scholarly journals Effect of earthquake and progressive collapse potential of rc frame structure: with and without the involvement of infill wall stiffness

2019 ◽  
Vol 2019 ◽  
pp. 1-18
Author(s):  
Guang Yang ◽  
Erfeng Zhao ◽  
Xiaoya Li ◽  
Emad Norouzzadeh Tochaei ◽  
Kan Kan ◽  
...  

The reinforced concrete (RC) frame with masonry infill wall is one of the most common structural systems in many countries. It has been widely recognized that the infill wall has significant effects on the seismic performance of RC frame structure. During the Wenchuan earthquake (China 2008), a lot of infilled RC frame structures suffered serious damages due to the detrimental effects brought about by the infill wall rigidly connected to the surrounding frame. In order to solve this problem, flexible connection, introduced by Chinese designers, is recommended by the updated Chinese seismic design code, because of its effect to reduce the unfavorable interaction between infill wall and frame. Although infilled RC frame structure with flexible connection has a lot of advantages, but because of the lack of research, this structure type is seldom used in practical engineering. Therefore, it is of great significance to scientifically investigate and analyze the effects of flexible connection on structure behaviors of infilled RC frame. In this study, a macrofinite element numerical simulation method for infilled RC frame with flexible connection was investigated. Firstly, the effects of connection between infill wall and surrounding frame on in-plane behaviors of infilled RC frame were discussed. Secondly, based on deeply studying the equivalent diagonal strut models for infilled RC frame with rigid connection, an improved equivalent diagonal strut model for infilled RC frame with flexible connection was proposed. Employed with inversion analysis theory, the parameter in the proposed model was estimated through artificial fish swarm algorithm. Finally, applied with the existing experiment results, a case study was conducted to verify the effectiveness and feasibility of the proposed model.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Wenming Wang

The strain rate effect can influence the seismic responses of reinforced concrete (RC) structures because the constitutive relationship of concrete and rebar is rate-dependent. This paper carries out progressive collapse analysis to research the influence of strain rate effects on collapse-resistant capacity, collapse mode, and collapse path of the RC frame structure. A progressive collapse simulation program for the reinforced concrete (RC) structure with a static and dynamic constitutive relationship is coded individually using the user subroutine VUMAT and then implemented in the advanced finite element program ABAQUS. The good agreement between experimental and simulation results proves that the coded subroutine is reliable. With the coded subroutine, by conducting progressive collapse analyses of a four-story RC frame structure under earthquake, the effect of strain rate on the response is investigated. The numerical results demonstrate that the collapse-resistant capacity of the structure is underestimated when the strain rate effect is neglected. It is shown that strain rate effects influence the collapse mode and collapse path of the structure. Therefore, strain rate effects should be considered in the progressive collapse analysis of the RC frame structure.


2013 ◽  
Vol 470 ◽  
pp. 1097-1100
Author(s):  
Bing Bing Tu ◽  
Dong Zhao

To illustrate the changes of important components during progressive collapse, this paper sums up the judgment method for important components. Based on the alternate path method and the concept of sensitivity analysis, we determine the key component of a RC frame structure. Then the changes of important components during progressive collapse are given. The results show that the location of key components changing with the structure damage in the process of progressive collapse.


2012 ◽  
Vol 204-208 ◽  
pp. 1286-1289
Author(s):  
Soo Yeon Seo ◽  
Jeong Hun Kim ◽  
Jae Yeong Yeon ◽  
Hyung Joo Park ◽  
Ki Bong Choi

In this study, a push down analysis was performed for reinforced concrete (RC) frame building with collapsed column at lower floor by shock due to abnormal load in order to find progressive collapse process of building. The nonlinear flexural behavior of each structural element was defined from sectional analysis by using X-tract program. For push-down analysis of frame structure, Zeus-NL program was used. Main parameters in the analysis are location of damaged column and story of building. As a result, the deflection at the time of collapse of internal column was lower than one at the time of collapse of external column. In the frame structure with severely damaged column at lower floor, the higher the story was, the smaller the change of moment in beams at upper floors was. And, deflections of beams were found to appear evenly. This can be judged to be caused by a beam's suspension action.


2014 ◽  
Vol 578-579 ◽  
pp. 1353-1356
Author(s):  
Liu Lei Shen ◽  
Qi Gao Hu ◽  
Fan Zhen Zhang

A progressive collapse of a RC frame structure may be initiated by an event that damages one member of the structure. FRP is widely used in the field of structural reinforcement for its high strength ratio, convenient construction and corrosion resistance. In this paper, the collapse scene of a RC frame specimen with the failure mid-column in three programs has been simulated by LS-DYNA. We can infer the ultimate bearing capacity of the structure is raised about 10% (retrofitted by CFRP), 15% (retrofitted by GFRP) by comparing the results of finite element analysis.


2011 ◽  
Vol 255-260 ◽  
pp. 644-648
Author(s):  
Yan Xia Ye ◽  
Hua Huang ◽  
Dong Wei Li

Comparative analyses of twenty-eight finite element structures with filler walls were established to study dynamic characteristics of RC frame structures under seismic waves. The results of these analyses show that filler walls have little influence on vibration modes of the structure. But as a result of soft storey in the bottom of building caused by reduction of the filler walls, vibration modes have a great influence. As the stiffness of filler wall decrease, the stiffness of soft storey decrease shapely, vibration mode curve becomes much smoother. Considering the filler wall has influence on the vibration periods of framework, the reduction factor of 0.7 should be taken. The influence of filler wall to the value of lateral drift and storey displacement angle of frame can not be ignored. The main effect factors to the dynamic characteristics of framework are included quantity, location, material of the fill wall and the selection of seismic waves.


2014 ◽  
Vol 556-562 ◽  
pp. 712-715
Author(s):  
Jing Zhao ◽  
Jing Zhao ◽  
Xing Wang Liu

In collapse-resistant design of a structure under accidental local action, it is important to understand the failure mechanism and alternative load paths. In this paper, a pseudo-static experimental method is proposed. Based on which, the collapse of frame structure was simulated with testing a 1/3 scale; 4-bay and 3-story plane reinforced concrete frame. In the experience, the middle column of the bottom floor was replaced by mechanical jacks to simulate its failure, and the simulated superstructure’s gravity load acted on the column of the top floor by adopting a servo-hydraulic actuator with force –controlled mode.


2012 ◽  
Vol 568 ◽  
pp. 85-88
Author(s):  
Ming Gao

In 5·12 Wenchuan earthquake, most of the buildings were damaged at different degrees in Mianyang. To analysis seismic damage of RC frame structure building, and investigate its reinforcement situation,the results show that: For destruction of frame column or bottom frame structure column, enlarge section method is used mostly for reinforcement in civil engineering;To serious damage of affiliated structure such as filler wall and Parapet, most of them will be demolished and built again, and add constructional column; To the situation of concrete bottom plate with crack, paste carbon fiber sheet or bottom plant steel was used depending on the structural damage degree, and jet concrete for strengthening.


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