Internal Piled Raft-to enable houses with considerable internal cracking and floor movement to be habitable
Houses in West Meath
We were tasked with underpinning three properties in a cul-de-sac whose internal walls were showing signs of subsidence.
The external walls were constructed off deep strip foundations and appeared intact however the internal walls were constructed off a ground bearing slab which had sunk due to it being constructed on a material with a low bearing capacity.
For the safety and stability of the properties we decided that we would keep the floor slabs in place and carry out our “Pin Piling System” to underpin them in-situ.
We diamond cored holes in the floor slab at a grid of 1200mm centre to centre and created small 300mm dia pile caps at each position beneath the floor slab.
105mm dia mini piles were installed through the holes and cut off within the pile cap approximately 225mm below the underside of the slab.
The piles, voids and cores were grouted transferring the weight of the slab to ground with a higher load bearing capacity.
The main contractor installed a Larsen liquid damp proof membrane over the floor slab and a Larsen self levelling compound was used to bring the slab back to its original level.
We installed a total of 189 No 105mm dia mini piles to a depth of 8.0m. The pile installation, pile cap construction and grouting were finished in 4 weeks.