Vertase FLI Making an Impact in Ground Improvement!


Vertase FLI Making an Impact in Ground Improvement with our “Science Machine”

Vertase FLI Making an Impact in Ground Improvement with our “Science Machine”

When it comes to the remediation of land affected by contamination, materials that come out must often go back in (after treatment and testing to ensure their suitability for proposed use of course!). As land remediation is a first step in preparing a site for redevelopment, it is essential that the remediation contractor appreciates the importance of compaction to minimise air voids, maximise density and ultimately help manage the risk of future unwanted ground settlements beneath valuable infrastructure.

The Specification for Highway Works (SHW) Series 600 offers a comprehensive range of methods to compact earthworks fill materials using well established, tried and tested, compaction plant that impart compactive effort via either pressure or impact (both of which can be enhanced by vibration).

From a productivity perspective, the ‘compacted layer thickness’ achieved by the methods in SHW Series 600 is of upmost importance. This is because it determines the volume of material that can be placed per day or week prior to ceasing placement operations to commence the application of compaction. In a time when the British climate is getting notably wetter during the summer months (think 2012!) and yet weather risks are often sat firmly in the hands of the contractor, the pressures of finding ways to maximise earthworks production rates (whilst ensuring quality) have arguably never been greater.

Unfortunately, compacted layer thicknesses that can be achieved by the compaction plant-specific methods available in SHW Series 600 range only up to 600mm (for a dropping weight compactor) and are often less than 275mm for the most common self-propelled drum rollers operating with vibration. Therefore a vast amount of time can be spent applying compaction and awaiting the results of layer-specific verification tests while storm clouds gather overhead threatening to stop works for the day.

To that end, it is unsurprising that Vertase FLI has invested in its own 26 tonne self-propelled roller with a polygonal drum capable of imparting compactive effort to depths of up more than 1000mm in some material types. The image below shows our roller (which affectionately won the name of “science machine” in our in-house naming competition) hard at work at our Liverpool Festival Gardens site where it is being used to enhance the density of unexcavated Made Ground at the base of a former landfill prior to upfilling above.

Of course, when compacting thicker layers of this magnitude, there comes the challenge of proving to others (i.e., project stakeholders and interested third parties) that the compaction has been applied uniformly throughout the compacted layer. However, the technical team at Vertase FLI are not known for shying away from challenge and have successfully used in-situ techniques to demonstrate the strength, stiffness and density of thicker layers of compacted materials to the satisfaction of all parties. These techniques include the continuous measurement of a soil modulus (Evib) which can be achieved using the innovative Bomap system supplied by Bomag with the roller itself.

For more information on how Vertase FLI can bring value to the preparation of your site for redevelopment, feel free to get in touch via email or phone and somebody shall be available to discuss your requirements.