Geopier Ground Improvement/ RAPs

Geopier Ground Improvement

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Geopier Ground Improvement/ RAPs

Geopier is a USA based company which specialises in an array of ground improvement techniques.

Geopier has consolidated its experience over approx. 50 years and formulated design techniques, design tables and construction techniques which they share with licensees all over the world.

The Geopier engineers and contractors have focused on cost effective techniques developed with specialised tooling and plant which compact aggregate into the soft soils generally without removing soil.

Geopier moved into NZ after the Christchurch earthquakes and aligned with the EQC to extensively test several ground improvement techniques, using explosive and mechanically simulated earthquakes in soils proven to be very susceptible to seismic settlement.

As a result, the Geopier techniques have been used extensively in Christchurch and latterly all over NZ to prevent both seismic and load induced settlement providing for cost effective foundation solutions.

CLL has the license for Geopier in NZ, and we have built up a large fleet of plant which installs the ground improvement.

The most common system we use in NZ is termed RAPs and involves compacting aggregate to form very stiff aggregate piers 600mm in diameter up to 25m deep.

This system improves the ground by densifying it, and by producing a series of stiff element’s which reinforce the earth preventing lateral spread, liquefaction and load induced settlement.

In cases where soil is too soft to adequately confine aggregate both in construction of the piers and in the case of an earthquake, CLL uses grout to confine the piers. We have used this grouting technique numerous times in both the North and South Islands with excellent results.

CLL has used RAPs to cost effectively provide foundation solutions for a large wind-farm with 34 x 100m high towers in Taranaki, the CHCH stadium, a shopping center in Tauranga and multiple other residential, infrastructure and commercial projects. The Geopier system has been used on over 300 sites in NZ since 2013.

Click here for a video of CLL installing RAPs

Click here to see CLL excavator loading the hopper