On the issue of improving the technology of making and calculation of various types of piles

Abstract

The article discusses the problems associated with construction of pile foundations in structurally unstable soils, including permafrost soil, and ways to solve such problems on the example of slurried and auger cast (grout-injected) piles. The results of a laboratory experiment simulating the construction process of a slurried pile in sandy frozen soils are presented. The authors give the functional connections of changes in the temperature of the soil and cement-sand solution in time, determined the maximum radius of thawing and the total duration of the process of thawing and reverse freezing of the soil to the natural state as well as recommendations for the design of slurried piles taking into account the thermal interaction with permafrost soils. A laboratory study of the interaction of auger cast (grout-injected) piles with frozen soil is presented. The results of laboratory studies of the strength of cement mortars of different compositions tsolidified at negative temperature are presented. Recommendations on the choice of the solution composition for the device of auger cast (grout-injected) piles in frozen soil are given. The authors believe that the solution of the problems identified in the article associated with the use of improved types of pile foundations in complex geotechnical conditions will significantly improve the reliability of structures, reduce construction time and reduce economic costs.