Blast Resistant Design

Single Abstract

338294 - Fragility analysis of girder bridges subjected to blast load

Saturday, April 21
8:00 AM - 9:30 AM
Location: 202CD

The occurring frequency of blast attacks increases significantly after 2001 as referred from the global trend. Bridges which are the important transportation infrastructures may become attractive targets because of their easy accessibility as well as the devastating consequence on society when damaged. Besides, blast caused by transportation vehicles which carry dangerous explosives due to collision and overturn happens frequently. However, blast hasn’t been considered carefully in design codes, and specific structural requirements on antiknock capacity of bridge components have not been put forward. Therefore, blast becomes a potential threat for normal serviceability of bridges. Under the above background, this paper have conducted fragility analysis of girder bridges subjected to blast load through numerical simulation. Dynamic behavior of bridge components under various loading scenarios has been observed, and componential and systematic fragility of girder bridges are assessed. Specific works in the research are listed here:

1. In this paper, considering one simply supported girder bridge as the prototype, 3D numerical bridge model is being built with the help of ANSYS/LS-DYNA. Key parameters such as section shape of main girder and pier, equivalent amount of TNT, explosive locations and feasible protective measures are analyzed considering displacement, element equivalent stress and internal forces of essential bridge components as index to comprehensively explore the dynamic character of girder bridges subjected to blast impact. Behavior of each components is investigated separately with ignorance of effect from some subsidiary facilities, for instance, the guardrail.

2. Various damage patterns of girder bridges subjected to shockwave array and close range explosion have been studied, and a number of available protective measures including increasing of reinforcement ratio, adding FRP paste layer and foam aluminum sacrificial layer for critical components have been put forward. In order to estimate the effectiveness of these measures, comparative analysis has been conducted adopting vibration amplitude of main girder under the above blasting scenarios as assessment criteria.

3. In the research, feasible damage index is established based on damage condition of bridge components under certain loading scenario. Evaluation criteria to estimate damage order of severity have been determined and quantifiable vulnerable safety degree value can be given. Considering the overpressure peak of shockwave as abscissa and structural exceedance probability as ordinate, fragility curves of selected components are generated based on the probabilistic seismic demand model and fragility function. In addition, systematic fragility curves of the whole bridge have been produced by Monte Carlo (MC) simulation method with consideration of the correlation between components.

This research shows the sensitivity of different structural components to explosive load and effectiveness of possible protective measures. Besides, results in this paper could be used in cost-effective retrofit of bridge structures and provide significant theoretical and experimental basis for comprehensive protection and support.

Keywords: Fragility analysis, Girder bridges, Blast Load, Parametric analysis, Protective measures, Exceedance probability

Jingyu Wang

Student
Tongji University

1. Sep. 2015–Present: Tongji University, Shanghai, China
PhD Student: Department of Civil Engineering
Expected Graduation: Spring 2021
2. Sep. 2016-Feb. 2017: Ecole Centrale de Paris, Paris, France
Exchange Student: Department of General Engineering
3. Sep. 2011–June. 2015: Tongji University, Shanghai, China
Bachelor of Civil Engineering: Department of Civil Engineering
4. Research Direction:
Disaster mitigation and reduction for bridge structures, especially fragility assessment of bridges subjected to blast load and earthquake.

Presentation(s):

Send Email for Jingyu Wang

Junya Yu

Tongji University

n/a

Presentation(s):

Send Email for Junya Yu

Wancheng Yuan

Prof.
Tongji University

1.Education:
09, 1987 – 12, 1990 Tongji University
PhD in Bridge Engineering
Spatial Nonlinear Seismic Response Analysis of Long-Span Bridges
09, 1984 – 06, 1987 Tongji University
MS in Bridge Engineering
Research on Bridge Seismic Isolation
09, 1980 – 06, 1984 Tongji University
BS in Civil Engineering

2.Work Experience:
12, 1994 – Present Department of Bridge Engineering, Tongji University
No. 1239, Siping Road, Shanghai 200092, China
Professor
05, 1997 – 12, 1997 Department of Civil Engineering, Hong Kong University of Science & Technology
Clear Water Bay, Kowloon, Hong Kong
Visiting Professor
04, 1994 – 11, 1994 Department of Bridge Engineering, Tongji University
No. 1239, Siping Road, Shanghai 200092, China
Associate Professor
04, 1991 – 03, 1994 Department of Bridge Engineering, Tongji University
No. 1239, Siping Road, Shanghai 200092, China
Lecturer
10, 1993 – 05, 1994 Concrete Institute, Technical University Darmstadt
Karolinenplatz 5, 64289 Darmstadt, Germany
Visiting Professor
12, 1990 – 03, 1991 Department of Bridge Engineering, Tongji University
No. 1239, Siping Road, Shanghai 200092, China
Teaching Assistant

Presentation(s):

Send Email for Wancheng Yuan


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