Nowadays, due to the increase in the number of storeys of structures under construction, the number of buildings erected on pile foundations has increased. A large number of theoretical and experimental studies of pile operation under load have allowed the development of various methods for calculating pile settlement. However, most of them do not take into account the technology of pile construction, which affects the change in the properties of the contact zone soils. In addition, most of the methods assume that the settlement of the pile is equal to the settlement of the soil, but in reality, after reaching the ultimate strength, the pile has the possibility of slipping through the soil. The main purpose of this paper is to investigate the influence of the interface friction coefficient (strength reduction factor Rinter) on the results of pile settlement calculations performed by numerical method in the geotechnical software package Plaxis. In this paper, the interface friction coefficient was determined from the results of laboratory shear tests of sandy and clayey soils over concrete, in accordance with the current regulatory documentation (SP 22.133330.2016 «Soil bases of buildings and structures») and back calculation based on field tests. Based on the results of the calculations, graphs of load-dependent settlement were plotted and a comparative analysis of the results obtained with the results of known field tests of bored piles by static loading was performed. Based on the comparative analysis, conclusions were drawn about the influence of the method of determining the interface friction coefficient on the pile settlement calculation results, the influence of the pile construction technology on the interface friction coefficient value and recommendations on how to take this coefficient into account in the calculations.
Sidorov et al. (Thu,) studied this question.