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Open AccessArticle
Intelligent Rebar Optimization Framework for Urban Transit Infrastructure: A Case Study of a Diaphragm Wall in a Singapore Mass Rapid Transit Station
by
Daniel Darma Widjaja
Daniel Darma Widjaja 1
and
Sunkuk Kim
Sunkuk Kim 2,*
1
Department of Architectural Engineering, Kyung Hee University, Yongin-si 17104, Republic of Korea
2
Department of R&D, Earth Turbine, Co., Ltd., Daegu 41507, Republic of Korea
*
Author to whom correspondence should be addressed.
Smart Cities 2025, 8(4), 130; https://doi.org/10.3390/smartcities8040130 (registering DOI)
Submission received: 30 June 2025
/
Revised: 1 August 2025
/
Accepted: 6 August 2025
/
Published: 7 August 2025
Abstract
As cities densify, deep underground infrastructure construction such as mass rapid transit (MRT) systems increasingly demand smarter, digitalized, and more sustainable approaches. RC diaphragm walls, essential to these systems, present challenges due to complex rebar configurations, spatial constraints, and high material usage and waste, factors that contribute significantly to carbon emissions. This study presents an AI-assisted rebar optimization framework to improve constructability and reduce waste in MRT-related diaphragm wall construction. The framework integrates the BIM concept with a custom greedy hybrid Python-based metaheuristic algorithm based on the WOA, enabling optimization through special-length rebar allocation and strategic coupler placement. Unlike conventional approaches reliant on stock-length rebars and lap splicing, this approach incorporates constructability constraints and reinforcement continuity into the optimization process. Applied to a high-density MRT project in Singapore, it demonstrated reductions of 19.76% in rebar usage, 84.57% in cutting waste, 17.4% in carbon emissions, and 14.57% in construction cost. By aligning digital intelligence with practical construction requirements, the proposed framework supports smart city goals through resource-efficient practices, construction innovation, and urban infrastructure decarbonization.
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MDPI and ACS Style
Widjaja, D.D.; Kim, S.
Intelligent Rebar Optimization Framework for Urban Transit Infrastructure: A Case Study of a Diaphragm Wall in a Singapore Mass Rapid Transit Station. Smart Cities 2025, 8, 130.
https://doi.org/10.3390/smartcities8040130
AMA Style
Widjaja DD, Kim S.
Intelligent Rebar Optimization Framework for Urban Transit Infrastructure: A Case Study of a Diaphragm Wall in a Singapore Mass Rapid Transit Station. Smart Cities. 2025; 8(4):130.
https://doi.org/10.3390/smartcities8040130
Chicago/Turabian Style
Widjaja, Daniel Darma, and Sunkuk Kim.
2025. "Intelligent Rebar Optimization Framework for Urban Transit Infrastructure: A Case Study of a Diaphragm Wall in a Singapore Mass Rapid Transit Station" Smart Cities 8, no. 4: 130.
https://doi.org/10.3390/smartcities8040130
APA Style
Widjaja, D. D., & Kim, S.
(2025). Intelligent Rebar Optimization Framework for Urban Transit Infrastructure: A Case Study of a Diaphragm Wall in a Singapore Mass Rapid Transit Station. Smart Cities, 8(4), 130.
https://doi.org/10.3390/smartcities8040130
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