Mechanical Responses to Different Excavation Methods of Qichongcun Tunnel in Guiyang City, China

Table 4

Main calculation steps of single-side wall construction.

Calculation step	Construction conditions
I.S.	Clear the displacement
S1	Excavate 1 m of the tunnel guide pit
S2	Excavate 1 m of the tunnel guide pit; make the first step of the steel arch and initial lining
S3	Excavate 1 m of the tunnel guide pit; make the second step of the steel arch and initial lining
S4	Excavate 1 m of the tunnel guide pit; make the third step of the steel arch and initial lining
S5	Excavate 1 m of the tunnel guide pit; make the fourth step of the steel arch and initial lining
S6	Excavate 1 m of the tunnel guide pit; make the fifth step of the steel arch and initial lining
S7	Excavate 1 m of the tunnel guide pit; make the sixth step of the steel arch and initial lining
S8	Excavate 1 m of the tunnel guide pit; make the seventh step of the steel arch and initial lining
S9	Excavate 1 m of the tunnel guide pit; make the eighth step of the steel arch and initial lining
S10	Excavate 1 m of the tunnel guide pit; make the ninth step of the steel arch and initial lining
S11	Excavate 1 m of the first step of the main tunnel; make the tenth step of the steel arch and initial lining
S12	Excavate 1 m of the first step of the main tunnel; make the steel arch and initial lining of the previous step
S13	Excavate 1 m of the second step of the main tunnel; make the steel arch and initial lining of the previous step
S14	Make steel arch and initial lining of the previous step
S15	Excavate 1 m of the third step of the main tunnel; make steel arch and initial lining of the previous step
...	...
S26	Excavate inverted arch
S27	Lay steel for inverted arch
S28	Inverted arch
S29	Second lining