scholarly journals LABORATORY TESTING THE COMBINED ELONGATE STRUCTURAL ELEMENTS OF SUPPORT OF A MINE OPENING

2021 ◽  
Vol 30 (1) ◽  
pp. 20-27
Author(s):  
G. Gasii ◽  
◽  
O. Hasii ◽  
Keyword(s):  
Laboratory Testing ◽  
Strain State ◽  
Concrete Slab ◽  
Triangular Prism ◽  
Structural Elements ◽  
Modular Element ◽  
Reinforced Concrete Slab ◽  
Combined Structure ◽  
Mine Opening ◽  
Service Conditions

The stress-strain state of test specimens of the new combined structure of support of a mine opening under loads is studied. The test specimens are compound modular elements of the designed earlier combined structure of support. Every single modular element is the triangular prism, consisting of a reinforced concrete slab and a steel grid made of tube web members. The slab and web members are grouped in a complete element while concreting the slab. The tension sensor’s method of experimental investigation is applied to the testing specimens. Tests of specimens are carried out under the load forced with cargoes. Loads are set in the ways that to simulate service conditions, counting the most adverse. Design features of the support and test specimens are shown. Particulars of the support and its elements, production technology, assemblies as well as the sizes are briefly described. The methodology of testing specimens, as well as the analysis of the outcomes, are presente.

scholarly journals TENDENCY IN STRUCTURAL ELEMENTS OF BUILDINGS FOCUSED ON REINFORCED CONCRETE SLAB WITHOUT BEAMS

2019 ◽  
Vol 25 (61) ◽  
pp. 1051-1056
Author(s):  
Nagayoshi SOU ◽  
Yoshihisa NAKATA ◽  
Kazuki TAJIMA ◽  
Atsunori MIYATA ◽  
Takumi ARAMAKI ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Structural Elements ◽  
Reinforced Concrete Slab

scholarly journals TENDENCY IN STRUCTURAL ELEMENTS OF BUILDINGS FOCUSED ON REINFORCED CONCRETE SLAB WITH BEAMS

2020 ◽  
Vol 26 (62) ◽  
pp. 37-42
Author(s):  
Nagayoshi SOU ◽  
Yoshihisa NAKATA ◽  
Kazuki TAJIMA ◽  
Takumi ARAMAKI ◽  
Atsunori MIYATA ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Structural Elements ◽  
Reinforced Concrete Slab

Bending Effect On The Mechanism Of Punching The Support Zone Of The Reinforced Concrete Slab

2019 ◽  
pp. 20-28
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Strain State ◽  
Concrete Slab ◽  
Experimental Studies ◽  
Reinforced Concrete Structure ◽  
Stress Strain ◽  
Reinforced Concrete Slab ◽  
Stress Strain State ◽  
Reinforced Concrete Slabs

The analysis of various regulatory methods for calculating reinforced concrete slabs for punching and comparing with experiment results is made. The tested sample, measuring equipment and test bench are described. Dimensions and materials for the production of the prototype were chosen on the basis of experience in the construction of girderless and capless regular monolithic reinforced concrete frames. The results of experimental studies of a fragment of a slab reinforced concrete structure in order to study the stress-strain state, when implementing the mechanism of punching, are presented. The results of observations obtained during the tests are presented. A comparison of the nature of operation of the tested fragment of the slab with the nature of operation of the full-fledged construction is given. A comparative analysis of the stress-strain state of the tested sample and the results of the calculation of the bearing capacity for punching according to various normative methods is performed. According to the results of the experiment, the main criteria determining the implementation of the punching mechanism are established, and a new method for calculating girderless floors is proposed on the basis of a fundamentally different approach in determining the bearing capacity.

scholarly journals The effect of cracks on the bearing capacity of reinforced concrete slabs

2019 ◽  
Vol 97 ◽  
pp. 03001
Author(s):  
Vladimir Agapov
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Strain State ◽  
Concrete Slab ◽  
Physical Nonlinearity ◽  
Concrete Slabs ◽  
The Finite Element Method ◽  
Reinforced Concrete Slab ◽  
Reinforced Concrete Slabs ◽  
Composite Fabrics

Cracks occur in reinforced concrete slabs for two reasons - due to increased operational loads and due to manufacturing and installation defects. When cracks are detected, the question arises about the residual bearing capacity of the slab and the need of its strengthening. To solve this problem by calculation, it is necessary to take into account physical nonlinearity. An algorithm for the calculation by the finite element method is proposed. The main feature of the algorithm is the use of multilayered finite elements, which allows modeling the cracks by specifying the corresponding material characteristics of those layers which the crack passes through. A method for determining the bearing capacity of a slab with cracks after its reinforcement with composite fabrics is also considered. An example of the study of the stress-strain state of a reinforced concrete slab with cracks by the proposed method is given. The implementation of the algorithm in the PRINS program is described and the possibility of using this program for solving practical problems is discussed.

scholarly journals Effect of Successive Impact Loads From a Drop Weight on a Reinforced Concrete Flat Slab

2019 ◽  
Vol 281 ◽  
pp. 02003 ◽  
Author(s):  
Ali Jahami ◽  
Yehya Temsah ◽  
Ossama Baalbaki ◽  
Mohamad Darwiche ◽  
Youmn Al-Rawi ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Impact Load ◽  
Concrete Slab ◽  
Residential Buildings ◽  
Structural Elements ◽  
Dynamic Impact ◽  
Rock Falls ◽  
Reinforced Concrete Slab ◽  
Flat Slabs ◽  
Different Types

Lebanon is one of the countries which are at high risk of experiencing rock falls. In order to ensure public safety, engineers must take into consideration this risk. In the past years, numerous researches were conducted on the behavior of horizontal structural elements, slabs, of different types under dynamic impact load. Reinforced concrete flat slabs are commonly used slabs in residential buildings. To build a profound understanding of the structural behavior of the slabs under such loadings, it is important to investigate the effect of energy dissipation on the equivalent impact force, mid-span deflection and damage pattern. In this study a sample reinforced concrete slab of 500 x 1000 x 100 mm dimensions is considered. The aim of this paper is to find how these factors vary with the increase in energy as the drop load resembling the real rock fall is left to drop freely from different heights 0.6 m and 1 m.

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.

DYNAMICS OF REINFORCED CONCRETE NON-BEAM FRAMES IN CASE OF DAMAGE TO SLABS PUNCHING

2021 ◽  
Vol 96 (4) ◽  
pp. 23-34
Author(s):  
A.V. ALEKSEYTSEV ◽  
◽  
M.D. ANTONOV ◽  
Keyword(s):  
Reinforced Concrete ◽  
Energy Method ◽  
Dynamic Process ◽  
Geometric Nonlinearity ◽  
Strain State ◽  
Concrete Slab ◽  
Dynamic Effects ◽  
Reinforced Concrete Slab ◽  
Static Assessment ◽  
Emergency Actions

An approach to the assessment of dynamic effects for reinforced concrete non-beam frames of structures under combined emergency actions is considered. Primary impacts imply an excess of operational loads, which causes damage to the slab-column junction from punching to the onset of a secondary impacts. Secondary impacts include considering the removal of any column from the design model over a finite time. The analysis of dynamic effects based on two approaches: the first is based on the energy method of G.A. Geniev and assumes a quasi-static assessment of the stress-strain state of the damaged system; the second is the analysis of the transient dynamic process taking into account physical and geometric nonlinearity. An approximate approach to modeling the damage of a reinforced concrete slab from punching is proposed and further prospects for its improvement are considered. The degree of danger at emergency impacts for structures pre-damaged by punching, as well as the influence of these damages on the survivability of frames under these effects, has been established. An example of assessing survivability on a model of an underground parking frame in the presence of damage from punching for one of the column-slab joints is considered.

scholarly journals Testing of the combined structural elements of support of a mine opening

2020 ◽  
Vol 168 ◽  
pp. 00028
Author(s):  
Grygorii Gasii ◽  
Olena Hasii ◽  
Vita Klimenko
Keyword(s):  
Concrete Slab ◽  
Hydraulic Press ◽  
Steel Tube ◽  
Uniform Load ◽  
Combined System ◽  
Concentrated Force ◽  
Reinforced Concrete Slab ◽  
Test Methodology ◽  
Load Carrying ◽  
Mine Opening

The stress-strain state of test specimens of the new combined system of support of a mine opening under imposed loads is studied. The test specimens are compound modular elements of the offered earlier combined system of support. Every single modular element is the regular quadrangular pyramid, consisting of a reinforced concrete slab and steel tube web members. The slab and web members are gathered in a complete element while concreting the slab. The tension sensor’s method of experimental research is applied to the test of specimens. The test of specimens is carried out under the load imposed with a hydraulic press. The load is set so that to imitate service conditions, including the most adverse. Design features of the offered support and test specimens are presented. Details of the support and its elements, sizes, production technology and assemblies are briefly described. The test methodology of specimens and the analysis of the results are presented. The load-carrying abilities of test specimens under the concentrated force and uniform load are obtained. Break down of slab and connection between the web members and the slab are the results of the test of the specimens under the concentrated force and the uniform load respectively.

scholarly journals Credibility of Design Procedures

10.14311/266 ◽  
2001 ◽  
Vol 41 (4-5) ◽  
Author(s):  
J. Marková ◽  
M. Holický
Keyword(s):  
Structural Reliability ◽  
Concrete Slab ◽  
Theoretical Models ◽  
Comprehensive Analysis ◽  
Structural Elements ◽  
Structural Element ◽  
Limit States ◽  
Reinforced Concrete Slab ◽  
Design Procedures ◽  
Design Value

Theory of structural reliability enables comprehensive analysis of structural elements with respect to various limit states, and provides valuable insights into the methodology of applied standards. In addition to reliability analysis of the structural element, a new concept of the credibility of theoretical models used to calculate the design value of basic variables is introduced. The presented example of structural verification for limit states of cracking shows that the credibility of commonly applied formulas and reliability of a reinforced concrete slab have a great scatter and are in some cases inadequate.

Sign in / Sign up

Export Citation Format

Share Document