**Jungwhee Lee, Keunki Choi \* and Chulhun Chung**

Department of Civil & Environmental Engineering, Dankook University, Gyeonggi-do 16890, Korea; jwhee2@dankook.ac.kr (J.L.); chchung5@dankook.ac.kr (C.C.)

**\*** Correspondence: ckk0204@dankook.ac.kr; Tel.: +82-31-8005-3493

Received: 19 October 2020; Accepted: 26 November 2020; Published: 28 November 2020

**Abstract:** Cable-stayed bridges are infrastructure facilities of a highly public nature; therefore, it is essential to ensure operational safety and prompt response in the event of a collapse or damage, which are caused by natural and social disasters. Among social disasters, blast accidents can occur in cable-stayed bridges as a result of explosions produced by vehicle collisions or terrorist attacks; this can lead to the degradation in their structural performances and subsequent collapse. In this research, a procedure to assess structural blast-resistance performance is suggested based on a numerical analysis approach, and the feasibility of the procedure is demonstrated by performing an example assessment. The suggested procedure includes (1) selection of major structural components that severely affect the global structural behavior, (2) set-up blast hazard scenarios consisting of various blast levels and locations, and (3) assessment of the components using numerical blast simulation. By performing an example assessment, the critical blast level for each component could be determined and the blast location that affects the considering components the most severely could be found as well. The scenario-based assessment process employed in this study is expected to facilitate the evaluation of bridge structures under blasts in both existing bridges and future designs.

**Keywords:** cable-stayed bridge; social disaster; blast scenario; blast analysis; LS-DYNA
