We raise the sagging floor slab and eliminate the problem of insufficiently compacted soil during construction

Initial data of the object

Private house

• Dimensions: 15 x 12 m.;
• Number of floors: 2 floors;
• Year of construction: 2012;
• Foundation: strip.

The house, built in 2012, has a well-groomed appearance and does not cause any serious comments. The facade remained neat, the foundation had no visible damage, and the building itself gave the impression of a reliable and stable structure.

However, over time, the owner began to notice changes inside the house. There were differences in the floor level, as well as signs of local subsidence of the slab. Although the house looked impeccable from the outside, such deformations could indicate changes in the soil base under the structure.

Understanding that such changes could indicate more serious processes occurring under the building, the owner decided not to postpone solving the problem and turned to our specialists.

Engineering survey

During the inspection of the building, engineers conducted a structural inspection and analyzed the condition of the foundation.

The following was recorded:

• Subsidence of the floor slab;
• Cavities under the slab;
• Significant subsidence of a separate section of the floor.

The cause of the subsidence was a violation of the technology of foundation preparation – the soil was not properly compacted.

Over time, the insufficiently compacted soil began to settle, as a result of which a cavity formed under the floor slab. Due to the loss of support, the slab gradually sank, which caused noticeable deformations.

The owner drew attention to the problem in time. This allowed to quickly restore the stability of the foundation and avoid more serious consequences in the future.

Technical solution

To stabilize the base and lift, a design and engineering solution was developed using GeoResin Deep Lifting & Floor Lifting technology, which included:

• Strengthening the soil base to a depth of -3 m;
• Filling voids under the slab;
• Restoring the slab-soil contact;
• Partial controlled lifting and leveling of the slab.

The principle of operation of the technology

To carry out the work, technological holes of small diameter are arranged in the floor slab in places determined by engineers based on the survey and calculations.

Through these holes, geopolymer material is injected into the soil base, which expands rapidly after injection. Due to this, important processes of stabilization and improvement of the characteristics of the base occur:

• displacing water from soil pores;
• compacts weak layers;
• fills voids;
• forms a rigid composite mass in the soil.

During expansion, a controlled rise of the slab is created.

The process is accompanied by real-time laser leveling with millimeter accuracy.

Progress and deadlines

The full range of work was completed in 4 days.

An important advantage of the technology is the ability to eliminate the problem without significant intervention in the existing building.

The work is performed locally, without digging foundations, dismantling structures and conducting large-scale construction activities. This allows you to preserve the landscaping of the territory and continue to use the facility throughout the entire period of work.

Result

The project included:

• An engineering survey of the building was carried out;
• A technical solution was developed and agreed with the customer;
• The soil base was strengthened, cavities were filled, and the floor slab was lifted.

Thanks to the technology of injection of geopolymer materials, it was possible to eliminate the cause of deformations and restore the stability of the base under the floor slab.

The slab was raised to the design level and leveled, which allowed to eliminate the existing differences and deformations of the surface.

As a result, the structure regained the necessary stability and is ready for further safe operation. The owner received a reliable foundation, and the risk of further subsidence was eliminated.

The customer received a 10-year warranty on the work performed.