METHOD FOR FREEZING-EXPANSION COUNTERMEASURE CONSTRUCTION

PURPOSE: To reduce an effect on a structure by forming holes or grooves into a frozen soil area, filling the holes or the grooves with sand, etc., preventing freezing, and absorbing displacement due to the expansion of frozen soil in foundation improvement by a freezing method in the vicinity of an underground structure. CONSTITUTION: Freezing tubes 4 are buried near an underground structure 6 such as a shaft for a shield excavator at regular intervals, a refrigerant is circulated and flowed into the freezing tubes 4, a peripheral ground is frozen, and the collapse of a wall surface is prevented when a tunnel 7 is excavated. Holes 1 or grooves are formed among the freezing tubes 4 at that time, and the insides of the holes 1 or the grooves are filled with fillers 2 such as muddy water while heating tubes 3 are inserted into the holes 1 or the grooves, thus preventing the freezing of the fillers 2. Expansion pressure by the expansion of frozen soil 5 in the ground G is absorbed by the fillers 2 in the holes 1 or the grooves. Accordingly, freezing pressure to the underground structure 6 is lowered, and construction cost can be reduced as a whole.