Change of dynamic properties of the pile-soil system during freezing

This paper is devoted to the study of the dynamic parameters of the pile–soil system, which is a main part of the most common foundation type used under conditions of seasonal soil freezing-thawing. At temperatures above zero degrees Celsius, a single screw pile was installed in the soil. A weight is attached to the head of the pile. Also located on the pile are the accelerometer, actuator, and temperature sensors. During the autumn–winter period, the experiments was carried out when the ground was frozen. In these experiments, the pile’s response to impact-induced vibrational excitations from the actuator and to natural background vibrations was measured, and the soil and air temperatures were also recorded. The measurements showed that when the soil freezes, there is a significant change in the system’s natural frequencies and damping ratio.