The Deformation Analysis of a Deep Frame Top-Down Excavation in Downtown Shanghai Based on the 3D FEM

Table 3

State of foundation pit construction.

Stage	Event	Date (yy/mm/dd)	Days spent
0	Construction of retaining wall, steel lattice column, and bored pile as the vertical support system and compaction grouting of the soils	20081217 –20090914	272
1	Excavation to 1.15 m BGS; construction of the roof beam (0.8 m × 0.65 m) and level 1 temporary RC ring struts (1.6 m × 0.8 m)	20090915–20091110	57
2	Excavation to 5.85 m BGS; construction of middle beam 1 (1.0 m × 0.6 m) and level 2 temporary RC ring struts (1.8 m × 0.8 m)	20091111–20100206	88
3	Excavation to 10.05 m BGS; construction of middle beam 2 (1.2 m × 0.6 m) and level 3 temporary RC ring struts (2.0 m × 0.8 m)	20100301–20100705	127
4	Excavation to 13.6 m BGS (final level)	20100706–20100928	84
5	Construction of the base slab	20100928–20101126	58
6	Construction of the podium block	20100903–20110227	177
7	Construction of the tower block	20101205–20110531	178