The moment-resisting reinforced concrete (RC) frame infilled with masonry walls is a common form of construction for low- to medium-rise buildings. The importance of considering the infill masonry walls (IMW) in seismic analysis is accentuated due to the interaction between infills and the surrounding frame. Several analytical IMW models have been proposed to model IMW as equivalent diagonal struts, and the appropriateness of those models has been justified through experimental and numerical calibrations. However, the reliability of those analytical models is not well substantiated. Therefore, the reliabilities of five different analytical models have been evaluated herein using the First-Order Reliability Method (FORM). The stochastic uncertainties involved in predicting the in-plane capacities of IMW-RC frames have been incorporated in the reliability analyses. Subsequently, reliabilities of IMW models have been ascertained using experimental data sets compiled at two different scales, namely (1) single story-single bay and (2) multistory IMW-RC frames. 120 experimental data sets of single story-single bay IMW-RC frames tested under in-plane loading and three multistory IMW-RC frames tested on shake-tables were used to assess the reliabilities of IMW models. The results showed that the IMW models considered have predicted the in-plane behavior of IMW-RC frames (single or multistory) to certain levels of accuracy. The predicted reliability indices (beta values) of the models vary between 1.03 and 4.13. The reliabilities differ when different aspects of the predictions are being considered, such as peak or ultimate load and drift capacities of single story-single bay frames or base shear and story drift of multistory frames. Therefore, depending on the requirement (strength- or displacement-based design), the IMW models should be selected appropriately to carry out the seismic analyses of IMW-RC buildings.
The construction industry faces multiple challenges due to shortcomings in project delivery, in government office buildings, resulting in occupant dissatisfaction. In Sri Lanka, limited empirical evidence exists regarding the level of user satisfaction in government office buildings and the influential factors. Therefore, this research aims to analyse the user satisfaction in government office buildings in Sri Lanka. Pragmatism philosophy was used, adopting mixed research choice, comprising semi-structured interview phase and a questionnaire survey administered among 52 respondents. Empirical data were analysed using content analysis, the employee net promoter score scale and technique for order preference by similarity to ideal solution. A satisfaction rate of -30% was recorded, reflecting a substantial dissatisfaction, while accessibility, building aesthetics, privacy and building design emerged as the most critical factors affecting the user satisfaction of government office buildings. Findings offer a guidance to the developing countries in improving government office buildings, while there is a methodological contribution to developed countries for conducting similar studies.
The municipal solid waste management sector is a nationally significant greenhouse gas source in Sri Lanka, yet decision makers lack comprehensive, city-level life-cycle assessment of full waste management chains. This study quantifies and compares greenhouse gas emissions and mitigation potential of alternative waste management scenarios for Colombo and Kandy, supporting nationally determined contributions (NDC) 3.0. Using IPCC 2021 GWP100 V1.03 as the impact assessment method, six scenarios were assessed, including business-as-usual, recycling, composting, confined cover windrow composting, anaerobic digestion, refuse-derived fuel production, incineration, pyrolysis, co-processing in cement kilns, open dumping, and sanitary landfilling. The business-as-usual scenario, dominated by open dumping, resulted in the highest greenhouse gas emissions in both Colombo and Kandy. In contrast, the integrated waste management approach (Scenario 3), combining anaerobic digestion, confined cover windrow composting, refuse-derived fuel production, and enhanced recycling, converted both cities from net emitters to net carbon sinks. Over the projection period of 2026-2035, this transition is expected to deliver substantial cumulative emission reductions, contributing significantly toward achieving NDC 3.0 waste sector targets in Sri Lanka despite the relatively small share of national baseline emissions in the sector. These findings highlight the strong mitigation potential of integrated waste management systems for advancing low-carbon urban strategies.
The perception of the sense of safety and comfort, embedded in the psychological state of an individual, plays a crucial role in the usability of urban public spaces. Existing literature elaborates that street configurations primarily impact the spatial cognition of the streets. Despite the comprehensive literature explored in the domain, there is a lack of practical analytical frameworks to be used in real-world urban environments. With the intention of filling this gap, this study aims to develop an indicator system for assessing the impact of streetscape configurations on the sense of safety and comfort of urban users. To enhance the replicability and timeliness of the developed system, the methodology employs a practical approach. Utilizing a comprehensive mixed-method approach, a 23-variable indicator system related to visual and spatial qualities was identified and weighted through expert and stakeholder input. Twelve randomly selected case studies in the Colombo Municipal area were assessed using the developed system as well as using expert scores in the related disciplines. The indicator system scores demonstrated a strong correlation with the expert scores (r(s) = 0.937, p < 0.001), indicating the validity of the developed system in real-world applications. Further analysis of the different categories of streets demonstrated that residential streets (compared to commercial and mixed streets), vehicle-priority streets (compared to pedestrian-priority streets), and multiple lanes (compared to single-lane and pedestrian-priority streets) were associated with higher perceived safety and comfort scores. Concludingly, this study forwards a structured yet user-friendly indicator system to urban designers, planners, and policymakers in creating safer and comfortable urban streetscapes.
PurposeConstruction small and medium enterprises (SMEs) often face resource constraints and rely on traditional procurement methods, leading to fragmented project delivery and persistent operational challenges. This study investigates how integrated project delivery (IPD) can mitigate these challenges and enhance SME resilience, using Paradox theory to conceptualise SME problems as enduring tensions between flexibility, capability and performance.Design/methodology/approachAdopting a pragmatist stance, a mixed-methods approach was employed. A systematic literature review using PRISMA identified SME challenges and the benefits of IPD. A questionnaire survey of 120 respondents was analysed using the relative importance index and a random forest algorithm. Additionally, 16 semi-structured interviews with industry experts explored IPD benefits, with qualitative data analysed using code-based content analysis in NVivo.FindingsThe study identifies 86 challenges faced by SMEs, grouped into management, technical, legal/political, financial and other issues. IPD was found to enhance collaboration, improve stakeholder engagement, support early decision-making, reduce design flaws and mitigate risks. Financially, IPD addresses budget overruns and cash flow constraints, while technologically, it promotes the adoption of innovative practices. Legal and policy barriers, however, remain significant constraints to IPD implementation.Originality/valueWhile IPD has been widely studied in large construction projects, its application to SMEs is underexplored. This study provides a systematic investigation of SME challenges and demonstrates how IPD can be used to strategically address them, offering practical recommendations for policymakers and industry practitioners. By linking IPD benefits to SME-specific constraints, the research contributes to theory, informs practice and supports sustainable growth and competitiveness in construction SMEs.
