, and a substantially uniform circumference from the first end to the second end.

The rapid consolidation and compaction method comprises (i) first driving a hollow pipe, (ii) driving a pipe with a removable end plate after filling and compacting the sandy material in it, through the hollow pipe, to required depth, creating high excess pore-water pressures in the range of 50 to 300 KPa in clayey soils, (iv) pulling out the pipe section leaving behind the removable end plate and thereby installing porous displacement piles which allows dissipation of the excess pore-water pressures horizontally to the porous displacement pile, in which the excess water flows out vertically to the ground surface, and (v) the length of the drainage path is reduced to half the spacing between adjoining porous displacement piles, allowing rapid consolidation resulting in increase in density. Installing the porous displacement piles in the layer of loose to medium dense sand layer results in the instantaneous increase in its density.

A vibrator assembly comprising a feed pipe that has a longitudinal axis as well as a first end and a second end. The vibrator assembly may further comprise a vibrator unit that is mechanically coupled to the feed pipe, and a filling assembly which extends into the feed pipe at the first end and is designed to pick up material and direct same into the feed pipe. The feed pipe may have at least two separate channels from the first end to the second end and parallel to the longitudinal axis.

A vibrator assembly comprising a feed pipe that has a longitudinal axis as well as a first end and a second end. The vibrator assembly may further comprise a vibrator unit that is mechanically coupled to the feed pipe, and a filling assembly which extends into the feed pipe at the first end and is designed to pick up material and direct same into the feed pipe. The feed pipe may have at least two separate channels from the first end to the second end and parallel to the longitudinal axis.