Environmental Engineering Reference
In-Depth Information
Figure 7. Results of the analysis when magma pressure
is applied to the tree-units model with the relatively poor
Mc properties as in Figure 6. a. x-displacement con-
tours related only to the application of magma pressure.
B. shear strain increments. c. plasticity indicators.
Figure 6. Results of the analysis considering three units
(Ve, Flcl, hP) and reasonably poor Mc properties.
a. displacement contours. B. shear strain increments
c. Plasticity indicators. D. shear strain increments result-
ing from a simulation with less stiff Ve and Flcl units
(lower elastic moduli).
(
Fig. 6c
) are concentrated along high-angle critical
zones below the volcano edifice, drawing the path
for magma rising. no critical deep-seated sliding
surfaces develop.
When rock mass elastic moduli are reduced, a
more evident subsidence phenomenon is observed.
in addition to the critical zone in the central part
of the model, a zone of shear strain increment
develops along the prosecution of the buried
hP steps, cropping out in correspondence of the
The introduction of the cl unit does not pro-
duce significant changes in the strain field if no
additional perturbations are added.
Figure 7 shows the results adding the magmas-
tatic pressure to the three-units model. The effect
on the strain field is symmetrical even if the gen-
eral cumulated pattern still presents an eastward
direction. The high angle critical zones below the
volcano edifice are better delineated.
The addition of a magma overpressure compo-
nent favors the development of shallow instability
on the eastern slope, especially when the cl unit is
included in the model.
Figure 8. FeM output of the case with 4 units and the
application of magma pressure components. a. Displace-
ment contours. B. Maximum shear strain contours.
Figure 9. x-displacement profiles across the volcano
(profile traces in
Fig. 9a
).
