A New Modified Peck Formula for Predicting the Surface Settlement Based on Stochastic Medium Theory

Table 1

Parameters of different settlement curves (#1 tunnel).

n	Width of settlement trough i (m)	Maximum settlement Smax (mm)	Relative error in width of settlement trough (%)	Relative error in maximum settlement (%)
4	10.64	−29.60	18.22	−9.75
8	9.27	−33.96	3.00	3.54
12	9.14	−34.46	1.56	5.10
16	9.13	−34.51	1.44	5.21
20	9.13	−34.51	1.44	5.21
24	9.13	−34.51	1.44	5.21

“−” in front of the maximum settlement indicates the vertically downward direction of the surface displacement. “−” in front of the maximum settlement relative error value indicates that the calculation value of the modified Peck formula is smaller than the calculation value of the Peck formula. “−” expresses the same meaning in the following tables.