Practical expressions to calculate the main vertical actions on load-bearing columns/walls to Eurocode

2017 ◽  
Vol 15 (4) ◽  
pp. 418-435 ◽  
Author(s):  
Osama A.B. Hassan
Keyword(s):  
Engineering Students ◽  
Civil Engineering ◽  
Limit State ◽  
Point Of View ◽  
Ultimate Limit State ◽  
Building Structures ◽  
Load Bearing ◽  
Content Type ◽  
Structural Membranes ◽  
Wind Actions

Purpose The aim of this review study is to present useful and practical expressions to compute the design vertical actions on load-bearing columns/walls of typical building structures on the basis of EN 1991: Eurocode 1. Design/methodology/approach It is derived by a typical case in which wind actions, snow actions and permanents actions are loading a roof construction. The results are finally used to calculate the loading on columns/walls. Both ultimate limit state and serviceability limit state are considered. Findings From an instructive point of view, the advantage of this method is that it is simplified, general, not time-consuming, and it can be standardised to typical building structures. Research limitations/implications A number of example applications are introduced to illustrate the calculation procedure. Practical implications From an educational point of view, this problem is of interest to civil engineering students because the reviewed method is not cumbersome or time-consuming. Social implications From an engineering educational point of view, this problem is of interest to civil engineering students because the reviewed method is not cumbersome or time-consuming. Originality/value New formulated expressions to calculate the loadings on structural membranes based on Eurocode are presented.

scholarly journals Practical Model Proposed for the Structural Analysis of Segmental Tunnels

2020 ◽  
Vol 10 (23) ◽  
pp. 8514
Author(s):  
Jatziri Y. Moreno-Martínez ◽  
Arturo Galván ◽  
Fernando Peña ◽  
Franco Carpio
Keyword(s):  
Finite Element ◽  
Soft Soil ◽  
Limit State ◽  
Structural Response ◽  
3D Models ◽  
Complex Model ◽  
Numerical Results ◽  
Point Of View ◽  
Simplified Model ◽  
Ultimate Limit State

The construction of tunnels has become increasingly common in city infrastructure; tunnels are used to connect different places in a region (for transportation and/or drainage). In this study, the structural response of a typical segmental tunnel built in soft soil was studied using a simplified model which considers the coupling between segmental rings. From an engineering point of view, there is a need to use simple and reliable finite element models. Therefore, a 1D model based on the Finite Element Method (FEM) composed of beam elements to model the segments and elastic-linear springs and non-linear springs to model the mechanical behavior of the joints was performed. To validate the modeling strategy, the numerical results were compared to (lab-based) experimental results, under an Ultimate Limit State, obtained from the literature, and a comparison between numerical results considering a 3D numerical complex model which included the nonlinearity of concrete, reinforcing steel and the joints was performed. With this simplified model, we obtained a prediction of approximately 95% of the ultimate loading capacity compared to the results developed in the experimental and 3D models. This proposed model will help engineers in practice to create “rational” structural designs of segmental tunnel linings when a “low” interaction between rings is expected.

scholarly journals Reliability of Buried Pipes in Heterogeneous Soil Subjected to Seismic Loads

2021 ◽  
Vol 11 (1) ◽  
pp. 6708-6713
Author(s):  
H. Benzeguir ◽  
S. M. Elachachi ◽  
D. Nedjar ◽  
M. Bensafi
Keyword(s):  
Structural Reliability ◽  
Limit State ◽  
Bending Moment ◽  
Longitudinal Direction ◽  
Point Of View ◽  
Ultimate Limit State ◽  
Buried Pipe ◽  
Limit States ◽  
Ground Acceleration ◽  
Buried Pipes

Dysfunctions and failures of buried pipe networks, like sewer networks, are studied in this paper from the point of view of structural reliability and heterogeneity of geotechnical conditions in the longitudinal direction. Combined soil spatial variability and Peak Ground Acceleration (PGA) induce stresses and displacements. A model has been developed within the frame of geostatistics and a mechanical description of the soil–structure interaction of a set of buried pipes with connections resting on the soil by a two-parameter model (Pasternak model). Structural reliability analysis is performed considering two limit states: Serviceability Limit State (SLS), related to large "counter slope" in a given pipe, and Ultimate Limit State (ULS), corresponding to bending moment.

scholarly journals METHODS FOR CALCULATING RECTANGULAR SECTION BEAMS MADE OF WOOD AND CONCRETE

2021 ◽  
pp. 1-5
Author(s):  
Ksenia Olegovna Dubrakova ◽  
Viacheslav Aseev ◽  
Aleksey Bulgakov
Keyword(s):  
Comparative Analysis ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Rectangular Cross Section ◽  
Limit State ◽  
Experimental Studies ◽  
Ultimate Limit State ◽  
Numerical Comparison ◽  
Building Structures ◽  
Ultimate Limit

The research aimed to study methods for calculating wood-concrete beams of rectangular cross-section when testing building structures according to the ultimate limit state. The article focuses on the comparison of theoretical methods for calculating structures and considers several methods of fastening the samples of a typical wood-concrete beam. There were obtained experimental data of the ultimate limit state for each sample and carried out a comparative analysis of the most advantageous scheme of fastening the sample parts. The scientific novelty is in the development of an algorithm for calculating composite wood-concrete beams of rectangular cross-sections. As a result, numerical comparison of the values for calculating a typical wood-concrete beam using two of the methods under consideration was given, experimental studies were carried out, as well as a comparative analysis of the obtained theoretical and experimental results.

Seismic behavior evaluation of zipper braced steel frames based on push-over and incremental dynamic analyses

2019 ◽  
Vol 16 (3) ◽  
pp. 401-411
Author(s):  
J. Esfandiari ◽  
Y. Khezeli
Keyword(s):  
Dynamic Analysis ◽  
Fragility Curves ◽  
Limit State ◽  
Steel Structures ◽  
Ultimate Limit State ◽  
Vertical Force ◽  
Braced Frames ◽  
Response Modification Factor ◽  
Content Type ◽  
Modification Factor

Purpose An analytical investigation is performed on zipper-braced frames. Zipper-braced frames are an innovative bracing system for steel structures. Conventional inverted-V-braced frames exhibit a design problem arising from the unbalanced vertical force generated by the lower story braces when one of them buckles. This adverse effect can be mitigated by adding zipper columns or vertical members connecting the intersection points of the braces above the first floor. Design/methodology/approach This paper critically evaluates over strength, ductility and response modification factors of these structures. To achieve the purpose of this research, several buildings of different stories are considered. Static pushover analysis, linear dynamic analysis and nonlinear incremental dynamic analysis are performed by OpenSees software concerning ten records of past earthquakes. Findings Also, ductility factor, over strength factor and response modification factor, has been calculated for zipper-braced frames system. The values of 3.5 and 5 are suggested for response modification factor in ultimate limit state and allowable stress methods, respectively. Originality/value The fragility curves were plotted for the first time for such kind of braces. It should be mentioned that these curves play significant roles in evaluating seismic damage of buildings.

scholarly journals Some considerations on shear and torsion in R/C structural members in fire

2018 ◽  
Vol 9 (2) ◽  
pp. 94-107 ◽  
Author(s):  
Patrick Bamonte ◽  
Pietro G. Gambarova ◽  
Nataša Kalaba ◽  
Sergio Tattoni
Keyword(s):  
Limit State ◽  
Ultimate Limit State ◽  
Structural Members ◽  
Zone Method ◽  
Concrete Core ◽  
Content Type ◽  
Dowel Action ◽  
In Fire ◽  
Ultimate Limit ◽  
Fire Conditions

Purpose This study aims to provide a factual justification of the extension to fire conditions of the well-known design models for the calculations of R/C members at the ultimate limit state in shear and torsion. Both solid and thin-walled sections are considered. In the latter case, the little-known topic of shear-transfer mechanisms at high temperature is introduced and discussed. Design/methodology/approach Both the effective-section method and the zone method are treated, as well as the strut-and-tie models required by the analysis of the so-called D zones (discontinuity zones), where heat-enhanced cracking further bears out the phenomenological basis of the models. Findings The increasing role played by the stirrups in shear and by the rather cold concrete core in torsion stand out clearly in fire, while high temperatures rapidly reduce the contributions of such resisting mechanisms as concrete-teeth bending, aggregate interlock and dowel action. Originality/value On the whole, beside quantifying the side contributions of web mechanisms and section core in fire conditions, this study indicates a possible approach to extend to fire the available models on the coupling of shear and bending, and shear and torsion in R/C members.

Work integrated learning model in relation to CDIO standards

2016 ◽  
Vol 8 (3) ◽  
pp. 278-286 ◽  
Author(s):  
Staffan Schedin ◽  
Osama A.B. Hassan
Keyword(s):  
Engineering Students ◽  
Learning Model ◽  
Geographic Region ◽  
Point Of View ◽  
Integrated Learning ◽  
Study Program ◽  
Content Type ◽  
Positive Effects ◽  
Industrial Companies ◽  
Work Integrated Learning

Purpose – The purpose of this paper is to develop a practical model of work integrated learning for undergraduate engineering students in relation to Conceiving-Designing-Implementing-Operating standards 7 (Integrated Learning Experiences) and 8 (Active Learning). Moreover, it is discussed the role of cultural-social perspective and peer learning in enhancing the developed learning model from a pedagogical point of view. Design/methodology/approach – The model is based on an organized collaboration with the industrial partners in the surrounding geographic region. As a part of the collaboration, each participating student is guaranteed internships at a chosen company over the summer period. In the model, company-based projects are integrated with some of the study program courses. Moreover, the participating students are given a possibility to perform their final thesis at the chosen company. Findings – A number of positive effects have been observed and documented as follows: first, the integrated learning improves the learning process for the students, where learning, knowledge and practice are integrated into the engineering curricula; second, the general quality of the study programs in the faculty has been developed and improved based on the professional skills as required by modern industrial companies; and third, the obtained advantage for the industrial partners has been to establish professional contacts with the students as well as the possibility to be acquainted with potential future employees. Research limitations/implications – The feedback the authors received so far from the industrial partners has been positive. A detailed evaluation will be made at a later stage when more information is available. Practical implications – The developed learning model supports the expected learning outcomes, especially with regard to interpersonal skills, teamwork and communication. As a part of the collaboration, each participating student is guaranteed internships at a chosen company over the summer periods. The authors consider this collaboration as a “win-win situation” for the three parties involved in the learning model: the students, the university/faculty and the industrial partners. Originality/value – Case study based on observations and evaluation of a developed learning model.

Facade inspections with drones–theoretical analysis and exploratory tests

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jorge Furtado Falorca ◽  
João Carlos Gonçalves Lanzinha
Keyword(s):  
Civil Engineering ◽  
Early Stage ◽  
Field Tests ◽  
Building Envelope ◽  
Point Of View ◽  
Qualitative Assessment ◽  
High Definition ◽  
Promising Alternative ◽  
Content Type ◽  
Technical Inspection

PurposeThis paper presents a reflection on the effectiveness of using drones in the technical inspection of building facades, as a practical alternative to more expensive and heavier conventional means. In order to verify this assumption qualitatively, a number of field tests are presented and discussed.Design/methodology/approachThe first stage consisted of a literature review. The analysis initially investigated drone technology. Then, an insight into some general applications in Civil Engineering was compiled, focusing in particular on the Construction Industry (CI), as well as the scope of building envelope inspections. In the second stage, field tests with drones were performed and the resulting data was appraised in order to get facade pathologies diagnosis as accurate as possible.FindingsThrough this study, the adaptability and versatility of using drones were checked. Thus, it has been confirmed that drone technology is an effective and promising alternative methodology to support technical inspection and diagnosis of building envelope pathologies. In fact, drones seem to be a worthwhile tool for supporting certain Civil Engineering activities–particularly when displaying a multirotor configuration, loading high-definition (HD) cameras, for both stills photography and video.Research limitations/implicationsAs the main goal of this approach was simply a qualitative assessment of evidence on the advantages of using drones compared with conventional means, other kinds of comparative analysis were not discussed in depth. However, this and other potential restrictive issues may represent an opportunity to push more developments. A deeper knowledge of data handling and clear procedures for the use of drones could be very valuable for the CI and for building envelope inspections.Practical implicationsIn investigating this subject, this research can offer valuable input to enable a greater awareness of the use of drones in the technical inspection of buildings, particularly in hard-to-reach locations, to the detriment of conventional means. In these circumstances, this methodology can bring great benefits, particularly from an environmental impact point of view, since the resources used are much lower. In addition, a very reliable diagnosis can be achieved more quickly, and at a much lower cost.Originality/valueThe introduction of a standard for drone inspection practice is still at an early stage, with initial steps being taken in an apparently well-focused effort to achieve consolidation. Research studies of this kind may have an important role to play in drawing the stakeholders' attention to the benefits of using this technique, particularly for those working in the building usage phase.

Afterthoughts of a Founding Structural Control Theorist

2011 ◽  
Author(s):  
Richard E. Klein
Keyword(s):  
Structural Control ◽  
Civil Engineering ◽  
Cost Effective ◽  
Building Structures ◽  
Engineering Structures ◽  
Load Bearing ◽  
Framed Structures ◽  
Spatially Distributed ◽  
Civil Engineering Structures ◽  
Interior Walls

This paper reflects back on the author’s research in structural control, originating in the early 1970’s. Upon reflection, in the early 1970’s and even as far as into the 1990’s, it constituted near heresy to suggest that large civil engineering structures could be candidates for control. The previous techniques of the 1930’s of building structures with masonry and stone were then being phased out, being replaced with lighter and more cost-effective steel-framed structures. The newer designs then emerging in the late 1960’s and early 1970’s were steel-framed structures that functioned as cantilevered tubes. The characteristic designs emerging included an absence of stone or masonry especially around the steel pillars, glass or similar non-load bearing cladding. Additionally, interior walls were non-load bearing affording more spacious rooms as well as affording the occupants the ability to reposition interior walls as desired. Moreover, the newly emerging steel-framed structures with increased compliance properties were increasingly prone to wind excitations as compared to the prior generation of structures. As a consequence, a number of these newer structures exhibited increased sway and other related dynamic behaviors. My mechanical engineering servomechanisms background included groundings in observability, controllability, as well as control of spatially distributed systems. Therefore, I felt confident then that control systems theoretic methods held promise to produce favorable and cost-effective results if properly applied to problematic civil engineering structures. That confidence still remains. I also realized the critical importance of being able to design structures in advance to be controlled, as opposed to the less desirable situation of dealing with an after-the-fact retrofit of an existing problematic structure. This paper affords an opportunity for the author to provide his anecdotal recollections and afterthoughts. Because the story to be told is of personal recollections, it is presented in first person.

scholarly journals Optimization of RC Structures in Terms of Cost and Environmental Impact—Case Study

2020 ◽  
Vol 12 (20) ◽  
pp. 8532
Author(s):  
Michal Ženíšek ◽  
Jan Pešta ◽  
Martin Tipka ◽  
Vladimír Kočí ◽  
Petr Hájek
Keyword(s):  
Reinforced Concrete ◽  
Environmental Impact ◽  
Environmental Impacts ◽  
Point Of View ◽  
Building Structures ◽  
Construction Costs ◽  
Load Bearing ◽  
Rc Structures ◽  
Rc Building

Reinforced concrete (RC) structures represent one of the most widespread building systems around the world. This paper deals with the optimization of load-bearing RC structures in terms of cost and environmental impact. The results of the optimization are the dimensions and reinforcement of structural elements for which the total construction costs and environmental impacts are the lowest. Six variants of RC building structures were designed and analyzed in a case study. The construction cost was evaluated on the basis of the national pricing system. The life cycle assessment (LCA) characterization model according to the ReCiPe methodology version 1.08 was used to assess environmental impacts. The main motivation of this article was to show the possibilities of the multi-criteria optimization of a load-bearing structure, not only from a structural point of view but also from economic and environmental points of view. The presented conclusions correspond to this specific construction of the RC structure used in the case study and may not be generalized. Nevertheless, they point to certain trends and patterns that can also be used in the design of other reinforced concrete structures. The method used in this case study could be applied to the analysis of other structures using specific datasets for cost and environmental impact evaluation.

Design and behaviour of R.C. beams to ACI318-and-SBC304; and EC2 codes when subjected to asymmetric loading

2014 ◽  
Vol 12 (2) ◽  
pp. 158-176
Author(s):  
Ayed E. Alluqmani
Keyword(s):  
Shear Failure ◽  
Limit State ◽  
Shear Capacity ◽  
Design Approach ◽  
Ultimate Limit State ◽  
Structural Requirements ◽  
Content Type ◽  
Limit State Design ◽  
Applied Loading ◽  
Strength Design

Purpose – Reinforced concrete (R.C.) beams are part of the structure so their design depends on the structural code and its requirements. In this paper, two simply supported R.C. beams were designed in terms of flexural and shear strength design requirements and investigated in terms of deflections and crack widths, when subjected to two asymmetric concentrated loadings, where one load is double the other one. Both beams had dimensions of 3,500 mm length, 200 mm width, and 300 mm height. The first beam (beam B1) was designed according to the combination of the structural requirements of American and Saudi building codes (ACI318-and-SBC304), while the second beam (beam B2) was designed according to the structural requirements of Eurocode (EC2). The paper aims to discuss these issues. Design/methodology/approach – The design of ultimate capacity (section capacity) to design both flexure and shear capacity according to the design provisions in EC2 code deals with the Ultimate Limit State Design Approach, while it deals with the Ultimate Strength Design Approach according to the design provisions in both ACI318 and SBC304 codes. In the serviceability (mid-span deflection and flexural crack width) check, the three codes deal with the Serviceability Limit State Design Approach. Findings – The laboratory behaviour of both test beams was as expected in flexure and failed in shear, but there was more shear cracks in the left shear span for both beams. This refers to the left applied loading and the spacing of shear links, where the failure occurred at the higher loading points. Perhaps, if the number of links was increased in the left side of the beam during the manufacture and reinforcing of the beam, the failure loading will be delayed and the diagonal cracks will be decreased. Originality/value – From this study, it was concluded that: the ACI318 and SBC304 design approaches are safer than the EC2 design approach. The EC2 design approach is more economic than the ACI318 and SBC304 design approaches. The structural behaviour of both test beams was as expected in flexure but both beams failed in shear. The shear failure was in the left side of both test beams which was referred to a high loading point. Diagonal cracks followed the applied loading until both beams reached to the failure.

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