Manual utilizator Slope - GeoStru Software

NORMATIVE 46
5.The design seismic inertia forces F H and F V acting on the ground mass, for
the horizontal and vertical directions respectively, in pseudo-static analyses
shall be taken as:
F H
= 0,5
S W
F V
= ± 0,5 F H
if the ratio a vg
/a g
is greater than 0,6
F V
= ± 0,33 F H
if the ratio a vg
/a g
is not greater than 0,6.
Where:
is the ratio of the design ground acceleration on type A
ground, a g
, to the acceleration of gravity g;
a vg
a g
is the design ground acceleration in the vertical direction;
is the design ground acceleration for type A ground;
S is the soil parameter of EN 1998-1:2004, 3.2.2.2;
W
is the weight of the sliding mass.
A topographic amplification factor for a g shall be taken into account according
to 4.1.3.2 (2).
6. A limit state condition shall then be checked for the least safe potential slip
surface.
7. The serviceability limit state condition may be checked by calculating the
permanent displacement of the sliding mass by using a simplified dynamic model
consisting of a rigid block sliding against a friction force on the slope. In this
model the seismic action should be a time history representation in accordance
with 2.2 and based on the design acceleration without reductions.
8. Simplified methods, such as the pseudo-static simplified methods mentioned
in (3) to (6) in this subclause, shall not be used for soils capable of developing
high pore water pressures or significant degradation of stiffness under cyclic
loading.
9. The pore pressure increment should be evaluated using appropriate tests. In
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