Temperature Field of Artificially Frozen Gravel Formation and Optimization of Freezing Pipe Layout Parameters under Seepage Flow

Table 4

Rang of values for freezing pipe layout parameters.

Parameters	The zone of the freezing pipes located in the tunnel connected aisle
	Upstream zone ()	Downstream zone ()	Top arch zone ()	Bottom zone ()
				—
				—

Note: where denotes the diameter of the freezing pipe.