Numerical investigation on degradation mechanism of reinforced concrete structures under close-in explosion

• Published in: Advances in structural engineering Vol. 28; no. 9; pp. 1610 - 1626
• Main Authors: Jiang, Ren, Shi, Yanchao, Zhong, Bo, Zhuang, Haiyang
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.07.2025
• Subjects: progressive collapse; Blast load; degradation mechanism; reinforced concrete substructure; damage assessment
• ISSN: 1369-4332; 2048-4011
• DOI: 10.1177/13694332251313865

In current practice, the analysis of progressive collapse in building structures widely employs the alternate load path method. However, there are very few collapse tests that can be utilized under blast loads, especially for investigating the degradation mechanism of progressive collapse resistance in post-blast building structures. In this study, the degradation mechanisms and methods for damage assessment of reinforced concrete structures under blast loads were investigated through numerical analysis. A substructure model derived from explosion loads based on a drop-hammer testing machine was validated by comparing with test results, and the established model accurately captured three typical failure modes in the substructure columns and confirmed the axial tensile effects of the columns on the adjacent components. A substructure damage assessment method was used to assess the degree of damage in a 5-story reinforced concrete frame structure under different explosion scenarios. The results show that the degree of damage distribution of the reinforced concrete frame structure exhibited an S-shaped distribution under corner column blast scenarios while an arch-shaped distribution was observed for middle column blast scenarios. Furthermore, empirical formulas based on the explosive mass and distance (M-R) curves were established. These empirical formulas can help to rapidly predict the damage levels of RC frame structures for a given explosion scenario within a certain scope.