International Journal of Structural Engineering (4 papers in press)

Regular Issues

• Study on the mechanical behaviour of assembly prestressed reinforced structure and shield lining composite system  
  by Fengbin Su, Yi Liu, Kai Wang, Huan Pang, Meng Chen 
  Abstract: Internal reinforcement technology is an important method for controlling deformation of shield tunnels However, existing internal reinforcement technologies fail to balance strengthening efficiency with economic feasibility, which also hinder the detection of cracks and water leakage This paper innovatively proposes a design approach of assembly prestressed reinforced structure (APRS) to solve the existing problems A full-size numerical model of APRS and shield lining composite system is established by using ABAQUS In the selection of prestressed types, the reinforcement efficiency is the highest when the vault member is set to tensile stress and the arch waist member is set to compressive stress Regarding the determination of prestressing magnitude, strengthening efficiency is proportional to the prestressing value, and the optimal limit of prestress setting is 50 MPa Moreover, strengthening efficiency of unit steel quantity of the APRS is 2 2 times that of the steel bonding reinforcement structure, demonstrating superior economic efficiency.
  Keywords: assembly prestressed reinforced structure; strengthening efficiency; upgrade rate; mechanical behavior.
  DOI: 10.1504/IJSTRUCTE.2025.10071331
   
  
• Towards identification of long-term building defects using transfer learning  
  by Aravinda Boovaraghavan, Christy Jackson Joshua, Abdul Quadir Md, Kong Fah Tee, V. Sivakumar 
  Abstract: Detecting long-term issues on various types of building wall surfaces, such as cracks, flakes, and roofs, is vital for timely maintenance and repairs before they become too risky and expensive. Currently, building managers manually assess the building conditions to survey and communicate the state of their buildings. However, this manual process is subjective, often leads to inaccuracies, and is time-consuming; thus, it needs to be more efficient. These flaws can severely influence a buildings structural stability if they go undiscovered and ignored. In this context, this study proposes an approach named towards identification of long-term building defects using transfer learning (TILT) to identify unnoticed defects such as cracks, flakes, and roofs robustly and accurately in buildings. The proposed model has been tested using images taken from real-world onsite deployments, and the types of construction issues have been determined with 98.33% accuracy predicted by the VGG16 model and 79.13% accuracy predicted by the ResNet50 model. Overall, the VGG16 model gives better results compared to ResNet50.
  Keywords: structural health monitoring; damage detection; building defects; classification; transfer learning; VGG16; ResNet50.
  DOI: 10.1504/IJSTRUCTE.2025.10071335
   
  
• Advanced computational approaches to multi-blast scenario analysis: insights into assessing vulnerabilities in multi-span masonry arch bridges  
  by Amin Bagherzadeh Azar, Ali Sari 
  Abstract: Bridges are critical components of transportation infrastructure and are increasingly vulnerable to intentional or accidental blast events. This study investigates the structural response and damage mechanisms of bridge systems under two distinct blast scenarios: above-deck and below-deck explosions. Using the Coupled Eulerian-Lagrangian (CEL) approach in finite element analysis, the complex interactions between the blast wave and bridge structure are accurately modelled. To enhance the realism of the simulations, a custom VUMAT subroutine is developed to define advanced material properties, including strain rate dependency and progressive failure criteria under high strain rates. The results reveal significant variations in the structural response between above-deck and below-deck blasts, with the latter causing more severe damage to critical load-bearing components, such as the deck slab and all components. Stress wave propagation, localised failure patterns, and overall bridge stability are analysed in detail for both scenarios. This research provides new insights into the dynamic behaviour of bridges under dual blast scenarios and offers a comprehensive framework for improving their safety and resilience against explosive threats. The integration of advanced computational modelling techniques and customised material behaviour codes underscores the potential for more accurate predictions in blast-induced damage assessments.
  Keywords: blast; bridges; numerical simulation; FE analysis; historical bridges.
  DOI: 10.1504/IJSTRUCTE.2025.10071350
   
  
• The impact of colloidal nanosilica on concrete performance: compressive strength, ductility, and microstructural analysis  
  by Mahmoud Malakouti Oloun Abadi, Sajjad Mousavi, Mojtaba Aslami, Seyed Shaker Hashemi, Abdoreza Fazeli 
  Abstract: In this study, we investigate the effects of colloidal nanosilica on the compressive behaviour and ductility of concrete. The primary objective is to understand how varying percentages of colloidal nanosilica, influence the mechanical properties and microstructure of concrete over different curing periods. The methodology involves preparing concrete specimens with specified nanosilica content and conducting comprehensive tests, including compressive strength, field emission scanning electron microscopy, and X-ray diffraction analysis. Key findings indicate that while the incorporation of colloidal nanosilica generally reduces the compressive strength of concrete, it significantly enhances its ductility. For instance, at seven days, the ductility increases by 26%, 36%, and 65% for samples containing 5%, 10%, and 15% nanosilica, respectively. The FESEM analysis reveals that nanosilica improves the microstructure by reducing porosity and promoting pozzolanic reactions. However, higher nanosilica content results in an irregular nanoparticle structure, contributing to the reduced compressive strength.
  Keywords: colloidal nanosilica; concrete ductility; compressive strength; microstructure improvement.
  DOI: 10.1504/IJSTRUCTE.2025.10071351