Research on Surface Subsidence of Long-Span Underground Tunnel

Table 5

Settlement changes of the surface subsidence monitoring point of Junfeng Road Station in different stages.

Stages of change	Cumulative settlement value (mm)	Cumulative change (mm)	Proportion of total settlement (%)
First stage	0～−6	0～−6	40
Second stage	0～−15	0～10	40
Third stage	0～−15	3～12	10
Fourth stage	−10	5	10