Assessment of the resistance of monolithic reinforced concrete bearing systems to progressive collapse based on the principle of the level of permissible damage

2021 ◽  
pp. 61-72
Author(s):  
Bozidar Mitrovic
Keyword(s):  
Reinforced Concrete ◽  
Progressive Collapse ◽  
Deformation Characteristic ◽  
Reduction Factor ◽  
Relative Deformation ◽  
Support Section ◽  
Main Criterion ◽  
Structural Element ◽  
Limiting State ◽  
The Stability

The paper presents a method of using the reduction factor to ensure the stability of monolithic reinforced concrete bearing structures to progressive collapse. Studies have established the values of the reduction factor based on the accepted value of the relative deformation corresponding to the formation of an admissible zone of "destruction" of the support section of the overlap under the action of transverse forces, as the main criterion for asessing the stress-strain state of monolithic reinforced concrete structures for the failure mode of a vertical supporting structure. The accepted deformation criteria for a special limiting state correctly reflect the conditions for the formation of an admissible amount of damage to elements of bearing reinforced concrete systems. The reduction factor (K1) obtained in the framework of the research performed is the most important deformation characteristic of the special limiting state of monolithic reinforced concrete bearing systems of buildings and structures for an emergency design situation associated with the failure of a local structural element.

VERIFICATION OF THE METHOD OF APPLICATION OF THE REDUCTION COEFFICIENT IN THE CALCULATION OF MONOLITHIC REINFORCED CONCRETE SYSTEMS TO RESIST PROGRESSIVE COLLAPSE

2021 ◽  
Vol 95 (3) ◽  
pp. 68-75
Author(s):  
B. MITROVIC ◽  
Keyword(s):  
Reinforced Concrete ◽  
Computational Analysis ◽  
Progressive Collapse ◽  
Deformation Characteristic ◽  
Reduction Factor ◽  
Structural Element ◽  
Limiting State ◽  
Reduction Coefficient ◽  
The Stability

The paper presents a method of using the reduction factor to ensure the stability of monolithic reinforced concrete bearing structures to progressive collapse. Within the framework of the verification study, the correctness and validity of the developed method for the computational analysis of monolithic reinforced concrete bearing systems of buildings and structures to resist progressive collapse were proved. The reduction factor (K1) obtained and justified in the framework of the research performed is the most important deformation characteristic of the special limiting state of monolithic reinforced concrete bearing systems of buildings and structures for an emergency design situation associated with the failure of a local structural element.

scholarly journals Deformation and power characteristics monolithic reinforced concrete bearing systems in the mode of progressive collapse

2018 ◽  
Vol 251 ◽  
pp. 02047 ◽  
Author(s):  
Oleg Kabantsev ◽  
Bozidar Mitrovic
Keyword(s):  
Reinforced Concrete ◽  
Progressive Collapse ◽  
Relative Deformation ◽  
Structural Elements ◽  
Structural Units ◽  
Power Characteristics ◽  
Ultimate Deformation ◽  
Deformation Amount ◽  
Vertical Bearing ◽  
Bearing Structure

The paper considers the question of substantiating the choice of criteria for limiting states of monolithic reinforced concrete bearing systems for the regime of progressive collapse. Based on the results of computational and theoretical studies, structural elements and structural units of monolithic reinforced concrete buildings are determined, the destruction of which occurs first of all in the event of a failure of the vertical bearing structure. It is established that the destruction of such structural units and structural elements leads to the initialization of the process of progressive collapse. A computational and theoretical analysis has been performed to determine the ultimate deformation effects or load values according to the criteria for the bearing capacity of crutial units of monolithic reinforced concrete systems with different span sizes. It is established that as a basic criterion for estimating the stress-and-strain state of monolithic reinforced concrete structures for the mode of failure of a vertical bearing structure, the relative deformation amount corresponding to the formation of the “fracture” zone of the retaining section of the overlap under the action of transverse forces can be adopted.

SURVIVABILITY OF THE FRAME-ROD REINFORCED CONCRETE BUILDING FRAMEWORK IN ACCIDENTAL ACTION

2021 ◽  
Vol 97 (5) ◽  
pp. 40-50
Author(s):  
N.B. ANDROSOVA ◽  
◽  
V.I. KOLCHUNOV ◽  
◽  
Keyword(s):  
Reinforced Concrete ◽  
Structural System ◽  
Reinforced Concrete Frame ◽  
Structural Element ◽  
Limiting State ◽  
Nonequilibrium Processes ◽  
Building Frame ◽  
Reinforced Concrete Building ◽  
Concrete Building

A methodology and an algorithm for calculating the survivability parameters of a long-term deformable reinforced concrete building frame in extreme states are presented. Analytical dependencies for determining the value of the creep measure are taken in accordance with the use of approximate dependencies from the recommendations of the NIIZHB. On this basis, a method is proposed for determining the cross-section bending stiffness of the frame elements. The deformation criterion of a special limiting state is formulated taking into account the nonequilibrium processes of prolonged deformation of the structural system elements. The numerical analysis results of the long-term deformable reinforced concrete frame survivability potential with a sudden removal of the one structural element, taking into account the long-term deformation prehistory of the considered building frame under an operating load, are presented. The exposure of the structural system survivability from the its loading moment to its transformation into a kinematically variable system has been determined.

scholarly journals DETERMINATION OF THE CRITERIA OF DEFORMATION IN A SPECIAL LIMITING STATE

2021 ◽  
Vol 17 (1) ◽  
pp. 108-116
Author(s):  
Nikolay Trekin ◽  
Emil Kodysh ◽  
Sergey Shmakov ◽  
Tere Terekhov ◽  
Konstantin Kudyakov
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Rational Design ◽  
Progressive Collapse ◽  
Concrete Strength ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Load Bearing Capacity ◽  
Limiting State ◽  
Load Bearing

Constructive measures taken to ensure the integrity of the entire building or its part in emergency situations with design based on the existing criteria of the limiting state method leads to a significantincrease of the construction cost. One of the ways to reduce additional costs of construction while the protection design against progressive collapse is the possible use of additional reserves of deformability of load-bearing elements. It leads to redistribution of loads and the use of non-destroyed structures. It also leads to possible changes of limiting states in non-standard emergency design situations, taking into account the peculiarities of the operation of structures in a special limiting state at a stage close to destruction. In the GOST 27751-2014 «Reliability for constructions and foundations. General principles» calculated states of the firstand second groups of limiting states are given, and for a special limiting state only the area of its permissible application is indicated. The work of reinforced concrete structures at the stage close to the depletion of the load-bearing capacity is little reflectedin the scientificand technical literature; the work of reinforced concrete structures at the unloading stage due to the redistribution of forces is represented in single publications. The article presents theoretical studies based on experimental data on the deformation of bent reinforced concrete beam elements at a stage close to the maximum load-bearing capacity and at the stage of unloading up to the transformation of a structural element into a mechanism. The influenceof the longitudinal reinforcement, the class of reinforcement, prestressing and the concrete strength on the deformation of reinforced concrete bending elements is considered in the article. The research of the behavior of structural elements continuation at this stage is relevant and contributes to the development of economical and rational design solutions for protection against progressive collapse and in the design of earthquake-resistant buildings.

scholarly journals Robustness of Reinforced Concrete Frames against Blast-Induced Progressive Collapse

Vibration ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 722-742
Author(s):  
Mattia Francioli ◽  
Francesco Petrini ◽  
Pierluigi Olmati ◽  
Franco Bontempi
Keyword(s):  
Reinforced Concrete ◽  
Numerical Models ◽  
Progressive Collapse ◽  
Local Level ◽  
Structural Response ◽  
Frame Structure ◽  
Blast Load ◽  
Response Analysis ◽  
Structural Element ◽  
Global Robustness

A quantitative procedure for the robustness and progressive collapse assessment of reinforced concrete (RC) frames under blast load scenarios is presented. This procedure is supported by multilevel numerical models, including nonlinear numerical analyses of the structural response of both local (i.e., response of the single structural element to the blast load) and global levels (i.e., response of the structural system to the blast-induced damage). Furthermore, the procedure is applied to a 2D RC frame structure. The novelty of the proposed procedure is that the global robustness is evaluated by the so-called “damage-presumption approach” where the considered damages are defined both in typology and extension depending on the blast scenario occurring at the local level. The dedicated local response analysis of a specified blast scenario leads to the proper definition of the so-called “blast-scenario dependent robustness curves”.

Resistance of Reinforced Concrete Frames with Masonry Infill Walls to In-Plane Vertical Loading

2016 ◽  
Vol 711 ◽  
pp. 982-988
Author(s):  
Alex Brodsky ◽  
David Z. Yankelevsky
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Progressive Collapse ◽  
Lateral Loading ◽  
Masonry Walls ◽  
Reinforced Concrete Frame ◽  
Masonry Infill ◽  
Concrete Frame ◽  
Vertical Loading ◽  
Infill Masonry

Numerous studies have been conducted on the in plane behavior of masonry infill walls to lateral loading simulating earthquake action on buildings. The present study is focused on a problem that has almost not been studied regarding the vertical (opposed to lateral) in-plane action on these walls. This may be of concern when a supporting column of a multi-storey reinforced concrete frame with infill masonry walls undergoes a severe damage due to an extreme loading such as a strong earthquake, car impact or military or terror action in proximity to the column. The loss of the supporting column may cause a fully or partly progressive collapse to a bare reinforced concrete frame, without infill masonry walls. The presence of the infill masonry walls may restrain the process and prevent the development of a progressive collapse. The aim of the present study is to test the in-plane composite action of Reinforced Concrete (RC) frames with infill masonry walls under vertical loading through laboratory experiments and evaluate the contributions of infill masonry walls, in an attempt to examine the infill masonry wall added resistance to the bare frame under these circumstances. Preliminary results of laboratory tests that have been conducted on reinforced concrete infilled frames without a support at their end, under monotonic vertical loading along that column axis will be presented. The observed damages and failure modes under vertical loading are clearly different from the already known failure modes observed in the case of lateral loading.

Performance of slabs in reinforced concrete structures to resist progressive collapse

Structures ◽  
2021 ◽  
Vol 33 ◽  
pp. 4843-4856
Author(s):  
Bo Pang ◽  
Feiliang Wang ◽  
Jian Yang ◽  
Sandy Nyunn ◽  
Iftikhar Azim
Keyword(s):  
Reinforced Concrete ◽  
Progressive Collapse ◽  
Concrete Structures ◽  
Reinforced Concrete Structures
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