Technical Review of the Lined Rock Cavern Concept and Design ...

Technical Review of the Lined Rock Cavern (LRC) Concept and Design Methodology 14
Results of FLAC Soil Anchor Model, Case of:
Ko=1.0; Fri=41°; Dil=20°; Coh=0; Dens=1800 kg/m 3
Figure 4-6 Experimental Results of Soil-Anchor Pullout [after Vesi , 1971] and
Results of the FLAC Soil-Anchor Model
Figure 4-7 shows the results of the soil-anchor model when the initial horizontal stress is
3 times higher than the vertical stress (i.e., Ko = 3); the dilation angle is 0 for these results.
Because we use an axisymmetric model, results are only shown for the right-half
of the model. The location of the anchor plate is indicated. Note that the results in Figure
4-7(a) reflect an earlier state of the anchor pull (i.e., less total anchor movement) than in
than in Figure 4-7(b). As the anchor plate is being pulled out (i.e., upward), the surrounding
soil (particularly above the plate) is set in motion, as indicated by the black velocity
vectors in the figure. After sufficient motion, the soil starts to yield in shear.
Actively yielding soil (shear failure) is indicated by red symbols. The green color appearing
in portions of the soil indicates that the soil was previously subjected to yield but,
as a result of load transfer, has now obtained a stress state that is below the Mohr-
Coulomb yield criterion.