Features of stabilization of soft soils at the base of emergency deformed buildings using finely powdered injection materials in low pressure mode

Abstract

At present, the strengthening of the soil base is often performed by high-pressure injection - injection of a solution under pressure that exceeds the structural strength of the soil (hydraulic fracturing mode). High-pressure injection makes it possible to successfully solve various geotechnical problems, but it has a number of disadvantages, first of all, the uncertainty of the shape and size of injection bodies created in the soil mass, as well as the impossibility of predicting the final deformation and strength characteristics necessary for design. It should be noted that directly from the production of injection works in the uncontrolled hydraulic fracturing mode, unpredictable technological deformations (rise followed by uneven settlement) of the Objects are observed, the base of which is stabilized, as a result of which crack formation processes in above-ground structures and fragmentary destruction of load-bearing elements develop. The article considers the possibility of solving the problem of predictable increase in the mechanical properties of stabilized soils on the example of a pilot production site in the central region of St. Petersburg. The proposed method makes it possible to ensure the absence of technological deformations from the production of injection works by using the author's kinematic scheme for the production of works and the use of modern solutions based on fine binders in the impregnation mode with an element of soil microfracture, that is, in the mode of controlled hydraulic fracturing at a reduced injection pressure of the injection solution.