UK AND United Arab Emirates subsidiaries of foundation firm Bauer have shared technical expertise and resources to increase the company's share of the vibro market in the UAE.
Projects have mainly been centred around Abu Dhabi and Dubai, carried out using Bauer TR85 vibroflots, powered by Bauer HD 420 hydraulic power pack units.
The vibroflots can be used for both vibrocompaction and vibro stone column installation and are suited to the sands and silty sands encountered in the UAE.
A variety of vibro stone columns up to 1m diameter and up to 9m deep have been installed for tank foundations, main foundations and ground-bearing floor slabs for light and heavy industrial developments.
Preliminary trials have been carried out in the UAE using the wet top feed vibro replacement stone column technique.A combination of vibrating action and high pressure water jetting through the nose cone is used to sink the vibroflot into the ground.
Once the vibroflot reaches the required depth a surging action is used to flush out the bore and increase its size, forming an annulus around the vibroflot. When the annulus is satisfactorily formed the pressure of the bottom water jets is reduced to a level which allows continual upward movement of water and fines in the annulus between the vibroflot and surrounding soil, maintaining the stability of the bore.
The stone column is then made by raising the vibroflot a short distance above the bottom of the bore and tipping stone aggregate down the annulus. As the aggregate accumulates at the base of the bore it is compacted by repenetration by the vibroflot. The vibroflot is then lifted in stages with further introduction and compaction of aggregate until a compact stone column is completed to the working platform level.