Seismic Demand Due to the Earthquake Hazard Map 2017

Determination in Indonesia

Restu Faizah and Elvis Saputra

Civil Engineering, Universitas Muhammadiyah Yogyakarta, Faculty of Engineering, Yogyakarta, Indonesia

Keywords: Seismic demand, Earthquake hazard map, Dynamic spectra response

Abstract: The Earthquake Hazard Map used in the design of earthquake resistant infrastructure in Indonesia has

developed from Earthquake Hazard Map 2010 to 2017. This development affects the improvement of

seismicity pattern in several areas in Indonesia, which may lead to the increase of seismic demand. Therefore,

it is needed to carry out a study to investigate the condition of seismicity in different cities in Indonesia. This

study analyzed a model structure located in 32 cities in Indonesia by referring to the Earthquake Hazard Map

2010 and 2017. The analysis uses a dynamic spectra response method through SAP2000 software to obtain

the value of a fundamental period of structure, deflection, and base shear. Based on the analysis, it can be

identified that 16 cities increase their seismicity pattern significantly and the highest escalation occurred in

Jayapura city of 60%. Meanwhile, the highest base shear value in 2010 is on Palu and changed into Jayapura

in 2017. The decrease of seismic conditions also occurred in 16 other cities with the highest decline is in

Merauke city of 53%. For particular areas affected by seismicity, further analysis of existing building

especially high-risk building is suggested.

1 INTRODUCTION

Ministry of Public Works and Housing (PUPR) in

Indonesia released the new Earthquake Hazard Map

2017 (EHM-2017) (PUSGEN, 2017) which is the

update of the Earthquake Hazard Map 2010 (EHM-

2010) (PU, 2010). The reason for map improvement

is because the map has been aged more than five years

and it new seismic sources has been identified. In

addition, the improvement was also made in order to

increase the accuracy estimation of important

parameters in the map, as well as the detail of

earthquake source using the equation of current

earthquake attenuation. This is according to Vipin et

al. (2009) statement that earthquake hazard is

controlled by three factors, i.e. properties of the

source, characteristics of the path, and local site

effects. Past earthquake data, characteristics of

earthquake sources in the region and attenuation

relationships are three important factors that must be

considered to assess the hazards of earthquakes

The preparation of EHM-2017 considers the

occurrence of major earthquakes in recent years and

the identification of earthquake sources such as active

faults that appear in various regions in Indonesia. The

National Center for Earthquake Study in Indonesia

states that the amount of active faults in Indonesia has

increased from 81 in 2010 to 295 in 2017 (PUSGEN,

2017). The improvement of seismic hazard in EHM-

2017 may affect the earthquake-stricken structural

response that may indicate the seismic demand in the

structural design. In principle, buildings should be

designed to withstand the seismic loads of 2017

safely which is exposed by acceptable deflection and

base shear. This case generates a further issue about

existing buildings that must be evaluated to determine

its performance of seismic loads in 2017 (Imran,

2007). Therefore, it is necessary to investigate

structural response in various cities in Indonesia, to

identify the seismic demand in each location.

Faizah and Widodo (2013) investigated the

previous improvement of EHM that is from 2002 to

2010 and reported that it resulted in changes of

seismic demand in 23 cities under review. There was

a significant increase in Semarang, Yogyakarta,

Kendari, Banda Aceh, and Palu, with the highest

escalation in Semarang by 126%. Meanwhile the

decline of seismic demand occurred in Bandar

Lampung, Palembang, Jakarta, Kupang,

Banjarmasin, Samarinda, and Makassar. Similar

research was conducted by Arfiadi (2014), by

evaluating 22 cities in Indonesia. The results showed

108

Faizah, R. and Saputra, E.

Seismic Demand Due to the Earthquake Hazard Map 2017 Determination in Indonesia.

DOI: 10.5220/0009007101080116

In Proceedings of the 7th Engineering International Conference on Education, Concept and Application on Green Technology (EIC 2018), pages 108-116

ISBN: 978-989-758-411-4

Figure 1: The map of spectral acceleration at short period (SS) with 5% damping ratio in bedrock (SB) for probability

exceeded 2% in 50 years (EHM-2017).

Figure 2: The map of spectral acceleration 1 second period (S

) with 5% damping ratio in bedrock (SB) for probability

exceeded 2% in 50 years (EHM-2017).

that Palu and Semarang have a significant increase of

spectral acceleration response both for a short period

(SS) and 1 second period (S1). It is also stated that the

difference of spectral acceleration response will be

greater than that of the soil type is harder.

This study analyzes a structure located in 32 cities

in Indonesia by referring to EHM-2010 (PU, 2010)

and EHM-2017. From this analysis, it can be

identified the base shear value that can indicate the

seismic demand in the site. The analysis of seismic

demand is very urgent in order to evaluate the

performance of existing buildings located in the

earthquake prone-area. There are areas which

experience an escalation or a decline for the others in

term of base shear value. This value must be

calculated as a requirement of a seismic load in the

design of a structure (ASCE, 2017). Therefore, the

escalation of seismic demand after the determination

of EHM-2017 generates a problem, especially for the

existing building. The paper contributes in

developing a new seismic building code especially to

assess the structural vulnerability of the existing

building.

1.1 Development of the Earthquake

Hazard Map (EHM) in Indonesia

Asrurifak (2017) explains that EHM was first created

in 1962 and published in the Indonesian Concrete

Standard (Peraturan Beton Indonesia/PBI) in 1966,

where the Indonesian’s territory is without Irian Jaya

city. In 1970, EHM was repaired and published in the

Indonesian Loading Standard (Peraturan Muatan

Indonesia/PMI) by integrating the Irian Jaya city in

the Indonesian’s territory. After 1970, there were

several major earthquakes, including the 1976-Bali

Earthquake. It causes PMI-1970 be revised into

Indonesian Loading Standard (Peraturan

Seismic Demand Due to the Earthquake Hazard Map 2017 Determination in Indonesia

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Figure 3: A reinforced concrete frame model.

Pembebanan Indonesia/PPI) in 1981 which are also

published in several standards, such as the Standard

of Earthquake Resistant Design-1983 and Standard of

Loading Procedures for Indonesian Building-1983.

This EHM has revised again to EHM-2002 and

published in SNI 03-1726-2002, where Indonesia was

divided into six seismic areas. After that, there were

several major earthquakes such as the 2004-Aceh

Earthquake, 2005-Nias, 2006-Jogja, 2009-Tasik,

2007-Bengkulu, 2009-Padang and 2010-Mentawai in

Indonesia, so EHM was revised to the EHM-2010 and

published in SNI-1726:2012, SNI-2847:2013, SNI-

1729:2014, and SNI-7973: 2013. EHM was finally

revised in 2017 which has considered several

earthquake events that are not yet to be calculated on

the previous map. Besides, there were 214 new faults

identified as the latest quake source parameter. The

value of spectral acceleration from EHM-2017 at

short period (SS) and 1 second period (S1) with 5%

damping ratio in bedrock (SB) for probability

exceeded 2% in 50 years shown in Figures 1 and 2

(PUSGEN, 2017).

2 RESEARCH METHODOLOGY

The analysis in order to find out the difference of

structure response that occurred due to seismic

loading in EHM-2010 and 2017 uses the dynamic

method of spectra response by SAP2000-3D

software. The structure model is a 10-story reinforced

concrete frame with four spans of each side which is

presented in Figure 3. The specifications of structure

model and the column/beam dimensions are shown in

Table 1 and Table 2 respectively. The structure model

is assumed as an office building located in 32 cities in

Indonesia as mentioned in Table 3, including the

spectral acceleration value that was observed from

EHM-2010 and 2012. Structure response due to the

2010 and 2017 seismic load which includes a

fundamental period of structure, deflection, and base

shear can be identified from the structure 3D analysis

using SAP-2000 software. The result is compared to

the structure response 2010 and 2017 to find out its

escalation or decline in 32 cities in Indonesia. The

response spectra design is also compared between

2010 and 2017 in each city to identify the difference

in structure response.

Table 1: Specification of structure model.

Specification Provisions

Building function Office

Concrete strength 30 MPa

Modulus of elasticity of concrete 25742 MPa

Reinforcement bar BJTD 41

Stirrups BJTD 34

Modulus of Elasticity of steel 2.105 MPa

Typical-height of story 4 m

Wide of spans 4 m

Table 2: Dimension of column/beam (mm).

Level

Side-

column

Middle-

column

Main

Beam

b h b h b h

1-4 700 700 800 800 350 700

5-7 600 600 700 700 300 600

8-10 500 500 600 600 250 500

b = width ; h = height.

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Application on Green Technology

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Table 3: Cities and values of S

and S

(sec.).

No.* City

EHM 2010 EHM 2017

1. Banda Aceh 1.349 0.642 1.71 0.65

2. Medan 0.526 0.332 0.58 0.28

3. Pekanbaru 0.435 0.273 0.35 0.24

4. Padang 1.398 0.600 1.25 0.52

5. Kuala Tungkal 0.210 0.170 0.32 0.19

6. Muara Bungo 0.544 0.310 0.62 0.36

7. Palembang 0.262 0.164 0.28 0.21

8. Bengkulu 1.372 0.567 2.15 0.81

9. Pangkal Pinang 0.057 0.077 0.14 0.11

10. Bandar Lampung 0.739 0.318 0.77 0.34

11. Serang 0.784 0,334 0.84 0.36

12. Jakarta 0.664 0.293 0.72 0.31

13. Bandung 1.450 0.486 1.20 0.40

14. Semarang 1.098 0.364 0.73 0.28

15. Yogyakarta 1.212 0.444 1.32 0.44

16. Surabaya 0.663 0.274 0.75 0.27

17. Denpasar 0.977 0.360 0.80 0.31

18. Mataram 0.960 0.385 0.94 0.34

19. Kupang 1.113 0.296 0.92 0.26

20. Pontianak 0.017 0.022 0.17 0.02

21. Palangkaraya 0.059 0.031 0.04 0.02

22. Banjarmasin 0.060 0.036 0.08 0.03

23. Samarinda 0.125 0.089 0.11 0.07

24. Palu 2.164 0.765 2.42 0.91

25. Makassar 0.317 0.142 0.22 0.08

26. Kendari 0.825 0.330 0.64 0.13

27. Manado 1.035 0.442 0.97 0.35

28. Ambon 1.380 0.490 0.92 0.30

29. Manokwari 1.454 0.561 1.65 0.62

30. Fak-fak 0.518 0.190 0.59 0.24

31. Jayapura 1.500 0.600 2.81 0.94

32. Merauke 0.055 0.021 0.02 0.01

*refer to Figure 2

3 RESULTS AND DISCUSSION

The study covers an analysis of the spectra response

design and structure response on the structure located

in 32 cities in Indonesia due to earthquake loads

according to EHM-2010 and 2017.

3.1 Response Spectra Design

Based on the spectral acceleration values in Table 3,

a spectra response design of 2010 and 2017 is

assigned, which has an own characteristic in each

city. In this manuscript, some results are given for the

sample to be analyzed. Figure 4.a shows Banda

Aceh’s spectra response design that increases from

2010 to 2017 in all variant structure’s period, but the

escalation is not fixed. For structures with 0.125 s –

0.69 s of fundamental period, the escalation is

significant. Whereas in Jayapura, it is estimated that

there is an increase of spectral acceleration for

structures with more than 1 second of the

fundamental period and decrease for others.

Afriadi (2014) compares the spectra value of 2002

and 2012-according to Indonesian Earthquake

Hazard Map and 2012 is higher than 2002. There

were 22 cities in Indonesia which was investigated

and it is reported that Palu and Semarang city

experience a very significant increase of spectral

acceleration both short and one-second periods. Cities

that have a significant increase in spectral

Seismic Demand Due to the Earthquake Hazard Map 2017 Determination in Indonesia

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(a)

(b)

Figure 4: Spectra response design of (a) Banda Aceh and (b) Jayapura.

acceleration due to seismic load 2012 also have a

significant increase in the internal force of building.

Therefore, with the enactment of the seismic load

2012, it is necessary to evaluate the resistance of the

structures, especially for a site which has an increased

value of S

and S

3.2 Fundamental Period

The fundamental period of structure model can be

obtained from the analysis, which is 2.79 s. This value

can be delineated in the curve of spectra response

design (Figure 4) to identify the spectral acceleration

due to the earthquake load on the structure. For Banda

Aceh (see Figure 4.a), the value of spectral

acceleration 2010 and 2017 are 0.208 g and 0.210 g

respectively, it means that the value of 2017 is

slightly larger than 2010. This value may affect the

magnitude of base shear of the structure. This

occurrence is different from Jayapura that has a value

of base shear 2017 which is significantly greater than

2010, especially for 0.124 s - 0.62 s of the

fundamental structure period. Based on Jayapura’s

spectra response design in Figure 4.b, it can be

determined that the value of spectral acceleration

2010 and 2017 are 0.201 g and 0.238 g respectively.

There is a significant dissimilarity between both of

the values. Based on this result, it can be concluded

that the spectral acceleration value depends on the

fundamental period of structure and the seismicity

pattern of the site, which is in accordance with the

statement (Adam et al., 2017; Borzouie et al., 2016;

Murthy, 2003) that in a typical city, there are

buildings of many different sizes and shapes. One

way of categorizing them is by their fundamental

natural period (T).

3.3 Base Shear

This study investigated base shear values of structure

to predict the magnitude of seismic demand as a

requirement of structure design. In addition, the

deflection of the structure is also quantified,

especially for the location of the base shear decline

from 2010 to 2017. Figure 5 shows the comparison of

the base shear value of structure between 2010 and

2017 at 32 cities in Indonesia due to the seismic loads

according to EHM-2010 and 2017. Jayapura has a

peak value of base shear in term 2017 and the highest

escalation from 2010 to 2017. The value of

Jayapura’s base shear-2017 is 4525.5 kN which

increases 60.2% from the 2010 value. The escalation

of base share value from 2010 to 2017 can be seen in

Figure 6. There are 16 cities have increased their base

shear value, while the other 16 cities have a decrease

in their base shear value.

The result of this study is similar to the result of

the research conducted by Faizah and Widodo (2013).

However there is a difference in the location that has

the peak value of escalation on the base shear. From

2002 to 2012, the peak value of base shear escalation

was in Semarang (126%), but from 2012 to 2017, it

shifted to Jayapura (60%). Some locations have

increased the seismic load design in 2012 but

decreased in 2017, conversely. For example is the

base shear of Semarang city which experienced a

significant increase in 2012 but decrease in 2017.

Meanwhile, Bandar Lampung’s base shear

experienced an increase in 2012, but decrease in

2017. These conditions may not apply equally to

various structures because each type of structure may

have a different fundamental period that affects its

spectral acceleration value. On the other hand, the

similar study with variations in structure types like

Earthquake Map 2010

Earthquake Map 2017

Fundamental Period

EHM 2010

EHM 2017

Fundamental Period

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Application on Green Technology

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Figure 5: The comparison of base shear value between 2010 and 2017.

Figure 6: The escalation of base share value from 2010 to 2017.

the number of story and span, type of materials,

various fundamental of structures, and etc. is

recommended to be done. The development of

seismic hazard map is also investigated in various

location (Gracia et al., 2018; Unal et al., 2014;

Courboulex, 2007).

3.4 Horizontal Deflection

Subsequently, this study reviews the horizontal

deflection emerging the structure that experienced an

increase base shear in 2017. The horizontal deflection

of structures affected by EHM-2017 in 16 cities is

presented in Figure 7. Jayapura has the largest

horizontal deflection of 0.087 m.

The drift ratio of the structure due to EHM-2017

can be calculated by dividing the deflection with the

height of the structure at each level and the results

obtained are mentioned in Table 4. The largest of drift

ratio in each structure always in 8 stories that are

written in bold font. This result is compared to the

allowable drift ratio requirement according to

Indonesian Earthquake Resistant Structure Design

Standard (BSN, 2012). The structure model is an

Seismic Demand Due to the Earthquake Hazard Map 2017 Determination in Indonesia

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Table 4: The drift ratio in each story of the structure in 16 cities (mm)

City / no. of story 1 2 3 4 5 6 7 8 9 10

Aceh 0.93 1.40 1.49 1.60 1.81 1.73 1.76 1.88 1.50 0.97

Bandar Lampung 0.55 0.84 0.89 0.96 1.09 1.04 1.06 1.13 0.90 0.58

Bengkulu 1.15 1.74 1.85 1.99 2.25 2.15 2.20 2.34 1.87 1.21

Jayapura 1.35 2.03 2.15 2.31 2.60 2.50 2.55 2.71 2.16 1.41

Pangkal Pinang 0.22 0.35 0.38 0.43 0.49 0.48 0.49 0.51 0.39 0.24

Pontianak 0.05 0.07 0.07 0.08 0.09 0.09 0.09 0.09 0.07 0.05

Palu 1.30 1.96 2.08 2.24 2.53 2.42 2.47 2.63 2.10 1.36

Fak Fak 0.44 0.66 0.70 0.76 0.85 0.82 0.83 0.89 0.71 0.46

Kuala Tungkal 0.36 0.55 0.59 0.64 0.72 0.69 0.70 0.75 0.60 0.38

Palembang 0.37 0.57 0.62 0.69 0.78 0.76 0.77 0.81 0.63 0.39

Manokwari 0.88 1.34 1.42 1.53 1.72 1.65 1.68 1.79 1.43 0.92

Muara Bungo 0.57 0.86 0.92 1.00 1.13 1.07 1.09 1.17 0.93 0.60

Serang 0.57 0.87 0.92 1.00 1.12 1.07 1.09 1.17 0.93 0.60

Jakarta 0.52 0.79 0.84 0.91 1.03 0.98 0.99 1.07 0.85 0.55

Surabaya 0.48 0.73 0.77 0.83 0.94 0.90 0.92 0.98 0.78 0.50

Yogyakarta 0.66 0.99 1.05 1.12 1.27 1.22 1.24 1.32 1.05 0.69

Figure 7: The horizontal deflection of the structure in 16 cities.

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Application on Green Technology

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Figure 8: The escalation of structure’s drift ratio located in 16 cities in Indonesia.

office building and it is classified as II-risk category.

Hence, the drift ratio should not be greater than 0.020

time the high of story. The allowable drift ratio for

this structure is 80 mm and the largest of drift ratio is

qualify clearly.

Maximum drift ratio of the structure due to EHM

2010 and 2017 are also compared. The escalation of

maximum drift ratio due to both of EHM 2010 and

2017 (Figure 8) is not similar to the escalation of base

shear value (Figure 6). The structure located in

Pontianak increased base shear value by 3% but

decreased its maximum drift by -12%. Similar

conditions may occur in the other cities. This

indicates that the increase in the base shear value is

not always proportional to the increase in the drift

ratio and cannot be used to predict the building’s

ability against earthquake. Further study needs to be

held to investigate the resistance of various types of

buildings located in other cities in Indonesia against

earthquakes according to the EHM-2017.

4 CONCLUSION

Seismic demand has been studied in this paper

through a dynamic spectra response analysis of the

structure model located in 32 cities in Indonesia. It

was indicated by the base shear value which was

calculated according to EHM-10 and EHM-17. The

result showed that there were 16 cities experienced an

escalation and degradation for the other city, in term

of base shear value. It also found that increase in base

shear value from 2010 to 2017 was occurred in

Jayapura city by 60%, in term of 2.79 seconds of

structure fundamental period. This increase might be

different from other structures which have different

fundamental periods.

Horizontal deflection was also presented in this

study to identify its correlation to base shear value.

The analysis concluded that the increase in the base

shear value could not be used to predict the building’s

ability against earthquake. A further study is also

suggested in order to investigate the resistance of

various types of buildings located in other cities in

Indonesia against earthquakes according to the EHM-

2017, whether it is in various materials, geometry,

located, and function of structures.

ACKNOWLEDGEMENTS

The authors gratefully acknowledge Universitas

Muhammadiyah Yogyakarta for their supports and

assistances during this study.

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Application on Green Technology

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