Vol.41/No.2(160)(2026)

第四十一卷第二期 (期別160) (115年)

Title

 

Shear Strength
Prediction of Shear Walls With Different Shapes in Reinforced Concrete Dual
Systems
Author

 

Yu-Che Ling ,
Shyh-Jiann Hwang
Keywords

 

shear strength,
reinforced concrete, shear wall, various shapes, strut-and-tie model, dual
system
Abstract  
Accurate shear strength prediction of reinforced concrete (RC) squat walls with different shapes is critical for structural safety and design in RC buildings using dual systems. However, wall shear strength equation in current Design Specifications for Concrete Structures (Civil 401- 112) exhibits significant scatter due to lack of a rational force transfer mechanism and limited parameter considerations. This study develops an analytical model based on the softened strutand-tie (SST) approach to improve shear strength predictions. A simplified equation for the concrete strut area is derived through curve approximation, enhancing computational efficiency of the SST model while maintaining accuracy. The proposed SST model is validated using experimental data from 281 squat walls, including rectangular, barbell, and flanged walls, and this study further presents a closer look into Civil 401-112 and American Concrete Institute (ACI) 318-25 code equations. Results show that the proposed model achieves competitive accuracy in both general shear strength and maximum shear strength predictions, offering a robust and mechanics-based model for wall shear capacity estimation.
Title Deep Learning–Based Post-Earthquake Building Damage Classification Enhanced by Collapse Simulation
Author

 

Cheng-Jen Hou,
Bao-Tian Chiang, Tsung-Chin Hou
Keywords

 

building collapse
simulation, deep learning, synthetic data, PointNet, point cloud
Abstract  
Taiwan, located in the Pacific Ring of Fire, experiences frequent earthquakes that pose significant risks to urban buildings. Conventional post-earthquake building damage assessment primarily relies on manual field inspections, which are time-consuming, costly, hazardous, and often subject to human judgment. To address these limitations and the scarcity of real-world damage data, this study proposes an automated post-earthquake building damage classification framework that integrates physics-based collapse simulation with deep learning. A simulationdriven data generation workflow is developed using the open-source 3D software Blender coupled with the bullet constraints builder (BCB) physics engine. Based on the discrete element method (DEM), large-scale synthetic point cloud datasets with explicit physical attributes are generated and manually labeled in accordance with established domestic and international standards for post-disaster assessment. For automated damage classification, the PointNet deep learning architecture is adopted, and K-fold cross-validation is applied to ensure robust model training and evaluation. Experimental results show that the proposed model achieves an average classification accuracy exceeding 95.00% on validation datasets structurally consistent with the training data. Moreover, an accuracy of 86.67% is maintained on an independent test dataset, indicating promising generalization capability and knowledge transfer potential. The results demonstrate the feasibility of combining synthetic collapse simulation data with deep learning for the automated assessment of post-earthquake building damage. The proposed framework offers a scalable, costeffective, and automation-oriented solution that supports rapid post-disaster decision-making and enhances the digitalization of structural damage assessment workflows.
Title  Soft Retrofit─A Simple Interior Seismic Retrofit Method and Evaluation Model for RC Frame Structures
Author

 

Yi-Hsuan Tu ,
Fong-Duo Chen, Wei-Chun Lian, Chun-Jung Lin
Keywords

 

reinforced
concrete, seismic retrofit, seismic assessment, soft first story
Abstract  
This study proposes a simple seismic retrofit method for typical low-rise street-houses in Taiwan by attaching steel members to reinforced concrete (RC) frames with chemical anchors. Full-scale column and frame cyclic lateral loading tests were conducted to verify its feasibility and effectiveness. Two connection types of retrofitting steel members were designed: compression connections and moment connections. Test results indicate that both significantly enhance the lateral stiffness and strength of retrofitted structures, effectively mitigating the common softfirst-story problem in street-houses. While moment connections provide higher strength with some potential reduction in ductility, compression connections yield slightly lower strength but maintain ductility and reduce anchorage demands on beam bottoms. The method requires no foundation excavation, can be installed entirely within the frame, and minimizes cost, time, and user disruption. A pushover analysis model and a simplified strength estimation method were also developed and validated, providing reliable tools for practical seismic assessment.
Title

 

Investigating the
Shear Resistance of RC T-Beams Retrofitted With CFRP Strings: Experimental
Observations and Analytical Evaluation
Author

 

Banu Ardi Hidayat,
Hsuan-Teh Hu1, Fu-Pei Hsiao, Muhammad Amirul Chanif Rizaldi, Salfarras
Rafliandra Aqil, Sri Tudjono, Bobby Rio Indriyantho , Yanuar Haryanto,
Laurencius Nugroho
Keywords

 

shear
strengthening, CFRP, NSM, shear capacity, failure
Abstract  
Existing reinforced concrete (RC) structures frequently demonstrate insufficient shear resistance owing to non-ductile detailing, rendering them vulnerable to brittle failure during seismic events. This study examines the alternative application of carbon fiber-reinforced polymer (CFRP) strings as a novel shear strengthening solution for RC T-beams. The CFRP strings were produced via a pultrusion and resin impregnation process, and thereafter integrated along the beam perimeter utilizing the near surface mounted (NSM) technique. Two beam specimens were subjected to testing under a two-point loading configuration to induce shear-critical behavior. Experimental observations indicated that CFRP string strengthening enhanced shear confinement and postponed diagonal crack propagation, leading to an increase in shear capacity and a significant enhancement in ductility. Analytical evaluation using the Indonesian Standard Code and Zararis’s model revealed that conventional design equations underestimated actual shear capacity, highlighting the necessity for updated formulations for beams with moderate shear span-to-depth ratios. Overall, the results demonstrate that CFRP strings serve as an efficient and lightweight retrofit option for enhancing the shear performance and deformation capacity of RC beams, presenting a sustainable solution for seismic strengthening applications.
Title

 

Behavior and
Modeling of Novel Unbonded Post-Tensioned Precast UHPC Walls
Author

 

Chin-Cheng Lin,
Tzu-Cheng Hsu, Chung-Chan Hung
Keywords

 

unbonded
post-tensioned precast walls, UHPC, damage control, gap-opening,
selfcentering, OpenSees
Abstract  
Unbonded post-tensioned precast walls are recognized for their excellent seismic resilience due to a self-centering ability that minimizes post-earthquake repair needs. While this system offers significant advantages, conventional concrete walls often experience concrete crushing at the corners under large displacements, limiting their performance and axial load capacity. To overcome this limitation, this study investigates the application of ultra-high-performance concrete (UHPC) in unbonded post-tensioned precast walls and evaluates their seismic behavior. Following the design principles outlined in ACI (American Concrete Institute) 550.6 and ACI 550.7, two scaled wall specimens were tested under cyclic loading, one with conventional concrete and one with UHPC. Compared to the conventional concrete wall, The results demonstrate that the UHPC wall exhibited no significant cracking and showed superior self-centering and minimal residual displacement under the same axial load. Digital image correlation (DIC) analysis revealed that the UHPC specimen exhibited a more uniform strain distribution and suppressed compression concentration at the wall corners. The fiber-bridging effect effectively controlled crack propagation, resulting in a stable flexural-dominated response and delayed localized crushing. Overall, the UHPC specimen more effectively satisfied the performance objectives corresponding to the design basis earthquake (DBE) level, indicating enhanced strength and deformation capacity. Furthermore, finite element models of the walls were developed in OpenSees (Open System for Earthquake Engineering Simulation) and validated against the experimental data. These models accurately simulate the load-displacement behavior of unbonded post-tensioned precast walls, providing a reliable tool for future seismic performance assessment.