Screw Piling on The Lonsdale

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The 12M high gable, left exposed to the elements was shored following concerns over its stability.

In order to commence the development of the site it was necessary to remove the shores.

To increase the lateral stability of gable to allow the shored to be removed it was achieved by the installation of Helifix ties into the floors and roof timbers.


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Once St Astier had installed the Helifix ties and allowing for curing of the resins and grouts the shoring components were carefully and systematically removed.


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The proposed new development included a basement and the ground levels would have to be reduced by 2.5m.

Without substantial support the gable would be at risk.  Traditional underpinning was considered to be high risk and costly so St Astier offered a high capacity, non-vibration piling system.


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Heavy duty triple helices screw piles were driven to varying depths and the load tests achieved the target load of 300kN at depths of 5-8M.


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The piling design, as proposed by St Astier’s Structural Engineering team included steel tubes, installed as the grout progressed to not only offer additional lateral strength but also allow the quick excavation of the ground levels without damaging the piles.


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The piles were connected to the building with heavy duty lifting brackets which then enabled each pile to be loaded immediately after installation.

During the installation, load readings are taken at 1M increments ensuring accuracy, efficiency, reducing waste and cost controls.

18 piles were fully installed, grouted, loaded and tested in 5 days.