scholarly journals Determination of natural modes of railway overpasses

2021 ◽  
Vol 19 (1) ◽  
pp. 1-10
Author(s):  
Seidulla S. Abdullayev ◽  
Gabit B. Bakyt ◽  
Muslim N. Aikumbekov ◽  
Ivan S. Bondar ◽  
Yerlan T. Auyesbayev
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Rolling Stock ◽  
Software Systems ◽  
Structural Elements ◽  
Natural Vibrations ◽  
Railway Bridges ◽  
Natural Modes

Currently, there are many software systems and environments that allow you to simulate and perform fairly complex and voluminous calculations associated with dynamic effects on structural elements of overpasses. The aim of the article is to make an analysis of a reinforced concrete railway overpass as a whole and its elements separately. The article presents the calculated and experimental data of the forms and frequencies of natural vibrations of reinforced concrete railway overpasses under constant loads and the rolling stock off the span. As a result of the analysis of the tests, it was determined that the effect of the rolling stock passing through the reinforced concrete beam spans of 16.5 m and 23.6 m appears with frequency perturbations that are in the range f = 4.41 ÷ 9.52 Hz. These studies can be further used in the design of artificial structures, as well as to identify defects in structural elements of railway bridges.

On-Site Determination of the Polarization Resistance in a Reinforced Concrete Beam

CORROSION ◽  
1988 ◽  
Vol 44 (10) ◽  
pp. 761-765 ◽  
Author(s):  
S. Feliu ◽  
J. A. Gonzalez ◽  
C. Andrade ◽  
V. Feliu
Keyword(s):  
Reinforced Concrete ◽  
Polarization Resistance ◽  
Concrete Beam ◽  
Reinforced Concrete Beam

scholarly journals Numerical Derivation of Iso-Damaged Curve for a Reinforced Concrete Beam Subjected to Blast Loading

2018 ◽  
Vol 149 ◽  
pp. 02016 ◽  
Author(s):  
Yehya Temsah ◽  
Ali Jahami ◽  
Jamal Khatib ◽  
M Sonebi
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Shock Waves ◽  
Concrete Beam ◽  
Blast Loading ◽  
Reinforced Concrete Beam ◽  
Structural Elements ◽  
Finite Element Program ◽  
Element Program ◽  
Structural Engineers

Many engineering facilities are severely damaged by blast loading. Therefore, many manufacturers of sensitive, breakable, and deformed structures (such as facades of glass buildings) carry out studies and set standards for these installations to withstand shock waves caused by explosions. Structural engineers also use these standards in their designs for various structural elements by following the ISO Damage Carve, which links pressure and Impulse. As all the points below this curve means that the structure is safe and will not exceed the degree of damage based on the various assumptions made. This research aims to derive the Iso-Damage curve of a reinforced concrete beam exposed to blast wave. An advanced volumetric finite element program (ABAQUS) will be used to perform the derivation.

scholarly journals Calculation of steel-reinforced concrete beam for instant loading taking into account the non-linearity of the concrete diagram ε-σ

2020 ◽  
Vol 17 (2) ◽  
pp. 85-94
Author(s):  
S. O. Chepilko ◽  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Neutral Axis ◽  
Reinforced Concrete Beams ◽  
System Of Equations ◽  
Nonlinear System Of Equations ◽  
Steel Reinforced Concrete

Issues of calculating steel-reinforced concrete beams are considered taking into account a nonlinear concrete diagram based on the Sargin formula. The nonlinear system of equations for determination of curvature and neutral axis, which is solved numerically, is written in explicit form. Explicit expressions for determination of other calculated quantities needed for design of steel-reinforced concrete beams are derived. Numerical examples are given. The analysis of accounting nonlinearity in comparison with the linear calculation is carried out.

scholarly journals Calculation of reliability of the reinforced concrete beam with the normal crack on the deflection at the operation stage

2017 ◽  
Vol 1 ◽  
pp. 4-9 ◽  
Author(s):  
Utkin V.S. ◽  
Karpushova K.A.
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Statistical Information ◽  
Normal Operation ◽  
Method Of Calculation ◽  
Operation Stage ◽  
Standard Value ◽  
Method Of Measurement

The deflection of a steel concrete beam at an operation stage sharply increases in case of formation of a normal crack in the stretched zone of concrete and can lead to violation of its normal operation, and in certain cases warns about possible accident. In article the method of measurement and monitoring of a deflection of a beam, a method of calculation of reliability of a beam by criterion of a deflection is considered in case of limited statistical information on values of a deflection in timepoint of t, determination of a residual temporary resource of a beam by criterion of a deflection in case of the known extreme (standard) value of a deflection of a beam.

Stress-Strain State of Reinforced Concrete Overpass under Load

2020 ◽  
Vol 18 (2) ◽  
pp. 68-81
Author(s):  
I. S. Bondar ◽  
M. Ya. Kvashnin ◽  
D. T. Aldekeeva
Keyword(s):  
Reinforced Concrete ◽  
Strain State ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Rolling Stock ◽  
Freezing And Thawing ◽  
Stress Strain ◽  
Stress Strain State ◽  
Operational Load ◽  
Calculation Results

Beam spans are the most vulnerable elements of the bridge system, as they are exposed to direct effects of mobile load, environmental and climatic factors (temperature and humidity effects, including freezing and thawing, shrinkage, humidity, etc.). Appearance of defects of the structure is inevitable; the refore civil engineers face a topical problem of strengthening of damaged structures of bridges. The article discusses some results of calculated values and instrumental measurements of stress-strain state (SSS) of reinforced concrete beam span structures of railway overpass under operational load caused by different rolling stock units. The objective of this study is to control stress-strain state of railway overpass for identification and elimination of defects at early stages. The calculation results obtained, carried out by finite-element method (FEM) in the program ABAQUS/Standard correlate well with experimental data. These results can be used for monitoring the state of artificial structures on main lines of JSC NC KTZ.

scholarly journals Reinforced Concrete Beam with Light Weight blocks and Steel Fibre added below Neutral Axis

2019 ◽  
Vol 9 (2) ◽  
pp. 4214-4218
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Steel Fibre ◽  
Shear Zones ◽  
Reinforced Concrete Beam ◽  
Neutral Axis ◽  
Control Specimen ◽  
Tension Zone ◽  
Structural Elements ◽  
Advantages And Disadvantages

The reinforced concrete is one of the widely used structural materials which have its own major advantages and disadvantages. Its behaviour when provided in various positions in the structural elements like compression, tension, and shear zones has significant impact. Since the concrete is excellent in the compression behaviour, and only a nominal performer in the tension behaviour, steel reinforcement are provided in required zones where tension occurs. Thus in a bending member, below the neutral axis, that is at the tension zone, the concrete acts only as a interface medium between reinforcement that carrying the tension and the concrete above neutral axis carrying compression forces. This concrete is also called as sacrificial concrete. Thus in order to efficiently use the concrete falls under the tension zone, the concrete can be swapped with any suitable lighter or cheaper material or the concrete may be strengthened to carry tensile stresses. In this present study, the concrete below neutral axis is replaced with lightweight ‘aerocon’ block cubes of 8 cu.cm and 64 cu.cm by 20% of volume of concrete and in another specimen, steel fibres are added in the concrete that are below neutral axis by 2% and 3% by weight to improve the local tensile strength of concrete as material The results obtained shows that the aerocon cubes replaced specimens has equivalent performance of the control specimen and the steel fibre added specimen had superior deflection and crack performance than the control specimen.

scholarly journals A review on the performance of reinforced concrete structures under blast loading

2020 ◽  
Vol 3 (4) ◽  
pp. 216-228
Author(s):  
K. Senthil ◽  
Iwansh Gupta ◽  
S. Rupali ◽  
Loizos Pelecanos
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Slab ◽  
Concrete Columns ◽  
Reinforced Concrete Beam ◽  
Structural Behavior ◽  
Charge Weight ◽  
Structural Elements ◽  
Reinforced Concrete Slab ◽  
Reinforced Concrete Columns

An explosion on the elevated structures caused by terrorist activities or manmade events can induce significant deformations in the Civil Engineering structures. Therefore, it is necessary to review the response of the structural behavior such as reinforced concrete slab, reinforced concrete beams, and columns. On the basis of this objective, a detailed literature review is conducted to understand the scope for protecting such structures and the structural behavior under blast loading. Based on the detailed literature survey, the investigations about the behavior of conventional reinforced concrete columns and slab initiated in 2005 however, the behavior of reinforced concrete beam was focused since the year 2010. Also, the literature reveals that the investigations on structural elements using analytical techniques are limited in comparison to experiments and simulations. In addition to that, the response of the structural elements was predicted and the trend was calibrated and fitted logarithmically with the experimental results. The predicted spall diameter in the reinforced concrete slab is 0.95 m corresponding charge weight of 100 kg however the influence of spalling was found to be negligible after the 100 kg of charge weight. The predicted spall length in the reinforced concrete beam is 1.6 m corresponding charge weight of 100 kg and the effect may be negligible after 100 kg of charge weight. The predicted deflection in the reinforced concrete columns is 30 mm corresponding to a peak reflected impulse of 1000 MPa-ms, whereas the deflection was found to be negligible after the 1000 MPa-ms of peak reflected impulse.

scholarly journals Estimation of cracking of reinforced concrete load-bearing construction structures at the stage of their technical inspection

2018 ◽  
Vol 251 ◽  
pp. 02040
Author(s):  
Anna Malakhova
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Structures ◽  
Reinforced Concrete Beam ◽  
Technical Condition ◽  
Complex Nature ◽  
Reinforced Concrete Structures ◽  
Structural Elements ◽  
Fracture Formation ◽  
The Relationship

The article describes the process and causes of cracking of bearing reinforced concrete structures, revealed during the inspection of the technical condition of structural elements of buildings at the stage of their erection, at the stage of suspended construction and in the operational stage. The reasons for the appearance of cracks in reinforced concrete structures under force loads and climatic influences are analyzed. Possible reasons for the appearance of cracks in a monolithic reinforced concrete beam ceiling of a multi-storey building of a column structural system and in monolithic walls of an underground cylindrical reservoir, identified by the author of the article when inspecting the technical condition of these structures, are given. The relationship between the appearance of destructive cracks and the design errors of a monolithic reinforced concrete beam ceiling is shown. The complex nature of the causes of the appearance of cracks in the monolithic walls of the underground reservoir is revealed. The article describes the capabilities of the LIRA-CAD software package for determining the pattern and parameters of fracture-formation of reinforced concrete structures for subsequent comparison with the results of an inspection of the technical condition of structural elements of buildings and structures.

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