Research Article
A Novel Excavation and Construction Method for an Extra-Long Underwater Tunnel in Soft Soils
Table 1
Main construction stages of Zone #1.
| | Stages | Construction activity | Date (mm/dd/year) |
| | 1(a) | Construction of DSSPs | 04/01/2018–06/27/2018 | | 1(b) | Discharge of lake water and dredging work | 06/28/2018–07/07/2018 | | 1(c) | Construction of bored piles, cut-off walls, and cement mixed piles | 07/18/2018–09/08/2018 | | 2(a) | Removal of embankment or transverse DSSPs | 09/09/2018 | | 2(b) | Excavation of the first layer of subsoil with thickness of 3.2 m | 09/10/2018–10/16/2018 | | 2(c) | Excavation of the second layer of subsoil with thickness of 4 m | 10/17/2018–12/19/2018 | | 2(d) | Installation of struts at Level 1 | 12/20/2018–12/31/2018 | | 2(e) | Excavation of the third layer of subsoil with thickness of 5.3 m | 01/01/2019–03/05/2019 | | 2(f) | Installation of struts at Level 2 | 03/06/2019–03/14/2019 | | 2(g) | Excavation of the fourth layer of subsoil with thickness of 3.6 m | 03/15/2019–04/13/2019 | | 3(a) | Casting of floor slabs | 04/14/2019–06/19/2019 | | 3(b) | Removal of struts at Level 2 | 06/20/2019–06/27/2019 | | 3(c) | Construction of side walls of tunnel | 06/28/2019–09/09/2019 | | 3(d) | Construction of inclined steel struts | 09/09/2019–09/18/2019 | | 3(e) | Removal of struts at Level 1 | 09/19/2019–09/26/2019 | | 3(f) | Construction of tunnel roof | 09/27/2019–05/07/2020 | | 3(g) | Removal of inclined steel struts | 05/08/2020–05/21/2020 | | 4(a) | Backfilling of soils | 05/22/2020–05/29/2020 | | 4(b) | Construction of earth cofferdam or truncated embankment | 06/01/2020–06/09/2020 | | 5 | Removal of longitudinal DSSPs | 06/20/2020–06/27/2020 |
|
|
