Determination of distribution width for shear stresses at support in reinforced concrete slab bridges

Author(s):  
E Lantsoght ◽  
A de Boer ◽  
C van der Veen
Author(s):  
O. Efimov ◽  
L. Gimranov ◽  
A. Fattahova ◽  
M. Chekanin

Combined steel-reinforced concrete floors using profiled flooring are the most common solution in buildings with a steel frame. Flexible stops ensure the joint work of the frame and the flooring disks. Deformations of the combined flooring, and therefore of the frame in the horizontal plane, can occur due to the possible appearance of uneven force effects that cause a shift. At the same time, the magnitude of these deformations is influenced by both the level of force influences and the shear stiffness of the flooring disk, as well as the malleability of the flexible stops connecting the latter to the supporting frame. The paper proposes a method for determining the deformations of the flooring disk and the supporting frame from a horizontal load. The problem is considered in which a square floor slab is based on a contour on the crossbars of the frame, but its fixing with flexible stops is provided on two parallel sides. A formula for determining the movements of the frame from the horizontal load is proposed. The displacement of the flooring disk is analytically determined, it is noted how the malleability of flexible stops affects the determination of the final result. Using the example of a numerical experiment, the possibility of using the proposed method is demonstrated. The movement in the flooring disks will allow to assess the rigidity of the frame from horizontal loads without focusing on the deformation of each component of the steel-reinforced concrete slab. In addition, it will help to use materials and resources more efficiently by optimizing design solutions.


Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1041 ◽  
Author(s):  
Krzysztof Śledziewski ◽  
Marcin Górecki

This paper presents the results of numerical investigations into the behavior of a sinusoidal web loaded in shear due to buckling in the period from the onset of buckling until failure, as well as the impact of a reinforced concrete slab on the stability of the web. The analysis concerned steel girders and composite girders with the top flange bonded to a reinforced concrete slab. Nonlinear analyses were performed using the finite element method. The results of the investigations support the conclusion that the appearance and propagation of shear stresses in the sinusoidal web of the composite steel–concrete beam are the same as those in an identical non-composite steel beam, but the bracing of the top flanges improves the shear strength and, at the same time, affects the location of initial stresses. In addition, it was found that, despite the three types of buckling, the predominant failure of the sinusoidal webs, regardless of the presence of the concrete slab, is global buckling. It occurs diagonally through several folds at the same time, including deformation of the web over its entire height.


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Meysam Aminitabar ◽  
Omar Kanaani ◽  
Amir Reza Eskenati

A finite element method was used in this study to investigate the effects of openings on the resistive behavior of concrete slabs. The presented modeling procedure is used to conduct numerical analyses on the response of reinforced concrete slab subjected to in-plane monotonic loads in X (perpendicular to the beam) and Z (parallel to the beam) directions. Initially, the developed numerical model was calibrated and compared with laboratory results. In building this three-dimensional model, it is attempted to accurately model all nonlinear properties of steel and concrete materials as well as the interactions between them. Then, the behavior of bilaterally concrete slabs under different loads was investigated and used as a reference. Finally, the effect of openings under different loads on the strength of concrete slabs was studied. The results confirm that openings have a great influence on the change of hardness, ductility, initiation and cracking path, and stress distribution under shear and gravitational loading. Moreover, by adding an opening inside the diaphragm, not only did beam and block flooring show more fragile behavior, but also its strength and resistance decreased against lateral load. Given the results of the parametric study of the effect of layout, generally, its place became critical at the state that opening disturbed transmission of shear stresses to the collector beams. By adding the area of the opening and loading in X direction, the concentration of the tensile stresses (equivalent to main maximum stresses) was at the tensile edge as well as at the middle of the flooring around the opening. It is worth noting that an increase in the opening’s area caused the number of tensile stresses to be increased at the middle of the flooring. Meanwhile, the concentration of maximum compressive stresses which is equivalent to the main minimum stresses was at the compressive edge, started at the area of the collectors, and stretched to the edge of the opening. Among different layouts, X-1 and Z-3 states were more critical than other states. Considering openings with different layouts, X-1 and Z-3 have the most stiffness deteriorating and strength in such a way that stiffness deteriorating and strength were 39.93% and 37.89%, respectively, for Z-3 model and 38.68% and 43.33%, respectively, for Z-3 model.


Author(s):  
Ralph Alan Dusseau

The results of a study funded by the U.S. Geological Survey as part of the National Earthquake Hazards Reduction Program are presented. The first objective of this study was the development of a database for all 211 highway bridges along I-55 in the New Madrid region of southeastern Missouri. Profiles for five key dimension parameters (which are stored in the database) were developed, and the results for concrete highway bridges are presented. The second objective was to perform field ambient vibration analyses on 25 typical highway bridge spans along the I-55 corridor to determine the fundamental vertical and lateral frequencies of the bridge spans measured. These 25 spans included six reinforced concrete slab spans and two reinforced concrete box-girder spans. The third objective was to use these bridge frequency results in conjunction with the dimension parameters stored in the database to develop empirical formulas for estimating bridge fundamental natural frequencies. These formulas were applied to all 211 Interstate highway bridges in southeastern Missouri. Profiles for both fundamental vertical and lateral frequencies were then developed, and the results for concrete highway bridges are presented.


1985 ◽  
Vol 50 ◽  
Author(s):  
A. Atkinson ◽  
D. J. Goult ◽  
J. A. Hearne

AbstractA preliminary assessment of the long-term durability of concrete in a repository sited in clay is presented. The assessment is based on recorded experience of concrete structures and both field and laboratory studies. It is also supported by results of the examination of a concrete sample which had been buried in clay for 43 years.The enoineering lifetime of a 1 m thick reinforced concrete slab, with one face in contact with clay, and the way in which pH in the repository as a whole is likely to vary with time have both been estimated from available data. The estimates indicate that engineering lifetimes of about 103 years are expected (providing that sulphate resisting cement is used) and that pH is likely to remain above 10.5 for about 106 years.


2014 ◽  
Vol 606 ◽  
pp. 229-232 ◽  
Author(s):  
Petr Tej ◽  
Vítězslav Vacek ◽  
Jiří Kolísko ◽  
Jindřich Čech

The paper focuses on a computer nonlinear analysis of the formation and development of cracks in a concrete slab exposed to a uniform continuous load on the lower surface. The analysis is based on an actual example of the formation and development of cracks in a basement slab exposed to ground water buoyancy.


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