FINITE-ELEMENT ANALYSIS OF STRENGTHENING THE SUBGRADE ON THE BASIS OF BORING AND MIXING TECHNOLOGY

Abstract

One of the effective techniques to strengthen the subgrade is boring and mixing technology, which is based on the immersion of vertical elements –piles into the subgrade. This method of strengthening significantly affects the stress state of the track superstructure. Two options of the placement of strengthening elements are examined in thispaper. Todetermine the influence of position of strengthening elements on the stress state of the track superstructure, appropriate finite-element models were created. The models fully reflect the geometric and deformation characteristics of a real subgrade, whichis strengthened by piles. The calculated stress state of the track superstructure is shown and analyzed in thispaper. The main contribution of the paper lies in optimization of the geometric parameters of the technologyto reduce the stress state of the "track superstructure–subgrade–soil basement" system. The results show that the location of piles near the rails is more effective than the location of piles near the ballast section.

Keywords

• finite-element model
• stress state
• boring and mixing technology
• track superstructure
• subgrade
• strengthening