Experimental study on adfreezing strength at the interface between silt and concrete

The mechanical behavior of the interface between soil and structure is the key to determine freezing behaviors of pile foundations in cold regions. In order to explain the formation mechanisms of adfreezing strength at the soilstructure interface and explore its influencing factors and changing rules, orthogonal direct shear tests and orthogonal tensile tests were carried out under various conditions of moisture content, temperature, and dry density. Test data shows that: (a) The influence of moisture content and temperature on the shear and tensile strength is significant, while the influence of dry density is not. (b) The shear and tensile strength of the contact surface are positively correlated with the absolute value of the temperature and moisture content, but they exhibit different growth characteristics. (c) Under the same test conditions, when the tensile strength is less than 100 kPa, there is little difference in the shear and tensile strength of the contact surface. When the tensile strength exceeds 100 kPa, the tensile strength of the contact surface will be significantly greater than the shear strength. There is an exponential relationship between shear strength and tensile strength. Based on the experimental results, a bond-friction interface model which confirms the reliability of the model in simulating the mechanical behavior of the pile-soil interface is established. Research results clarify the mechanical behavior of the pile-soil interface at low temperatures, which can provide references for the interactive mechanisms of tapered pile-soil and the establishment of anti-freeze models.