Experimental Investigation on the Influence of Regional Concrete Spalling on Shield Tunnel Segments

Table 7

Test load applying scheme.

Loading step	Jack pressure of direction III (MPa)	Load of direction I
		Jack pressure (MPa)	Formation pressure of the model vault (kPa)	Formation pressure of the prototype vault (kPa)
0	0	0	0	0
1	4	2	2.7	32.4
2	6	4	6.5	78.0
3	8	6	10.4	124.8
4	10	8	13.9	166.8
5	12	10	17.3	207.6
6	14	12	20.9	250.8
7	16	14	24.2	290.4
8	17	16	28.3	339.6
9	18	18	31.6	379.2
10	18	19	35.3	423.6
11	18	20	38.7	464.4
12	18	21	42.2	506.4
13	18	22	45.8	549.6
14	18	23	49.6	595.2
15	18	24	53.5	642.0
16	18	25	56.9	682.8
17	18	26	60.6	727.2
18	18	27	64.8	777.6