Abstract:

The study carried out the physical and mechanical properties test of frozen rock in the area of east and northwest, and compared the differences between difference area, then the physical properties of rock in Cretaceous and Jurassic strata such as the big thermal conductivity coefficient, the small specific heat and the small frost heaving and so on have been obtained. Rock is high in strength, under the condition of low temperature, with the decrease of the maintenance temperature, the strength is further improved, but mainly in -5~-10℃, in -10℃, the strength is more than 10MPa, the limit fracture strain is in 1%~3%. The freezing method in deep alluvium in east has been discussed, based on this experience, the freezing method in Cretaceous and Jurassic strata mainly considers waterproof and the influence of blasting on freezing tube when driving, so it should be appropriately increased the diameter of freezing pipe, but with the single coil tube can meet the engineering requirements. The results can provide a reference for the design of freezing in Northwest China.

Key words: Northwest region, Freeze sinking, Freezing method, Physical and mechanical properties