Earthquake and impact of soil type on content of the result spectrum

Article Citation:
Shahryar Heidari and Siyamak Bagheriyan
Earthquake and impact of soil type on content of the result spectrum
Journal of Research in Ecology (2016) 6(8): 2131-2141
JournalofResearchinBiology
Earthquake and impact of soil type on content of the result spectrum
Keywords:
Response spectrum, earthquake, soil type, accelerogram, seismosignal.
ABSTRACT:
There are various factors which effect on spectrum of earthquake such as:
soil type, magnitude of earthquake, distance to earthquake center, type of fault,
duration and damping of earthquake. The research was aimed to investigate the
effects of soil on the spectrum of earthquake. Therefore, several accelerograms for
three different locations around the world have been selected from Berkeley
University website. Then the selected accelerograms were scaled up with number 1
for scaling the spectrums. The spectrums of accelerograms and the records of
earthquake were drawn by seismosignal software. Finally, the effect of different soil
were investigated on the spectrum of response earthquake. For increasing the
accuracy of results, similar effective parameter have been selected in choosing of
accelerograms. Results of the research were as follows; the domain of spectrum was
higher due to increasing the hardness of soil in harez um similar design factor in low
periods and the domain of spectrum was higher due to increasing the softness of soil
in higher periods. The diagrams are more gatherer and possess a greater amount in
harder soil and are is more extent and possess a lower amount in the softer soil.
2131-2141 | JRB | 2016 | Vol 6 | No 8
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www.jresearchbiology.com
Journal of Research in Biology
An International
Scientific Research Journal
Authors:
Shahryar Heidari and
Siyamak Bagheriyan
Institution:
Department of Civil
Engineering, Shahryar
Branch, Islamic Azad
University, Tehran, Iran.
Corresponding author:
Shahryar Heidari
Email Id:
Web Address:
http://jresearchbiology.com/
documents/RA0614.pdf
Dates:
Received: 28 Sep 2016 Accepted: 16 Oct 2016 Published: 18 Nov 2016
Short Communication
Journal of Research in Biology
An International Scientific Research Journal
ISSN No: Print: 2231 –6280; Online: 2231- 6299

INTRODUCTION
Transferring the load of structures is done di-
rectly or indirectly by foundation to the soil. Especially
during an earthquake, behaviours of structures are
effected by the soil conditions under the foundation and
soil properties that poses important role in the transfer-
ring of seismic waves from the bedrock to structures.
The accuracy of transmission mechanisms of waves,
determination and applying lateral force caused by the
earthquake is a main issue in safe and optimized design-
ing structure. The diffused fluctuations caused by the
earthquake of bedrock can be intensified or weakened
due to the characteristics of soil and the structure. The
project was aimed to investigate and compare the effects
of soil on spectrum earthquake for three different loca-
tions all around the world. For increasing the accuracy
of results, similar effective parameters have been select-
ed in the choosing of accelerograms. The reflectance
spectrum of an accelerogram indicated the factors such
as ground motion acceleration, frequency content and
duration ground motion at Location.
The spectrum of location against earthquakes
are well-known in the designing of structures. Based on
the conducted research, there are two methods for con-
sidering the intense vibration caused by the earthquake
and its impact on the structure during an earthquake
(earthquake design) Imanpour and Mehobbi, 2008
1. The reflection spectrum of project is obtained from
the spectrums of different reflection records.
2. The obtained spectrum was converted into an elastic
design by averaging of four accelerograms.
Heidari and Bagheriyan, 2016
2132 Journal of Research in Biology (2016) 6(8): 2131–2141
Figure 1. Triple graph of spectrum Havzner design
(Moghadam, 1992)
Figure 2. Coordinated response spectrum (no dimen-
sions) of EL Centro earthquake (Moghadam, 1992)
Figure 3. Acceleration spectrum average (50%) no
dimensions for different types of ground
(Moghadam, 1992)
Figure 4. Acceleration spectrum above-average
(84.1%) No sayed dimensions for different types of
ground (Moghadam, 1992)

MATERIALS AND METHODS
Some researchers had evaluated various factors
on the shape of the reflection spectra. Most of the cases
are as follows Imanpour and Mehobbi, 2008:
1. Specifications of soil location
2. Magnitude of earthquake and ground motion parame-
ters including acceleration, velocity and displacement
Journal of Research in Biology (2016) 6(8): 2131–2141 2133
Figure 5. Spectrum of Moahrez design for deprecia-
tion 5% and ground acceleration 1g/
(Moghadam, 1992)
Figure 6. Normalized response spectrum, damping
5% (Bazyar and Ghanad, 2003)
Soil type A
Soil type B
Soil type C
Soil type D
Soil type E
Figure 9. Recorded accelerograms of Duzce earthquake (Duzce, Turkey 1999/11/12)

maximum Earth
3. The distance to the epicenter of the earthquake site
and the type of soil classification in the passage of seis-
mic waves to site
4. The characteristics and mechanisms of origin earth
quakes and duration of ground motion in time of earth-
quake
Therefore, a real spectrum includes the above
factors. There are some methods to calculate the
resistance of structure against earthquakes. The most
common methods are equivalent static analysis, modal
and dynamic Moghadam (1992). One of these methods
are using the spectrum seismic reflection in structure
Amiri, 2003. The seismic force can be determined in
quasi-static method by follow simple equation
Moghadam (1992):
Earthquake Force = Structural weight * Acceleration of
spectrum
In this way, Structural force can be calculated
by using the spectrum acceleration of the earthquake.
Figure 7. Building reflection coefficient for a variety
of lands for earthquake with low and moderate risk
[BRC, 2005]
Figure 8. Building reflection coefficient for a variety
of lands for earthquake with high and very high risk
[BRC, 2005]
SoiltypeBSoiltypeASoiltypeC
SoiltypeDSoiltypeE
Figure 10. The spectrum of Duzce earthquake (Duzce, Turkey 1999/11/12)

Soil type is one the most important factors which have a
significant impact on the amount of spectrum. There are
different methods for soil classification as follows: re-
gional geological method, speed method, using SPT,
microtremor method (microtremore) and the shape of
response spectrum method Amiri, 2003. Havzner was
the first researcher who presented the design of spec-
trum earthquake in the late of 1950’s. The Havzner de-
signing spectrum for acceleration, velocity and displace-
ment are shown in Figure 1. This spectrums are appro-
priate for analysis and designing in field of reactionary,
while more structure are related to inelastic field. The
spectrums are co-ordinated on base of ground accelera-
tion 0.2 g and they should be divided on 0.2g for certain
ground acceleration A. In the late 60s, Newmark and
Hall studied the triple spectrum of many accelerogram.
They noted there are several specified areas in triple
spectrum diagram which the results are presented for El
Centro earthquake in Figure 2 (Moghadam, 1992).
1. Acceleration response is equal to acceleration ground
in high frequency.
2. Acceleration response is almost constant in range of
two to eight Hz.
3. Velocity is almost constant In range of 0.2 to 2 Hz.
4. Relocation is almost constant in the range less than
0.2 Hz.
5. Relocation of structure is equal to relocation of
ground in very low frequency.
The effect of type ground wasn’t considered in
initial spectrum of Newmark and Hall. Other research-
ers noted that there were difference between the content
of the recorded frequency of accelerograms on bedrock
Journal of Research in Biology (2016) 6(8): 2131-2141 2135
Soil type A
Soil type B
Soil type C
Soil type D
Soil type E
Figure 11. Recorded accelerograms of Kocaeli earthquake (Turkey 1999/08/17)

and recorded frequency on illuviation. The results of
the research indicated in Figures 3 and 4 (Moghadam,
1992). The effect of the soften ground type appeared as
decreasing the amplification factor of acceleration in
high frequencies and also increasing of the factor in low
frequencies. (Moghadam, 1992)
The curves of Figure 6 were obtained by the
results of seismic designing structures Bazyar and Gha-
nad (2003). Regulations of buildings design against
earthquakes (Iran 2800) presented the spectrum design
for soil types and intensity of relative risk by using the
newest results (version 3, 1382) in accordance with
SoiltypeASoiltypeBSoiltypeC
SoiltypeDSoiltypeE
Figure 12. The spectrum of Kocaeli earthquake (Turkey 1999/08/17)
Table 1. Classification of land
Type
of land
Description of ingredients
Approximately
Vs (meters per
second)
S. No
I
(A) Igneous rocks (coarse and fine texture), hard and very resistant rocks
and metamorphic mass (gneiss-crystalline silicate rocks) conglomerate
classes
(B) Hard soils (sand dense, very hard clay) with a thickness of less than 30
m
More than 750
More than 750
1
II
(A) Loose igneous rocks (eg tuff), sedimentary rocks, foliated metamor-
phic rocks, loose rocks generally caused by weathering (degraded).
(B) Hard soils (sand dense, very hard) with a thickness greater than 30 m
375≤Vs≤057
375≤Vs≤057
2
III
(A) Shattered rocks by the weathering.
(B) In soils with medium density, layers of sand and clay with medium
bond between don and clay with moderate hardness.
375≤Vs≤105
375≤Vs≤105
3
IV
(A) Soft sediments with high humidity due to the high ground water level
(B) Any kind of soil profile consisting of at least 6 meters of clay with
plasticity index greater than 20 and more than 40 percent moisture.
Less than 1754

Figures 7 and 8. According to the regulations, classifica-
tion of ground is presented in Table 1 [BRC, 2005].
Soil classification
Four soil classifications were used to evaluate
the effect of soil on response spectrum
A: Rock
B: Shallow (stiff soil)
C: Deep narrow soil
D: Dep broad soil
E: Soft deep soil
Choosing the earthquake
The first selected earthquake was Duzce earth-
quake (1999). The record of this earthquake has been
registered on different soils and corresponding spectrum
Journal of Research in Biology (2016) 6(8): 2131-2141 2137
Table 2. Recorded Information of Duzce earthquake (Duzce, Turkey 1999/11/12)
Soil
type
Station
Data
source
MagnitudeDistance (km)
Site
conditions
S.
No
A
Station:1060
Lamont
1060
LAMONT
M (7.1)
Ml (7.2)
Ms (7.3)
Closest to fault rupture (30.2)
Hypocentral()
Closest to surface projection of rupture
(30.2)
Geomatrix
or CWB
(A)
1
B
Station: 362
Lamont 362
LAMONT
M (7.1)
Ml (7.2)
Ms (7.3)
Hypocentral()
(27.4)
Geomatrix
or CWB
(B)
2
C
Station:
Fatih
KOERI
M (7.1)
Ml (7.2)
Ms (7.3)
Hypocentral()
(172.5)
Geomatrix
or CWB
(C)
3
D
Station:
Duzce
ERD
M (7.1)
Ml (7.2)
Ms (7.3)
Hypocentral()
(8.2)
Geomatrix
or CWB
(D)
4
E
Station:
Ambarli
KOERI
M (7.1)
Ml (7.2)
Ms (7.3)
Hypocentral()
(193.3)
Geomatrix
or CWB
(E)
5
The second selected earthquake was Kocaeli earthquake (1999).The record of this earthquake has been registered on
different soils and corresponding spectrum of each accelerogram has been drawn. All of accelerograms data are
presented for different soils in Table 3 and Figure 11. Kocaeli earthquake spectrum is shown in Figure 12.
Soil
type
Station
Data
source
Site
conditions
S.
No
A
Station:
Gebze
ERD
M (7.4) Ml
()
Ms (7.8)
Closest to fault rupture (17.0) Hypocentral()
Closest to surface projection of rupture (17.0)
Geomatrix or
CWB (A)
1
B
Station:
Cekmec
e
KOERI
M (7.4) Ml
()
Ms (7.8)
Geomatrix or
CWB (B)
2
C
Station:
Fatih
KOERI
M (7.4) Ml
()
Ms (7.8)
Geomatrix or
CWB (C)
3
D
Station:
Atakoy
ITU
M (7.4) Ml
()
Ms (7.8)
Geomatrix or
CWB (D)
4
E
Station:
Ambarli
KOERI
M (7.4) Ml
()
Ms (7.8)
Geomatrix or
CWB (E)
5
Table 3. Recorded information of Kocaeli earthquake, (Turkey 1999/08/17)

of each accelerogram has been drawn. All of accelero-
grams data are presented for different soils in Table 2
and Figure 9. Duzce earthquake spectrum is shown in
Figure 10.
The second selected earthquake was Kocaeli
earthquake (1999). The record of this earthquake has
been registered on different soils and corresponding
spectrum of each accelerogram has been drawn. All of
accelerograms data are presented for different soils in
Table 3 and Figure 11. Kocaeli earthquake spectrum is
shown in Figure 12.
The third selected earthquake was Morgan Hill
earthquake (1984). The record of this earthquake has
been registered on different soils and corresponding
spectrum of each accelerogram has been drawn. All of
accelerograms data are presented for different soils in
Table 4 and Figure 13. Morgan Hill earthquake spec-
trum is shown in Figure 14.
RESULTS AND DISCUSSION
Spectrum is a response of a structure with 1
degree freedom against different earthquakes. This
means that created acceleration is specified in mass by
applying recorded acceleration in past different earth-
quake to a system by one degree of freedom with differ-
ent natural periods, on depending on soil structure.
Modified cover of the acceleration is drawn in terms of
natural periods for each type of soil structure. Sys-
mosygnal software was used for spectral analysis in this
project. (Seismosoft, 2015). It is a useful application for
processing the accelerograph data. Several spectrums
are drawn as follows; acceleration spectrum, velocity,
Soil type A
Soil type B
Soil type C
Soil type D
Soil type E
Figure 13. Recorded accelerograms of Morgan Hill earthquake (Morgan Hill 1984/04/24 21:15)

SoiltypeCSoiltypeB
SoiltypeESoiltypeD
SoiltypeA
Figure 14. The spectrum of Morgan Hill earthquake (Morgan Hill 1984/04/24 21:15)
Figure 15. Spectrum earthquake of Studied accelerograms on different soils
Duzce earthquake Kocaeli earthquake
MorganHillearthquake

displacement, fourie and other diagrams.
For each earthquake, the soil type impact on
spectrum diagram is indicated by evaluating the results
of the analysis on data derived from three mentioned
earthquakes in the Figures of section five and also
drawing the graphs of spectrum earthquake accelero-
grams for different soils on a chart (Figure 15). As can
be seen, the domain of spectrum was higher because of
increasing the hardness of soil in harez um similar de-
sighn factor in low periods and the domain of spectrum
was higher due to increasing the softness of soil in high-
er periods. And also in initial periods, the diagram is
more gatherer and possess a greater amount in harder
soil and the diagram is more extent and possess a lower
amount in the softer soil.
CONCLUSION
It wouldn’t generally be conducted that the
harder soil is better or the softer soil is weaker, but a
balance between soil and structure should be created
according to the type of structure and frequency content.
For example in short structure with softer soil, less force
is applied to structures during earthquake and in high-
rise structures with harder soil under the foundation,
less force is applied to the structures. The force of earth-
quake reaches completely from bedder to ground in
harder soil and there is a less possibility of creation
plasticity in the soil but it contrary happens in soft soil.
The force of earthquake quickly transfer the soil to plas-
ticity stage and doesn’t transfer the force completely.
 As can be seen in graphs; the domain of spectrum
was higher due to the increasing hardness of soil in
low periods and the domain of spectrum was higher
due to increasing the softness of soil in higher peri-
ods.
 In general, and also in initial periods, the diagram is
more gatherer and possess a greater amount in
harder soil and the diagram is more extent and pos-
sess a lower amount in softer soil.
REFERENCES
Imanpour A and Mohebbi S. (2008). The effect of
different factors on the response land and compare the
results with spectrum design of buildings in seismic
reflections in Regulations (2800). The 3rd
Congress of
Civil Engineering, Tabriz, 1 and 2:1386 p.
Moghadam H. (1992). Earthquake engineering re-
search center for transportation studies.
Ghodrati Amiri. (2003). Classification of land stations
of recording the seismic on the spectrum. 6th
Interna-
Soil
type
Station
Data
source
Site
conditions
S.
No
A
Station: 47379
Gilroy Array
#1
CDMG
M (6.2)
Ml (6.2)
Ms (6.1)
Closest to surface projection of rupture ()
Geomatrix
or CWB
(A)
1
B
Station: 57383
Gilroy Array
#6
CDMG
M (6.2)
Ml (6.2)
Ms (6.1)
Geomatrix
or CWB
(B)
2
C
Station: 57191
Halls Valley
CDMG
M (6.2)
Ml (6.2)
Ms (6.1)
Geomatrix
or CWB
(C)
3
D
Station: 47380
Gilroy Array
#2
CDMG
M (6.2)
Ml (6.2)
Ms (6.1)
Geomatrix
or CWB
(D)
4
E
Station: 58375
APEEL 1 -
Redwood City
CDMG
M (6.2)
Ml (6.2)
Ms (6.1)
.Closest to surface projection of rupture ()
Geomatrix
or CWB
(E)
5
Table 4. Recorded information of Morgan Hill earthquake (Morgan Hill 1984/04/24 21:15)

tional Conference of Civil Engineering, Isfahan, 2 p.
Bazyar H and Ghanad Z. (2003), Soil dynamics, Uni-
versity of science and technology center.
Newmark NM, Blume JA and Kapur KK. (1973).
Seismic design criteria for nuclear power plants. J. Pow-
er Div. 99: 287–303.
Regulations for designing against the earthquake.
3rd
ed. Building Research Center [BRC]. Housing, peri-
odicals S- 253, 2005.
Seismosoft [YEAR OF RELEASE]. SeismoSignal - A
computer program for signal processing of time-
histories. [Cited 2015]. Available from URL:
www.seismosoft.com
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