Problem
After the completion of work on installing a tray with supply utilities, loosening of the foundation beneath the foundation slab was recorded. As a result, the entire structure (including the foundation slab) underwent settlement with a tilt towards the utility tray of up to 65 mm.

Task:
Return the foundation slab to the design level and restore the verticality of the tank.

To solve the task, a preliminary comprehensive survey of the tank foundation was carried out. The results confirmed loosening of the foundation soils, a tilt (on the foundation slab surface), and voids were also identified at the foundation slab‑soil interface with a volume of 1.6 m³. To restore the operational condition of the tank, the foundation beneath the foundation slab was first strengthened using the Deep Injection method. 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, and the verticality of the tank was also restored. All work on lifting and levelling the structure was carried out under constant supervision of the surveying service.