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Pounding Between Adjacent Buildings: Comparison of Codal
Provisions
by
Rajaram Chenna, Pradeep Kumar Ramancharla
in
Indian Concrete Journal
Report No: IIIT/TR/2012/-1
Centre for Earthquake Engineering
International Institute of Information Technology
Hyderabad - 500 032, INDIA
August 2012
Pounding between adjacent buildings:
comparison of codal provisions
Chenna Rajaram and Ramancharla Pradeep Kumar
It is not uncommon to find buildings in seismically
active regions built adjacent to each other without
following the prescribed codal separation distance. If
the separation distance is insufficient, in the event of an
earthquake, pounding may cause severe architectural and
structural damage, and may even lead to the collapse of
the structure. Seismic design codes suggest minimum
separation distance between two adjacent structures;
however, the spacing has to be enough to withstand
earthquake excitations. To understand the effect of codal
provisions on pounding, two buildings were idealised as
linear single degree of freedom oscillators. The separation
distance between them was provided following the
codal provisions of select countries. By subjecting the
buildings to five different ground motions the first impact
force due to collision was calculated and the results were
analysed to compare the codal provisions.
Keywords: Pounding, separation distance, ground motion,
impact force, predominant frequency.
Pounding describes collision between adjacent buildings
or different parts of the same building during strong
vibrations. It may cause either architectural or structural
damage or both and may lead to partial or complete
collapse of the structure. Some reported cases of
pounding include Mexico City earthquake of 1985 that
damaged more than 20% of the buildings in the city;
Loma Prieta earthquake of 1989 (Mw7.1*) that affected
over 200 structures and Chi-Chi earthquake of 1999 in
central Taiwan that caused severe destruction in the
towns and villages near the epicentre.1,2,3
In the case of the Loma Preita earthquake, a ten storey
building 90 km away from the epicenter, experienced
pounding with an adjacent five-storey building. The
typical floor mass of the five-storey building was about
eight times that of the ten-storey building. The distance
separating them was about 4 centimeter. Pounding
occurred at the 6th level in the ten-storey building
and at the roof level in the five-storey building. The
Taiwanese quake also left marks of pounding on many
structures.
Some other notable pounding cases include Sumatra
earthquake [(Mw9.3) (2004) at the junctions at the top
ends of piles of the approach jetty], Diglipur earthquake
[(Mw6.5), (2002) at the junction of the approach segment
and main berthing structure] and Sikkim earthquake
[(Mw5.3) (2006) a nine storey masonry infill RC frame
hostel building of Sikkim Manipal Institute of Medical
Sciences].4,5 Figure shows the case of Sikkim involving
two long wings of a building and the connecting
corridors (Figure 1).
*The moment magnitude scale denoted as Mw is used by seismologists
to measure the size of earthquakes in terms of the energy released.
The scale Mw was developed in the 1970s to succeed the 1930s-era
Richter magnitude scale. The magnitude is based on the seismic
moment of the earthquake, which is equal to the rigidity of the Earth
multiplied by the average amount of slip on the fault and the size of
the area that slipped
..... 2012 The Indian Concrete Journal
Australia, Canada, France, India, Indonesia, Mexico,
Taiwan and the USA take pounding into account by
specifying a minimum separation distance between
adjacent buildings. However, the procedure to determine
the distance varies from country to country.
In the USA, for example, Uniform Building Code 1997
or UBC-1997 says that it depends on the maximum
displacements of each building.10 In Canadian and
Israeli codes, the separation distance is a sum of the
displacements of each building. The French find it using
a quadratic combination of the maximum displacements.
The Taiwanese code fixes it depending on the building
height and the site soil conditions.3 The Argentinean
code suggests a minimum gap of 2.5 cm.
According to the International Building Code, IBC-2009
the separation distance between two adjacent buildings
11
is computed by Equation 1:
This paper reviews the separating distance codal
provisions in select countries and estimates the impact
force between structures by introducing stipulations
from various codes.
Literature review
Pounding damages during earthquakes have aroused the
interest of many researchers. Stavros A Anagnostopoulos
(1987) studied the pounding damages of several
buildings in a block, following strong earthquakes.6 He
modelled each structure as a single degree of freedom
(SDOF) system and simulated pounding using impact
elements. The parametric investigation of this case
showed that the end structures in the row housing he
studied were displaced more than the interior structures.
Maison and Kasai (1992) studied pounding between a 15storey building and an 8-storey building.7 They assessed
the influence of building separation, relative mass, and
contact location on the impact force. Van Jeng, Kazuhiko
Kasai and B.F. Maison (1992) developed spectral
difference method (Double Difference Combination
rule) to estimate the required separation to preclude
pounding.8 Their study was based on the response
spectrum approach. This method is useful not only
for the assessment of pounding but also for studying
the relative displacement. Filiatrault and Wagner
(1995) proposed pounding mitigation techniques.9 By
introducing a separation distance their solutions dealt
with pounding and included either filling the gaps
between buildings with an elastomeric material or
connecting them with collision or bumper walls.
The literature review on the subject reveals that seismic
design regulations of many countries such as Argentina,
The Indian Concrete Journal .....2012
......(1)
where, δmax is the maximum elastic displacement that
occurs anywhere in a floor by the application of the
design base shear to the structure. Cd is the deflection
amplification factor and ’I’ is the importance factor for
seismic loading.
According Indian Standard, IS 1893:2002 the separation
between two adjacent units or buildings shall be equal to the
response reduction factor (R) times the sum of the calculated
storey displacements.12 However, when the two buildings are
at the same elevation levels, the factor R may be replaced by
R/2. This clause assumes only two dimensional behaviour
of building, that is, only translational pounding, and
ignores the torsional pounding. However, during real
ground motions torsional pounding is also possible
along with uni-directional pounding.
According to the Federal Emergency Management
Agency (FEMA: 273-1997) the separation distance
between adjacent structures shall be more than 4% of the
building height to avoid pounding.13 FEMA states that
for meeting the enhanced design objective, the buildings
shall be adequately separated from the adjacent
structures to prevent pounding as the structures respond
to earthquakes, except as indicated in section 2.11.10.2
of FEMA 273:1997. This section states that pounding is
assumed not to occur when the buildings are separated at any
level ‘i’ by a distance greater than or equal to si. The value of
si need not exceed 0.04 times the height of the buildings above
grade at the zone of potential impacts.
Table 1. Building separation distance between two adjacent structures from different country code provisions
S.No
Country
Formula for distance between two adjacent structures
R times the sum of the calculated storey displacements using design seismic forces to avoid damage
of the two structures when the two units deflect towards each other. When the two buildings are at
the same elevation levels, the factor R may be replaced by R/2.
(Clause 7.12.3)
1
INDIA (IS- 1893:2007
(Draft))
2
IBC-2009
3
UBC 1997
4
FEMA:273-1997
Separation distance between adjacent structures shall be more than 4% of the building height to avoid
pounding.
5
NBC Peru E030-2003
This minimum distance not be lower than 2/3 of the sum of the maximum displacement of adjacent
blocks nor lower than S=3+0.004(h-500). (Clause 3.8.2)
6
ASCE:7-2010
(Adjacent Buildings located on the same property line) (Clause 1633.2.11)
(Clause 12.12.3)
S = Separation distance (in cms); h = Height of structure (in cms); R = Response reduction factor;
δM = Separation distance between two structures; δM1 and δM2 = Peak Displacement response of adjacent structures 1 & 2
Cd = Total deflection amplification factor; δmax = Maximum elastic displacement that occurs anywhere in a floor from the application of
design base shear to the structure; I = Importance factor for seismic loading
National Building Code of Peru (NBC-PERU) states
that every structure should be separated from other close
structures by a minimum distance to avoid contact during
strong ground motions. This minimum distance shall not
be less than 2/3 of the sum of the maximum displacement of
adjacent blocks.14 American Society of Civil Engineers
ASCE 7-10 stipulates that all portions of a structure
shall be designed and constructed to act as an integral
unit resisting seismic forces unless separated by a
distance sufficient to avoid damaging contact under
total deflection as determined in section 12.12.3 of ASCE
7-10.15 According to this section the separations shall allow
for the maximum inelastic response displacement (δM). δM
shall be determined at critical locations with consideration
for translational and torsional displacement of the structure
including torsional amplification, where applicable.
Table 1 summarises the key codal provision of select
countries. From the table and above discussion, it is
clear that the minimum separation distance not only
depends on the response of the structure but also on
the amplification factor and importance factor. To
understand the effect of codal provisions on pounding,
two buildings were idealised as linear single degree of
freedom oscillators. The separation distance between
them was provided following the codal provisions
of select countries. By subjecting the buildings to five
different ground motions the first impact force due to
collision was calculated. The study in particular dealt
with the collision force of first impact of the structure
by using linear impact models. Only the translational
response was considered and the torsional response
was ignored.
Minimum separation between buildings
To carry out this numerical study, two adjacent buildings
were idealised as two equivalent linear single degree of
freedom (SDOF) systems (Figure 2).
The buildings labelled as Building 1 and Building 2 and
separated by a distance δ, were assumed to have lumped
masses m1 = 11400kg, m2 = 6410kg, equal stiffness k =
45000kN/m and equal damping ratios ξ=0.05. u1(t) and
u2(t) represent the responses of building 1 and building
2 respectively. Typical response of building subjected to
El-Centro ground motion is shown in Figures 4 and 5.
The governing differential equation of motion for SDOF
system is expressed in equation (2).
......(2)
Where, ‘i’ denotes the building under consideration.
For the purpose of studying the collision between
the buildings, the south-east component of El-Centro
ground motion (Figure 3) with peak ground acceleration
(PGA) of 0.348 g was considered. Also for finding out
the response of building to earthquake ground motion,
Newmark’s approach was used. This approach is an
implicit method, to calculate the response of a structure
under dynamic loading.
..... 2012 The Indian Concrete Journal
Now if Building-2 is placed adjacent to Building-1, the
minimum distance between the buildings can be checked
by the following conditions.
......(3)
Collision occurs if the above condition is satisfied
For the purpose of finding the minimum gap between
the buildings, different periods or the time taken by the
wave to complete one cycle of motion of the earthquake
wave for Building 2 were considered. These were: 0.075,
0.10, 0.125, 0.15, 0.175, 0.20, 0.225 and 0.25 sec. The peak
relative response of the adjacent buildings gives the
minimum separation distance between them. Figure 6
shows the minimum separation distance between the
two adjacent structures.
From this figure it can be observed that as the period of the
structure increases the minimum distance also increases.
When the two structures have the same natural period,
there is no need to provide any separation distance. This
is because these buildings will vibrate in phase and not
collide at any point of time. However, this situation is not
practicable because it is very difficult to construct two
structures with the same natural period. Also, it can be
observed from this curve that the minimum separation
distance is getting flat when natural period of building
The Indian Concrete Journal .....2012
2 increases beyond 0.25 sec. However, to study this case,
nonlinear analysis is necessary. In contrast, most of the
code provisions are based on linear analysis, so the same
was used in this study.
Case study
Impact force was estimated by providing the minimum
separation distance between the buildings following
the codal recommendations. This exercise considered
Building 1 with 0.1 sec natural period and Building 2
with natural periods, ranging from 0.075 sec to 0.2 sec
with an interval of 0.025 sec.
Five earthquake records, namely Loma-Prieta earthquake,
El centro earthquake, Parkfield earthquake, Petrolia
earthquake and Northridge earthquake were selected
for factoring in the ground motions characteristics
(Table 2).
Kelvin approach takes into account damping also. The
calculation of collision force using this approach is as
follows:
......(6) & (7)
The damping co-efficient c k can be related to the
coefficient restitution e by equating energy loss during
impact.
When subjected to ground motion, collision between
buildings may take place transferring energy from one
structure to the other. This results in the loss of energy
from one and the gain of energy to the other with the two
structures behaving differently. Impact force calculation
uses models available on the subject. For example,
Kelvin model are linear spring models.16 On the other
hand, hertz model and hertz damp model are nonlinear
models. In linear spring model, the energy loss during
impact is not considered for calculating the impact force.
The contact force during impact is taken as,
......(4) & (5)
..... 2012 The Indian Concrete Journal
Table 2. Details of ground motion data
S. No
Earthquake
Name
Location
Year
Mw
PGA,
(g)
Trifunac
Duration
(sec)
Predominant
Time Period
Range, sec
Energy,
ergs
1
Lomaprieta
Lomaprieta, California,
USA
1989
6.9
0.220
9.58
0.41-1.61
1.41x1022
2
Elcentro
Imperial Valley,
California, USA
1940
7.1
0.348
24.44
0.45-0.87
2.81x1022
3
Parkfield
Parkfield, California,
USA
1966
6.0
0.430
6.76
0.30-1.20
6.31x1020
4
Petrolia
Cape Mendocino,
California, USA
1992
7.2
0.662
48.74
0.50-0.83
4.00x1022
5
Northridge
Northridge, California,
USA
1994
6.7
0.883
8.94
0.20-2.20
7.08x1021
Trifunac and Brady Duration: It is the time interval between the points at which 5% and 95% of the total energy has been recorded.
Predominant period. The period (s) at which maximum spectral amplitudes is shown on response spectra. Normally, acceleration response spectra are used to
determine the predominant period(s) of the earthquake ground motion.
Ergs: Energy released by an earthquake (1 erg=1dyne.cm=1g.cm2/s2)
......(8) & (9)
structure’s natural period increased, the response of
the structure also increased for a given ground motion
and damping.
Subjecting the structure to Lomaprieta
ground motion
In this study, Kelvin model was used. k k was
4378 MN/m (assumed).16 The co-efficient of restitution,
which is defined as the ratio of the relative velocities of
the bodies after collision to the relative velocities of the
bodies before collision, e = 0.6 (assumed).
Results and discussion
The minimum separation distances were calculated
from the codal provisions listed in Table 3. As the
Table 3. Minimum gap required between adjacent
structures having time period T1 and T2 with respect
to different codal provisions
T1=0.10 sec
No
Code
T2=0.075 T2=0.10
sec
sec
T2=0.15
sec
T2=0.20
sec
Gap(m) Gap(m) Gap(m) Gap(m)
1
IS:1893-2002
0.0005
0.001
0.004
0.01
2
UBC-1997
0.0001
0.0004
0.002
0.004
3
FEMA:273-1997
0.120
0.120
0.120
0.120
4
NBC-Peru:E0302003
0.022
0.022
0.022
0.022
5
ASCE:07-2010 and
IBC-2009
0.0001
0.0003
0.001
0.003
The Indian Concrete Journal .....2012
The structures (T1=0.10 sec, T2 = 0.075 sec, 0.15 sec
and 0.20 sec) were subjected to Lomaprieta ground
motion. The predominant frequencies range present
in the ground motion was 0.41-1.61 sec, which was far
more than the fundamental period of the structures.
All ground motion records considered in this analysis
and their Fourier spectrua are shown in Figures 7 to
11. These Figures show the predominant frequency of
an earthquake. The left side diagrams are the ground
motions, which were applied to the structure and the
right side diagrams are the Fourier amplitude spectra
for corresponding ground motions. From the Fourier
amplitude spectra one can find the predominant
frequency of ground motion.
Using the separation distances from the codal provisions
and Kelvin model approach, the initial impact forces
were calculated (Table 4).
According to UBC-1997, ASCE and IBC, the initial
collision force generated between T 1=0.1 sec and
T 2=0.075 s was 137 kN when the structures were
subjected to Lomaprieta ground motion. It may be
noted that the separation distance was the least at 0.0001
m (Table 3) in these codes. Table 4 summarises the
impact forces for all structures and codes. For structures
..... 2012 The Indian Concrete Journal
T1=0.1 s and T2=0.15 s, the impact force was 800 kN
following the ASCE and IBC codal provisions.
Subjecting the structure to El centro ground motion
The impact force between the buildings with periods
(T1=0.10 and T2=0.075 s) was 389 kN as per IS 1893:2002
(Table 5) when subjected to El centro ground motion. For
other buildings (T2=0.1, 0.15 and 0.2 s) it was zero. For the
structures having the same time period, there is no need
to provide separation distance between them, because
they will vibrate with same amplitude and phase.
The Indian Concrete Journal .....2012
The impact force for the structures having time period
0.1 and 0.075 s was 26.57 kN according to UBC-1997
even though the separation distance in this code was
less than that in the IS 1893 2002 (Table 3). The amount
of impact depends on the response of the structures at a
particular time, minimum space between the structures
and the velocity response of the structures.
The velocity response of structures with time period
0.1 sec and 0.075 sec in UBC code is less than that in IS
code. As the minimum separation distance between the
Table 4. Initial impact forces : Structures subjected to
Lomaprieta ground motion
Table 6. Initial impact forces : structures subjected to
Parkfield ground motion
T1=0.10 sec
No
Code
T2=0.075
sec
T2=0.10
sec
T2=0.15
sec
T1=0.10 sec
T2=0.20
sec
No
Code
Force(kN) Force(kN) Force(kN) Force(kN)
1
IS:1893-2002
0
0
0
0
2
UBC-1997
137
0
0
0
3
FEMA:2731997
0
0
0
0
4
NBC-Peru:
E030-2003
0
0
0
0
5
ASCE:072010 and
IBC-2009
137
0
800
0
structures decreases, the impact force also increases.
However, the time of impact does not change. If the
separation distance between these buildings is say 0.01
m. The impact may occur at 15 sec. (If the separation
distance is less than 0.01 m, the force of impact increases.
But this impact may not occur at 15 sec. It may occur at
either before or after 15 sec.)
The separation distance and impact forces are the same
in ASCE:07-2010 and IBC-2009.
According to UBC-1997, the impact force is 1170 kN for
the structures having period of 0.1 and 0.15 s, however
ASCE: 07-2010 and IBC-2009 give an impact force of
6052 kN for the same structures. Between the former and
the duo of the latter, the separation distance decreases
Table 5. Initial impact forces: structures subjected to
Elcentro ground motion
T1=0.10 sec
No
Code
T2=0.075
sec
T2=0.10
sec
T2=0.15
sec
T2=0.20
sec
Force(kN) Force(kN) Force(kN) Force(kN)
1
IS:18932002
2
UBC-1997
3
FEMA:2731997
0
0
0
4
NBC-Peru:
E030-2003
0
0
5
ASCE:072010 and
IBC-2009
26.57
0
389
0
0
0
26.57
0
1170
460
T2=0.075
sec
Force(kN)
T2=0.10
sec
T2=0.15
sec
T2=0.20
sec
Force(kN) Force(kN) Force(kN)
1
IS:18932002
150
0
0
0
2
UBC-1997
248
0
2442
3757
3
FEMA:2731997
0
0
0
0
4
NBC-Peru:
E030-2003
0
0
0
0
5
ASCE:072010 and
IBC-2009
248
0
412
2236
from 0.002 m to 0.001 m and the time of impact does
not change.
For structures with periods T1=0.10 and T2=0.2 s, the
impact forces are 460 and 5762 kN as per UBC and
ASCE/IBC respectively. In this case the impact force
reduces as the separation distance increases because the
time of impact does not change.
Subjecting the structures to Parkfield ground motion.
According to IS 1893:2002, the impact force between
structures with periods T1=0.1 s and T2=0.075 s is 150 kN
(Table 6). But UBC and ASCE/IBC give 248 kN. Here the
impact occurs at the same time. For structures having
same period, there is no need to provide separation
distance, because they will vibrate with same amplitude
and phase.
Table 7. Initial impact forces: structures subjected to
Petrolia ground motion
T1=0.10 sec
No
Code
T2=0.075
sec
T2=0.10
sec
T2=0.15
sec
T2=0.20
sec
Force(kN) Force(kN) Force(kN) Force(kN)
1
IS:1893-2002
326
0
2032
0
2
UBC-1997
72
0
598
911
0
3
FEMA:2731997
0
0
0
0
0
0
4
NBC-Peru:
E030-2003
0
0
0
0
6052
5762
5
ASCE:072010 and
IBC-2009
72
0
1582
3466
..... 2012 The Indian Concrete Journal
Table 8. Initial impact forces : Structures subjected to
Northridge ground motion
T1=0.10 sec
No
Code
T2=0.075
sec
T2=0.10
sec
T2=0.15
sec
T2=0.20
sec
Force(kN) Force(kN) Force(kN) Force(kN)
1
IS:1893-2002
1130
0
348
20878
2
UBC-1997
51
0
2204
88
3
FEMA:2731997
0
0
0
0
4
NBC-Peru:
E030-2003
0
0
0
10700
5
ASCE:072010 and
IBC-2009
51
0
1505
245
For structures having periods T1=0.1 and T2=0.15 s,
the impact force is 2442 kN as per UBC1997. However,
according to ASCE/IBC, impact force is 412kN, much
less than that by UBC even though the separation
distance is less. This means the time of impact changed
under these conditions.
Subjecting the structures to Northridge ground
motion.
The structure having period 0.2 s was matched with
ground motion frequency. At predominant frequencies,
the response of structure will be more and may lead
to a high impact force. This effect can be clearly seen
in Table 8 for structures with periods T1=0.10 s and
T2=0.20 s. The impact force initially increases and then
decreases with increasing eparation distance. With
the same separation distance between two structures,
the initial impact force will be same in both linear and
nonlinear analysis before yielding starts. The impact
values between structures having period 0.1 s and 0.2
s, are 20878 kN, 88 kN, 10700 kN and 245 kN as per
IS:1893-2002, UBC-1997, NBC-PERU and ASCE/IBC
respectively ( Table 8) . A comparison of codal provisions
suggest, FEMA:273-1997 and NBC-PERU codes have no
collisions in most ground motions except Northridge
ground motion. It is noteworthy that the calculated
separation distances are high in FEMA and NBC-PERU.
Also the clauses on pounding in these codes are based
on height of the structure only.
Conclusions
The case with the structure having period T2=0.2 s is
similar. Even though the ground motion is same, the
time of impact did not change for structure 0.075 s but
not so for structures with period 0.15 and 0.2 s.
The following conclusions may be drawn from this
study:
These data clearly show that the impact is dependent
on the velocity response of the structure The structure
is not affected by the amplitude of ground motion but
by the frequency of ground motion.
• In general as the separation distance between
the two structures decreases, the force of impact
increases; except when they vibrate out of
phase.
Subjecting the structures to Petrolia ground motion.
For structures with periods 0.10 s and 0.075 s, the initial
impact force is 326 kN as per IS: 1893-2002 (Table 7).
However, according to UBC and ASCE/IBC it is 72
kN, even though the separation distance decreases
from 0.0005 m in UBC to 0.0001 m in ASCE/IBC. This
means that the time of impact changed under these
conditions.
The impact force between structures having periods
0.1 s and 0.15 s is 2032 kN as per IS 1893:2002. But it
is less as per UBC and ASCE/IBC even though the
separation distances in these codes are small compared
to IS 1893:2002. Here, the impact force initially increases
and then decreases. For structures with periods 0.1 s and
0.2 s, the impact values are 911 kN and 3466 kN as per
UBC and ASCE/IBC respectively. Here, the impact force
decreases as the separation distance increases.
10
The Indian Concrete Journal .....2012
• The duration of strong motion increases with the
the magnitude of ground motion.
• The response of structure with period 0.2 sec and
subjected to Northridge ground motion, which
has 0.2 sec predominant frequency suggest that
at predominant frequencies, the structure may
collapse
• Among the codal provisions discussed, FEMA:
273-1997 and NBC PeruE030-2003 give a higher
separation distance than other codes. The
separation distance in these two codes depends
on the height of the structure.
• For structures having same period, there is no
need to provide separation distance, because they
will vibrate with same amplitude and phase.
• The strength of impact depends on velocity
response of the structures at a particular time and
minimum space between the structures.
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Vol. 21, Issue 9, pp. 771-786.
8. Van Jeng, Kazuhiko Kasai and Bruce F. Maison., A Spectral Difference Method
to Estimate Building Separations to Avoid Pounding, Earthquake Spectra, May
1992, Vol. 8, Issue 2, pp. 201-223.
Mr. Chenna Rajaram received his MS
by Research degree in Computer Aided
Structural Engineering (CASE) from IIIT-H
and is currently pursuing his PhD under the
guidance of Dr. Ramancharla Pradeep Kumar
at Earthquake Engineering Research Centre
(EERC), International Institute of Information
Technology, Hyderabad (IIIT-H). He has published 4 papers
in journals and conferences. His areas of interests are
Earthquake engineering and structural dynamics, analysis
and design of RC structures.
Dr. Ramancharla Pradeep Kumar, holds a
PhD degree in civil engineering from University
of Tokyo, Japan. He is an Associate Professor
and Head of Earthquake Engineering Research
Centre (EERC) at IIIT Hyderabad. His research
interests are numerical modelling of faults and
tectonic plates, collapse simulation of buildings,
seismic evaluation and strengthening of buildings and
concrete codes in India. Presently he is a panel member of
CED 2: IS 456 and IS 1343.
9. Andre Filiatrault and Pierre Wagner., Analytical prediction of experimental
building pounding, Earthquake Engineering and Structural Dynamics, August
1995, Vol. 24, Issue 8, pp. 1131-1154.
10. ______Uniform Building Code, UBC-1997, Volume-2, Structural Engineering
Design Provisions, International Conference of Building Officials,
California.
11. ______ International Building Code, IBC-2009, International Code Council.
INC.
12. ______ Indian standard criteria for earthquake resistant design of structures, part1 general provisions and buildings, IS:1893-2002, Bureau of Indian standards,
New Delhi.
13. ______ Federal Emergency Management Agency (FEMA), NEHRP Guidelines
for the seismic rehabilitation of buildings, FEMA: 273-1997, Washington D.C.,
USA.
14. ______National Building Code- PERU, Technical Standard of Building E.030,
Earthquake Resistant Design.
15. ______American Society of Civil Engineers for Minimum Design Loads for
Buildings and Other Structures, ASCE/SEI 7-10, USA
16. Susender Muthukumar and Reginald Desroches., Evaluation of impact
models for seismic pounding, Proceedings of Thirteenth World Conference on
Earthquake Engineering, August 2004, paper No.235.
..... 2012 The Indian Concrete Journal
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