During the development of a project to convert industrial warehouses and implement automated warehousing systems, an additional survey of the foundation soils became necessary to assess their ability to withstand new point and distributed loads on the floor slab. After the survey and load collection, insufficient bearing capacity of the foundation soil was determined. A cycle of geodetic surveys was also carried out to identify critical unevenness of the floor slab.

Foundation:
Monolithic reinforced concrete floor slab with a thickness of 200–400 mm.

Task
Strengthen the foundation soils, level the floor slab in the horizontal plane with tolerances of ±4 mm (height difference) per 8 m.

Before starting the foundation strengthening work, a set of activities was carried out to determine the density of the foundation and identify weak‑bearing soil horizons. A zero cycle of geomonitoring was also performed to determine height differences. To solve the task of strengthening the foundation soils, the deep injection method – Deep Injection – was chosen. All work was carried out inside the building (in sections), with injections performed at several levels, strictly vertically. To level the floor, the Slab Lifting method was chosen. Injections were also carried out in sections, strictly in one direction. After completion of the foundation soil strengthening and floor slab levelling, a set of geodetic works was performed to install control marks for further monitoring and annual geomonitoring. Subsequent surveys revealed no movement in the control mark levels.