research paper about earthquake ground motion at Saqqara (Zoser) pyramid.

2. Motivation
The motivation of the present was initiated to
help in the concurrent efforts to restore Zoser
Pyramid after the severe damages
encountered after Cairo Earthquake in
October 1992.

3. Objective
Simulation of earthquake ground motion
During the 1992 Cairo (Dahshour) at Saqqara
pyramid to aiding the present archeological
restoration projects there.

4. 1- Area of Study.
2- Seismicity near Zoser Pyramid.
3- Site effects using H/V method.
4- Simulation technique (SMSIM).
5- Ground motion summary.
6- Discussion.

5. Area of Study

6. Damages in Zoser (Saqqara) Pyramid
Saqqara pyramid
encountered severe
damages. These
damages is believed to
be related to Cairo
earthquake. Since
2003 efforts are
exerted to restore the
pyramid.

7. Earthquake activities near Zoser
Pyramid
Cairo earthquake
epicenter was only
14 km away from
Zoser Pyramid.
The magnitude of
this event was
about 5.8.
Previous study by
Deif and Khalil
(2002) pointed out
that this event is
the design
earthquake for the
area of Study

8. Site response using H/V method
• H/V method has received notable attention in recent
years due to its low cost and relative simplicity.
• The method was invented in the 50’s of the last
century, however, it was not widely used until the work
of Nakamura 1989.
• Debates about the nature of seismic type involved in
the estimation. Some believe it is Rayleigh wave type,
others believed it is SH wave trains entrapped in the
soil layers.
• The method gives the natural frequency with high
accuracy, however, the amplification factor suffer from
high uncertainties.

9. H/V field work
Ambient noise was
recorded using k2-Altus
Accelerograph. The
time windows used
was 5 minutes at a
sample rate of 100
sample/sec. 25
recording points were
selected mainly at the
southern side of the
Pyramid.

10. Sample H/V curves

11. Simulation Method (SMSIM)
This method was first based entirely on generation of
stochastic (random) time series to imitate the overall
shape of strong motion recordings. Afterwards the
method is modified by using a representation of the
seismic source to scale the simulated record. The input
parameters are the magnitude, distance, and corner
frequency of seismic source. Filtering and tapering of
simulated time series to get a closer simulation of the
overall features of the accelerogram. The SMSIM
software (David Boore) to simulate the time series due
to an earthquake of magnitude 6.3 (credible
earthquake) at a distance of 14 km (at the site of Zoser
pyramid).

12. Simulated ground acceleration
-E+
-E+
-E+
E+
E+
E+
E+
A
A

13. Response Spectra
E+
E-
E+
E+
E+
E+
E+
per
PSA response specra
PSA response specra

14. Discussion
The simulation of strong ground motion during
Cairo Earthquake at Zoser pyramid showed that
the peak ground acceleration equals 135 gal. The
site response using the H/V method yielded a
natural frequency of 1 Hz and amplification of
about 1.5.
The result of the present work will help in the
restoration projects at Zoser pyramid specially
the proper solution to the shaft ceil of the
pyramid.