Development of measuring system by pile-pressing method and experimental study on adfreezing strength at interface between frozen soil and structure

In order to study the influence factors and rules of adfreezing strength at the interface between frozen soil and structure, according to the traditional definition of adfreezing strength at the interface, a measuring system for determining the adfreezing strength by pile-pressing method is developed. Based on this system, a series of experimental studies on the adfreezing strength at the interface are carried out under various influence factors. The experimental results show that the adfreezing strength at the interface between frozen soil and structure exhibits brittle failure and strain softening, and the residual adfreezing strength is characterized by periodic fluctuation and decay. The adfreezing strength is significantly affected by the temperature and roughness of the interface, and they are linear and logarithmic functions respectively in the test temperature range. Using the micro-earth pressure sensor embedded at the side of the compression pile, the variation laws of the compressive stress at the interface with the freezing time, shear displacement and distribution along the pile are revealed, and then they are compared with and verified by those of the interface temperature and adfreezing strength.