Research on Surface Subsidence of Long-Span Underground Tunnel

Table 2

Comparison of construction methods of shallow buried excavation.

Number	Construction method	Conditions of use	Stratum subsidence	Construction period	Construction cost
1	Full-section method	Good stratum, span ≤ 8 m	General	Shortest	Low
2	Step method	Poor stratum, span ≤ 12 m	General	Short	Low
3	Double-wall pit guide method	Poor stratum, generally used in stations with a large-span	Comparatively large	Comparatively long	High
4	CRD method	Poor stratum, large-span	Comparatively large	Comparatively long	High
5	CD method	Poor stratum, span ≤ 14 m	Comparatively large	Comparatively long	General