Prediction of the Required Supporting Pressure for a Shallow Tunnel in Layered Rock Strata Based on 2D and 3D Upper Bound Limit Analysis

Figure 5

Change laws of the required supporting pressure under varying parameters. (a) Thickness of the upper and lower layers; (b) tunnel span; (c) additional ground load; (d) parameter A; (e) parameter B; (f) rock compressive strength; (g) rock unit weight; (h) rock tensile strength.

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)