Three-Dimensional Upper Bound Limit Analysis on the Collapse of Shallow Soil Tunnels considering Roof Stratification and Pore Water Pressure

Figure 7

Collapse surfaces for varying other parameters: (a) cohesion; (b) nonlinear coefficient; (c) unit weight; (d) support pressure; (e) ground overload.

(a)

(b)

(c)

(d)

(e)