Re-leveling and strengthening of the foundations and floors due to the weakening soil and subsidence of the base

Problem:

During the construction work of the zero cycle, a certain technological sequence was not followed, and therefore, after some time, the floor and foundation structures were wetted at the base level, which led to soil leaching and a significant change in the e-modulus.

Task:

Determine the degree of loosening of the base bearing capacity and provide conditions for normal operation of the premises

Decision:

First of all, GeoResin specialists performed a visual inspection of the object and assigned a list of further actions. In order to determine the mechanical properties of the base soil, assess the uniformity of its composition, identify and delineate the zones of decompression, dynamic penetration test of the soil was performed from the surface of the floor of premises at 39 points. To determine the volume of voids formed under the floor slab structure, a videoscope survey of the sub-floor space was performed. Data on the slab irregularities were obtained by means of a leveling survey and recorded in the report on the work performed. After in-house processing of the obtained results, a technical solution was designed and included:

- strengthening of the foundation soil under 32 columnar foundations of the building frame using the Deep Lifting method;

- depth down reinforcement of ground under the constructions with area of 380 m2 by the method of Deep Lifting;

- filling of 14m3 voids in the base of the floor slab construction by Floor lifting;

- lifting and leveling of 430m2 floor slabs area to ensure normal operation of the object by Floor lifting. The maximum height difference was 15 cm.

All work was performed inside a operating facility, with variable restrictions on the functioning of its zones. The use of the GeoResin injection method did not require big equipment, allowed to improve the construction properties of soils in their natural occurrence, made it possible to work in the confined conditions of the existing premises, eliminated the filtration capacity of soils, and also protected the foundations from possible exposure to aggressive environments during the operation of the object.