DOI: 10.3303/CET24114131
Paper Received: 11 June 2024; Revised: 20 October 2024; Accepted: 14 November 2024
Please cite this article as: Silitonga S.A., Bektaş N., 2024, Seismic Performance and Sustainability of Reinforced Concrete Buildings: A
Comprehensive Assessment, Chemical Engineering Transactions, 114, 781-786 DOI:10.3303/CET24114131
CHEMICAL ENGINEERING TRANSACTIONS
VOL. 114, 2024
A publication of
The Italian Association
of Chemical Engineering
Online at www.cetjournal.it
Guest Editors: Petar S. Varbanov, Min Zeng, Yee Van Fan, Xuechao Wang
Copyright © 2024, AIDIC Servizi S.r.l.
ISBN 979-12-81206-12-0; ISSN 2283-9216
Seismic Performance and Sustainability of Reinforced
Concrete Buildings: a Comprehensive Assessment
Samuel Alexandro Silitonga*,a, Nurullah Bektaşb
aSzéchenyi István University, Department of Architecture, Civil Engineering and Transport Sciences, 9026, Győr, Hungary
bSzéchenyi István University, Department of Structural Engineering and Geotechnics, 9026, Győr, Hungary
samuelsilitonga@gmail.com
Recent earthquakes such as the 2023 Türkiye-Syria, Morocco, and Afghanistan, 2015 Gorkha Nepal, and 2009
Indonesia earthquakes have demonstrated the vulnerability of existing building stock. Throughout Europe, many
existing buildings were constructed considering low or moderate standards or without considering them. This
study investigates the seismic performance of reinforced concrete (RC) buildings, exemplified as a six-story RC
dormitory building, focusing on various support and foundation conditions, soil characteristics, and site
seismicity scenarios representing the seismicity of Europe. The research aims to assess the potential effects of
exceeding anticipated site seismic intensities, potentially leading to safer communities and infrastructure in the
face of impending earthquakes. Robot Structural Analysis Professional software is used for structural analysis
and design throughout soil-structure interactions and site seismicity considerations. Moreover, this study
investigates the environmental implications of RC buildings, which represent the future building inventory in
Europe. It examines the varying material usage required to design structures compliant with Eurocode standards
through a life cycle analysis. The methodology employed in this investigation aligns with the core principles of
practical design encompassing economic and environmental sustainability. The study's key findings indicate
that increasing member size can enhance performance at lower intensities, but this may not be a sufficient
strategy at higher intensities, where shear walls may be necessary in high seismic zones. Sustainable design
necessitates a balance between material use, performance, and environmental impact.
1. Introduction
Earthquakes have shaped the world's physical and cultural landscapes, from ancient ruins to recent tremors
like Kathmandu (2015), Bam (2003), Tangshan (1976), Yogyakarta (2006), Baghdad (2017), and Ancona-Fano
(1930). Europe, often seen as stable, is actively shaped by earthquakes. Recent data collection in Italy on
earthquake damage to buildings fuels research in seismic risk assessment for existing structures (Tatangelo et
al., 2023). Analysing past damage helps researchers understand building vulnerabilities and develop mitigation
strategies. The 2009 L'Aquila earthquake in Italy (6.1 magnitude) devastated the Abruzzo region, with L'Aquila
bearing the brunt (300 deaths) (Moro et al., 2013). The psychological trauma and recovery were immense. The
February 2023 earthquake in southeastern Türkiye (Figure 1) and northern Syria claimed over 50,000 lives and
caused widespread damage, marking the deadliest earthquake in Turkey since 1939. Disaster experts like
Earthquake Engineering Field Investigation Team (EEFIT) and Earthquake Engineering Research Institute
deployed a team to assess the damage and recommend vulnerability reduction strategies (Aktas et al., 2023).
Figure 1: Damaged buildings after the 6 February 2023 Türkiye-Syria Earthquake
781
In Hungary, the 1763 Komárom earthquake, the strongest recorded in the Pannonian Basin in the past
millennium, provides valuable data for studying seismic activity. Extensive documentation from Hungarian towns
details building damage, aftershocks, and economic impacts (Varga et al., 2021). This earthquake highlights
the region's vulnerability and the need for preparedness. Following such a major earthquake, assessing building
damage is crucial for managing the crisis and recovery. Post-earthquake surveys serve two key purposes, which
include determining building functionality and damage assessment for financial assistance. Many buildings in
Europe are earthquake-prone due to their age and outdated design standards. They were constructed without
modern seismic considerations, making them vulnerable (Palermo et al., 2018). Residential buildings are
particularly at risk. Despite comprising 90% of existing structures, they account for roughly half of earthquake-
related losses. This emphasises the critical need to prioritise seismic design and construction practices in the
residential sector. Over time, buildings experience wear and tear, compromising their original energy efficiency
and seismic safety features. Insulation materials deteriorate, and structural components weaken, reducing their
ability to withstand earthquakes (Menna et al., 2013). As a result, older buildings become less energy-efficient
and more susceptible to earthquake damage as they age. Some buildings have simply reached the end of their
design life, further increasing their vulnerability. These factors combine to create a significant seismic risk for
many European structures, highlighting the need for evaluation and potential upgrades.
The unpredictable nature of earthquakes necessitates exceeding current seismic design standards. Eurocode
regulations are a good start, but inherent earthquake uncertainty requires structures resistant to stronger
shaking. Incorporating additional safety margins and advanced seismic technologies protects the infrastructure
from unforeseen seismic activity. During earthquakes, soil composition significantly impacts ground motion. Key
soil characteristics influence earthquake effects such as soil type (soft, saturated soils like loose sand amplify
ground motion, while stiffer soils like rock dampen shaking intensity), density (denser soils transmit seismic
waves more efficiently leading to stronger ground motions, while loose soils can absorb some wave energy
reducing intensity), water content (saturated soils are more susceptible to liquefaction, where soil loses strength
and behaves like a liquid, causing severe damage to foundations), and topography (hillsides and slopes with
loose soils are more prone to earthquake-triggered landslides). These soil characteristics directly influence how
earthquake-induced ground motions behave, including amplification (soft, saturated soils can amplify seismic
waves, significantly increasing ground motion intensity at the surface), attenuation (denser soils attenuate
seismic waves, meaning the wave energy is absorbed or scattered, reducing ground motion reaching the
surface), and site response (the combined effect of soil properties on a specific location is known as site
response which significantly affects the amount of ground shaking experienced during an earthquake).
Seismicity, the frequency and intensity of earthquakes in a region, presents challenges and opportunities for
sustainable development. Earthquakes can devastate infrastructure, disrupting daily life, hindering economic
activity, and limiting access to essential services. Rebuilding requires significant resources, potentially
exceeding 40 % of the initial cost (Gonzalez et al., 2023), diverting funds from other sustainability initiatives.
This study investigates the seismic performance of RC buildings in Hungary, a moderately seismically active
country, focusing on structures connected by fixed supports. It aims to understand how this configuration affects
stability and failure modes compared to isolated buildings. The research will use a specific soil type to isolate
the effect of building configuration on seismic response. It will consider multiple earthquake intensities exceeding
Eurocode standards to evaluate the safety margins in current design approaches. This comprehensive analysis
will identify potential vulnerabilities in existing structures for enhancing future design and retrofit strategies.
Ultimately, it aims to create safer and more resilient communities in earthquake-prone regions. This analysis
using AutoCAD (architectural drawing) and Autodesk Robot Structural Analysis (structural analysis) will provide
a comprehensive understanding of the structural behaviour under diverse seismic loading conditions by
considering Peak Ground Acceleration (PGA) values from 0.1g to 0.6g and soil interactions utilising soil type C
(clay), leading to an optimised design for safety, efficiency, and resilience.
2. Soil Properties
Eurocode 8 (EC8) classifies soil based on its influence on earthquake effects. It defines five standard types (A-
E) based on shear wave velocity (Vs), a measure of how fast earthquake shaking travels through the ground.
Rock (Type A) is the most stable foundation with minimal vibration amplification. Very dense soil (Type B) is a
very good foundation material with good drainage and high bearing capacity. Moderately dense soil (Type C)
may require more detailed investigation for seismic design than A and B. Loose soil (Type D) is most susceptible
to shaking amplification, requiring careful design considerations. Very soft soil (Type E) is the most challenging
for seismic engineering, often requiring special foundations. EC8 also recognises two special site conditions
(S1 and S2). Rock with shallow overburden (S1) experiences minimal amplification. Lastly, other site conditions
(S2) include a wider range of soil profiles with potential for amplification. Understanding soil properties is crucial
for earthquake engineering, including seismic design parameters (soil type and site classification influence the
782
design response spectrum used for structural analysis), foundation design (soil properties determine the
selection of foundation types (shallow vs. deep) and their design parameters), and structural design
(understanding soil behaviour allows engineers to design structures that efficiently channel seismic forces). In
this case study, the research utilises soil type C.
3. Seismicity
Earthquake Hazard Maps are vital tools for assessing seismic risk and guiding mitigation efforts in Europe.
These maps depict the expected level of ground shaking as a unit of PGA at various locations due to potential
earthquakes. PGA values, expressed as a percentage of Earth's gravity (g), are derived from advanced models
like the European Seismic Hazard Model 2020 (ESHM20) (EFEHR, 2020). ESHM20 analyses historical
earthquake data, geology, and active faults across Europe. It estimates earthquake probabilities and
magnitudes in different regions and then simulates ground shaking intensity at various points. The map in Figure
2 (a) uses a colour scheme to communicate shaking intensity, including white to green as low hazard (minimal
shaking), yellow to orange as moderate hazard (greater shaking potential), and red to purple as high hazard
(potential for significant shaking). These zones correlate with building design codes. Many regions require
earthquake-resistant structures to withstand a specific shaking level, typically corresponding to a 10 %
probability of occurrence in 50 y (Design Basis Earthquake). This translates to a shaking intensity expected to
be exceeded only once every 475 y, on average. The maps show PGA values for different return periods,
providing valuable insights into areas likely to experience stronger or weaker shaking during future earthquakes.
PGA, measured in units of g, quantifies earthquake ground shaking intensity. Higher PGA signifies stronger
shaking and greater damage potential. PGA has two key applications in earthquake engineering, including
structural design. Engineers use PGA to calculate seismic forces acting on structures. This information is crucial
for designing earthquake-resistant buildings and infrastructure. Building codes specify design PGA values based
on seismic risk assessments, and correspondingly usage PGA helps to estimate potential earthquake induced
damage to existing structures. This aids post-earthquake response by prioritising buildings for inspection and
repair. EC8 incorporates importance factors (γi) to account for varying seismic vulnerability of buildings. These
factors are assigned based on a building's societal importance, potential life loss, and economic consequences
in an earthquake. Higher factors are assigned to critical structures like hospitals (γi = 1.4) compared to
warehouses (γi = 0.8). This prioritises life safety and critical infrastructure by classifying buildings into four
categories which are lesser importance (γi = 0.8), ordinary buildings (baseline: γi = 1.0), important for seismic
resistance (γi = 1.2), and important for disaster response (γi = 1.4). This system ensures buildings are designed
to withstand earthquakes based on their societal importance. Seismic hazard map of Hungary, in Figure 2 (b),
shows color-coded five seismic hazard zones with PGA values ranging from 0.08 g (blue) to 0.15 g (orange). A
north-south zone of heightened seismic activity is evident west of Győr, aligning with historical data of major
earthquakes impacting both Komárom and Győr.
Figure 2: (a) Earthquake Hazard map of Europe 2020 (EFEHR, 2020), (b) Seismic Hazard map of Hungary and
Fault line map of Hungary (GeoRisk Earthquake Engineering Ltd., 2006)
In this study, the response spectrum analysis considered a PGA range from 0.1 g to 0.6 g, importance factor of
1.2 (increased seismic design requirements), damping of 5 % (typical for reinforced concrete), and soil type of
C (consistent with the case study site). Figure 3 shows the corresponding design response spectra.
783
Figure 3: 0.1 g to 0.6 g design response spectrum
4. Structural Modelling and Analysis
To illustrate the seismic performance of Hungarian RC buildings, this research utilises a six-story RC dormitory
building as a case study. Inspired by a similar building at Széchenyi István University in Győr, the model features
a total height of 21 m and a footprint of 14.5 m x 43 m (rectangular). This CAD model (Figure 4) avoids vertical
irregularities but has a plan irregularity due to the significant difference between its short and long sides.
Figure 4: Front and right side view of RC dormitory structure
This table (Figure 6) summarises findings from a scientific study on building performance under various stress
levels. It categorises building functionality based on five levels, which are “Operational Performance” meaning
building remains fully functional, “Immediate Occupancy” meaning minor to moderate damage, safe for
immediate occupancy, “Damage Control” meaning repairable structural damage, “Life Safety” meaning
significant or severe damage, may require evacuation, “Collapse Prevention” meaning building on the verge of
collapse. Each level corresponds to a specific inter-story drift ratio, indicating how much floors move relative to
each other. This data helps emergency responders assess building safety and guides engineers in designing
structures that can withstand urban stresses.
Table 1: Performance level of built structures
Performance Level Abbreviation EMS-98 (1998) damage states Inter-story Drift Ratio (%)
Operational Performance OP No / Slight 0.5
Immediate Occupancy IO Slight / Moderate 1
Damage Control DC Moderate / Heavy 1.5
Life Safety LS Heavy / Very Heavy 2
Collapse Prevention CP Destruction 2.5
5. Environmental Impact Assessment
Life Cycle Assessment (LCA) is a tool to assess a product or service's environmental impact throughout its
lifespan, from material extraction to disposal. It helps identify areas for sustainability improvement. Life Cycle
Cost Analysis (LCCA) is crucial for sustainable construction projects, particularly when considering concrete, a
common building material. LCCA considers the costs of material acquisition, processing, and disposal
throughout the concrete lifecycle. This study uses IdematLightLCA to perform a life cycle assessment and
calculate the environmental impact of the materials utilised in each building configuration that is built surrounding
certain PGA values in order to withstand different magnitudes of earthquakes. With regard to the unit, the LCCA
will assess the unit eco-costs, which represent the environmental damage associated with the material, and the
carbon footprint, which measures the greenhouse gas emissions during material production.
784
https://idematapp.com/coll-page-section/lightlca/
6. Results and Discussion
A structural analysis was performed for a 7-story building with a fixed support system. The analysis considered
seismic performance (deflection) and material usage for sustainability. The building model had 252 columns
(3 m tall), 413 Beams (5 m), 28 cantilevers (2 m), column spacing of 5 m, and floor slab thickness of 15 cm. The
seismic analysis input includes ground response acceleration (ag) of 0.12g to 0.72g (considering PGA,
importance factor, and unit conversion), soil type C, spectrum type using design spectrum, analysis direction of
horizontal, and behaviour factor of 1.5 (constant). The analysis explored how member dimensions and PGA
values affect a building's seismic performance. Performance is measured by inter-story drift ratio, indicating
deflection under load. Lower PGA values (0.1g and 0.2g) had all member configurations achieved good
performance (OP to IO) with minimal to moderate damage expected. Moderate PGA values (0.3g) had initial
configurations that fell under damage control (DC), and increasing member sizes improved performance in
terms of immediate occupancy (IO). As for higher PGA (0.4 g to 0.6 g), even with member size adjustments,
performance remained between immediate occupancy and damage control. This suggests the limitations of
relying solely on member size at higher seismic intensities. The study recommends investigating the use of
shear walls in future analyses, as they can significantly improve seismic performance.
Table 2: Combined Eco-costs and Carbon footprint in each case for each PGA value & Life Cycle Cost
Analysis for Concrete and Steel used in each case for each PGA value
PGA Config Column
Dimensions (cm)
Beam
Dimensions (cm)
Combined Eco-
Costs (€)
Deflection
(cm)
Inter-story Drift
Ratio (%)
Combined Carbon
Footprint (kg)
a 50x50 30x60 103,177.666 9.1 0.4333 517,964.4
0.1g b 45x45 25x40 67,450.428 6.9 0.3285 337,358.2
c 45x45 25x60 86,284.559 7.7 0.3666 432,292.6
a 60x60 30x60 135,915.886 11.6 0.5523 668,082.2
0.2g b 45x45 25x40 79,013.342 18.3 0.8577 386,237.8
c 50x50 30x50 107,825.564 14.8 0.7047 528,419.4
a 50x50 35x60 141,314.16 20.7 0.9857 688,367.4
0.3g b 45x45 30x40 95,004.02 27.1 1.2904 459,963.4
c 50x50 35x45 119,325.9 23.2 1.1047 579,332.7
a 50x50 50x70 214,955.64 27.1 1.2904 1,042,574
0.4g b 45x45 40x60 160,615.64 31 1.4761 774,093.6
c 50x50 50x50 170,782.4 29 1.3809 823,084.7
Table 2 presents the analysis of the trade-off between material usage and deflection (seismic performance) for
PGA values of 0.1g to 0.4g. PGA values of 0.5g and 0.6g were found to have dangerous values of deflection.
So, LCA was not conducted, and it is recommended that shear walls be used in this case. Lower deflections
under a specific PGA value require more material but lead to better performance (less damage) under seismic
loads. Finding a balance between these factors is crucial for sustainable design (minimal material, good
performance). For each PGA value, configurations with minimum, maximum, and intermediate deflection were
compared. At 0.1g, configuration “a” used the most material but had the least deflection. Configuration “b” used
the least material but had the most deflection, and configuration “c” offered a compromise. Similar trends were
observed for higher PGA values. The configurations based on performance and sustainability find that 0.1g
configuration “a” is the best option due to lower material use with minimal performance compromise. For 0.2g,
configuration “c” might be the most reasonable option as it balances material usage and deflection while
maintaining good performance. For 0.3g, configuration “c” provides the best performance despite high material
use. For 0.4g, all configurations fall within the same performance range; selecting the most sustainable option
depends on project priorities (minimising material use vs slightly lower deflection) and configurations “a”, “b”, or
“c” could all be potential candidates. The choice depends on project-specific priorities and constraints, such as
the relative weight, minimising material usage versus achieving a slightly lower deflection.
The analysis revealed a significant increase in material usage as the PGA increased. For RC structures
designed for a PGA of 0.1g to be modified to meet the performance requirements of 0.2g, the quantities
increased approximately 28 % for concrete and 61 % for steel. This trend continued at higher seismic intensities.
Transitioning from a 0.2g design to a 0.3g design required increases in concrete & steel of 20 % & 31 %.
Similarly, from a 0.3g design to a 0.4g design resulted in an additional 32 % & 38 % increase in concrete & steel
consumption. In essence, these results suggest that constructing an RC structure designed for a 0.1g PGA in a
location with a 0.4g PGA would require approximately 60 % more concrete and 83 % more steel. This highlights
the significant impact of seismic intensity on the material requirements for RC structures. Building in earthquake-
prone areas (higher PGA) requires stricter designs to ensure safety. This often leads to increased material use,
which has a negative environmental impact. The study found that a structure designed for low PGA (0.1g) would
need 52 % more eco-cost and 51 % more carbon footprint to meet safety standards in a high PGA (0.4g)
785
location. While minimising material use is ideal for sustainability at low PGA levels, prioritising performance at
higher intensities becomes more important. Lastly, a higher-performing structure is less likely to suffer damage,
reducing risk to human life, earthquake waste, and the need for reconstruction (saving resources)
7. Conclusions
This study investigated the seismic performance of RC buildings in Europe. A 6-story building model was
analysed under various earthquake intensities (PGA: 0.1g to 0.6g) and soil conditions (dense sand/gravel, stiff
clay) using software incorporating soil-structure interaction and site seismicity. LCA considered the
environmental impact of material usage. The key findings include member size vs. seismic performance:
(increasing member size improved performance at lower PGA of 0.1g & 0.2g but had diminishing returns at
higher intensities of 0.3g & 0.4g, where shear walls may be necessary for high seismic zones of 0.5g & 0.6g).
Regarding performance levels, lower PGAs of 0.1g & 0.2g achieved operational and immediate occupancy
performance, while higher PGAs of 0.3g & 0.4g remained in damage control even with member size
adjustments. In terms of material use vs. deflection, lower deflection (achieved with more material) resulted in
less seismic damage, indicating that sustainable design requires a balance between these factors. For material
use vs. seismic zone, lower seismic zones of 0.1g & 0.2g allowed prioritising minimal material use
configurations, while higher zones of 0.3g may require slightly more material for significantly better performance
and lower maintenance costs. The environmental impact analysis showed that stricter building codes in high
seismic zones lead to increased material use and higher environmental costs, with eco-cost rising by 52 % and
the carbon footprint increasing by 51 % from 0.1g to 0.4g PGA values. Finally, LCA can balance environmental
impact with safety, prioritising higher-performance structures in high seismicity zones, which can reduce waste
and long-term environmental impact by reducing the need for reconstruction. To further enhance this research,
incorporating shear walls into the structural model is recommended. Analysing the influence of shear walls on
building performance under different seismic scenarios can provide valuable insights into improving structural
efficiency and seismic resistance in RC buildings.
References
Aktas Y.D., So E., Johnson C., Cabuk E. et al., 2023, Hybrid EEFIT Mission to February 2023 Kahramanmaraş
Earthquake Sequence, Proceedings of the SECED 2023 Conference Earthquake Engineering & Dynamics
for a Sustainable Future, Society for Earthquake and Civil Engineering Dynamics (SECED), Cambridge, UK,
, accessed 27.10.2024.
European Committee for Standardization (CEN), 2004, Eurocode 8: Design of structures for earthquake
resistance – Part 1: General rules, seismic actions, and rules for buildings (EN 1998-1:2004), CEN, Brussels,
Belgium.
EFEHR, 2020, The earthquake hazard map of Europe. European Facilities for Earthquake Hazard and Risk.
, accessed 27.10.2024.
GeoRisk Earthquake Engineering Ltd., 2006, Seismic Hazard Map of Hungary, , accessed
27.10.2024.
Gonzalez R.E., Stephens M.T., Toma C., Dowdell D., 2023, Incorporating potential environmental impacts in
building seismic design decisions. Bulletin of Earthquake Engineering, 21(9), 4385–4428, DOI:
10.1007/s10518-023-01686-y.
Grünthal G., Musson R.M.W., Schwarz J., Stucchi M., 1998, European Macroseismic Scale 1998 (EMS-98),
European Seismological Commission, Luxembourg,
, accessed 27.10.2024.
Menna C., Asprone D., Jalayer F., Prota A., Manfredi G., 2013, Assessment of ecological sustainability of a
building subjected to potential seismic events during its lifetime. International Journal of Life Cycle
Assessment, 18(2), 504–515, DOI: 10.1007/s11367-012-0477-9.
Moro M., Gori S., Falcucci E., Saroli M., Galadini F., Salvi S., 2013, Historical earthquakes and variable
kinematic behaviour of the 2009 L’Aquila seismic event (central Italy) causative fault, revealed by
paleoseismological investigations. Tectonophysics, 583, 131–144, DOI: 10.1016/j.tecto.2012.10.036.
Palermo V., Tsionis G., Sousa M.L., 2018, Building Stock Inventory to Assess Seismic Vulnerability Across
Europe, 16th European Conference on Earthquake Engineering, Thessaloniki, Greece, June 2018.
Tatangelo M., Audisio L., D’Amato M., Gigliotti R., 2023, Seismic risk analysis on masonry buildings damaged
by L’Aquila 2009 and Emilia 2012 earthquakes. Procedia Structural Integrity, 44, 990–997, DOI:
10.1016/j.prostr.2023.01.128.
Varga P., Győri E., Timár G., 2021, The Most Devastating Earthquake in the Pannonian Basin: 28 June 1763
Komárom. Seismological Research Letters, 92(2A), 1168–1180, DOI: 10.1785/0220200411.
786