Calculation Model and Influencing Factors of Surrounding Rock Loosening Pressure for Tunnel in Fold Zone

Figure 5

Relationship between and vertical looseness pressure q of surrounding rock. (a) Side pressure coefficient  = 0.2. (b) Side pressure coefficient  = 0.4. (c) Side pressure coefficient  = 0.6. (d) Side pressure coefficient  = 0.8. (e) Side pressure coefficient  = 1.0. (f) Side pressure coefficient  = 1.2. 1— = 7.5°; 2— = 12.5°; 3— = 23°; 4— = 43°; 5— = 60°; 6— = 73°.

(a)

(b)

(c)

(d)

(e)

(f)