【英文摘要】Frost heave and thaw settlement are the objective defects of the artificial ground freezing method. To solve this problem, the mechanism of grouting to control thaw-settlement was researched. According to the characteristics of the artificial ground freezing method in the urban and coastal areas, considering the conditions of pressure, rich water and three-dimension, experimental study on physical mechanics, thermodynamics, frost heave and thaw settlement properties were conducted to saline soils and secondary freeze-thaw soils. Based on which, the influences of salt and cement content on the frozen soil properties were obtained through a series of experiments. The laws of thawing and grouting to control thaw-settlement in the conditions of natural and artificial thawing via a large-scale in-situ test were gained. From the laboratory tests and the large-scale in-situ test, consolidation characteristic and frozen-thawed soil properties after frost heave and grouting under the artificial ground freezing conditions for underground engineering were theoretically analysed, and the rules of consolidation settlement after grouting in the thawing process of the main soil layers after artificial ground freezing in Shanghai, and the calculation method of thaw settlement was set up. In view of the phenomenon of freezing temperature depression of saline strata, the classic temperature field models of artificially frozen soil wall were modified. Considering the actual freezing temperature, the analytical solutions of frozen soil temperature field of single pipe, single-rowed pipes and double-rowed pipes were established, and calculation methods for the average temperature of frozen soil wall by single-rowed pipes, double-rowed pipes and multi-rowed pipes were deduced based on the Bakholdin temperature field models. Finally, according to the generality between frost heave and thaw settlement, a new philosophy of "artificial ground improving & freezing method" was put forward in order to control frost heave and thaw settlement.