The Prototype Test on Sealing Capacity and Mechanical Behavior of the Underground Segmental Lining in a Low Vacuum Environment

Table 2

Maximum strain of concrete at monitoring point.

Monitoring point	Initial frequency f1	Working frequency f2	Compressive strain ε (με)
K3	2221	2215	10.96
1A3	2189	2186	5.26
1A10	2210	2207	5.23
1A11	2199	2188	19.48
2A4	2260	2249	20.57
3A4	2202	2200	3.56