A new measurement method of volumetric frost heave deformation of freezing soil under complex pressure and constraint conditions

Preventing and controlling frost heave deformation is critical to artificial freezing construction. Compared to road engineering, the soil experienced complex pressure and constraint conditions during the freezing process. Therefore, this study introduces a new method for measuring the volumetric frost heave coefficient (VFHC) of freezing soil under complex pressure and constraint conditions. Series experiments were performed to validate the method and explore the pressure effects. Experimental results demonstrate that this method consistently produces stable and well-reasoned outcomes, providing valuable reference for the development of specialized three-dimensional frost heave testing apparatus in subsequent research. Furthermore, this research reveals that pressure and constraint conditions have a significant influence on the volumetric frost heave deformation of soil. An empirical equation that describes the variation of the VFHC with moisture content, considering the pressure and constraint effects, was proposed. These findings have significant implications for underground engineering employing the artificial ground freezing method.