After a large‑scale rupture of a water supply pipe, a large amount of water got under the floor slab and under the foundation. In particular, the soil around the piles was washed away, resulting in cracks in the walls of the house with openings of up to 1–2 mm. The identified slab settlement ranged from 15 mm to 155 mm. After a set of investigations into the physical and mechanical characteristics of the soil, local voids up to 300 mm thick were found, as well as very serious soil loosening in the range from 0 to 3 metres.

Task:
Return the foundation slab to the design levels and also stabilise the foundation piles.

To restore the operational condition of the residential house, the foundation beneath the foundation slab was first strengthened: the piles were stabilised using deep injection technology (Deep Injection). After increasing the bearing capacity of the foundation, the foundation slab was gradually lifted and levelled to the design levels using the Slab Lifting method. All work on lifting and levelling the structure was carried out under constant supervision of the surveying service.