Modified Rheological Model for Deep-Buried Silty Mudstone and Support Time Analysis Application

Table 6

Key steps of proper supporting time analysis.

Key step	Numerical simulation content
Step 1	Calculation of in situ stress field by applying lateral-pressure coefficients
Step 2	Tunnel excavation through ten excavation cycles in one day
Step 3	First lining conducted along with excavation
Step 4	Shotcrete hardening for 28 days
Step 5	Time interval between first and second lining to be determined by numerical simulation
Step 6	Second lining subsequently completed
Step 7	Long-term analysis for three years in the operation period