Simply supported needles
Property in Co. Louth
We were asked to design an underpinning scheme to support the gable end and return walls to this property. The end of the property was constructed in a fill material with low bearing capacity causing subsidence.
The chimney breast in the gable wall weighed 30 tonnes and had moved approximately 90mm from vertical and for health and safety reasons it was decided to remove the gable wall to floor level.
The front and rear walls remained and were underpinned using simply supported needle beams. The underbuild block work to the gable wall was also underpinned using this method allowing the main contractor to rebuild the gable without having to remove the existing foundation to facilitate construction of a new piled ground beam.
In total we installed 32No. 105mm dia low vibration mini piles to depths of up to 3.5m and constructed 16No. simply supported needle beams.
The pile installation and underpinning works were completed in five days.