The progressive deterioration of flexible pavements, driven by increasing traffic loads, environmental influences, and material aging, necessitates the implementation of effective structural reclamation strategies to restore functional performance and extend service life. This study focuses on a critical segment of the Libyan coastal road network, specifically the 27.5 km part from Tripoli Street Bridge to Al-Krarim Gate. An analytical and quantitative investigation is undertaken to evaluate the structural condition and rehabilitation potential of the existing flexible pavement system, with particular attention to distress mechanisms, material degradation, and the effectiveness of various rehabilitation techniques. The assessment integrates field investigations, laboratory testing, based on AASHTO 1993, and to evaluate pavement distress, base soil strength, and asphalt concrete layers performance; Pavement Condition Index (PCI) values and core sample analyses are employed to determine the extent of structural failure. Visual distress surveys supplement the data to provide a comprehensive understanding of surface and sub-surface conditions. Analytical modeling, based on layered elastic theory is used to simulate pavement response under rehabilitated conditions and forecast long-term performance under loading. The study examines several rehabilitation methods, including full-depth reclamation (FDR), cold in-place recycling (CIR), and mechanical stabilization using cementitious additives. Each method is evaluated based on structural capacity enhancement, cost-efficiency, and service life extension. Results demonstrate that the selection of reclamation techniques tailored to subgrade conditions and traffic loads significantly improves structural performance and minimizes maintenance needs. The study concludes that full-depth repaving offers the most sustainable and economically viable solution for restoring the targeted roadway section.

Abstract:

The construction of residential buildings in the state of Libya has become increasingly expensive, necessitating cost-effective design solutions. Structural engineers play a critical role in reducing construction costs while ensuring safety and efficiency. One approach to achieving an optimal design is minimizing the dimensions of structural elements ,a critical factor influencing structural performance and economy is the rigidity of beam-to-column connections, which significantly affects deformations and then internal forces. According to beam bending theory, bending moments and shear forces are directly proportional to deformation. Therefore, reducing primary curvature leads to a decrease in design moments, allowing for more economical structural sections. This study investigates the impact of considering partial rigidity in beam-to-column connections within reinforced concrete (RC) frame, particularly for single-story buildings. In conventional structural design, connections are often assumed to be either fully rigid or fully pinned, neglecting partial rigidity effects. This oversimplified modeling approach results in overdesign and increased material consumption, deviating from sustainability principles. The research use SAP2000 structural analysis software to assess various degrees of connection rigidity and their influence on member deformation. The findings indicate that incorporating realistic connection rigidity can reduce beam deformation by up to 20% (at 0.7 rigidity) , leading to smaller and more cost-effective frame sections. Furthermore, common construction methods in the state of Libya inherently provide a certain degree of rigidity at beam-to-column interfaces, yet current design practices often overlook this advantage. This study underscores the importance of optimizing beam-to-column connection rigidety to enhance structural performance, reduce material usage, and align with sustainable design principles. The findings contribute to improving cost efficiency in RC frame construction, providing valuable insights for engineers seeking to optimize structural design in residential buildings

Keywords:Beam-to-Column,Connection, Sustainability, Optimum Design , Rigidety

Abstract::

This paper presents a comprehensive analysis of linear and nonlinear structural analysis methods, evaluating their Its effect in optimizing and sustaining structural designs. By leveraging advanced scientific data and analytical techniques, this study aims to discern the optimal conditions and scenarios for employing each method. The research includes detailed calculations, comparative data, and case studies, emphasizing the sustainability implications and long-term benefits of each approach.

Abstract::

The growing urgency for sustainable construction practices has necessitated a reevaluation of traditional design approaches in favor of more environmentally responsible methodologies. This paper presents a comparative analysis between optimal and adequate structural design within the context of sustainable construction. Focusing on two case studies—a cutting-edge, sustainably designed commercial building (the Bullitt Center) and a conventional mid-rise residential building in Chicago—the research explores how different design philosophies impact material efficiency, environmental footprint, economic performance, and occupant satisfaction.Through detailed life cycle assessments (LCA) and life cycle energy analyses (LCEA), the study quantifies the advantages of optimal design, which integrates advanced materials, renewable energy systems, and water conservation technologies. The findings demonstrate that while optimal design requires a higher initial investment, it significantly reduces long-term operational costs and environmental impact, achieving a net-zero energy status and greatly improving occupant well-being. In contrast, the conventional building, which adheres to standard design practices, exhibits higher embodied energy, greater environmental degradation, and lower occupant satisfaction.The paper concludes that optimal structural design is not only more sustainable but also economically viable over the building's life span. It emphasizes the importance of integrating sustainability from the earliest stages of design to achieve meaningful environmental and economic benefits. The study calls for the adoption of policy incentives and advanced modeling tools to facilitate the widespread implementation of optimal design principles in the construction industry.

Abstract

This investigation examines the performance of tension and compression connections in steel beam-column assemblies and concrete slabs, with a particular focus on end-plate joints employing four bolts. By utilising advanced finite element modelling (FEM) and simulation techniques, the study aims to elucidate the behaviour of these joints under both service and extraordinary load conditions. While these connections exhibit favourable flexibility and resilience during typical use, they present challenges in transmitting exceptional loads without incurring joint failure and potential structural collapse, particularly when subjected to unexpected loading scenarios. The research employs a meticulous analytical approach utilising ABAQUS/CAD software. This analysis incorporates a comprehensive evaluation of various parameters, including inherent structural imperfections, material properties, the interplay between steel and concrete, and the influence of non-linear material behaviour. The findings indicate that while these joints perform adequately under standard loading conditions, they may exhibit susceptibility to failure under extreme stresses. This underscores the critical need for the development of adaptable and robust steel beam-column connections to ensure paramount structural safety and stability. Furthermore, the study emphasises the significance of continuous advancements in modelling and simulation techniques, enabling the effective resolution of intricate structural challenges. This investigation offers valuable insights that can be harnessed to develop more efficient and secure composite steel-concrete structures. Furthermore, the study emphasises the significance of continuous advancements in modelling and simulation techniques, which can be employed to mitigate potential structural hazards and enhance building practices, ultimately leading to safer and more resilient structures. © 2024 by authors, all rights reserved.

Author keywords

ABAQUS/CADComposite JointsDurabilityEnd Plate ConnectionsExceptional LoadsFlexibilitySimulation

• ISSN: 23321091
• Source Type: Journal
• Original language: English
• DOI: 10.13189/cea.2024.120437
• Document Type: Article
• Publisher: Horizon Research Publishing

  Saleh, B.; Department of Civil Engineering, School of Science Engineering, Libyan Academy, State of Libya

© Copyright 2024 Elsevier B.V., All rights reserved.

Buildings exert a profound influence on the environment, with the design phase recognized as the pivotal determinant of a building’s overall performance. Green building design, in particular, introduces heightened complexity, where the attributes of the design team play a pivotal role in shaping performance outcomes. Consequently, the characteristics of the design team emerge as crucial factors in the enhancement of both green building design performance and client attributes. This study aims to empirically examine a model formulated to gauge the extent to which Effective Design Team Attributes contribute to the enhancement of performance in designing green buildings and influencing client attributes. To achieve this objective, a comprehensive questionnaire survey was administered to professionals within the architecture and engineering domains actively engaged in the design and consulting sectors of the building industry. The collected data underwent meticulous scrutiny for authenticity and dependability using the WINSTEPS 5.2.5 software before undergoing subsequent analysis. Statistical analyses were conducted using SPSS version 19, with Principal Components Analysis (PCA) and the Structural Equation Modeling (SEM) approach implemented through Amos version 18 to derive the most robust model. The findings underscore the pivotal role of an adeptly managed design team in significantly improving both the performance of green building designs and the qualities of clients. Rasch’s analysis confirmed the validity of our 5-point Likert scale for Design Green Building Performance (DGBP), Effective Design Team Attributes …

Abstract

Depending on the type of configuration and connector arrangement, beam-to-column end-plate joints can be rigid, semi-rigid, or pinned. Fully restrained joints are required for rigid frames in which it is anticipated that the frame joints will have adequate rigidity to maintain the angles between intersecting parts in the service condition, ensuring full moment transfer. In contrast, partially restrained joints in semi-continuous frames are distinguished by relative rotations between crossing members, allowing the bending force to be transferred only partially. The concept of utilizing partially restricted, unstiffened joints in construction has gained traction since it looks to be more feasible and inexpensive. Bending transfer in partially constrained joints allows semi-continuous frames to withstand actions. Semi-continuous frames can survive actions due to bending transfer in partially restricted joints. At the same time, a certain degree of rotation is permitted, which improves the overall ductility of these structures. Using thinner end plates than those used in practical applications is one of the most effective ways to affect the ductility of end-plate beam-to-column joints. It was confirmed in a previous experimental study that the composite joints, where the thickness of the end plates is equivalent to about 60% of the diameter of the bolt used in composite joints, were taken into account in subsequent tests, and these studies can be confirmed using ABAQUS and Ls-Dyna modelling. All of these concerns are addressed, and recommendations for numerical modelling methodologies are made in order to ultimately analyse the reaction of the symmetric extended end plate joints with 8-bolts under hogging and sagging bending moments.