Assessment of Design and Retrofitting Solutions on the Progressive Collapse of Hongqi Bridge

Amir Seyed Khoei,Alireza Gharighoran,Reza Akbari,Shahrokh Maalek

doi:10.1155/2020/4932721

Abstract

In 2009, the Hongqi Bridge, a multispan reinforced concrete bridge located in Zhuzhou, Hunan Province, China, collapsed progressively in the form of domino, due to extreme effect of deck to pier, during demolition process of the bridge. In this study, progressive collapse of Hongqi Bridge was investigated using nonlinear dynamic analysis in the Applied Element Method, which has been proven as one of the best methods that can follow the collapse behavior of structures. Good agreements were obtained between numerical results and field observations as well as previously reported results. After verifying the bridge collapse procedure, the effects of different alternatives for superstructure and substructure systems on the progressive collapse procedure were investigated. In addition, application of restrainers at the connection of deck to abutment was studied as an effective solution in order to prevent collapse propagation and to minimize associated damages. The results of the study showed that all chosen methods and factors could be helpful and effective in the procedure of collapse propagation for this kind of bridge.

Highlights

Progressive collapse (PC) is defined as an extension of a local failure in a structure from one element to another, resulting in the collapse of the whole or a large part of the structure [1]
Bridge hangers were failed and subsequent failure of stiffening plates of longitudinal beams was determined as the main reason for the bridge collapse [7]. e Silver Bridge, an eyebar-chain suspension bridge in Ohio, USA, collapsed without any alarm after 40 years of service in December 1967 because of the failure of an eyebar in a joint of the north eyebar suspension chain [7]. e Viadotto Cannavino Bridge, a four-span continuous girder bridge in Italy, collapsed progressively in 1972 during construction, after the failure of the bridge deck molds in some regions [8]. e Haengju Bridge, a continuous prestressed bridge in Seoul, South Korea, collapsed in 1992 when it was under construction
Regarding the importance and application of PC analysis for the assessment of the behavior of bridges against different loading conditions, in this study, domino-type progressive collapse of Hongqi Bridge was investigated by nonlinear dynamic analysis using Applied Element Method (AEM). e simulated collapse procedure of the bridge that occurred due to inaccurate mechanical demolition method was compared with the results of finite element simulation and field observations

Summary

Introduction

Progressive collapse (PC) is defined as an extension of a local failure in a structure from one element to another, resulting in the collapse of the whole or a large part of the structure [1]. Salem and Helmy investigated the cause of I-35 bridge collapse using AEM and developed the bridge model by considering all structural details and loading condition at the time of the collapse. Regarding the importance and application of PC analysis for the assessment of the behavior of bridges against different loading conditions, in this study, domino-type progressive collapse of Hongqi Bridge was investigated by nonlinear dynamic analysis using AEM. Us, it has been proven to be the best method that can follow collapse behavior of a structure under dynamic analysis through all stages of material behavior such as linear behavior, start and propagation of crack in tension-weak materials, yielding of reinforcement, separation of adjacent element, and collision (contact) of separated element with neighboring structures or ground [18]. Steel reinforcement spring rupture in failure strain is defined for steel material

The Bridge under Study

Effects of Different Structural Systems on PC

Conclusion