关键词: 人工冻结, 温度场, 冻胀变形, 浅覆土, 模型试验

Abstract: In order to obtain the temperature distribution and frost deformation law of frozen wall, the shallow-buried rectangular freezing engineering, which is a construction of the line 3 to cross line 6 in Guangzhou metro, was studied through the model test based on similarity theory. Conclusions are drawn as follows. Firstly, the temperature of the soil closed to the ground surface drops slowly under the influence of ground heat dissipation in shallow-buried freezing engineering .And the frozen wall closed to the ground surface is relatively weak. In the process of freezing, the average development speed of internal frozen wall is about 1.5 times that of the outward frozen wall. Secondly, small amount of frost heaving deformation is generated in the initial freezing stage. The freezing construction is proceeding with high-temperature brine; and the closed frozen wall is not formed at this stage. Thirdly, when the frozen wall is closed, the frost deformation of frozen wall increases obviously at the time of the freezing construction with low-temperature brine. In general, the soil frost heave deformation tends to decrease when the soil layer depth becomes smaller because the upper soil layer is compacted. There is significant interaction effect between the upper shallow covering and frozen wall in shallow-buried rectangular freezing engineering. This implies that the upper soil layer, which will produce deformation in the advance of the freezing process, will affect the temperature field distribution in frozen wall.

Key words: artificial ground freezing, temperature field, frost heave deformation, shallow-buried, model test