Parametric analysis of a strain state of a soil base strengthened with vertical elements

Abstract

Purpose is to identify vertical displacements of the “soil basem strengthened with piles or micropiles based upon drilling-mixing technology” system relying upon parametric analysis of strain state of the mentioned system, and arrangement of the strengthening elements. Methods. Mathematical modeling took place for twelve finite-element models using the computing complex SCAD intended to analyze strength of structures by means of finite-element method. Numerical analysis was carried out with variation of elastic-strain modulus of vertical reinforcing elements and change in distance between them (3d and 6d of micropiles). Findings. Results of parametric analysis have been obtained for a model without a micropile (non reinforced soil base); a model with a single micropile; a model with two micropiles where distance between them is 1.5 m, i.e. 3d of micropiles; and a model with two micropiles where distance between them is 3.0 m, i.e. 6d of micropiles. The performed comparative analysis has made it possible to obtain the results proving the hypothesis by the authors as for the specific nature of vertical displacement formation of the “soil base strengthened with piles or micropiles based upon drill-mixing technology” system. Originality. It has been identified for the first time that basing upon the standardized document for the auger or displacement piles, it is impossible to decrease efficiently vertical displacements while approaching micropiles since distance between the micropiles is 3d for elements, developed on the basis of the drilling-mixing, is minimal. Practical implications. The obtained results of a strain state may become the keystone for the development of the genera-lized strain theory of the composite “soil base strengthened with piles or micropiles based upon drilling-mixing technology” system as a medium differing in minor changes of strain characteristics.