Soil Stabilisation – East Anglia

A prominent regional construction firm had started work on a development but this was halted because of unforeseen ground conditions and encountering a wet fibrous soil with peat deposits. The majority of the site was too soft for plant to operate on, especially the piling rigs which were required in the later stages of the construction programme.

Ash Remediation Management stabilised the majority of the site down to a maximum depth of three metres. Soils were excavated and temporarily stockpiled whilst bases of the void were treated in-situ. The excavated material was treated ex-situ and then replaced and compacted in layers. 

CBR testing was carried out to verify the works and the end result was a geotechnically suitable piling mat and working platform (>30% CBR) which allowed the installation of the site infrastructure to continue. 

University of Canterbury

Physical Stabilisation Canterbury

As part of the development of a new campus at the University of Canterbury, Ash Remediation Management carried out 11,000m2 of physical stabilisation. A CBR in excess of 30% was achieved with the project completed inside the required deadline.

Hampshire Technology College

Physical Stabilisation Hampshire

Due to a prolonged period of wet weather, ground conditions on site deteriorated which severely hampered the progress of our Clients development. Ash Remediation Management reacted promptly and carried out suitability testing and the subsequent physical stabilisation to achieve CBR values >5%. The improved ground conditions achieved by Ash Remediation Management allowed the development to ‘get back on track’ with minimal programme losses.

Piling Mat Stabilisation

Physical Stabilisation Treatment - Piling Mat

In all piling projects stability of the plant is key and as such, a suitable piling mat is essential if the works are to be executed in a safe and controlled manner. It is particularly important that the working platform does not deteriorate or encounter heave because in piling work the specialist equipment used has a high centre of gravity and the consequences of a collapse can be fatal.

A traditional method of constructing a piling mat is to import and layer stone. This can be an expensive and unsustainable method with the transport alone adding numerous unnecessary lorry movements. In contrast to this method Ash Remediation Management offer on site stabilisation of material to piling mat standards. We have achieved specifications of in excess of 30% CBR (dependent on the ground type) and all on site testing is included.

The stabilisation process was facilitated through the use of a tractor pulled Spader. The Spader dosed the specifically designed binder and ensured maximum mixing and pulverisation of the soil material. This was completed to the required compacted depth with a minimum of three passes. The validation testing confirmed that the target of CBR of 30% had been exceeded allowing the piling work to commence. Ash Remediation Management also carried out the trimming works. This was achieved using GPS guided machinery and to a tolerance of +20 – 30mm.

Gloucestershire Secondary School

Earthworks and Physical stabilisation School

As part of the construction of a state of the art sports facility, Ash Remediation Management carried out a programme of earthworks and physical stabilisation.

Ash Remediation Management achieved CBR values of in excess of 30% which more than exceeded the development requirements. Additionally, the project was completed in a timely and efficient manner allowing the client to achieve their project completion deadline.

Widnes Galligu Stabilisation 2

Galligu Stabilisation Treatment

Following successful completion of the initial galligu stabilisation project our client did not hesitate to get Ash Remediation Management back on board when a second area of galligu was identified.

Ash Remediation Management always complete treatability trials prior to site works commencing and despite previously carrying out galligu stabilisation on the same site these bench top trials were still conducted. Again the treatment was applied through the use of the Allu Power Mixer and Pressure Feeder and a total of 850m3 of galligu was stabilised.

Widnes Galligu Stabilisation 1

Physical Stabilisation Treatment 2

In the late 19th Century the synthetic production of sodium carbonate was prevalent in the Widnes and St Helens region of North West England. The rapid growth of the chemical industry dictated the requirement for this product however there were some associated problems.

The process used in manufacturing sodium carbonate was massively inefficient with the quantity of raw materials outnumbering the saleable product by a ratio of 6:1. Moreover, large amounts of a waste material called galligu were produced. Geotechnically galligu is an interesting material and the properties it exhibits differ according to its oxidation state and water content. When dry galligu is similar in texture to silt however an increased water content or indeed physical handling quickly transforms the material into a thixotropic mass.

Huge quantities of galligu were produced and owing to the unregulated manner in which it was disposed it underlies much of the region. The presence of galligu can heavily constrain land development and construction and this was certainly the case for our client Britcon.

This shift between geotechnical states of galligu presented an issue for Britcon as part of their development required excavation of up to 4.5m bgl for installation of underground tanks and basement floor levels. Simple excavation of the galligu did not prove successful as the physical handling process changed the physical state from solid to liquid. Even if the excavation had have been successful the sides of the void would not have been stable enough to allow work to continue safely.

It was at this stage that Ash Remediation Management were appointed as the stabilisation contractor. Ash Remediation Management conducted laboratory based trials to optimise a treatment mix and through the use of the Allu Power Mixer and Pressure Feeder stabilisation of the galligu was carried out. A total of 1500m3 of galligu was stabilised and following approximately seven days curing the galligu was in solid state and subsequent excavation was possible. Moreover, the sides of the excavations were stabilised which allowed work to be completed safely within the void.