Displacement Characteristics of a Deep Excavation in Hangzhou Soft Clay

Table 1

Construction phases and sequence of the excavation.

Stage		Day	Construction activities
Preexcavation	O1	—	Construct diaphragm wall
	O2	—	Cast the first concrete prop 1
	O3	—	Construct high pressure jet grouting (−18.2 m −22.2 m)
Main excavation (I)	A1	1–8	Excavate to level 2 (−5.2 m)
	A2	9–13	Install prop 2, prestressed axial force
	A3	14–19	SP: excavate to level 3 (−8.5 m)
	A4	20–24	NP: cast the concrete prop 2 and waist beam
	A5	25–27	SP: install prop 3, prestressed axial force
	A6	28–34	Excavate to level 3 (−12.1 m)
	A7	35–37	Install prop 3, prestressed axial force
	A8	38–44	Excavate to level 4 (−15.65 m)
	A9	45–47	Install prop 4, prestressed axial force
	A10	48–57	Excavate to level 5 (−18.2 m)
	A11	58–60	Install prop 5, prestressed axial force
After excavation (II)	B1	61–92	SP: construct the second floor and reduce prop 5
	B2	93–119	SP: construct the first floor and reduce prop 2,3,4
	B3	120–125	SP: construct the roof of the first floor and reduce prop 1
	B4	61–94	NP: construct the second floor and reduce prop 4,5
	B5	95–150	NP: construct the first floor and reduce prop 1,2,3