Study on Dynamic Response Characteristics and Damage Mechanism of Tunnel Lining at Entrance of Shallow Bias Tunnel

Table 6

Minimum principal stress values at key points A1–A8 and corresponding times C25 = 1.78

Key point	A1	A2	A3	A4	A5	A6	A7	A8
Stress (MPa)	−1.847	−2.791	−2.029	−1.512	−2.244	−3.501	−2.248	−2.551
Time (s)	5.218	5.450	5.418	5.386	5.328	5.468	5.428	4.388