Improving the concrete sections after removing intermediate support of RC continuous non-prismatic beam

An experimental study was conducted to investigate the performance of the 2-span continuous reinforced concrete beams of different section depth after removing the middle support by adding steel fibers or steel plates. The beams were loaded monotonically with two-point loads. One continuous beam and six simply supported beams of non-prismatic section were tested using two different content of steel fibers and three different locations of steel plates welded to the reinforcement. The test results reveal that using inclined steel plates at the region of changing of cross section thickness at the middle support increase the load capacity of the beam significantly up to 75% of the continuous beam capacity, and a significant warning before failure is shown. Adding steel fibers to the concrete has less influence on the capacity of the beam. The failure mode of the beams with no middle support is the same, but with different values of deflection. The inclined steel plate again is the most effective way to decrease the deflection because of the increased stiffness of the cross section. To achieve the same capacity of the continuous beam after removing the middle support, it is recommended to use horizontal steel plates welded to the reinforcement at the region of the middle support extended within one fourth the length of each span of different thickness to avoid the stress concentration resulted from the large deflection at that region

Evaluation of the critical success factors (CSFs) in selecting building contractors using pareto analysis and the analytical hierarchy process

The purpose of this paper is to obtain a set of critical success factors (CSFs) for selecting building contractors in Qatar to help investors effectively and efficiently build their houses. First, a systematic review of the previous research was carried out to capture the 20 most frequently occurring CSFs for constructing houses. Then, a survey was distributed to 280 investors to determine their perceptions of the importance of CSFs. The survey was evaluated using Pareto analysis and the analytical hierarchy process (AHP) to determine which CSFs are most relevant to investors when building houses. The contribution of this study to the current knowledge is studying the investor’s behavior by considering frequency, cost, and time components simultaneously to capture the most significant Critical Success Factors (CSFs) in selecting building contractors. The strategy developed by this study provides a ready set of criteria that can be used by investors and local authorities in qualifying building contractors

A Framework for Construction Workspace Management: A Serious Game Engine Approach

Construction workspace is regarded as one of the main constraints on construction sites. Construction workspaces are generally difficult to proactively plan and manage due to the dynamic nature of a site where workspace requirements keep changing as time evolves. However, project managers are looking for ways to develop proactive site plan for the workspaces required for construction activities as this can impact not only on the cost and project duration, but can also contribute to provide a safer site. This research paper presents an approach for integrating workspace management within the planning process using a serious game engine technology. This paper first illustrates a review of the workspace management practices and advanced visualization techniques in the construction industry. Then, it presents a process framework for an interactive decision support system that integrates workspace planning into 5D planning in order to enable safer, efficient and more productive construction sites. The decision support system will identify schedule conflicts, workspace conflicts and the severity of their conflicts, and workspace congestions on a construction site and allow construction planners to resolve spatial conflicts prior to construction. Finally, the paper shows the current progress in the development of an initial prototype and outlines the future work and research. © 2012 American Society of Civil Engineers

Methods for modeling and evaluating construction disputes: A critical review

Cost and time are the targeted outcomes of any successful construction project, and disputes over these two key factors constitute a major obstacle to successful project outcomes. As escalated levels of dispute are becoming increasingly unavoidable, the construction industry is aiming to develop dispute identification strategies to reduce and eliminate them during construction. However, existing research on construction disputes appears to give more consideration to dispute resolution than it does to avoiding conflict and preventing disputes from arising in the first place. This paper aims to minimize disputes during construction by addressing the causes of disputes during the pre-construction phase. As an integral part of ongoing research, it presents the results of a thorough study encompassing a critical review of previous research on construction disputes. Several conflicts and disputes are categorized and analyzed to allow for the future determination of their direct and/or indirect links to the pre-construction phase. This review also elaborates on the different methods of research adopted in the literature and the relevant research tools utilized. The research highlights the use of fuzzy logic coupled with structural equation modeling (SEM) as a recognized and valid modeling tool in construction projects, as it models and establishes an appropriate framework for dispute modeling and evaluation. The findings of this review therefore call for a further investigation of and deep research into the relationship between the characteristics of the pre-construction phase and the types of disputes and their likelihood of taking place during the construction phase itself. These findings can be utilized to develop an operational framework for predicting dispute occurrences during construction. The paper concludes by providing a developed hybrid fuzzy-SEM model to quantify the probability of dispute occurrence in construction projects, thereby enabling project stakeholders to predict, identify, and properly manage dispute occurrences during the pre-construction phase

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation

Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

Work-In-Progress: Examining Engineering Students' Perception of Student Agency in Solving Complex Engineering Problem

The general source of engineering education knowledge is content driven where engineering is considered as a process of solving problems using a reductionist approach. Once each sub-system is solved, within certain assumptions and hypotheses, they are brought back together to provide an overview of the potential solution for the problem. It promotes mechanistic thinking to solve well-structured problems with known solution paths (process) and convergent answers. Little emphasis is given to solving complex engineering problems. One approach to cultivating solving complex engineering problems is through learners/ student agency. Student agency is based on the guiding principle that students have the ability and will to influence their own lives and the world around them. The aim of this is then to investigate the role of Problem-Based Learning (PBL) as an environment setting to encourage students’ agency in solving complex engineering problems. The work will incorporate existing theories in relation to students’ agency

Construction Simulation Using Virtual Reality

Two main simulation methodologies namely, the network-based simulation and the graphical simulation technique are being used in the construction industry. While the network-based simulation technique, which was originally developed for manufacturing processes, is very tedious, complex, and time consuming, the graphical simulation technique is taking many forms and it is gaining more support within the construction industry. The graphical simulation technique, which was originally derived from what is called the Visual Interactive Simulation (VIS). Tthe Virtual Reality (VR) technology may be used to model, design, and simulate construction operations. There are some attempts in that direction, however, these attempts have either been or are being made within research institutes and large construction companies where expensive computer hardware were purchased and sophisticated software were developed. There is no indication that these attempts were made on non-expensive computer workstations or on the PC platform. This paper describes some state of the art techniques by which construction operations (such as earth removing operations, material handling, manipulating building components.. etc.) can be modeled, visualized, and graphically simulated in real-time 3D environments on the PC. The construction industry will benefit from this study since it introduces new software and hardware technologies that are capable of delivering comparable workstation performance on the PCs at a fraction of the cost

Analysis of Critical Project Success Factors—Sustainable Management of the Fast-Track Construction Industry

Fast-track construction has recently become the prevailing construction approach globally. It enables owners and developers to make rapid returns on investment through shortened construction periods. This strategy has many effects on the industry; therefore, four groups of factors were studied in this project: (1) financial, (2) logistics and finance, (3) management, and (4) legal. A 22-question survey was distributed to 155 professionals in the construction industry, who evaluated the impact of the stated factors on a 5-point scale. The results revealed a high level of consistency determined through Cronbach’s alpha, and a positive correlation was found by Spearman’s rank coefficient. The Relative Importance Index was used to rank the factors based the evaluation by the professionals, resulting in the following impact ranking: (1) poor communication among design and construction teams, (2) large amounts of rework, (3) low quality of work by the contractor, (4) design errors, (5) late or insufficient payment according to terms agreed with the client, and (6) unavailability of materials in the market. By providing a quantitative RII model to evaluate fast-track project management performance with the use of corresponding performance indicators, this study will benefit industry practitioners and researchers as it identifies the most significant factors that impact fast-tract project management performance

Development of a Campus Facility Management Operational Framework Using a Modified Delphi Method

An effective facility management process is crucial to overall firm performance and is becoming a core competency for organizations seeking to gain a competitive advantage. The recent literature on facility management reveals that poor facility management is a major cause of management inefficiency, leading directly to budget overruns, maintenance delays, repetition of work, variations, noncompliance incidents, unnecessary risk, and dissatisfied customers. Therefore, facility management firms should pay close attention to the most critical success factors in order to effectively manage and measure performance. This paper presents a multidimensional campus facility management performance framework (CFMPF) that addresses both operational and systematic factors. Facility management companies, owners, contractors, and consultants can use this framework to identify systemic weaknesses using key indicators to specifically assess the effectiveness and success of facility management. The significance of 45 key facility management success factors across seven categories was determined via a literature review, expert interviews, and the Delphi method. The seven process groups are: Campus Facility Work Force Management, Campus Facility Communication Management, Campus Facility Systems Management, Campus Facility Organizational Management, Campus Facility Financial Management, Campus Sustainability & Environment Management, and Campus Facility Assets Management. To verify the overall agreement via the Delphi rounds, the score percentage and standard deviation to mean ratio were examined. Mean value and interrater agreement (IRA) analyses were conducted to evaluate the correlation between the factors and facility performance. This research adds to the body of knowledge by presenting a systematic operational framework for campus facility management that identifies the underlying factors influencing performance and fills the gaps left by previous studies