Construction Technologies and Architecture Vol. 23

Abstract: Reinforced concrete (RC) shear walls are fundamental lateral load–resisting components in high-rise structures, where their seismic performance is critical to ensuring structural safety. This study presents a nonlinear seismic performance evaluation of an RC shear wall using modal pushover analysis in SAP2000, with advanced material models calibrated from experimental stress–strain data. Four concrete mixes were investigated: plain concrete (PC), 2% nano-silica doped concrete (NS), 2% nano-calcium carbonate doped concrete (NC), and a 1% nano-silica + 1% nano-calcium carbonate doped concrete (NSC). The wall geometry and layered cross-section were modeled in accordance with established experimental benchmarks, while nonlinear constitutive properties were directly assigned from reported experimental curves. Pushover capacity curves (base shear–displacement) were analyzed to assess stiffness, strength, ductility, and energy dissipation. Results indicate that PC exhibited the lowest seismic capacity. NS enhanced stiffness but showed lowest ductility. The NC model provided highest ductility with balanced strength and NSC delivered the most balanced and superior performance, achieving synergistic gains in both strength and ductility. These findings highlight the potential of nanoparticle-modified concrete to significantly enhance the seismic resilience of RC shear walls, offering valuable insights for advancing performance-based seismic design in high-rise construction.

Abstract: This paper presents a comparative seismic performance evaluation of reinforced concrete (RC) buildings Fiber-reinforced elastomeric isolator (FREI), and fiber-reinforced nanocomposite elastomeric isolator (FRNEI) configurations using Response Spectrum Analysis (RSA) in ETABS, following ASCE 7‑22 provisions. A regular G+8 RC moment-resisting frame was analyzed under Site Class D conditions, with isolator properties corresponding to a 67 kN axial load case derived from experimental data. Response parameters such as maximum lateral displacement and story shear in both principal directions were examined to quantify the influence of isolation stiffness on seismic demands. Results indicate that both FREI and FRNEI systems substantially reduce story shear compared to the fixed base, with FREI producing larger base displacements and FRNEI achieving additional reductions in both displacement and shear due to its higher lateral stiffness and improved damping, as nano clay is used as a nanocomposite material. The findings confirm that FRNEI offers a more balanced performance, effectively limiting deformation while maintaining isolation benefits, thereby enhancing the seismic resilience of mid-rise RC buildings.

Abstract: This study evaluates hybrid fluid viscous damper (FVD) layouts for seismic control of a 20-storey reinforced-concrete tower. Two retrofit configurations (C1, C2), each employing 120 FVDs with a combined damping capacity of approximately 60,000 kN·s/m per configuration, were modelled in ETABS as nonlinear link elements and subjected to nonlinear time-history analyses using representative ground motions. Device constitutive behavior was represented by a velocity-dependent law and model verification included explicit link spring/area settings to prevent silent unit-scaling of damper properties. Both hybrid layouts substantially reduce peak inter-story drifts and increase system energy dissipation, though performance varies by direction: relative to the undamped frame, C1 reduced peak drift by ≈28.7% in X and ≈44.6% in Y, while C2 reduced peak drift by ≈26.2% in X and ≈53.9% in Y. Damper contribution to seismic energy dissipation reached ≈47.3% for C1 and ≈45.6% for C2, with total (structural plus device) dissipation of ≈52.4% and ≈55.6%, respectively. Directional asymmetry is attributed to modal shapes and damper distribution. The results indicate that carefully arranged hybrid FVD systems can deliver significant, orientation-aware improvements to seismic resilience.

Abstract: Seismic base isolation has emerged as one of the most effective strategies for mitigating vibrations induced by seismic excitations in structures. However, its efficiency can be compromised if the foundation system is incompatible with the isolator type or soil conditions, leading to undesirable structural responses during seismic events. While extensive research exists on isolator mechanisms and damping performance, comparatively fewer studies address the influence of foundation systems on the overall efficiency of base-isolated structures. This paper reviews the influence of foundation type and soil conditions on the performance of base isolation systems, emphasizing the importance of soil–structure interaction (SSI) and energy dissipation capacity. A comprehensive literature review of studies published over the last decade is presented, focusing on the comparative performance of shallow, deep, and hybrid foundations in supporting passive base-isolation systems. Findings indicate that shallow foundations, such as mat and spread footings, are effective for low to mid-rise structures on stiff soils, whereas deep and hybrid foundations offer superior stability and isolation efficiency in soft or liquefiable soil conditions. The study concludes that integrating foundation design with base-isolation mechanisms is essential for optimizing seismic performance.

Abstract: Building Information Modeling (BIM) is revolutionizing the architecture, engineering, and construction (AEC) industries worldwide by enhancing collaboration, efficiency, and safety. Despite its proven benefits, BIM adoption remains minimal in third-world countries like Pakistan, primarily due to infrastructure limitations, high implementation costs, and a lack of skilled professionals. This study focuses on leveraging BIM's potential in the local context through three dimensions: 3D modeling using Revit, 4D scheduling with Primavera, and 8D health and safety analysis in Quetta City. The study aligns with UN Sustainable Development Goals 9, 11, and 12, aiming to demonstrate BIM's utility in promoting sustainable construction practices, reducing costs, and improving project outcomes. By addressing barriers to BIM adoption, this research aspires to lay the foundation for a transition from traditional workflows to BIM-based methodologies, setting a precedent for enhanced infrastructure development in emerging economies.

Abstract: In this study, survey data from distinct sources includes Total Station measurements, ArcGIS, and Global Mapper at a planned dam location at Qila Abdullah district in Balochistan are compared. Because of the study area's complicated topography, a precise elevation assessment is essential to the feasibility of the project. Elevation information from open-source NASA SRTM models integrated using ArcGIS and Global Mapper was contrasted with high-precision Total Station data, which served as the reference benchmark. In the field, 146 survey points were gathered, and AutoCAD Civil 3D was used to process all of the datasets for a thorough analysis. Significant elevation differences between the datasets were observed in the results, with SRTM-based models demonstrating large deviations from ground-truth observations. The analysis between total station and ArcGIS Pro reports a mean error of 15.647917m and standard deviation of 3.894677m. The results between total station and Global Mapper give similar results reporting a mean error of 14.870448m and standard deviation of 3.960269m. These differences directly affect feasibility studies, especially when it comes to cost estimation, design precision, and possible overestimation of material requirements. Because relying on broad open-source data might result in significant errors in project planning and execution, the findings point out the significance of accurate survey methodologies for infrastructure projects in rough terrains.

Abstract: Risk management is essential for the successful execution of public sector construction projects (PSCPs), especially in developing cities like Quetta, Pakistan. This research aimed to identify and rank the major risks affecting public sector construction projects in Quetta City using a quantitative survey approach. A total of 49 risk factors were identified through literature review and expert input, classified into ten major risk categories. Data were collected from 62 construction professionals and stakeholders through a structured questionnaire. It was analyzed using MS Excel and risks were ranked through Relative Importance Index (RII) method. The results show that political risks, market risks, financial risks, safety risks, and construction risks are the top five risk categories based on both their average RII values and the presence of their factors in the top 10 rankings. Considering risks with same RII as similar rank, the top five ranked individual risks that affect public sector construction projects success the most are political instability, fluctuation in material prices, security issues, lack of safety equipment, market competition, financial/payment delays, and corruption and bribery. These findings highlight the most critical threats to public sector construction projects in Quetta. Based on the results, the study provides actionable recommendations to strengthen risk mitigation and improve the successful delivery of public sector construction projects.

Abstract: The resistance created by vegetation against flow in open channels should be taken into account in projects focused on watercourse management and river restoration. Staggered patches of vegetation in an open channel significantly influence flow structure and river geomorphology. This study numerically examines flow characteristics through longitudinal discontinuous vegetation patches using three-dimensional software FLUENT, with a Reynolds stress turbulent model applied. ANSYS FLUENT Computational Fluid Dynamics techniques were utilized to analyze variations in mean stream velocity within the model domain. This study presents different distributions and profiles of mean stream velocities. It was observed that velocity decreases in the vegetation zones due to resistance. To monitor their effects on flow velocity, experimental vegetation patches should be installed along riverbanks, wetlands, or in stormwater channels.

Abstract: This study investigates riparian vegetation as a mitigation measure for overflow and bank erosion in the Jumman Shah Canal, Pakistan, using Computational Fluid Dynamics (CFD) with the Volume of Fluid (VOF) method for free-surface flow simulation. Three cases were modeled: bare floodplain (existing condition), submerged vegetation, and emergent vegetation. Vegetation was represented as uniformly spaced cylinders to maintain consistent porosity, with a 1:100 geometric scale replicating prototype peak-flow conditions. Field velocity measurements validated the model, showing strong agreement with simulations. Results showed submerged vegetation induced moderate backwater effects and broader low-velocity zones, while emergent vegetation produced greater upstream water level rise, higher momentum attenuation, and a delayed, confined high-velocity core. Both vegetation types increased hydraulic resistance and improved flow uniformity compared to the bare channel, with emergent vegetation offering the highest flood energy dissipation. The findings advocate vegetation-based stabilization as a sustainable, cost-effective approach for enhancing canal resilience.

Abstract: This study evaluates water resource management at the Artistic Milliners Unit 5 (AM-5) factory in Landhi, Karachi, under Alliance for Water Stewardship (AWS) standards through a WWF-commissioned assessment (Contract No: 137/Freshwater/24-25). It analyzed catchment delineation, aquifer characteristics, and rainfall trends from 1960–2023, highlighting increasing extreme weather events and vulnerabilities in local water infrastructure, with findings revealing an annual water shortfall of 6.49 MCM alongside challenges such as groundwater depletion, high salinity, and unreliable municipal supply. Despite these constraints, AM-5 adopts a hybrid water strategy integrating recycled water and reverse osmosis treatment to reduce freshwater dependency, while recommended mitigation measures include expanding wastewater recycling, adopting advanced treatment systems, and strengthening stakeholder collaboration to improve resilience. The study emphasizes the importance of integrated water stewardship in industrial zones and provides scalable recommendations to enhance urban water security amid climate variability and rising demand.