Strengthening the foundations of columns after subsidence during the spring thawing of the base

Problem:

At the final stage of construction of the logistics centre, during the thawing of the spring soil, part of the column foundations (21 pieces) were subjected to uneven sbsidence. Geological surveys carried out during the construction phase did not reveal waterlogged or swampy ground under part of the building. Surveys were carried out in winter, on the frozen base, which caused inaccurate determination of the physical and mechanical characteristics of the soil.

Task:

To strengthen the foundation soil, to stop the uneven settlement of the foundations of the columns. Confirmation of the result of the work is the movement of foundations by 1-3 mm.

Solution:

Before starting the work on strengthening the foundation, a set of geodesic surveys was conducted to accurately determine the position of the columns in space (in the vertical and horizontal planes), as well as to identify the loosened ground horizons of the foundation by dynamic penetrometer test.

To solve this problem, the method of deep Lifting was chosen. All work was carried out from the surface of the plinth foundation (one side of the foundation was exposed), injection was performed at right and sharp angles. All work was performed by grabs, no more than 2 foundations per day. The result of the work was the lifting of each "cup foudation" by 2-3 mm. All work was carried out under the constant supervision of the geodesic service.