Ontario Power Generation's Response to the Joint Review

3.6 Numerical Analyses
CLOSURE WALL CAPACITY
An elastic boundary element model was constructed to assess the shear stress distribution along the closure
wall interface, and to assess if partial loss of contact between the closure wall and the rock due to the normal
(lateral) displacements of the tunnel walls is a factor of concern.
The host rock is the Lower Member of the Cobourg formation and has the following rock mass elastic
parameters [1] :
The tunnel and the closure wall face on the emplacement room side of the closure wall were pressurized to
10 MPa in the numerical analyses. Because the analysis is limited to elastic behaviour, the results can be
normalized to the applied pressure. The mesh and loading conditions are shown in Figure 2.
Figure 2: Tunnel and closure wall geometry – boundary element mesh and load conditions.
August 27, 2012
Report No. 1011170042-TM-G2170-0001-00 5