Crack width calculation methods for large-scale concrete structures for the Ferry-Free E39

2018 ◽  
Author(s):  
Reignard Tan ◽  
Terje Kanstad ◽  
Mette R. Geiker ◽  
Max A. N. Hendriks
Keyword(s):  
Cross Sections ◽  
Calculation Method ◽  
Crack Width ◽  
Large Scale ◽  
Concrete Structures ◽  
Calculation Methods ◽  
Empirical Formulas ◽  
Eurocode 2 ◽  
Semi Empirical

<p>Motivated by the establishment of a Ferry-Free E39 coastal highway route, crack width calculation methods for design of large-scale concrete structures are discussed. It is argued that the current semi-empirical formulas recommended by Eurocode 2 is inconsistent and overly conservative for cross sections with large bar diameters and covers. A suggestion to formulating a more consistent crack width calculation method is given.</p>

Relative Variation of K- And L-Shell Ionization Cross Sections by Electron Impact

1999 ◽  
Vol 5 (S2) ◽  
pp. 584-585
Author(s):  
X. Llovet ◽  
C. Merlet ◽  
J.M. Fernández-Varea ◽  
F. Salvat
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Carbon Films ◽  
X Rays ◽  
Empirical Formulas ◽  
Relative Variation ◽  
Ionization Cross ◽  
Ionization Cross Sections ◽  
Semi Empirical ◽  
Shell Ionization

Knowledge of inner-shell ionization cross sections by electron impact is needed for quantitative procedures in electron probe microanalysis (EPMA) and Auger electron spectroscopy (AES) The common practice is to use semi-empirical formulas, based on the asymptotic limit of the Bethe theory, which sometimes are used beyond their domain of validity. Experimental measurements of ionization cross sections are scarce and affected by considerable uncertainties, thus a mere comparison with experimental data does not permit to draw a definite conclusion abou the accuracy of the various formulas. In this communication, we present new measurements o the relative variation of K- and L-shell ionization cross sections deduced from the counting rate of characteristic x-rays emitted by extremely thin films of Cr, Ni, Cu, Te, Au and Bi bombardec by keV electrons.The studied films were produced by thermal evaporation on backing self-supported 30 nm carbon films.

SEMI-EMPIRICAL SYSTEMATICS OF (n, 2n), (n, α) REACTIONS CROSS SECTIONS AT 14–15 MeV NEUTRON ENERGY

2008 ◽  
Vol 17 (03) ◽  
pp. 567-583 ◽  
Author(s):  
E. TEL ◽  
Ş. OKUDUCU ◽  
M. H. BÖLÜKDEMIR ◽  
G. TANIR
Keyword(s):  
Cross Sections ◽  
Asymmetry Parameter ◽  
Incident Energy ◽  
Empirical Formulas ◽  
Chi Square ◽  
Fitting Method ◽  
The Cross ◽  
Experimental Values ◽  
Semi Empirical ◽  
Original Formula

In this study we propose new semi-empirical formulas by modifying the formula of Levkovskii with the new parameters for (n, 2n) and (n, α) reactions cross-sections at 14–15 MeV neutron incident energy. The cross sections have been calculated using the asymmetry parameter depending on empirical formulas for the incoming energies of 14–15 MeV neutrons. The parameters obtained by modifying the original formula of Levkovskii and Konno et al. have been determined by applying the least squares fitting method to the experimental cross sections, and the systematics of the (n, 2n) and (n, α) reactions have been studied. We have also suggested different parameters for the empirical formula to reproduce the cross sections of the (n, 2n) and (n, α) reactions for the neutron incident energy of 14–15 MeV. The modified formulas yielded cross sections representing markedly smaller chi-square (χ2) deviations from experimental values, and values much closer to units as compared with those calculated using Levkovskii's and Konno et al. original formulas. The results obtained have been discussed and compared with the other empirical formulas, and found to be well in agreement when used to correlate the available experimental σ(n, 2n) and σ(n, σ) data of different nuclei.

Study of the Dynamic Response of Large Scale Buildings Using Simplified Approaches

2003 ◽  
Author(s):  
Olivier Loiseau ◽  
Karine Cheval ◽  
Bruno Autrusson ◽  
Didier Brochard
Keyword(s):  
Dynamic Response ◽  
Large Scale ◽  
Plate Theory ◽  
Fe Analysis ◽  
Structural Elements ◽  
Structural Damping ◽  
Empirical Formulas ◽  
Thin Plate Theory ◽  
Precision Level ◽  
Semi Empirical

The dynamic response of large scale concrete buildings submitted to an explosion cannot always be obtained by means of classical FE analysis codes at reasonable costs. Indeed, the precision level required to predict efficiently the local failure of structural elements needs very fine meshes, which rapidly becomes unaffordable especially in the case of dynamics. The approach presented in this paper relies on a partitioning of the phenomena and their study by simplified methods: (1) The loading of the structure resulting from the detonation of an explosive charge is computed by a numerical implementation of semi-empirical formulas (Kinney and Graham, 1985, Baker et al., 1983); (2) The response of external walls elements, directly impacted by the aerial shock wave, is studied by a modal projection method, based on the use of analytical solutions from the thin plate theory; (3) Longitudinal propagation of the shock through the floors and walls of the building, including material and structural damping, is modeled by a 1D approach. This allows to determine finally whether the resistance limit of the constituting material is locally exceeded or not. Examples taken from a representative building study are presented in order to illustrate the approach.

scholarly journals BEARING CAPACITY OF A HORIZONTALLY LOADED SINGLE PILE SUPPORT WITH SLEEPERS

Vestnik MGSU ◽  
2015 ◽  
pp. 51-60
Author(s):  
Anatoliy Semenovich Buslov ◽  
Evgeniy Sergeevich Mokhovikov
Keyword(s):  
Bearing Capacity ◽  
Cross Sections ◽  
Carrying Capacity ◽  
Calculation Method ◽  
Rail Transport ◽  
Power Lines ◽  
Single Pile ◽  
Calculation Methods ◽  
Material Consumption ◽  
Urban Road

The supports of a overhead wiring used in transport take up substantial loads both because of wires and constructions holding them and wind, dynamic and other extraordinary impacts. In case of using single-member piles a question about their stability appears. For this reason different sleepers constructions are used. In order to improve the bearing capacity of horizontally loaded single pile supports of the contact systems used in urban, road and rail transport, power lines, etc.., it is recommended to use sleepers as horizontally laid under the ground in the depth of support beams. The calculation methods for different support sleepers of different lengths and cross sections are not well investigated. The proposed calculation method allows determining the carrying capacity of horizontally loaded bearings with soil pieces of different structural dimensions and their location in the soil, which allows choosing the best option for cost and material consumption. The calculations offered by the authors prove the efficiency of sleepers use in order to increase the bearing capacity of horizontally loaded piles and the possibility to chose their size.

scholarly journals DETAILS OF NORMAL SECTIONS STRENGTH CALCULATION OF FLEXIBLE REINFORCED CONCRETE STRUCTURES BY THE WOOD’S METHOD IN PC "LIRA SAPR"

2021 ◽  
pp. 41-49
Author(s):  
Yu.V. DMYTRENKO ◽  
Yu.V. HENZERSKYI ◽  
I.A. YAKOVENKO ◽  
Ye.A. BAKULIN
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Calculation Method ◽  
Concrete Structures ◽  
Building Codes ◽  
Reinforced Concrete Structures ◽  
Equilibrium Equations ◽  
Concrete Element ◽  
Deformation Method ◽  
Automated Algorithms

Problem statement. The problem of realization of the calculation method of normal cross-sections strength of reinforced concrete constructions under flat bending, which is established in the current building codes of Ukraine, is considered. The main attention is paid to atypical and practically not considered calculation cases, typical for automated algorithms in the environment of SP "LIRA SAPR". The purpose of the article. Analysis of the feasibility of using the calculation method of current building codes with further development of recommendations, based on the specifics of computerized calculations. Methodology. Within the framework of the performed research, rectangular cross-sections of reinforced concrete structures with single and double reinforcement (provided a significant increase in the area of reinforcement of the compressed cross-sectional area) with variation of concrete classes, reinforcement coefficient and ratio of reinforcement areas were considered. The stress-strain diagrams of concrete and reinforcement are bilinear with characteristic values set for the first group of limit states. The character of change of cross-sections’ status diagrams "M - εc(1) " is investigated. Research results. It is found that for single-reinforced sections with decreasing reinforcement area there is a decrease of the value of deformation of the compressed fiber of concrete, which is used to find solutions for systems of nonlinear equilibrium equations of the deformation method. This leads to an increase of the execution time of calculations of the flat elements’ reinforcement by the Wood method. It is established that for sections with double reinforcement at relatively large values of the ratios of the reinforcement areas, the equilibrium of the section is at the maximum deformations of the compressed concrete fiber. Conclusions. An approach aimed at accelerating the calculation of sections with single reinforcement, which is based on the use of the relationship between the percentage (area) of reinforcement and the deformation of the most compressed fiber of the reinforced concrete element. Features of analytical algorithms for calculating the selected sections are taken into account by implementing this technique in the PC "LIRA SAPR", optimization and acceleration of automated algorithms for calculating reinforced concrete structures.

Newly developed semi-empirical formulas for (p,α) at 17.9 MeV and (p, np) at 22.3 MeV reaction cross-sections

Pramana ◽  
2010 ◽  
Vol 74 (6) ◽  
pp. 931-943 ◽  
Author(s):  
Eyyup Tel ◽  
Abdullah Aydin ◽  
E. Gamze Aydin ◽  
Abdullah Kaplan ◽  
Ömer Yavaş ◽  
...  
Keyword(s):  
Cross Sections ◽  
Reaction Cross ◽  
Empirical Formulas ◽  
Semi Empirical ◽  
Reaction Cross Sections

EXPERIMENTAL STUDIES OF REINFORCED CONCRETE STRUCTURES WITH CROSS-SHAPED SPATIAL CRACK UNDER TORSION WITH BENDING

2020 ◽  
Vol 92 (6) ◽  
pp. 13-25
Author(s):  
Vl.I. KOLCHUNOV ◽  
◽  
A.I. DEMYANOV ◽  
M.M. MIHAILOV ◽  
◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Experimental Determination ◽  
Calculation Method ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Design Parameters ◽  
Reinforced Concrete Structures ◽  
Experimental Scheme

The article offers a method and program for experimental studies of reinforced concrete structures with cross-shaped spatial crack under torsion with bending, the main purpose of which is to check the design assumptions and experimental determination of the design parameters of the proposed calculation method. The conducted experimental studies provide an opportunity to test the proposed calculation apparatus and clarify the regularities for determining deflections, angles of rotation of extreme sections, and stresses in the compressed zone of concrete. For analysis, the article presents a typical experimental scheme for the formation and development of cracks in the form of a sweep, as well as characteristic graphs of the dependence of the angles of rotation of end sections.

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