Building Better Ground Geopier’s Helical Pipe System for Aggregate Pier Installation

Geopier Foundation Company, Inc. – a specialist in ground improvement technologies – has filed a patent for an innovative system and method for installing aggregate piers in soil. The invention uses a hollow helical pipe to displace soil, deliver aggregate and form a reinforced column, combining the advantages of displacement installation with the efficiency of aggregate delivery through the pipe itself.

The Problem

Aggregate piers – also known as rammed aggregate piers or stone columns – are a well-established ground improvement technique used to increase the load-bearing capacity of weak or compressible soils. They work by installing vertical columns of compacted aggregate material into the ground, which stiffen the surrounding soil matrix and create a reinforced composite that can support structures including buildings, roads, embankments and storage tanks. They are particularly valuable on sites with soft clay, loose sands or fill materials that would otherwise be unsuitable for direct foundation construction.

The traditional method of installing aggregate piers involves drilling or auguring a hole, removing the excavated spoil, and then filling and compacting aggregate in lifts. This process generates spoil that must be managed and disposed of, requires multiple pieces of equipment for drilling and compaction, and can be relatively slow. It is also sensitive to soil conditions – in some soils, the drilled hole may collapse or heave before aggregate can be placed.

Displacement methods, which push soil aside rather than removing it, address some of these limitations. A displacement tool driven into the ground compacts the surrounding soil laterally rather than generating spoil. However, conventional displacement methods have their own challenges in terms of how aggregate is introduced to form the pier column – separate backfilling steps or multiple tool changes can add complexity and reduce efficiency.

What This Invention Does

Geopier’s invention combines displacement installation with an innovative internal aggregate delivery system. The core element is a hollow pipe that extends from a proximal end (at the surface) to a distal end (at the installation depth). The pipe has a helix – similar to an auger flight – attached to its outer surface along part of its length. When the pipe is rotated in one direction (the first direction), the helix acts on the soil to advance the pipe into the ground, displacing and compacting the soil laterally rather than removing it.

The critical innovation is that the bore running through the pipe is also the channel for aggregate delivery. Aggregate is introduced through a second opening at the proximal end of the pipe, passes through the hollow bore, and exits through a first opening near the distal end. As the pipe is rotated in the opposite direction (the second direction) and withdrawn, the aggregate is deposited and can be compacted in place to form the pier. The helix geometry, operating in reverse, assists with compaction and controlled withdrawal.

This integrated design means that a single tool performs both the soil displacement and the aggregate delivery functions. There is no need to remove the drilling tool and introduce a separate backfill equipment. The result is a faster, more integrated installation process that can be operated efficiently in a range of soil conditions. The use of a torque driver interface on the pipe allows the system to be used with standard construction equipment capable of providing rotational force.

Key Features

Integrated hollow pipe and helix design. A single tool combines soil displacement via the external helix with aggregate delivery through the hollow bore, eliminating the need for separate excavation and backfill steps.

Bi-directional rotation. The pipe can be rotated in either direction – advancing into soil in one direction, and withdrawing while depositing aggregate in the opposite direction, with the helix geometry optimised for both functions.

Lateral soil displacement. The helical advancement displaces soil laterally rather than excavating it, eliminating spoil generation and compacting the surrounding soil to improve bearing capacity.

Continuous aggregate delivery. Aggregate passes from the surface through the hollow pipe bore and exits near the distal end, enabling continuous pier formation without interrupting the installation sequence.

Torque driver compatibility. The pipe includes a designed interface area for engagement with a torque driver, making the system compatible with standard rotary construction equipment.

Who Is Behind It?

Geopier Foundation Company, Inc. is a US-based geotechnical company specialising in ground improvement through proprietary rammed aggregate pier systems. The company works extensively on commercial, industrial and infrastructure projects where weak or variable soils require improvement before construction. The sole inventor is Alan Matthew, whose work focuses on the mechanical design of ground improvement installation systems. This application is a divisional of an earlier filing (AU 2022339936) and is filed through GLMR. The divisional relationship indicates ongoing refinement and expansion of the company’s proprietary installation technology.

Why It Matters

Ground improvement is one of the most important and frequently underappreciated aspects of construction. The bearing capacity and compressibility of the founding soils determine whether a structure will stand safely, settle acceptably and perform reliably over its lifespan. In many parts of the world – and increasingly in Australia, where urban development continues to push into marginal and challenging ground conditions – natural soils are simply not strong enough or stiff enough to directly support the loads imposed by buildings, infrastructure and industrial facilities.

Aggregate pier technology offers a cost-effective and relatively rapid alternative to deep piling or complete soil replacement, and innovations that make installation faster, more integrated and more adaptable to different soil types are commercially valuable. By combining soil displacement and aggregate delivery in a single helical pipe tool, Geopier’s invention reduces equipment requirements, minimises spoil handling and potentially accelerates installation rates. For contractors, these efficiencies translate directly into project cost savings and schedule benefits. For the construction industry more broadly, better ground improvement tools mean more sites are economically viable for development – expanding the range of locations where construction can proceed safely and sustainably.

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AU 2026201576 was published in the Australian Official Journal of Patents on 19 March 2026 and is open for public inspection. Patent applications represent inventions that are sought to be protected and do not necessarily reflect commercially available products.