A Closed-Form Solution for the Analysis of Antifreeze Disease Fortification Length in a Permafrost Tunnel

Table 2

Causes of tunnel frost damage [1].

Tunnel name	Insufficient waterproofing and drainage design	Water leakage	Extreme weather	Low temperature	No consideration of frost heave	Invalidation of thermal insulation material
Tiziling	✓
Qidaoliang	✓
Dabanshan					✓
Lingding		✓
Kuixian	✓
Xinganling		✓
Yuximole		✓
Beiweizi			✓
Baikaer						✓
No. 2 Xiluoqi						✓
Yaling					✓
Nenlin					✓
No. 2 Cuiling					✓
Kunlunshan		✓
Nanshan	✓
Qingshanli	✓
No. 1 Songyue	✓
Aolaling	✓
Mijiang		✓
Guanjiao
Habutegai
No. 2 Hujiriyan				✓
Yongan				✓
Fenshuiling		✓
No. 2 Tianshan		✓