RESEARCH ON FROST HEAVING CHARACTERISTICS OF ARTIFICIAL FROZEN SOIL BASED ON UNLOADING EFFECT BY DISCHARGE HOLES

Ground freezing envelope method in foundation pit support and metro tunnel engineering has excellent adaptability and prominent technical advantages in complex geological environmental conditions of special aquifers. As a new geotechnical technique in foundation pit engineering, it depends on artificial refrigeration to freeze aquifer to form curtains. With excellent waterproof, higher rigidity and strength, it is used in unstable soil reinforcement and groundwater insulation. The frost-heaving force is one of the main loads in artificial frozen pit engineering, and the frost force and deformation have great influences on retaining and supporting structures. In application, discharge holes are employed to relieve the frost pressure and deformation. The finite element analysis, experiment and in-situ test show the frozen mechanics and deformation in artificial frozen soil, and may provide theoretical basis for future applications of ground freezing envelope method.