Seismic Safety Assessment of Existing Low-rise RC Buildings with Rapid Visual Screenings and Preliminary Evaluation Methods

Abstract

Mandalay, the second largest city in Myanmar, is situated near the Sagaing Fault (the major fault in Myanmar) and so it’s a seismic prone area. In Mandalay region, the number of low-rise buildings is much more than that of high-rise buildings. And hence, the seismic safety assessment of low-rise building takes an important role to survive and develop Mandalay as smart city. Detailed seismic evaluation can determine the seismic performance level of the buildings and can give strategies to technically retrofit the structures. First of all, rapid visual screening and preliminary evaluation must be carried out to identify the buildings which need the detailed assessment. Thus, in this study, the rapid visual screening (RVS) and preliminary evaluation will be executed for 26 number of three to eight story RC buildings are investigated for the requirements of detailed assessment with three different RVS and preliminary evaluation methods. The methods used are FEMA P-154, Indian standards and Bangladesh methods. According to the investigation, the results given by FEMA P-154 level 1 and level 2 are more vulnerable than that of other methods. Seismic elevation using seismic index method by Bangladesh can give a reliable data for detail seismic evaluation and retrofit method.

Full text

ASEAN Journal on Science &Technology for Development
Vol 38, No 1, 2021, 29–36
DOI 10.29037/ajstd.649
RESEARCH
Seismic Safety Assessment of Existing Low-rise RC Buildings with Rapid Visual
Screenings and Preliminary Evaluation Methods
Moe Myat Myat Aung1,* and Mya Nan Aye1
1Civil Engineering Department, Mandalay Technological University, Shin Taw Gone Village, Patheingyi Township, Mandalay, Myanmar
*Corresponding author: moe040604@gmail.com
KEYWORDS
Low-rise building
Rapid visual screening
Preliminary evaluation
Seismic safety assessment
SUBMITTED 6 October 2020
REVISED 8 April 2021
ACCEPTED 15 April 2021
ABSTRACT Mandalay, the second largest city in Myanmar, is situated near the Sagaing Fault (the major
fault in Myanmar). In the Mandalay region, the number of low-rise buildings is much greater than that
of high-rise buildings. As such, seismic safety assessments of low-rise buildings play an important role
in developing Mandalay as a smart city. In this study, the rapid visual screening (RVS) and preliminary
evaluation for 26 numbers of three- to eight-story RC buildings were investigated with three different
RVS and preliminary evaluation methods. Based on the RVS methods, the FEMA P154 Level 1 and 2
results gave the highest risk. With the Bangladesh method, the higher the story, the more vulnerable
the building. Meanwhile, the Indian method showed a medium risk status. According to the preliminary
evaluation, the assessed buildings need a detailed seismic evaluation, except for one building in the
Indian method. Similarly, all buildings need a detailed evaluation in the Bangladesh method. The
most convenient RVS and preliminary evaluation can be derived from these results for buildings in
Mandalay, Myanmar. Moreover, a method can be developed for seismic safety assessments in other
ASEAN countries with subsequent research.
© The Author(s) 2021. This article is distributed under a Creative Commons Attribution-ShareAlike 4.0 International license.
1. INTRODUCTION
Earthquakes are random in nature and unpredictable.
Therefore, analysis of the structures under the action of
earthquakes requires better engineering approaches and
tools to economically design the structures. Mandalay is
in the a seismic zone and 0.2s (S2) and 1.0s (S1) spectral re-
sponse accelerations are 2.01 and 0.8 (UN-Habitat 2016). In
the Seismic Zoning Map of Myanmar for Alternative Seismic
Design Procedure, according to Chapter 16 of the UBC97
Code, Mandalay belongs to seismic zone V (0.4–0.5g) and
has an equivalent modied Mercalli Scale class IX.
Most of the low-rise buildings in Mandalay are more
vulnerable to seismic load than high-rise buildings because
seismic design regulations for low-rise buildings in Myan-
mar were been dened until 2019. Thus, seismic safety as-
sessments for existing low-rise buildings in Mandalay need
to be carried out.
The seismic vulnerability assessment methods consti-
tute three stages: rapid, preliminary, and detailed assess-
ments. Rapid visual screening (RVS) is the basic key to mea-
suring the seismic capacity of buildings. It is carried out
with rapid visual assessments and street surveys. Prelimi-
nary evaluation is the second step of the seismic vulnera-
bility assessment, and some simple calculations are carried
out with more accurate input data. Detailed seismic evalu-
ations are very important for seismic safety assessments of
buildings. This procedure needs a lot of time, cost, much
effort, a complex technical background, and procedure.
Rapid assessment and preliminary assessment proce-
dures have been developed to handle large building stocks
for ranking and prioritizing their seismic risk (Yakut 2014).
These two steps can provide support data for the detailed
seismic evaluation and strengthening of seismically vulner-
able buildings.
In previous studies featuring RVS by Win and Zaw (2018)
and Aye and Aye (2019), the RVS of buildings in Myanmar
was carried out with the FEMA standard because this is the
most common RVS method. Therefore, FEMA is used to
assess the seismic safety of the low-rise buildings in the
present study. India and Bangladesh, which are developing
ASEAN countries, also developed their own methods to de-
termine seismic safety. These methods may be more com-
patible with Myanmar. And hence, FEMA P-154, the Indian
method, and the Bangladesh method are used for the RVS
of buildings in Mandalay, Myanmar.
Meanwhile, past researchers in Myanmar, such as Phyu
and Cho (2016) and Aung (2018), have performed prelimi-
nary evaluations using the priority index (PI) method de-
ned by Hassan and Sozen (1997). In the PI method, only
the cross-sectional area of the column, reinforced concrete
wall at base level, masonry walls lling frame bays, and sum-
mation of the oor area are used. The strength of the struc-
tural material and seismic vulnerability characteristics are
not considered. Therefore, the PI method was not consid-
ered for the present study. Instead of the PI method, an
Indian preliminary evaluation, which considered the facts
that are not present in the PI method, was used.
In Linn and Tajiri (2014), the authors used the Japanese
standard for design evaluation. Similarly, in Bangladesh,
Rasel et al. (2015) and Halder et al. (2015) carried out a
A journal of the ASEAN Committee on Science and Technology PRINT ISSN 0217-5460 ONLINE ISSN 2224-9028 www.ajstd.org

seismic evaluation with the Bangladesh method derived
from the Japan Standard. As stated above, the Bangladesh
method is more favorable than the Japanese method for
the seismic assessment of buildings in Myanmar because
Japan is a well-developed country and building technology
is too different from Myanmar. Therefore, the Bangladesh
method was chosen for the present study. And hence, RVS
and preliminary evaluation are carried out for 26 numbers
of low-rise buildings in the Mandalay region using FEMA P-
154 (USA method), the India standard, and the Bangladesh
method. These are executed to investigate the condition
of the existing buildings and to determine which buildings
need detailed seismic safety assessments and retrotting.
The buildings were selected based on their seismically vul-
nerable characteristics, such as vertical irregularities, plan
irregularities, soil condition, etc.
2. MATERIALS AND METHODS
2.1 Rapid visual screening
Rapid visual screening was carried out and each method
followed an individual scoring system depending on the
need and objectives. The scoring systems for the proposed
method can be seen in Figure 1.
The results from these three RVS methodologies are
scaled from one to ve. They can be calculated from Equa-
tion 1(Harirchian et al. 2020).
Xs=X−Xmin
Xmax −Xmi n
×(5−1) + 1(1)
where Xsis the scaled value of the obtained result, Xmin is
the lowest score, and Xmax is the highest score.
2.1.1 FEMA P-154 (USA method)
In FEMA P-154, the basic score is dened on building type,
the structural framing. The FEMA P-154 data collection
form differs with the level of seismicity. The score modi-
ers used in level 1 are severe vertical irregularity VL1, mod-
erate vertical irregularity VL1, plan irregularity, PL1, pre-
code, post-benchmark and soil type. This level 1 form re-
quires building information such as latitude, longitude, oc-
cupancy, and exterior falling hazards.
In level 2, detailed structural multipliers are included
for vertical irregularity, plan irregularity, redundancy,
pounding, building type, and retrot. If the score is less
than the minimum score, the screener can know this build-
ing will suffer 100% damage during an earthquake. If the
score is less than the basic score, a detailed seismic evalu-
ation is needed for this building (FEMA 2015).
FIGURE 1. Proposed rapid visual screening methods.
2.1.2 Indian method
The RVS score evaluation using the Indian method is based
on the number of stories, vertical irregularity, plan irregu-
larity, code detailing, soil type, and liquefaction. The seis-
mic zone is classied as per IS 1893:2002 (Part 1), depending
on the earthquake magnitude MSK. The damage classica-
tions are based on the European Macroseismic Scale (EMS-
98), which delineates building damage according to Grades
1to5(Sinha and Goyal 2004). Since Mandalay has an equiv-
alent modied Mercalli Scale class IX, lling the form of the
Rapid Visual Screening of Building for Potential Seismic Vul-
nerability (Seismic Zone IV&V) can be used for the seismic
safety assessment of buildings in Mandalay.
2.1.3 Bangladesh method
The basic score in the Bangladesh method is determined
from the number of stories and seismic hazard zone based
on the peak ground velocity (PGV) (Equation 2). Soft story,
heavy overhang, apparent quality, pounding effects, short
columns, buildings on slope, plan irregularities, liquefac-
tion vulnerability, and landslide vulnerability are taken into
account by the vulnerability score and score multiplier.
This method has a risk status that is concerned with the cor-
responding interval of the performance score (Amit et al.
2017). Mandalay has a higher PGV than that of the highest
seismic hazard zone in Bangladesh. Thus, its buildings are
more vulnerable than those of Bangladesh.
PS =BS −Σ(VSM ×V S)(2)
where PS is the performance score, BS is the basic score,
VS M is the vulnerability score multiplier, and VS is the vul-
nerability score.
2.2 Preliminary vulnerability assessment
This assessment comprises a collection of drawings, on-
site drawings, redrawing in AutoCAD, load calculation,
and preliminary evaluation. Structural conguration and
strength-related checks using NDT methods are also
needed for this evaluation (Taru 2014). The Indian and
Bangladesh methods were used for the preliminary assess-
ment, which are for mid- to low-rise buildings with six sto-
ries or fewer. A detailed seismic evaluation must be carried
out for buildings with more than six stories, such as the
eight-story building no. 26, which was thus excluded.
FIGURE 2. Building locations for case study.
30 Aung and Aye

TABLE 1. Survey data for seismic safety assessment.
Building no. Township No. of stories Latitude Longitude
1 AMTZ 1 3 N21.9825 E96.1117
2 AMTZ 2 4 N21.9819 E96.1116
3 AMTZ 3 4 N21.9990 E96.0838
4 CATZ 1 4 N21.9708 E96.0892
5 CATZ 2 4 N21.9823 E96.0942
6 CATZ 3 5 N21.9800 E96.0847
7MHAM 1 3N21.9634 E96.1088
8 MHAM 2 4 N21.9658 E96.0917
9 MHAM 3 5 N21.9650 E96.0894
10 CMTZ 1 3 N21.9339 E96.1056
11 CMTZ 2 3 N21.9490 E96.0769
12 CMTZ 3 4 N21.9329 E96.1075
13 PGTG 1 3 N21.9278 E96.0987
14 PGTG 2 3 N21.8914 E96.1065
15 PGTG 3 4 N21.8935 E96.1097
16 AMRPR 1 3 N21.9042 E96.0434
17 AMRPR 2 4 N21.9058 E96.0512
18 AMRPR 3 4N21.8976 E96.0455
19 PTG 1 3 N22.0028 E96.1640
20 PTG 2 3 N21.9891 E96.1570
21 PTG 3 3 N22.0011 E96.1729
22 PTG 4 3 N21.9895 E96.1583
23 PTG 5 4 N21.9836 E96.1659
24 PTG 6 4 N21.9263 E96.1562
25 PTG 7 5 N21.9870 E96.1668
26 CATZ 4 8 N21.9790 E96.1114
Note: AMTZ = Aung Myay Thar Zan Township, CATZ = Chan Aye Thar Zan
Township, MHAM = Mahar Aung Myay Township, CMTZ = Cha Mya Thar Zi
Township, PGTG = Pyi Gyi Tagon Township, AMRPR = Amarapura Township,
PTG = Pathein Gyi Township.
2.2.1 Indian method
The preliminary vulnerability assessment using the Indian
method needs to check the following stresses (Rai 2005): (i)
shear stress in RC frame columns, which can be calculated
using Equation 3, and (ii) axial stress in moment frames,
which can be calculated using Equation 4.
τcol = ( nc
nc−nf
)×(Vj
Ac
)<0.4 Mpa or 0.1fc k (3)
where ncis the total number of columns, nfis the total
number of frames in the direction of loading, Acis the
FIGURE 3. RVS results for all buildings based on FEMA P-154 Level 1.
total cross-sectional area of columns, and fc k is the cube
strength of concrete.
F0=2
3×VB
nf
×H
L(4)
where nfis the total number of frames in the direction of
loading, VBis the base shear, His the total height, and Lis
the length of the building.
2.2.2 Bangladesh method
In the Bangladesh method, the seismic index of the struc-
ture and seismic demand index are calculated, and an eval-
uation is also carried out. These can be calculated using
Equations 5to 10 (Public Work Department 2015).
Is≥Iso (5)
where Isis the seismic index of the structure, and Iso is the
seismic demand index of the structure.
Is=E0×SD×T(6)
where E0is the basic structural seismic capacity index
(equal to C[Strength Index]×F[Ductility Index],SDis a fac-
tor to modify the E0-Index due to structural irregularity
(torsion, soft story mechanism, etc.), and Tis a factor to
allow for the deterioration of the original performance.
For the second level screening procedure, the calcula-
tions are as follows.
E0=n+1
n+i(E12+E22+E32)(7)
where E1=C1×F1;E2=C2×F2;E3=C3×F3;C1,C2,
and C3are the strength indices; and F1,F2, and F3are the
ductility indices.
E0=n+1
n+i×(C1+Σj(αj×Cj)) ×F1(8)
where ajis the effective strength factor, C=Qu/(ΣW),Qu
is the ultimate lateral load carrying capacity of the verti-
cal members in the story concerned, ΣWis the weight of
the building including live load for seismic calculation sup-
ported by the story concerned, and E0is taken as the lesser
of the two values.
FIGURE 4. RVS results for all buildings based on FEMA P-154 Level 2.
ASEAN J SCI TECHNOL DEV 38(1): 29–36 31

FIGURE 5. RVS results for all buildings based on Indian method.
Is0=0.8 ×2
3Z×I×Cs(9)
where Zis the seismic zone coefcient (seismicity, ex-
pected PGA, etc.), Iis the structure importance factor,
and Csis the normalized acceleration response spectrum.
Moreover, this will satisfy the following equation.
CTU ×SD≥0.4 ×2
3×ZI Cs(10)
where CTU is the cumulative strength index at the ultimate
deformation of the structure, SDis the irregularity index.
2.3 Data survey and collection
The seven major townships in Mandalay were selected for
the collection and surveying of data, namely Aung Myay
Thar Zan, Chan Aye Thar Zan, Mahar Aung Myay, Chan Mya
Thar Zi, Pyi Gyi Tagon, Amarapura, and Patheingyi. The re-
spective buildings’ locations are shown in Figure 2, and the
survey data can be seen in Table 1.
2.4 Seismic safety assessment using rapid visual
screening methods
A street survey was carried out for all 26 buildings using the
three rapid visual screening methods. The Indian method
is based on FEMA P-154 and the score lling systems are
nearly the same, whereas the Bangladesh method differs.
2.5 Seismic safety assessment using preliminary
evaluation methods
The preliminary evaluation is a quick procedure to estab-
lish the actual structural layout and assess its characteris-
tics that can affect its seismic vulnerability. In the present
FIGURE 6. RVS results for all buildings based on Bangladesh method.
study, preliminary evaluation using the Indian method and
seismic evaluation using the seismic index method with the
Bangladesh method were implemented. These methods
are from mid- to low-rise buildings with six stories or fewer.
In contrast, a detailed seismic evaluation must be carried
out for buildings that have more than six stories. As such, a
total of 25 (three- to ve-storied) buildings were assessed
using the aforementioned methods.
2.5.1 Preliminary evaluation using Indian method
Building no. 2 was selected as the example of the prelimi-
nary evaluation using the Indian method. The shear stress
in X and Y directions can be seen in Table 2while the ax-
ial stress can be checked using equations 11–18, specically
the axial stress in moment frames in the X and Y directions
for building no. 2 (Equations 11 and 15, respectively) and
their corresponding axial stresses (Equations 12,13,14 and
Equations 16,17,18, respectively).
F0=2
3×VB
nf
×H
L
=2
31.5 ×637.594
2×54
52
=331.058 kN
(11)
τ=331.058
12×12
122×3.2812
×10−3
=3.564 Mpa
(12)
τall =0.25 ×fck
=0.25 ×2500
145
=4.31 Mpa
(13)
TABLE 2. Shear stress for building no. 2 in X and Y directions.
Story ncnfAc(m2)Vjx1.5 τ
col (M pa)τall 0.1(fc k1/2 )Remark
X Y X Y X Y X Y X Y X Y X Y
SR 4 4 2 2 0.37 0.37 11.27 11.27 0.06 0.06 0.4 0.4 0.42 0.42 Satisfactory
RF 10 11 2 2 0.93 1.02 447.59 447.59 0.60 0.54 0.4 0.4 0.42 0.42 Unsatisfactory
3F 10 11 2 2 0.93 1.02 763.34 763.34 1.03 0.91 0.4 0.4 0.42 0.42 Unsatisfactory
2F 10 11 2 2 0.93 1.02 911.80 911.80 1.23 1.09 0.4 0.4 0.42 0.42 Unsatisfactory
1F 10 11 2 2 0.93 1.02 955.36 955.36 1.29 1.14 0.4 0.4 0.42 0.42 Unsatisfactory
GF 10 11 2 2 0.93 1.02 956.39 956.39 1.29 1.14 0.4 0.4 0.42 0.42 Unsatisfactory
32 Aung and Aye

τ<τall , satised (14)
F0=2
3×VB
nf
×H
L
=2
3×1.5 ×637.594
2×54
60
=286.917 kN
(15)
τ=286.917
12×12
122×3.2812
×10−3
=3.089 Mpa
(16)
τall =0.25 ×fck
=0.25 ×2500
145
=4.31 Mpa
(17)
τ<τall , satised (18)
From these equations, the axial stress was satised, in both
directions of building no. 2.
2.5.2 Seismic evaluation using seismic index method with
Bangladesh method
The seismic evaluation of building no. 2 was carried out
following Table 3.
3. RESULTS AND DISCUSSION
3.1 RVS
3.1.1 FEMA level 1 and level 2
In RVS using FEMA P-154 level 1, all of the buildings required
detailed seismic evaluations, because their seismic perfor-
mance scores were lower than the basic score (Figure 3).
Fourteen out of 26 buildings had the minimum score. Thus,
over 50% of the buildings observed (S< 0.3) may encounter
a high probability of Grade 5 damage and the remaining
buildings, which are 0.3 < S< 0.7, will have a high proba-
bility of Grade 4 damage.
The scores for all buildings were lower than the basic
score and 22 out of 26 buildings had the minimum score,
based on FEMA P-154 level 2 (Figure 4). According to the re-
sults, these 22 buildings will face a high probability of Grade
5 damage during an earthquake. A high probability of Grade
4 damage was accorded to three of the remaining buildings
and only one building may have a high probability of Grade
3 damage during an earthquake.
In FEMA level 1 and level 2 screenings, all buildings re-
quired further detailed seismic evaluation. The three-story
buildings in Aung Myay Thar Zan, Mahar Aung Myay, Pyi
Gyi Tagon, and Patheingyi will have a probability of Grade 5
damage and they may collapse during a strong earthquake.
Three-story buildings in Chan Mya Thar Zi and Amarapura,
meanwhile, will encounter Grade 4 damage.
In four-story buildings, all of the buildings except for
one in Patheingyi township will have a high probability of
Grade 5 damage based on FEMA P-154 level 2 screening.
Although some buildings have a high probability of Grade
4 damage in FEMA P-154 level 1, their scores dropped to
the minimum score in FEMA P-154 level 2. Consequently,
only one four-story building, in Patheingyi, may have a high
probability of Grade 3 damage.
The ve-story building in Chan Aye Thar Zan township
may face a high probability of Damage 5 based on FEMA
P-154 levels 1 and 2 RVS. The ve-story building in Mahar
Aung Myay may have a high probability of Grade 4 damage
in both FEMA P-154 level 1 and level 2 screenings.
The eight-story building in Chan Aye Thar Zan town-
ship and ve-story building in Patheingyi township were
found to have a high probability of Grade 4 damage at level
1 screening, but they may possess Grade 5 damage based
on level 2 screening.
Ramly et al. (2014) conducted a seismic vulnerability
assessment of existing buildings in Bukit Tinggi, Pahang,
Malaysia. They used the FEMA P-154 level 1 rapid visual
screening method in moderate seismicity, and found that
26% of buildings needed further evaluation. In contrast, it
can be seen that all of the buildings needed a detailed seis-
mic evaluation in the present study, because Mandalay is
in a high seismicity zone, and hence, the FEMA P-154 level 1
and level 2 rapid visual screening methods in high seismic-
ity were used. Moreover, the buildings in this study were
selected based on their seismic vulnerability parameters.
3.1.2 Indian method
Based on the Indian method results, only six in total three-
story buildings were found to have a high probability of
Grade 4 damage, and the remaining buildings have a high
probability of Grade 3 damage. None of the buildings as-
sessed have a high probability of Grade 5 damage. The In-
dian method RVS results are shown in Figure 5.
Verma et al. (2017) conducted a seismic vulnerability
assessment of buildings in Locknow by using the Indian
method. Visuvasam et al. (2017) also carried out a seismic
vulnerability assessment of existing residential buildings at
Vellore using this method. Their results showed that RVS
can be effectively used for seismic safety assessments.
TABLE 3. Seismic evaluation of building no. 2 in X and Y directions using seismic index method.
Story ΣWikN (n+1)/(n+j)ΣC E0ISIS0CTUSD0.4 ×2/3ZI CsEvaluation
X Y X Y X Y X Y X Y X Y X Y X Y
RF 2029 2029 0.60 0.60 1.69 1.51 1.01 0.91 0.91 0.82 0.58 0.58 0.91 0.82 0.29 0.29 Safe
3F 4955 4955 0.67 0.67 0.69 0.62 0.46 0.41 0.42 0.37 0.58 0.58 0.42 0.37 0.29 0.29 Not safe
2F 7881 7881 0.75 0.75 0.43 0.39 0.33 0.29 0.29 0.26 0.58 0.58 0.29 0.26 0.29 0.29 Not safe
1F 10807 10807 0.86 0.86 0.32 0.28 0.27 0.24 0.24 0.22 0.58 0.58 0.24 0.22 0.29 0.29 Not safe
GF 13733 13733 1.00 1.00 0.18 0.18 0.18 0.18 0.16 0.17 0.58 0.58 0.16 0.17 0.29 0.29 Not safe
ASEAN J SCI TECHNOL DEV 38(1): 29–36 33

TABLE 4. Ranges of scaled RVS results with damage state denition.
Scaled
RVS
results
Considered
integer for
damage state
Denition
1.00–1.55 1 Very high probability of Grade 5 and
high probability of Grade 4.
1.56–2.55 2 Moderate probability of Grade 4 and
high probability of Grade 3.
2.56–3.55 3 Very high probability of Grade 3 and
little probability of Grade 2.
3.56–4.55 4 Very high probability of Grade 2 and
little probability of Grade 1.
4.56–5.00 5 Little probability of Grade 2
and very high probability of Grade 1.
In the present study, a total of 26 buildings in Mandalay
were assessed using the Indian RVS method in high seismic-
ity. The basic score depends on the building type, while the
score modiers primarily depend on the vertical irregular-
ity, plan irregularity, and soil type. The Mandalay regions
has good soil properties and no liquiable soil. Therefore,
the vertical irregularity and plan irregularity are important
with respect to this study.
Our results showed that a detailed evaluation for all
buildings needs to be carried out because the buildings
have vertical irregularity, plan irregularity, or both of these
irregularities. The structural damage states are a little
lower than FEMA Level 1 and Level 2 screenings.
3.1.3 Bangladesh method
In terms of the Bangladesh method, 10 out of 11 three-story
buildings were low risk and only one three-story building
was found to have a moderate risk (Figure 6). Similarly, only
one four-story building is at low risk while the other four-
story buildings are at moderate risk. Of the ve-story and
eight-story buildings, two in Chan Aye Thar Zan Township
are at high risk and the other two ve-story buildings may
suffer moderate damage in an earthquake.
A study by Amit et al. (2017) showed that the seismic
risk level of a nine-storied building is higher than that of a
six-storied building. The results in the present study were
consistent with theirs. Here, the Bangladesh method also
revealed that the buildings which may encounter moder-
ate risk and high risk require a subsequent detailed seismic
evaluation. According to the results, it was found that the
base score mainly depends upon the number of stories and
thus the higher the story, the higher the seismic risk status.
3.1.4 Scaled damage based on all methods
According to all of the aforementioned assessments, all
buildings need further detailed seismic evaluations. RVS re-
sults can be scaled to have similar results from Equation 1
(Harirchian et al. 2020). For FEMA P-154 levels 1 and 2, and
the Indian method, Xmin can be used as 0.3. Xmax is 2.5
for FEMA and 3 for the Indian method. In the Bangladesh
method, Xmax is 80 for three- to eight-story buildings.
Xmin is used as 20 because the minimum scaled value of
the obtained result is 22. The ranges of the scaled rapid
visual screening results with damage state denitions fol-
lowed those outlined in Table 4.
Taking the damage states of all buildings from the com-
bined RVS results into account, all three-story buildings in
Pathein Gyi township, and four-story buildings in Pyi Gyi
Tagon township and Amarapura may be highly vulnerable
to seismic loads (Figure 7). It can be seen that the ve- and
8-story buildings in Chan Aye Thar Zan township are the
most vulnerable according to the seismic assessment re-
sults. Almost all buildings in Chan Mya Thar Zi township
may undergo severe damage during an earthquake.
Harirchian et al. (2020) presented an overview of the
common RVS methods, FEMA P-154, Indian method (IITK-
GGSDMA), and Turkish method (EMPI). They found that
FEMA P-154 was the most prone to overestimation during
damage evaluations and Indian RVS was more signicant
than the Turkish RVS method. Similarly, the present study
found that FEMA P-154 level 1 and level 2 showed extremely
an high possibility of damage. The Indian method showed
more damage situations than the Bangladesh method. The
preliminary evaluation was implemented to get more spe-
cic data for the seismic safety assessment.
3.2 Preliminary vulnerability assessment
The preliminary evaluation results using the Indian and
Bangladesh methods are shown in Tables 5and 6. In the
Indian standard, one signicant factor in these calculations
is the assessment result of building no. 6. This building has
the required strength, but the structural irregularity and
other important factors were not considered in the calcu-
lation. The Bangladesh method requires more detailed pa-
rameters in the calculation and thus it can result in a more
accurate data and vulnerability assessment.
Hashmi (2015) analyzed the shear stress generated in
the column section, the axial force, and the axial stress gen-
erated in the column at base level by varying the control
parameters. He concluded that the building is marginally
safe against shear strength demand, and very safe against
axial compression under seismic loading. From his study,
it can be known that the concrete strength mainly controls
the shear stress, and that concrete strength and ratio of
height to length of the buildings are important for overturn-
ing force and axial stress.
In the present study, most of the buildings were found
to be safe against axial stresses and not safe against shear
stresses. It can be considered that the buildings may not
have the required concrete strength, and number and ar-
eas of the columns. After further research, the specied
concrete strength and area of the column can be dened
for the buildings in high seismic regions.
In Bangladesh, Rasel et al. (2015) proposed the
retrotting process of existing buildings to resist seismic
FIGURE 7. Damage state for all building data from RVS methodologies.
34 Aung and Aye

TABLE 5. Preliminary evaluation results based on Indian method.
Building
no. Shear stress
direction Axial stress
direction Detailed seismic
evaluation is required
X Y X Y
1 NS S S S Yes
2 NS NS S S Yes
3 NS S S S Yes
4 NS S S S Yes
5 NS NS S S Yes
6 S S S S No
7 NS NS S S Yes
8 NS S S S Yes
9 NS NS S S Yes
10 NS NS S S Yes
11 S NS S S Yes
12 NS NS S S Yes
13 NS NS S S Yes
14 NS NS S S Yes
15 NS NS S S Yes
16 NS NS S S Yes
17 NS NS S S Yes
18 NS NS S S Yes
19 NS NS S NS Yes
20 NS NS NS S Yes
21 NS S S S Yes
22 NS NS NS S Yes
23 NS NS S S Yes
24 NS NS NS NS Yes
25 NS NS S S Yes
Note: NS = not satised, S = satised.
loads. They calculated the demand capacity ratio and car-
ried out retrotting of beams by steel plating and inte-
rior columns by concrete jacketing. All of the buildings as-
sessed in the present study require detailed seismic evalu-
ations, because their seismic indices are less than the seis-
mic demands of the respective structures. These buildings
should be retrotted to have the required seismic demand.
From the results of the preliminary evaluation based on
the Indian standard and Bangladesh method, not only are
detailed seismic evaluations necessary for these buildings,
but retrotting strategies must be carried out for some of
them, as well.
4. CONCLUSIONS
In this study, rapid visual screening methods comprising
FEMA P-154 level 1, FEMA P-154 level 2, the Indian method,
and the Bangladesh methods were used to assess the seis-
mic safety of 26 existing three- to eight-story RC buildings
in Mandalay, Myanmar. The results of each method can be
concluded as follows.
1. FEMA P-154 level 1 and level 2 showed the highest
risk. This method is not recommended because it is
an overestimation.
2. The Indian method is a moderate way for both rapid
visual screening and preliminary evaluation. It is
recommended for low-rise buildings and is an ef-
cient way for RVS methodology.
TABLE 6. Preliminary evaluation results based on Bangladesh method.
Building
no. Seismic evaluation
direction Detailed seismic
evaluation is required
X Y
1 NS S Yes
2 NS NS Yes
3 NS NS Yes
4 NS NS Yes
5 NS S Yes
6 NS NS Yes
7 NS NS Yes
8 NS S Yes
9 NS NS Yes
10 NS NS Yes
11 NS NS Yes
12 NS NS Yes
13 NS NS Yes
14 NS NS Yes
15 NS NS Yes
16 NS NS Yes
17 NS NS Yes
18 NS NS Yes
19 NS NS Yes
20 NS NS Yes
21 NS NS Yes
22 NS NS Yes
23 NS NS Yes
24 NS NS Yes
25 NS NS Yes
Note: NS = not satised, S = satised.
3. The results of the Bangladesh method depend
mainly on the number of stories and so it is more
suitable for the assessment of high-rise buildings.
4. The preliminary evaluation using the Bangladesh
method can result in more detailed seismic vulner-
ability results than the Indian method. However, in
the Bangladesh method, the seismic index and seis-
mic demand index calculations take more factors
into account and more effort and technical skill are
needed to obtain accurate data.
Seismic vulnerability assessments with different methods
can save time, funds, and energy. RVS and preliminary eval-
uations should be carried out for all existing buildings and
new buildings located in high seismic regions. Some seis-
mic design control parameters such as column size, steel
percentage, and material strength can be determined from
the seismic safety assessment of existing buildings and
these design parameters should be standardized for new
buildings. Finally, further research can employ standard
RVS methods and preliminary evaluations can be derived
for the buildings in Myanmar and those in other ASEAN
countries with similar seismic zones.
ACKNOWLEDGMENTS
The authors would like to acknowledge Dr. Nilar Aye, Pro-
fessor and Head, Department of Civil Engineering, Man-
dalay Technological University for her kind permission and
ASEAN J SCI TECHNOL DEV 38(1): 29–36 35

suggestions throughout the preparation of this paper. The
rst author also wishes to express her deepest gratitude to
her beloved family for providing mental support and needs.
AUTHORS’ CONTRIBUTIONS
MMMA designed the study. MMMA carried out the data
survey. MMMA analyzed the data. MMMA and MNA wrote
the manuscript. All authors read and approved the nal ver-
sion of the manuscript.
COMPETING INTERESTS
The authors have no competing interests to declare.
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