Factor’s Influence Analysis of Frost Heave during the Twin-Tunnel Construction Using Artificial Horizontal Ground Freezing Method

Table 4

Significance analysis of three factors.

Source	Quadratic sum	Degree freedom	Mean square	F	Significance
Correction model	364.383^a	8	45.548	30.088	0.000
Nodal increment	28079.430	1	28079.430	18548.9	0.000
				56
Clear distance	350.056	5	70.011	46.249	0.000
Buried depth	9.726	2	4.863	3.212	0.069
Freezing order	1.086	1	1.086	0.717	0.410
Error	22.707	15	1.514	—	—
Total	56434.425	24	—	—	—
Total correction	387.090	23	—	—	—
a: R^2 = 0.941 (revised R^2 = 0.910)	—	—	—	—	—