scholarly journals Experimental Study on the Progressive Collapse Resistance of Two-Storey Half-Scale Fabricated Reinforced Concrete Column-Steel Beam Composite Frame Structure

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Youquan Liu ◽  
Jingang Xiong ◽  
Jiancong Wen
Keyword(s):  
High Speed ◽  
Progressive Collapse ◽  
Experimental Results ◽  
Frame Structure ◽  
Amplification Coefficient ◽  
Space Frame ◽  
Composite Frame ◽  
Weak Part ◽  
Collapse Resistance ◽  
Composite Frame Structure

Progressive collapse behavior of case-in-place concrete and steel frame structures has been extensively investigated over the past years. However, studies on progressive collapse resistance and characteristics of prefabricated RCS composite frame structure (space frame) are limited. In this study, a half-scale prefabricated RCS space frame structure (two-storey, 1 × 2-bay) was designed and manufactured and then tested through the sudden failure of the long-side central column. The weakened part of failure column was rapidly pulled out using vehicle traction force, and displacement was obtained with a dynamic data acquisition instrument supplemented by high-speed camera to record the deformation process of the structure. Additionally, the remaining structure displacement variation and the beam-to-column connections of fem model under progressive collapse were simulated using SAP2000. The FEA results were compared with the experimental results to verify the effectiveness of the numerical analysis. Experimental results demonstrated that the prefabricated RCS composite frame structure designed in accordance with Chinese building codes shows improved resistance to progressive collapse. The dynamic effect demonstrates no significant influence on the prefabricated RCS composite frame structure, and the suggested dynamic amplification coefficient is 1.28. Steel plates (A, B, and C) of the beam-to-column connection are the weak part of the structural failure, and appropriate measures should be applied to strengthen the steel plate of the beam-to-column connection when the prefabricated RCS composite frame structure is designed to resist progressive collapse. SAP2000 FEM program verified that the numerical simulation results are basically consistent with the experimental results.

scholarly journals Retrofit Strategies against Progressive Collapse of Steel Gravity Frames

2020 ◽  
Vol 10 (13) ◽  
pp. 4600 ◽  
Author(s):  
Lei Zhang ◽  
Honghao Li ◽  
Wei Wang
Keyword(s):  
High Speed ◽  
Progressive Collapse ◽  
Steel Structures ◽  
Element Model ◽  
Steel Plates ◽  
Frame Structure ◽  
Composite Frame ◽  
Collapse Resistance ◽  
Simulation Results ◽  
Gravity Frames

Two retrofit strategies, aiming at increasing the collapse resistance of simple connections by adding seat angles and steel plates with long-slotted holes, are proposed in order to address the vulnerability of steel gravity frames under column loss scenarios. A high-fidelity, detailed, finite element model for a planar composite frame is developed and calibrated against experimental data and is used to conduct numerical analysis to explore the effectiveness of the proposed retrofit strategies. The simulation results show that the planar composite frame with enhanced connections exhibits significantly higher collapse resistance and better ductility under column loss scenarios compared with the one with conventional connections. Meanwhile, it is also revealed that the proposed retrofit strategies have an insignificant impact on the behavior of the structural system under earthquakes. These two retrofit strategies are then implemented to retrofit the gravity system of a 10-story, seismically designed steel frame structure, which has been shown to be vulnerable to progressive collapse after an interior gravity column is forcibly removed or impacted by a heavy vehicle with high speed. Numerical simulations were performed using a 3-D micro-based model and the simulation results illustrate that progressive collapse of the structure with enhanced gravity systems is prevented under both scenarios. Therefore, the proposed retrofit strategies are effective in preventing the progressive collapse of existing steel structures employing simple connections.

scholarly journals Analysis of the robustness of a steel frame structure with composite floors subject to multiple fire scenarios

2021 ◽  
pp. 136943322199249
Author(s):  
Riza Suwondo ◽  
Lee Cunningham ◽  
Martin Gillie ◽  
Colin Bailey
Keyword(s):  
Progressive Collapse ◽  
Three Dimensional ◽  
Steel Structure ◽  
Frame Structure ◽  
Worst Case ◽  
Collapse Resistance ◽  
Fire Scenarios ◽  
Element Approach ◽  
The One ◽  
Steel Frame Structure

This study presents robustness analyses of a three-dimensional multi-storey composite steel structure under the action of multiple fire scenarios. The main objective of the work is to improve current understanding of the collapse resistance of this type of building under different fire situations. A finite element approach was adopted with the model being firstly validated against previous studies available in the literature. The modelling approach was then used to investigate the collapse resistance of the structure for the various fire scenarios examined. Different sizes of fire compartment are considered in this study, starting from one bay, three bays and lastly the whole ground floor as the fire compartment. The investigation allows a fundamental understanding of load redistribution paths and member interactions when local failure occurs. It is concluded that the robustness of the focussed building in a fire is considerably affected by the size of fire compartments as well as fire location. The subject building can resist progressive collapse when the fire occurs only in the one-bay compartment. On the other hand, total collapse occurs when fire is located in the edge three-bay case. This shows that more than one fire scenario needs to be taken into consideration to ensure that a structure of this type can survive from collapse in the worst-case situation.

scholarly journals Research on the Mechanical Characteristics of H-section Steel Frame under the Action of Thermo Mechanical Coupling

2021 ◽  
Vol 233 ◽  
pp. 03022
Author(s):  
Yucheng LI ◽  
Wei WANG ◽  
Xing WANG
Keyword(s):  
High Temperature ◽  
Plastic Strain ◽  
Mechanical Characteristics ◽  
Simulation Software ◽  
Frame Structure ◽  
Concentrated Load ◽  
Composite Frame ◽  
Fire Environment ◽  
Full Cross Section ◽  
Composite Frame Structure

The research on the mechanical characteristics of concrete-filled steel tubular composite frame under high temperature fire environment is one of the research hotspots. In this paper, the finite element simulation software is used to analyze the concrete-filled steel tubular composite frame structure. The failure mode of the flexural deformation of the composite frame structure under high temperature fire environment is introduced. The simulation results of the deformation and displacement of the single-layer single span and two-layer two-span composite frame structure are deeply studied, including the different temperature field, structural field, structural field of each beam and column The results show that: with the temperature rising, the horizontal plastic strain, vertical displacement and local plastic region of beam and column are redistributed and changed in high temperature fire environment, and the flexural effect of two-story two-span concrete-filled steel tubular composite frame under different fire positions is analyzed. The results show that: with the temperature rising, the horizontal plastic strain at the concentrated load is not the results show that the deflection and deformation redistribution are obvious, and the deflection and deformation redistribution are obvious at the joint points of beams and columns. Finally, a mechanism is formed and destroyed. The flexure effect of mode 1 is larger than that of condition 2, which indicates that the flexural effect of two-story two span CFST composite frame under full cross-section fire is larger than that of condition 2 It should be better. The research results can provide reference value for the reinforcement and repair of CFST composite frame under high temperature fire.

Seismic fragility analysis of two-story ultra-high ductile cementitious composites frame without steel reinforcement

2020 ◽  
Vol 23 (11) ◽  
pp. 2373-2387
Author(s):  
Fangyuan Dong ◽  
Jiangtao Yu ◽  
Kaili Zhan ◽  
Zhanhong Li
Keyword(s):  
Seismic Vulnerability ◽  
High Performance Concrete ◽  
Steel Reinforcement ◽  
Frame Structure ◽  
Seismic Fragility ◽  
Cementitious Composites ◽  
Cementitious Composite ◽  
Major Earthquake ◽  
Composite Frame ◽  
Composite Frame Structure

This article numerically studies the seismic vulnerability of the frame structure made of ultra-high ductile cementitious composites without longitudinal and transverse reinforcement. A non-linear finite element model is established with the help of Open System for Earthquake Engineering Simulation and calibrated by shaking table test results on an ultra-high ductile cementitious composite-RC frame whose seismic vulnerable parts were replaced by ultra-high ductile cementitious composites without steel reinforcement. Subsequently, an analysis on the structural seismic vulnerability is performed on pure ultra-high ductile cementitious composite frame structure based on the incremental dynamic analysis method. Finally, a seismic vulnerability matrix of the ultra-high ductile cementitious composite frame under various structural limit states is obtained from seismic fragility curves. Under the major earthquake of magnitude 7.5, the probability of ultra-high ductile cementitious composite frame structure under basically intact, slight damage, moderate damage, serious damage, and collapse is 14.2%, 48.1%, 31.7%, 5.3%, and 0.7%, respectively. The achieved results also demonstrate that the ultra-high ductile cementitious composite frame can satisfy the objectivity of “No collapsed under major earthquake” at least for major earthquakes of magnitude 8. It is demonstrated that the ultra-high ductile cementitious composite frame satisfies three-level performance objectivity stipulated in GB 50011-2010 and, thus, preliminarily verifying the feasibility for constructing structures just using high-performance concrete.

Progressive Collapse Resistance of RC Structures with Tension Cables

2013 ◽  
Vol 405-408 ◽  
pp. 835-840
Author(s):  
Tie Cheng Wang ◽  
Zhi Ping Li ◽  
Hai Long Zhao
Keyword(s):  
Static Analysis ◽  
Progressive Collapse ◽  
Stable Condition ◽  
Frame Structure ◽  
Nonlinear Static Analysis ◽  
Force Model ◽  
Rc Structures ◽  
Concrete Frame ◽  
Collapse Resistance ◽  
Nonlinear Static

In this study, three tie force models of a 10-storey concrete frame structure were prepared to investigate the effects of these methods on the resistance of frame structures against progressive collapse. Four cases of different first-storey column removed were considered using nonlinear static analysis method and their performances were compared with each other. From the nonlinear static analysis, the tie force methods in DoD 2005 and DoD 2009 cannot improve progressive collapse resistance of the structure because horizontal cables don't play a full role. X-type tension cables provide alternative load paths after loss of a single column, and improve progressive collapse resistance of the structure. The X-type tie force model remained in stable condition after sudden removal of a corner column, an exterior column, or an interior column in the first storey.

Static load test on progressive collapse resistance of fully assembled precast concrete frame structure

2019 ◽  
Vol 200 ◽  
pp. 109719 ◽  
Author(s):  
Yun Zhou ◽  
Taiping Chen ◽  
Yilin Pei ◽  
Hyeon-Jong Hwang ◽  
Xiang Hu ◽  
...  
Keyword(s):  
Static Load ◽  
Progressive Collapse ◽  
Precast Concrete ◽  
Load Test ◽  
Frame Structure ◽  
Static Load Test ◽  
Concrete Frame ◽  
Collapse Resistance
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