Study on the Influence of Excavation of Superlarge and Ultra-Deep Foundation Pits on the Pile Foundation of Existing Viaducts

Table 2

Construction steps.

Excavation stage no.	Description
1	Initial in situ stress analysis and self-weight load application
2	Viaduct structure construction
3	Displacement clearance
4	Drilled occlusal pile construction
5	Crown beam construction, inner support and lattice column construction, and the first stage of the foundation pit excavation to the elevation of −5 m
6	The second stage of the foundation pit was excavated to an elevation of −8 m
7	The third stage of the foundation pit was excavated to an elevation of −12.5 m
8	The fourth stage of the foundation pit was excavated to an elevation of −17 m