Rapid construction of maintenance free infrastructure on very compressible soil demands new foundation techniques which can be applied economically on large-scale projects. A new system named AuGeo Piling System was developed to construct embankments on piles, whereby a geogrid is used to transfer the weight of the embankment to the pile foundation. With this so-called AuGeo piling system it is possible to construct settlement free embankments within a very short time period.

The AuGeo piling system is characterized by a relatively light piling system provided with a cap and an enlarged point. The piles are pushed into the soil at short distances by a modified drain stitcher. Compared to a standard ramming method, where it is very important that no rest settlements occur, small settlements will not affect the construction of an AuGeo system or the geogrid mattress.

The AuGeo piling system consists of a corrugated HDPE casing which is filled with a cement mortar. The piles are installed from a working platform. A circular steel tube of dimension 190mm diameter is pushed into the soil by a drain stitcher type MY-200 with a force of approx. 40tons. The tube is closed at the bottom by a 5mm thick steel plate, which acts as an enlarged pile point. This plate remains in the soil. The tube is installed at a regular speed to avoid disturbance of the subsoil and any potential damage to the piles already installed. When the steel tube has reached its final depth, the HDPE tube of diameter 150mm is lowered into the steel casing and filled with a comment mortar. The mortar is mixed on site in a mobile mixing plant and pumped to a temporary storage bin on the installation rig or pumped directly from ready mix trucks. The steel tube is retracted and the pile is cut at its correct level, filled to the top if necessary, and provided with a concrete cap of dimensions 300×300mm. During normal operations, production rate of 20 piles per hour can be achieved.

Areas Of Usage

1) Highways and Railway Embankments

2) Approach Embankments to Bridges

3) Light and medium Industrial Structures

4) Housing Development Area

Advantages Of The AuGeo Piling System

1) Competitive costing. It is cheaper than normal piled embankments.

2) Speed of installation compliments fast track construction projects.

3) Easy to install, no vibrations and very small displacement.

4) Environmentally friendly system.

5) No post construction settlements.

6) Effective load transfer via 2 layers of high strength Geogrid.

Micropile is another type of pile which is act as a supporting structure to transfer the load from the building to the ground. As the name implies, micropile is small diameter piles constructed by the drilling process and are often keyed into rock. There is various diameter of micropile can be found in the market ranging from 100mm to 250mm. Of late, technological advancement in machinery has made it possible for micropile of much greater diameters to be constructed.

Application of Micropile

In the past micropile was only used when the ground conditions warranted it because of considerations on cost and speed. Micropile is slow because of the drilling and flushing process, it might takes minutes or hours to complete.

But the trend is such, micropile is now gaining greater popularity and getting wider acceptance because of the requirement to comply with no noise and low vibration regulations, expecially in congested environments.

Geotechnically, micropile is most suitable in the following ground conditions :

1) Shallow Bedrock

2) Boulders and Cavities

3) Intermediate Hard Strata

4) Underpinning

How To Install Micropile

Micropile is widely used in the construction field because of the low vibration and no noise, micropile is widely used in housing area, school, hospital or any location which doesn’t allow to make noise while pile driving process. As you know, concrete pile like spun pile and reinforced concrete square pile produce high volume while driving pile. The installation procedure for micropile is almost similar to bored piling, it’s using drilling method.

1) Drilling and Flushing

2) Withdrawing Drilling String

3) Inserting Steel Reinforcement and Grouting

4) Completed Micropile

Construction Photos For Micropile

1) Micropile for underpinning an existing 4-storey office building which showed signs of settlement.

2) The workers are doing micropiling works.

3) Micropiling work in progress. A high pressure compressor is being used for flushing out the drilled materials.

4) A mini, but powerful hydraulic crawler drill which is useful for micropiling works in :
a) Congested locations with extreme headroom constraint.
b) Difficult hillside development where rock is encountered.