Basic Principal and Design Methodology of Progressive Storey Collapse Resistance in a New Type RC Twin-Frame Structure

2011 ◽  
Vol 368-373 ◽  
pp. 946-952
Author(s):  
Hao Hua Jia ◽  
De Min Wei
Keyword(s):  
Progressive Collapse ◽  
Earthquake Hazard ◽  
Frame Structure ◽  
Structure System ◽  
Weak Layer ◽  
Load Paths ◽  
Collapse Resistance ◽  
Normal Frame ◽  
New Type ◽  
Two Stages

According to earthquake hazard, normal frame structures could hardly avoid failure of ‘Strong Beam and Weak Column’, weak layer and even progressive storey collapse under strong earthquakes, a main reason is the lack of second seismic fortification line in frame structure. Based on the design thought of multiple seismic fortification lines, reinforced concrete twin-frame structure is initiated in this paper. Major feature is increases of redundant constraints and load paths due to added outer limb-columns could take effect as the second seismic fortification line. Twin-frame structure could not only fulfill the demand of ‘three levels, two stages’ in seismic code, but also have been designed through the third stage of ‘resist progressive collapse’, using key member method to promote safety storage and deformability of outer limb-columns, using removal key member method to verify vertical ultimate load of frame beams in weak layer. Though twin-frame structure could not completely avoid plastic hinges in column ends, progressive storey collapse will not appear in this kind of structure. Twin-frame structure is a new structure system which could be applied in constituting new projects as well as strengthening and rebuilding existing projects, further research can be done on this structure system.

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 CASCO: a simulator of load paths in 2D frames during progressive collapse

2020 ◽  
Vol 2 (9) ◽  
Author(s):  
Enrico Masoero
Keyword(s):  
Progressive Collapse ◽  
Structural Topology ◽  
Matlab Simulation ◽  
Concrete Frames ◽  
Dynamic Simulations ◽  
New Approach ◽  
Load Paths ◽  
Collapse Resistance ◽  
Simplifying Assumptions ◽  
Damage Tolerant

Abstract Modern structural design software can simulate complex collapse dynamics, but the main physical processes driving collapse propagation are often hidden among structure-specific details. As a result, it is still unclear which structural geometries and material properties should be preferred when approaching the design of a damage-tolerant structure. This manuscript presents a new approach to explore the relationships between structural geometry, local mechanical properties, and collapse propagation. The insight comes from a unique ability to trace the evolution of load paths during collapse, achieved by combining energy conservation with local mechanisms of plastic failure and a few simplifying assumptions. The method is implemented in a new simulator of collapse of 2D frames, called CASCO and programmed in MATLAB. Simulation results for reinforced concrete frames predict collapse loads and mechanisms in agreement with fully non-linear, dynamic simulations, while also providing a graphical description of the evolving structural topology during collapse. A first application of CASCO to mechanically homogeneous and heterogeneous frames, indicates certain evolutions in number and density of load paths during collapse that may be targetted to improve collapse resistance.

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.

Progressive Collapse and Structural Robustness of Bridges

2012 ◽  
Vol 193-194 ◽  
pp. 1021-1024 ◽  
Author(s):  
Min Rong Wang ◽  
Zhi Jun Zhou
Keyword(s):  
Progressive Collapse ◽  
Fundamental Property ◽  
Protective Measures ◽  
Structural Robustness ◽  
Load Paths ◽  
Local Element ◽  
Collapse Resistance ◽  
Bridge Structures ◽  
Multiple Load ◽  
Modern Building

Structural robustness has been recognized as a fundamental property of structural systems to prevent the occurrence of disproportionate failure events and progressive collapse. Bridges are primarily horizontally aligned structures with one main axis of extension. Only a few of many modern building codes provided methods can be applied to bridges. In this paper, associated strategies to enhance collapse resistance can be addressed by controlling abnormal events, individual local element behavior and global system behavior. Various design methods towards preventing progressive collapse such as non-structural protective measures, local resistance, multiple load paths or structural segmentation are applied to bridges. The suitability depends on the type of bridge structures.

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

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.

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