Research

Jump to: Review

13 pages, 4168 KiB

Open AccessArticle

Numerical Investigation of the Seismic Performance of an Innovative Type of Buckling-Restrained Brace (BRB)

by Ali Naghshineh, Oliver Fischer, Nasreen B. Pathan, Logan Couch and Fariborz M. Tehrani

Eng 2023, 4(4), 2978-2990; https://doi.org/10.3390/eng4040167 - 01 Dec 2023

Viewed by 945

Previous studies have demonstrated that the inclusion of tire-derived aggregate (TDA) enhances the damping, ductility, and toughness of concrete mixtures. The effectiveness of tire-derived aggregate as a ductile material with a higher damping ratio and lower density in buckling-restrained braces has been examined [...] Read more.

Previous studies have demonstrated that the inclusion of tire-derived aggregate (TDA) enhances the damping, ductility, and toughness of concrete mixtures. The effectiveness of tire-derived aggregate as a ductile material with a higher damping ratio and lower density in buckling-restrained braces has been examined at California State University’s Structures Laboratory (CSU). Through experimental and theoretical investigations, this study compares the structural application of buckling-restrained braces with TDA and with conventional concrete infill subjected to various ground motions as well as artificial excitations. The evaluations include modeling a full-scale experimental setup equipped with a single-leg BRB utilizing ETABS 2016 and OpenSees 2000 software. The effectiveness of the application is demonstrated through a comparison of accelerations, displacements, stiffness, and damping ratios between TDA and concrete filling. Additionally, a design guideline for TDA-filled buckling-restrained braced frames is provided. Full article

(This article belongs to the Special Issue Advances in Structural Analysis and Rehabilitation for Existing Structures)

► Show Figures

Figure 1

16 pages, 2951 KiB

Open AccessFeature PaperArticle

Assessment of Groundwater Contamination in the Southeastern Coast of Brazil: A Potential Threat to Human Health in Marica Municipality

by Maria Cristina M. Publio, Jessica F. Delgado, Bruno S. Pierri, Leonardo da S. Lima, Christine C. Gaylarde, José Antônio Baptista Neto, Charles V. Neves and Estefan M. Fonseca

Eng 2023, 4(4), 2640-2655; https://doi.org/10.3390/eng4040151 - 17 Oct 2023

Viewed by 942

Abstract

Groundwater pollution is a current issue that may result in considerable negative effects on human health and the ecological balance. In the present study, the authors evaluated pollutants in groundwater in Maricá Municipality, located on the east side of Rio de Janeiro state [...] Read more.

Groundwater pollution is a current issue that may result in considerable negative effects on human health and the ecological balance. In the present study, the authors evaluated pollutants in groundwater in Maricá Municipality, located on the east side of Rio de Janeiro state in Brazil. The evaluated parameters were temperature, pH, electrical conductivity, Eh, dissolved oxygen, chlorides, nitrates, dissolved organic carbon, total inorganic carbon, phosphates, and total and thermotolerant coliforms. Due to the large number of evaluated points, they were divided into zones according to the respective hydrographic basin. The local accelerated urbanization accompanying income from oil production has led to uncontrolled population growth and associated groundwater pollution. The results of the present study suggest that sewage pollution of Maricá groundwater is already a significant issue. The lack of investment in basic sanitation has led to an imbalance in the local groundwater reservoir. In certain locations of the municipality, dissolved organic carbon (DOC), nutrient, and bacteria concentrations increase and spread in the aquifers because of domestic waste disposal. As aquifers are the main source of freshwater for the residents, contamination of them represents a potential threat to local public health. Full article

(This article belongs to the Special Issue Advances in Structural Analysis and Rehabilitation for Existing Structures)

► Show Figures

Figure 1

28 pages, 11267 KiB

Open AccessArticle

A Parametric Study on the LDB Strength of Steel-Concrete Composite Beams

by Alexandre Rossi, Adriano Silva de Carvalho, Vinicius Moura de Oliveira, Alex Sander Clemente de Souza and Carlos Humberto Martins

Eng 2023, 4(3), 2226-2253; https://doi.org/10.3390/eng4030128 - 27 Aug 2023

Cited by 2 | Viewed by 723

Abstract

Lateral distortional buckling (LDB) is an instability phenomenon characteristic of steel-concrete composite beams (SCCB) that occurs in the presence of hogging moments in regions close to internal supports. The LDB behavior in SCCB is not yet fully understood. The procedures for determining the [...] Read more.

Lateral distortional buckling (LDB) is an instability phenomenon characteristic of steel-concrete composite beams (SCCB) that occurs in the presence of hogging moments in regions close to internal supports. The LDB behavior in SCCB is not yet fully understood. The procedures for determining the LDB strength are based on the classic lateral torsional buckling theory or on the inverted U-frame model. In addition, the standard procedures make use of the classic design curves of the SSRC (Structural Stability Research Council) and ECCS (European Convention for Constructional Steelwork) developed to analyze the stability behavior of steel elements. However, studies indicate that the use of the same empirical curves obtained for the analysis of steel elements leads to the conservative results of the LDB strength in SCCB. Therefore, this article aims to assess the LDB strength in SCCB through the development of post-buckling numerical analysis using the ABAQUS software. In the parametric study, four types of steel with different mechanical properties were analyzed. In addition, the I-section, the unrestrained length, and the reinforcement rate in the concrete slab were varied. The results showed the influence of the steel type on the LDB strength and deviations from the standard procedures. A small influence of the longitudinal reinforcement area variation was verified in the LDB strength in the FE analyses; however, this factor is significantly important in the standard procedures, causing considerable divergences. These results can provide a reference for future research and specification reviews. Full article

(This article belongs to the Special Issue Advances in Structural Analysis and Rehabilitation for Existing Structures)

► Show Figures

Figure 1

15 pages, 6721 KiB

Open AccessArticle

Insight into the Optimization of Implementation Time in Cob Construction: Field Test and Compressive Strength Versus Drying Kinetics

by Karim Touati, Baraa Al Sahmarany, Malo Le Guern, Yassine El Mendili, François Streiff and Steve Goodhew

Eng 2023, 4(3), 2075-2089; https://doi.org/10.3390/eng4030117 - 25 Jul 2023

Cited by 1 | Viewed by 1283

Abstract

Mastering construction times is of paramount importance in making vernacular earth construction techniques attractive to modern clients. The work presented here is a contribution towards the optimization of the construction time of cob buildings. Therefore, this paper follows the evolution of a cob’s [...] Read more.

Mastering construction times is of paramount importance in making vernacular earth construction techniques attractive to modern clients. The work presented here is a contribution towards the optimization of the construction time of cob buildings. Therefore, this paper follows the evolution of a cob’s mechanical properties during its drying process in the case of a double-walling CobBauge system. Laboratory tests and in situ measurements were performed, and further results were described. Volumetric water content sensors were immersed in the walls of a CobBauge prototype building during its construction. The evolution of the cob layer’s compressive strength and Clegg Impact Value (CIV) as a function of its water content has been experimentally studied and discussed. These studies showed that compressive strength and CIV are correlated with water content, and both properties decrease exponentially with time. In this study, a new tool to evaluate cob’s mechanical performances in situ has been proposed, Clegg Impact Soil Tester. This was linked to compressive strength, and a linear relationship between these two properties was found. Finally, appropriate values of compressive strength and CIV to satisfy before formwork stripping and re-lifting were proposed. For this study’s conditions, these values are reached after approximately 27 days. Full article

(This article belongs to the Special Issue Advances in Structural Analysis and Rehabilitation for Existing Structures)

► Show Figures

Figure 1

19 pages, 7570 KiB

Open AccessFeature PaperArticle

Seismic Resilience and Design Factors of Inline Seismic Friction Dampers (ISFDs)

by Ali Naghshineh, Ashutosh Bagchi and Fariborz M. Tehrani

Eng 2023, 4(3), 2015-2033; https://doi.org/10.3390/eng4030114 - 18 Jul 2023

Viewed by 1163

Abstract

While damping devices can provide supplemental damping to mitigate building vibration due to wind or earthquake effects, integrating them into the design is more complex. For example, the Canadian code does not provide building designs with inline friction dampers. The objective of this [...] Read more.

While damping devices can provide supplemental damping to mitigate building vibration due to wind or earthquake effects, integrating them into the design is more complex. For example, the Canadian code does not provide building designs with inline friction dampers. The objective of this present article was to study the overstrength, ductility, and response modification factors of concrete frame buildings with inline friction dampers in the Canadian context. For that purpose, a set of four-, eight-, and fourteen-story ductile concrete frames with inline seismic friction dampers, designed based on the 2015 National Building Code of Canada (NBCC), was considered. The analyses included pushover analysis in determining seismic characteristics and dynamic response history analysis using twenty-five ground motion records to assess the seismic performance of the buildings equipped with inline seismic friction dampers. The methodology considered diagonal braces, including different 6 m and 8 m span lengths. The discussion covers the prescribed design values for overstrength, ductility, and response modification factors, as well as the performance assessment of the buildings. The results revealed that increasing the height of the structure and reducing the span length increases the response modification factors. Full article

(This article belongs to the Special Issue Advances in Structural Analysis and Rehabilitation for Existing Structures)

► Show Figures

Figure 1

19 pages, 3466 KiB

Open AccessFeature PaperArticle

Improved Structural Health Monitoring Using Mode Shapes: An Enhanced Framework for Damage Detection in 2D and 3D Structures

by Marzieh Zamani Kouhpangi, Shaghayegh Yaghoubi and Ahmadreza Torabipour

Eng 2023, 4(2), 1742-1760; https://doi.org/10.3390/eng4020099 - 19 Jun 2023

Cited by 1 | Viewed by 1238

Abstract

Structural health monitoring (SHM) is crucial for ensuring the safety and performance of offshore platforms. SHM uses advanced sensor systems to detect and respond to negative changes in structures, improving their reliability and extending their life cycle. Model updating methods are also useful [...] Read more.

Structural health monitoring (SHM) is crucial for ensuring the safety and performance of offshore platforms. SHM uses advanced sensor systems to detect and respond to negative changes in structures, improving their reliability and extending their life cycle. Model updating methods are also useful for sensitivity analysis. It is feasible to discuss and introduce established techniques for detecting damage in structures by utilizing their mode shapes. In this research, by considering reducing the stiffness of elements in the damage scenarios, we conducted simulations of the models in MATLAB, including both two-dimensional and three-dimensional structures, to update the method suggested by Wang. Wang’s method was improved to produce a sensitivity equation for the damaged structures. The sensitivity equation solution using a subset of mode shapes data was found to evaluate structural parameter changes. Comparing the updated results for Wang’s method and the suggested method in the two- and three-dimensional frames showed a noticeable modification in damage recognition. Furthermore, the suggested method can update a model containing measurement errors. Since Wang’s damage detection formulation is suitable only for 2D structures, this modified framework provides a more accurate decision-making tool for damage detection of structures, regardless of whether a 2D or 3D formulation is used. Full article

(This article belongs to the Special Issue Advances in Structural Analysis and Rehabilitation for Existing Structures)

► Show Figures

Figure 1

25 pages, 9354 KiB

Open AccessArticle

Chemo-Thermo-Mechanical FEA as a Support Tool for Damage Diagnostic of a Cracked Concrete Arch Dam: A Case Study

by Noemi Schclar Leitão and Eloísa Castilho

Eng 2023, 4(2), 1265-1289; https://doi.org/10.3390/eng4020074 - 22 Apr 2023

Cited by 1 | Viewed by 1168

Abstract

Most of the larger hydropower plants in Western Europe, the former Soviet Union, North America and Japan were constructed between the 1940s and 1970s. This implies that the rehabilitation or repair of existing dams is a top priority, which entails new challenges for [...] Read more.

Most of the larger hydropower plants in Western Europe, the former Soviet Union, North America and Japan were constructed between the 1940s and 1970s. This implies that the rehabilitation or repair of existing dams is a top priority, which entails new challenges for the dam engineering community. Since no two dams are the same, in cases in which abnormal behavior is suspected, an in-depth diagnosis of the state of the dam to define the causes and consequences of the damage is required. To illustrate the diagnostic process, an old concrete arch dam is presented which showed signs of reservoir water seepage through some construction joints, resulting in a buildup of calcium carbonate on the downstream face. After analyzing the available data, we put forward a hypothesis that the high temperature gradient promoted the opening of some construction joints on the upstream face during the first filling of the reservoir. Over time, water penetration expanded the cracks, reaching the downstream face. To prove our diagnosis, a chemo-thermo-mechanical finite element analysis was carried out in order to simulate the behavior of the dam during its construction and initial impoundment. Full article

(This article belongs to the Special Issue Advances in Structural Analysis and Rehabilitation for Existing Structures)

► Show Figures

Figure 1

Review

Jump to: Research

20 pages, 6998 KiB

Open AccessReview

Surface Waterproofing Techniques: A Case Study in Nova Lima, Brazil

by Lorena Carias de Freitas Gomes, Henrique Comba Gomes and Elvys Dias Reis

Eng 2023, 4(3), 1871-1890; https://doi.org/10.3390/eng4030106 - 04 Jul 2023

Cited by 1 | Viewed by 2777

Abstract

Considering the various problems caused by infiltration in civil construction, this study aimed to identify the most appropriate waterproofing methods for different types of surfaces. A study was conducted on the mechanisms of water infiltration on surfaces and the waterproofing methods available on [...] Read more.

Considering the various problems caused by infiltration in civil construction, this study aimed to identify the most appropriate waterproofing methods for different types of surfaces. A study was conducted on the mechanisms of water infiltration on surfaces and the waterproofing methods available on the market, focusing on asphalt blankets, in addition to a literature review highlighting state-of-the-art methods on this topic. A case study was also conducted in a residence in Nova Lima, Brazil, analyzing different waterproofing techniques, including their characteristics and stages. Among the conclusions, it is highlighted that the implementation of adequate project, installation, inspection, and maintenance techniques can significantly reduce the waterproofing failure rate and repair costs, and that the excellent choice of materials, along with the skill of the labor force in the application, is fundamental to guarantee the adequate performance of these materials in buildings. Full article

(This article belongs to the Special Issue Advances in Structural Analysis and Rehabilitation for Existing Structures)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Advances in Structural Analysis and Rehabilitation for Existing Structures

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (8 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI