At the final stage of construction of a logistics centre (commissioning works), during the spring‑summer soil thawing period, part of the column foundations (21 units) underwent uneven settlement. Geological surveys carried out during the construction stage did not reveal waterlogged or marshy soils under part of the building. The surveys were carried out in winter on frozen ground, which caused inaccurate determination of the physical and mechanical characteristics of the soils.

Task:
Strengthen the foundation soils, stop uneven settlement of the column foundations. Confirmation of the work result is the lifting of the foundations by 1–3 mm.

Before starting the foundation strengthening work, a set of geodetic surveys was carried out to accurately determine the position of the columns in space (in the vertical and horizontal planes), and loosened horizons of the foundation soil were also identified using dynamic probing. To solve the task, the deep injection method – Deep Injection – was chosen. All work was carried out from the surface of the foundation slab of the “socket” (one side of the foundation was exposed); injections were performed at right and acute angles. All work was carried out in sections, no more than two foundations per day. The result of the work was the lifting of each “socket” by 2–3 mm. All work was carried out under constant supervision of the surveying service.