the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 23 Jun 2026
2023 Kahramanmaraş Earthquake Doublet: Seismic Performance of RC Buildings, Code Implications and Geotechnical Evaluation
Abstract. The February 6, 2023, Kahramanmaraş earthquake doublet subjected reinforced concrete (RC) buildings in southern Türkiye to exceptionally severe near-fault seismic demand, with recorded ground motions locally exceeding the highest design level of the current Turkish seismic code. This study investigates the seismic performance of RC buildings based on post-earthquake field observations conducted across eleven affected cities, with a particular focus on comparing damage mechanisms in older building stock and in more recently constructed code-era buildings. Field evidence indicates that damage in older RC buildings was predominantly associated with well-established deficiencies, including inadequate detailing, poor material quality, soft-storey mechanisms, torsional effects, and pounding between adjacent structures. In contrast, severe damage observed in newer buildings was more closely related to structural system inadequacy and implementation-related shortcomings, such as low shear-wall ratios, inconvenient wall distribution within the plan, and deficiencies arising from construction quality and site supervision. The findings demonstrate that, while successive improvements in seismic regulations have significantly enhanced design requirements, satisfactory earthquake performance cannot be ensured by code-compliant design alone under extreme near-fault shaking. Instead, structural performance is strongly influenced by system-level adequacy, execution quality, and site conditions. The study provides field-based evidence highlighting the need to strengthen not only seismic design provisions but also implementation practices, construction control, and site-sensitive decision-making to improve earthquake resilience in Türkiye.
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Status: open (until 18 Aug 2026)
- RC1: 'Comment on egusphere-2026-3178', Anonymous Referee #1, 30 Jun 2026 reply
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RC2: 'Comment on egusphere-2026-3178', Anonymous Referee #2, 01 Jul 2026
reply
Title: 2023 Kahramanmaraş Earthquake Doublet: Seismic Performance of RC Buildings, Code Implications and Geotechnical Evaluation
The manuscript presents field observations regarding reinforced concrete (RC) building performance following the 6 February 2023 Kahramanmaraş earthquake sequence. The paper combines structural damage mechanisms with geotechnical observations obtained from several affected provinces. The topic is highly relevant because the Kahramanmaraş earthquakes constitute one of the largest modern earthquake disasters worldwide, and documenting observed failures is valuable for future seismic design. However, in its current form the manuscript resembles a well-illustrated field report rather than a scientific research article. Most conclusions are descriptive and many of the presented damage mechanisms have already been extensively documented in the post-earthquake literature. Consequently, the scientific novelty remains limited. Before publication, the manuscript requires substantial revisions regarding methodology, scientific contribution, interpretation of observations, and quantitative support for the conclusions. The following suggestions will contribute to the authors' improvement of the article.
- The manuscript mainly summarizes column failures, soft-story collapse, pounding, torsional effects, liquefaction, settlement, and landslides, all of which have already been extensively documented in previous studies following the 2023 Kahramanmaraş earthquakes. Although the authors repeatedly state that they compare "older" and "newer" buildings, this comparison remains largely qualitative. Therefore, the manuscript should clearly demonstrate what new scientific insights this study provides beyond the existing post-earthquake reconnaissance literature. At present, this aspect is not sufficiently addressed.
- The Methods section is insufficiently detailed. Although the authors mention conducting field surveys, they do not provide essential methodological information, such as the number of inspected buildings, selection criteria, survey dates, inspection protocol, building age classification, damage classification criteria, sampling strategy, inter-investigator consistency, or uncertainty assessment. Without these details, the study cannot be reproduced or its robustness adequately evaluated.
- Throughout the manuscript, the authors use terms such as older buildings, newer buildings, and code-era buildings without providing clear definitions. The criteria used to distinguish these categories should be explicitly stated. For example, which construction years define each category? Which version of the Turkish Seismic Code applies to each group? Are these classifications based on construction records, occupancy permits, or field estimates? Without objective and reproducible definitions, the comparison between building categories remains subjective.
- Nearly all conclusions are descriptive and lack quantitative support. The manuscript would be considerably strengthened by including quantitative analyses, such as the percentage of buildings exhibiting each failure mode, the frequency of soft-story failures, the proportion of damaged newer versus older buildings, statistical comparisons, GIS-based spatial analyses, the relationship between damage and site class, correlations with PGA and PGV, and the relationship between damage and distance from the fault. At present, the conclusions are not sufficiently supported by quantitative or statistical evidence.
- Section 3.1 discusses the recorded response spectra; however, the manuscript does not establish a clear link between the observed building damage and the corresponding nearby strong-motion stations. This weakens the interpretation of the observed damage mechanisms. The discussion would be considerably strengthened by relating each representative building (or study area) to the nearest strong-motion station, together with the corresponding spectral demand, PGA/PGV values, and the observed failure mechanisms.
- The geotechnical section is primarily based on field photographs and qualitative observations, while quantitative geotechnical data are largely absent. Essential information, such as borehole logs, groundwater table depth, SPT and CPT data, Vs30 values, soil classification, liquefaction susceptibility analyses, and settlement estimates, is not presented. Without these supporting data, several geotechnical interpretations are insufficiently substantiated and remain largely qualitative.
- Several statements imply direct cause-and-effect relationships, such as attributing damage to liquefaction or to low shear-wall ratios, without providing sufficient engineering evidence. Field observations alone are generally insufficient to establish causality. The authors should adopt more cautious language throughout the manuscript. For example, expressions such as "may have contributed to" or "is likely associated with" would be more appropriate than definitive statements such as "caused" or "led to."
- The discussion mostly repeats observations. A proper discussion should compare findings with previous Kahramanmaraş studies, Christchurch, Kobe, Wenchuan, Türkiye earthquake experience, recent code developments.
- The conclusions largely repeat well-known engineering recommendations. The authors should instead summarize new findings, quantitative evidence, engineering implications, limitations.
- The abstract claims newer buildings failed mainly because of structural system inadequacy. This statement requires quantitative evidence.
- The introduction is generally well organized. However, it overemphasizes literature review while insufficiently defining the research gap.
- Figure 2 - The caption contains a grammatical error. "The effected area" should be "The affected area"
- Some section titles could be improved. For example, "Geotechnical Evaluation" could become "Influence of Geotechnical Conditions on Observed Damage"
- Several grammatical issues should be corrected. Examples, "the affected area" "the affected area", "missing of an adequate seismic separation gap" "absence of an adequate seismic separation gap", "low bearing capacity of soil" "low soil bearing capacity" "inconvenient wall distribution" "unfavourable wall distribution"
- Figures - The manuscript contains a very large number of photographs. Several figures appear repetitive. The paper would benefit from fewer figures, more interpretation
- the manuscript would benefit from citing additional international post-earthquake reconnaissance studies.
Citation: https://doi.org/10.5194/egusphere-2026-3178-RC2 -
RC3: 'Comment on egusphere-2026-3178', Anonymous Referee #3, 02 Jul 2026
reply
his manuscript presents a comprehensive and well-structured field-based investigation of the seismic performance of reinforced concrete buildings affected by the 2023 Kahramanmaraş earthquake sequence. The study combines structural and geotechnical observations from a large affected region and provides valuable insights into the behavior of both older and newer reinforced concrete buildings under extreme near-fault ground motions.
The manuscript is clearly organized, and the objectives, methodology, results, and conclusions are logically presented. The comparison between conventional damage mechanisms in older buildings and the emerging vulnerabilities observed in modern code-era buildings is particularly valuable. The integration of structural engineering and geotechnical evaluations offers a comprehensive perspective that enhances the scientific contribution of the work.
The field observations are extensive and are supported by high-quality photographic documentation and an up-to-date review of the relevant literature. The discussion effectively relates the observed damage mechanisms to seismic design practice, construction quality, and implementation issues, leading to meaningful engineering implications for future seismic resilience.
Overall, the manuscript represents a significant contribution to post-earthquake reconnaissance literature and provides important lessons for seismic design, construction practice, and disaster mitigation. The study is technically sound, scientifically rigorous, and suitable for publication in its current form.
Citation: https://doi.org/10.5194/egusphere-2026-3178-RC3 -
RC4: 'Comment on egusphere-2026-3178', Anonymous Referee #4, 08 Jul 2026
reply
This study examines the seismic performance of reinforced concrete (RC) buildings by comparing damage mechanisms between old and new (regulation period) building stocks, based on field observations conducted in 11 different cities following the February 6, 2023 Kahramanmaraş twin earthquakes. Given the magnitude of the earthquake, the breadth of field data, and its approach to both structural and geotechnical issues, this study has the potential to contribute to the literature. However, in its current form, the study is more of a comprehensive field observation report than a scientific paper. I believe that article needs revisions. Suggested revisions;
The readability and resolution of the figures need to be improved.
The abstract should be rewritten to better represent this study, rather than simply detailing the research conducted on this earthquake.
In the introduction, it will be useful to highlight the importance and necessity of the study, especially in light of the destructive impact of seismic activity and the devastating earthquakes that have occurred worldwide. In order to reveal the importance of the study, it would be useful to add the effects of the major destructive earthquakes that have occurred in the world in recent years on the structures to the beginning of the introduction section. Thus, the importance of the study can be revealed more clearly.
It is important to include current literature in the article, taking into account the main topics considered in this study. In this way, the novelty/difference of your study can be more clearly demonstrated. For example, there are numerous recent studies that examine in detail the damage occurring in reinforced concrete structures. (Hatay, Adıyaman, Kahramanmaraş, Malatya, Gaziantep, Adana, Gölbaşı, Elbistan, Pazarcık etc.). There are also many current studies comparing ground motion characteristics and PGA values, and their effects on target displacements in RC structures. And there are many studies that have been done using building examples in the field. The majority of the references considered in this study belong to the authors. The self-citation rate should be checked.
A very large portion of the introduction needs to be moved to section 2.1. Therefore, the introduction needs to be completely redesigned.
The introduction should include a definition of the problem and a description of the direct and indirect studies conducted on this topic.
The stages of the study should be added in detail at the end of the introduction.
There are many studies on the Kahramanmaraş earthquakes. Please add a comparative analysis of how your study differs/is novel compared to other studies at the end of the introduction.
More theoretical information about the figures should be added, and the results should be included in more detail after the figure.
2018 Turkish Seismic Code (TSC-2018). This must be Turkish Building Earthquake Code.
This large-scale study conducted in 11 cities lacks precise information on the exact number of buildings examined and the approximate classification of these buildings as new and old. At the very least, a numerical or percentage distribution table should be provided for the buildings examined, categorized by type.
Figure 3 compares seismic demand with TSC-2018 (Turkish Building Earthquake Code) design spectra. However, the soil classifications (ZA, ZB, ZC, etc.) of the station data (Stations 4614 and 4612) and the seismic distances of the buildings from these stations should be clearly presented in the text and/or on the figure.
It should be clearly distinguished which regulatory period "old" buildings belong to (1975, 1998, etc.), and whether "new" buildings are directly subject to the 2018 regulation or the 2007 regulation. Examining the causes of damage according to the regulatory boundary lines will increase academic depth.
In Figure 1, Base map data from (https://tadas.afad.gov.tr) contributors created by Onur Onat is not required. This is already stated in the figure caption.
The article should include sample size, observation criteria, and evaluation method.
The Discussion and Conclusion sections are largely identical. Please revise them.
The maps need to be improved from an academic perspective; they are too simplistic.
Citation: https://doi.org/10.5194/egusphere-2026-3178-RC4
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I think the submitted article has enough novelty for potential consideration. My comments for minor revision:
English language needs polishing – awkward phrasing and preposition errors throughout (e.g., "subjected to" vs. "exposed to").
Hyphenation is inconsistent ("near- fault," "near-fault," "post earthquake," "post-earthquake") – standardize throughout.
Abstract: change "subjected" to "exposed" and "demand" to "demands" (plural).
Keywords are awkward – revise to: "Kahramanmaraş earthquakes; reinforced concrete damage patterns; damage classification in new buildings; soil amplification effects."
Define "code-era" clearly – specify which Turkish code versions (post-1998, 2007, or 2018).
Figure references vary ("Figure" vs. "Fig.") – standardize to one format.
Line 103: "dominant and several structural" is confusing – revise to "dominant structural and geotechnical damage patterns."
Line 159: "loose bearing capacity of soil due to high ground water table" – rephrase to "loose soils with high groundwater tables reducing bearing capacity."
Line 211: "inadequate lap splice regions" – change to "inadequately detailed lap splice regions" or "insufficient lap splice lengths."
Line 374: "such mechanisms reflect" – change to "such mechanisms are characteristic of" for better flow.
Line 390: add "ensuring" – "toward ensuring system-level adequacy."
Line 408: change "site-sensitive" to "site-specific" – standard term.
Conclusion, Line 450: rephrase to "moving beyond code-based approaches and adopting integrated frameworks."
Conclusion, Line 454: change "in" to "for" – "intervention for vulnerable existing building stock."
Title is too long – consider shortening.
Mention approximate number of buildings surveyed to contextualize representativeness.
British vs. American English inconsistency ("storey" vs. "story") – choose one and stick to it.
Formatting gap on Page 9 (blank lines) – fix.
Some references lack complete details (e.g., Tura et al., 2024) – verify all.
Add a brief note on methodological limitations already acknowledged – but make it more prominent in the conclusions.