COMPUTATIONAL ANALYSIS OF METHODS FOR PROTECTING MONOLITHIC FRAMES OF MULTI-STOREY BUILDINGS WITH FLAT FLOORS FROM PROGRESSIVE COLLAPSE

2021 ◽  
Vol 96 (4) ◽  
pp. 35-44
Author(s):  
V.I. KOLCHUNOV ◽  
◽  
V.S. MOSKOVTSEVA ◽  
O.B. BUSHOVA ◽  
D.I. ZHUKOV ◽  
...  
Keyword(s):  
Computational Analysis ◽  
Progressive Collapse ◽  
Sudden Change ◽  
Structural System ◽  
Design Scheme ◽  
Design Load ◽  
Flat Slabs ◽  
Numerical Studies ◽  
Steel Consumption ◽  
Design Solutions

The paper presents new design solutions for the protection of monolithic frames of multi-storey buildings with flat floors from progressive collapse. At the same time, two variants of strengthening the support zones - the zones of coupling of the plate with the column, providing the perception of peak bending moments in the event of a sudden change in the force flows of the structural system caused by the removal of one of the supporting columns, are considered: the 1st variant-reinforcement with the use of metal insert plates, the 2nd variant - reinforcement with the use of support frames with inclined reinforcing rods. Numerical studies of a fragment of the considered monolithic frame of a building according to the primary design scheme for the effect of the design load and according to the secondary design scheme for the out-of-design impact show the effectiveness of the proposed design solutions for strengthening the interface zones of flat slabs with columns to protect the monolithic frames of buildings from progressive collapse. It is established that in the considered numerical example, the steel consumption when using the option of reinforcing the support zone with frames with inclined rods, other things being equal, is reduced to 46%.

RESISTANCE OF THE PRECAST - CAST-IN-SITU REINFORCED CONCRETE FRAMES OF CIVIL BUILDINGS UNDER SPECIAL EMERGENCY IMPACT

2021 ◽  
Vol 96 (4) ◽  
pp. 45-55
Author(s):  
P.A. KORENKOV ◽  
◽  
S.S. FEDOROV ◽  
Keyword(s):  
Thermal Protection ◽  
Progressive Collapse ◽  
Structural System ◽  
Concrete Frames ◽  
Limiting State ◽  
Space Planning ◽  
Numerical Studies ◽  
Design Loads ◽  
Multi Level

The paper obtained and analyzed the results of a numerical analysis of the survivability of a new industrial structural system of residential and public buildings that meets modern requirements for protection against progressive collapse, improved space-planning, architectural and thermal protection solutions. The presence of a significant number of enterprises with technological lines for the production of structures for large-panel housing construction and their market share, combined with a number of disadvantages of the applied technical and space-planning solutions, indicates the need to modernize these enterprises in order to produce products that meet modern requirements. The purpose of this study was to qualitatively and quantitatively study the parameters of the stress-strain state of the industrial structural system of civil buildings proposed by the authors with increased resistance to progressive collapse, the production of which would not require expensive modernization of the construction industry enterprises. On the basis of multi-level design schemes, an algorithm for calculating such a system for a special emergency effect is proposed. Numerical studies have established the compliance of the developed structural system with the requirements of a special limiting state under design loads and emergency effects caused by the sudden removal of a vertical load-bearing element.

scholarly journals Experimental Investigation of the Maximum Punching Resistance of Slab-Column Connections

2018 ◽  
Vol 26 (3) ◽  
pp. 22-28 ◽  
Author(s):  
Jaroslav Halvoník ◽  
Lucia Majtanová
Keyword(s):  
Experimental Investigation ◽  
Progressive Collapse ◽  
Transverse Reinforcement ◽  
Test Results ◽  
Structural System ◽  
Structural Behaviour ◽  
Shear Forces ◽  
Flat Slab ◽  
Direct Verification ◽  
Flat Slabs

Abstract Flat slabs represent a structural system with a typical concentration of shear forces near the vicinity of its local supports. A possible failure from punching is a dangerous phenomenon due to the brittleness and possible progressive collapse of a whole structure. An improvement in the structural behaviour of a slab-column connection provides transverse reinforcement. The amount of this reinforcement and thus its contribution to the resistance against punching has a limit, which is represented by the maximum punching capacity. This capacity can be assessed using the kmax factor or by direct verification of the strut capacity. The article deals with the results of a test campaign carried out on flat slab specimens with their transverse reinforcements designed in such a way that the crushing of the struts is the governing mode of any failure. The test results obtained allowed for an evaluation of the kmax factors and provide an answer as to whether it is possible to cover failures due to the crushing of struts by this factor.

scholarly journals Numerical Study on the Behavior and Bearing Mechanism of Flat Slabs in Column Loss Events

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Aidin Mohammadi ◽  
Alireza Pachenari ◽  
Behnam Sadeghi
Keyword(s):  
Numerical Study ◽  
Progressive Collapse ◽  
Great Tendency ◽  
Load Bearing ◽  
Collapse Potential ◽  
Flat Slabs ◽  
Collapse Mode ◽  
Damaged Zone ◽  
Initial Load ◽  
Cracking Pattern

This study investigates the behavior and the load-bearing mechanism of a typical flat slab with rectangular panels in several scenarios including the removal of a corner, penultimate, and internal columns. The scenarios are rather similar to those used in the conventional evaluation of the progressive collapse potential; however, application of the uniformly distributed loading over panels adjacent to the removed columns was not limited to twice the value of the initial load. Thus, load-deflection curves were drawn up to the point in which a great number of longitudinal slab bars ruptured. Introducing 5 stages on each curve, finite element outputs on concrete cracking pattern and rebar stress state were presented. A significant increase in the stresses along the diagonals of the slab panels accompanied by bar ruptures around columns adjacent to the removed column proved contribution of an important load-bearing mechanism in addition to the behavior called “quasiframe action.” Consecutive rupture of bars showed formation of a zipper-type collapse mode as well as a great tendency to transfer load share of missing column mainly along shorter direction of slab panels. Moreover, the findings indicated that the slab damaged zone could exceed the panels under uniform overloading.

scholarly journals A Review on Numerical Analysis of RC Flat Slabs Exposed to Fire

2020 ◽  
Vol 27 (1) ◽  
pp. 1-5
Author(s):  
Hanadi Naji ◽  
Nibras Khalid ◽  
Mutaz Medhlom
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Numerical Analysis ◽  
Bending Moment ◽  
Mechanical And Thermal Properties ◽  
Vertical Deflection ◽  
Element Analysis ◽  
Flat Slabs ◽  
Numerical Studies ◽  
The Finite Element Analysis

This paper aims at presenting and discussing the numerical studies performed to estimate the mechanical and thermal behavior of RC flat slabs at elevated temperature and fire. The numerical analysis is carried out using finite element programs by developing models to simulate the performance of the buildings subjected to fire. The mechanical and thermal properties of the materials obtained from the experimental work are involved in the modeling that the outcomes will be more realistic. Many parameters related to fire resistance of the flat slabs have been studied and the finite element analysis results reveal that the width and thickness of the slab, the temperature gradient, the fire direction, the exposure duration and the thermal restraint are important factors that influence the vertical deflection, bending moment and force membrane of the flat slabs exposed to fire. However, the validation of the models is verified by comparing their results to the available experimental date. The finite element modeling contributes in saving cost and time consumed by experiments.

scholarly journals Assessment of Progressive Collapse Resistance of Steel Structures with Moment Resisting Frames

Buildings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 19 ◽  
Author(s):  
Osama Mohamed ◽  
Rania Khattab
Keyword(s):  
Progressive Collapse ◽  
Three Dimensional ◽  
The United States ◽  
Dimensional System ◽  
Structural System ◽  
Linear Elastic ◽  
Load Carrying ◽  
Non Linear ◽  
Moment Resisting ◽  
Primary Load

This paper evaluates the practice of using moment connections in the perimeter of the structural system and shear connections within the interior connections of the three-dimensional structural system from the perspective of resistance to progressive collapse. The enhanced resistance to progressive collapse associated with using moment resisting connections at the perimeter as well as internal to the three-dimensional system is assessed. Progressive collapse occurrence and system resistance are determined using the alternate path method which presumes a primary load carrying-member is notionally removed. The paper compares the structural response determined using linear elastic, non-linear elastic and non-linear dynamic analyses. Linear and non-linear static analyses are found to be incapable of capturing the response pursuant to the loss of the primary load carrying member. The analysis procedures used in this study followed (for the most part) the United States Department of Defense Guide for Progressive Collapse Resistant Design of Structures.

Pilot experimental and numerical studies on a novel retrofit scheme for steel joints against progressive collapse

2019 ◽  
Vol 200 ◽  
pp. 109667 ◽  
Author(s):  
Benyamin Ghorbanzadeh ◽  
Guido Bregoli ◽  
George Vasdravellis ◽  
Theodore L. Karavasilis
Keyword(s):  
Progressive Collapse ◽  
Numerical Studies ◽  
Steel Joints

PROGRESSIVE COLLAPSE RESISTANCE OF FACILITIES EXPERIENCED TO LOCALIZED STRUCTURAL DAMAGE - AN ANALYTICAL REVIEW

2021 ◽  
Vol 95 (3) ◽  
pp. 76-108
Author(s):  
N.V. FEDOROVA ◽  
◽  
S.YU. SAVIN ◽  
Keyword(s):  
Bearing Capacity ◽  
Structural Damage ◽  
Scientific Literature ◽  
Progressive Collapse ◽  
Structural Systems ◽  
Structural System ◽  
Scientific Review ◽  
Collapse Resistance ◽  
The World ◽  
New Research

During the entire life cycle, the facilities are experienced to force and environmental actions of various nature and intensity. In some cases, such influences can lead to a loss of the bearing capacity of the structural elements of a building, which in turn can lead to a disproportionate failure of the entire structural system. Such phenomenon was called progressive collapse. Major accidents at facilities, such as the collapse of a section of the Ronan Point high-rise residential building (London, 1968), the Sampoong department store (Seoul, 1995), the Transvaal Park pavement (Moscow, 2004), the World Trade Center (New York, 2011) and others, clearly demonstrated the urgency of this problem. In this regard, the regulatory documents of the USA, Great Britain, EU, China, Australia, Russia and other countries established requirements for the need to calculate structural systems of buildings for resist to progressive collapse after sudden localized structural damage. However, the steady increase in the number of new publications on the problem of progressive collapse observed in the world scientific literature indicates that the results of such studies do not yet provide exhaustive answers to all questions related to this phenomenon. In this regard, the proposed review article is aimed at systematizing, generalizing and analyzing new research results on resistance to progressive collapse of facilities, identifying new trends and proposing new research directions and tasks to improve the level of structural safety of design solutions for buildings and structures. In order to achieve this goal, the following aspects were considered: the nature of the impacts leading to progressive collapse; features of modeling the progressive collapse of structural systems of buildings and structures; mechanisms of resistance to progressive collapse and criteria for evaluation of a progressive collapse resistance. Particular attention in the scientific review is paid to the analysis of works related to a new direction of research in the area under consideration, associated with the assessment of the bearing capacity of eccentrically compressed elements of structural systems, the effect on their resistance to progressive collapse of the parameters of the loading mode, degradation of material properties and the topology of the structural system. The significance of the proposed scientific review is that, along with the well-known and new results presented in the English-language scientific literature, it summarizes and analyzes the original approaches, methods and research results published in Russian-language scientific publications, primarily included in the RSCI Web of Science.

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.

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