Bender, W.; Waytuck, D.; Wang, S.; Reed, D. A. (2018). In Situ Measurement of Wind Pressure Loadings on Pedestal Style Rooftop Photovoltaic Panels. Engineering Structures, 163, 281 – 293.
View Publication
Abstract
The installation of rooftop photovoltaic (PV) arrays is increasing throughout the US. Until recently, pedestal type PV framing systems for rooftops were basically designed using procedures from the ASCE7-10 Components and Cladding Standard for rooftop equipment. The 2011 Japanese Standard Load design guide on structures for photovoltaic arrays was useful in characterizing the pressure coefficients on rooftops, but the Standard employs different wind speed and importance factors, making its use in the US quite limited, Even the updated 2017 version is written for a different audience. Because rooftop pressure loadings are high due to flow separation, SEAOC and other organizations contracted boundary layer wind tunnel tests of panels attached to rooftops to ascertain if the ASCE7-10 equipment loadings were appropriate. The investigations resulted in new standards for pedestal-style arrays that appear in Chapter 29 of ASCE7-16. However, the new standards are limited to simple geometries and orientations, and the dynamics of the simply-supported thin PV plates do not appear to be considered. Questions regarding the ability of the boundary tunnels to simulate accurately the turbulence at the scale required for the attached panels have been raised. In response, very limited full-scale investigations in large-scale tunnels and in situ have been undertaken to calibrate the tunnel results. The results of this paper represent one of these calibration investigations. Specifically, in situ full-scale net wind pressure loadings on a rooftop PV array in a pedestal-style framing system located on the three story Hogue Technology Building of Central Washington University (CWU) in Ellensburg, Washington were measured. The CWU campus has a rural setting in a region with steady winds: Ellensburg is located in the Kittitas Breezeway portion of the Northwest wind power region. Indeed, the Wild Horse Wind and Solar Farm is located on the outskirts of town. The data described here were collected from April through August 2014. The measured net pressure coefficient time series were similar to those for rooftop pressure loadings for low-rise buildings described in the literature such as the Wind Engineering Research Field Laboratory at Texas Tech University (Ham and Bienkiewicz, 1998 [1]; Levitan and Mehta, 1992 [2]). The analysis of the net pressure time series data included an examination of the minimum, maximum, mean, and RMS values. Preliminary results suggest that the range of the values is larger than assumed in the ASCE7 Standard, and that the magnitude of the loadings vary considerably spatially over the multiple panel array. The pressure loading measurements are ongoing.
Keywords
Building Integrated Photovoltaics; Buildings (structures); Calibration; Design Engineering; Pressure Measurement; Roofs; Solar Cell Arrays; Standards; Time Series; Turbulence; Wind Tunnels; Japanese Standard Load Design Guide; Wind Pressure Loading Measurements; Asce7-10 Components-cladding Standard; Tunnel Calibration; Texas Tech University; Kittitas Breezeway Portion; Wild Horse Wind And Solar Farm; Ellensburg; Central Washington University; Hogue Technology Building; Boundary Layer Wind Tunnel Test; Flow Separation; Multiple Panel Array; Wind Engineering Research Field Laboratory; Net Pressure Coefficient Time Series; Northwest Wind Power Region; Pedestal-style Framing System; Pv Plates; Rooftop Equipment; Pedestal Style Rooftop Photovoltaic Panels; Solar-arrays; Loads; Simulation; Wind Engineering; Photovoltaic Modules; Solar Energy; Full-scale Measurements; Wind Loadings; Photovoltaic Cells; Roofing; Wind Power; Structural Engineering; Boundary Layers; Cladding; Wind Tunnel Testing; Solar Cells; In Situ Measurement; Framing; Photovoltaics; Engineering Research; Wind Measurement; Pressure; Panels; Wind Pressure; Design Standards; Fluid Dynamics; Low Rise Buildings; Colleges & Universities; Wind Speed; United States--us
Abdirad, Hamid; Dossick, Carrie Sturts. (2020). Rebaselining Asset Data for Existing Facilities and Infrastructure. Journal Of Computing In Civil Engineering, 34(1).
View Publication
Abstract
This paper introduces rebaselining as a workflow for collecting reliable and verifiable asset management data for existing facilities and infrastructure. Reporting on two action research case studies with two public owners in the US, this research structures rebaselining in four phases: (1) preparing technology enablers, (2) collecting data from existing documents, (3) conducting field verification, and (4) updating asset management databases. These workflows address some of the common challenges in managing existing assets, including the fast-paced changes in asset data requirements, the inaccuracies in data and documentation of these existing assets portfolios, and the need to update data and documents over their life cycle. The findings set the groundwork for implementing workflow by mapping the rebaselining business processes in each phase, listing the technological requirements for these processes, and explaining the feasibility and examples of customizing building information modeling (BIM) platforms for rebaselining workflows. This customization of BIM platforms aims to offer simplified solutions that reduce the facility management staff's need for advanced BIM software knowledge.
Keywords
Asset Management; Building Management Systems; Business Data Processing; Database Management Systems; Facilities Management; Production Engineering Computing; Project Management; Risk Analysis; Software Tools; Reliable Asset Management Data; Verifiable Asset Management Data; Action Research Case Studies; Public Owners; Research Structures; Technology Enablers; Asset Management Databases; Facility Management Staff; Rebaselining Workflows; Technological Requirements; Rebaselining Business Processes; Existing Assets Portfolios; Documentation; Asset Data Requirements; Managing Existing Assets; Information; Bim; Existing Buildings; Infrastructure; Asset Data; Rebaselining
Aziz, Ahmed M. Abdel. (2021). The Practice of Roadway Safety Management in Public-Private Partnerships. Journal Of Construction Engineering And Management, 147(12).
View Publication
Abstract
As a matter of course, the private party in public-private partnerships (PPPs) assumes the responsibility for roadway safety management (RSM). However, because most PPPs are performance-based, public highway agencies must articulate the specifications and methods they develop to enforce RSM practices. Despite the increased interest in PPPs in recent decades, little has been published on developing and propagating the RSM practices used with this delivery system. To fill this research gap and explore RSM practices in PPPs, this work took a synthesis research approach, using content analysis to critically review and analyze 16 PPP agreements in seven states and provinces leading in PPP contracting in North America. The study discovered several methods and organized them under five mechanisms: Mechanism 1, integrating roadway safety into project performance specifications and initiating new tools such as safety compliance orders; Mechanism 2, imposing nonconformance monetary deductions based on point and classification systems; Mechanism 3, regulating safety payments on the basis of crash statistics; Mechanism 4, promoting safety initiative programs; and Mechanism 5, enforcing administrative countermeasures such as work suspension and default/termination triggers for persistent developer noncompliance. Mechanisms 1 and 5 were the default mechanisms in all toll- and availability-based projects, whereas Mechanism 2 was common in availability-only projects. The research reviewed the RSM packages in the PPP agreements, elucidating the particulars of the RSM mechanisms, highlighting RSM design considerations, presenting implementation guidelines, and articulating research needs. The research results were validated against PPP highways in five other states and provinces. This synthesis research provides highway agencies with an extensive practice review to support RSM package design for future PPP projects.
Keywords
Qualitative Research; Incentives; Public-private Partnerships (ppps); Performance Specifications; Roadway Safety; Payment Mechanisms; Availability Payment; Highways
Yi, June-Seong; Kim, Yong-Woo; Kim, Ki-Aeng; Koo, Bonsang. (2012). A Suggested Color Scheme for Reducing Perception-Related Accidents on Construction Work Sites. Accident Analysis And Prevention, 48, 185 – 192.
View Publication
Abstract
Changes in workforce demographics have led to the need for more sophisticated approaches to addressing the safety requirements of the construction industry. Despite extensive research in other industry domains, the construction industry has been passive in exploring the impact of a color scheme: perception-related accidents have been effectively diminished by its implementation. The research demonstrated that the use of appropriate color schemes could improve the actions and psychology of workers on site, thereby increasing their perceptions of potentially dangerous situations. As a preliminary study, the objects selected by rigorous analysis on accident reports were workwear, safety net, gondola, scaffolding, and safety passage. The colors modified on site for temporary facilities were adopted from existing theoretical and empirical research that suggests the use of certain colors and their combinations to improve visibility and conspicuity while minimizing work fatigue. The color schemes were also tested and confirmed through two workshops with workers and managers currently involved in actual projects. The impacts of color schemes suggested in this paper are summarized as follows. First, the color schemes improve the conspicuity of facilities with other on site components, enabling workers to quickly discern and orient themselves in their work environment. Secondly, the color schemes have been selected to minimize the visual work fatigue and monotony that can potentially increase accidents. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords
Construction Industry Accidents; Industrial Hygiene; Industrial Safety; Empirical Research; Sensory Perception; Work Environment; Demographic Surveys; Job Performance; Color Scheme; Construction Industry; Labor Demography; Perception-related Accident; Accident Prevention; Accidents; Demography; Human Resource Management; Population Statistics; Color Schemes; Construction Works; Dangerous Situations; Rigorous Analysis; Safety Requirements; Temporary Facilities; Work Environments; Psychological Climate; Drivers; Emotion; Model
El-Anwar, Omar; Aziz, Tamer Abdel. (2014). Integrated Urban-Construction Planning Framework for Slum Upgrading Projects. Journal Of Construction Engineering And Management, 140(4).
View Publication
Abstract
Slums are areas of population concentrations developed in the absence of physical planning and lack access to life essentials. Slums represent major national challenges in countries where they exist, especially developing countries. Various intervention strategies can be adopted to upgrade and/or replace slums, but are often faced with serious construction challenges, such as lack of access to sites and poor terrain conditions. Moreover, during the execution of slum upgrading projects, resident families can experience significant social and economic disruptions. The objective of this paper is present an integrated urban-construction planning framework for slum upgrading projects. This framework incorporates participatory upgrading and is designed to achieve three important objectives, including (1)maximizing the benefits of slum upgrading projects by identifying and accelerating the delivery of urgent projects; (2)providing more accurate and practical estimates of upgrading projects costs and timelines, which enables controlling and minimizing the total projects costs and durations; and (3)minimizing the social and economic disruptions for resident families during construction. An illustrative example is presented to demonstrate the potential of the proposed framework and its core multiobjective optimization process.
Keywords
Construction; Industrial Economics; Optimisation; Planning; Project Management; Social Sciences; Integrated Urban-construction Planning Framework; Slum Upgrading Projects; Physical Planning; Intervention Strategies; Construction Challenges; Economic Disruptions; Social Disruptions; Urgent Projects Delivery; Project Costs; Multiobjective Optimization Process; Logistics; Constructability; Optimization; Design; Build; Urban Areas; Slums Upgrading; Logistics Planning; Multi-objective Optimization; Integrated Design-build; Project Planning And Design
Kim, Sang-chul; Kim, Yong-woo; Park, Kun Soo; Yoo, Choong-yuel. (2015). Impact of Measuring Operational-Level Planning Reliability on Management-Level Project Performance. Journal Of Management In Engineering, 31(5).
View Publication
Abstract
The earned value management system (EVMS) and the last planner system (LPS) have been widely used as effective performance measurement tools for construction managers and production units at construction projects. While the EVMS measures project-level costs and scheduling performances, the LPS measures the percent plan complete (PPC), which indicates the level of planning reliability. This paper investigates the relationship between planning reliability at the operational level and project performance at the management level (i.e., the success or failure of a project). Analyzing the empirical data of 23 residential projects of a large construction company, the authors find that, while the production plan in the weekly schedule is correlated rigidly with the daily plan in successful projects, such a rigid correlation is not observed in unsuccessful projects. To understand this finding, the authors further conducted interviews with project stakeholders. Taken together, this study suggests that an emphasis on LPS indices causes subcontractors to engage in myopic behaviors such as modifying operational-level indices. Consequently, management-level production plan rigidity is at risk. The findings in this paper offer valuable insights and help project stakeholders understand the attributes of operational-level and management-level indices and their relationships. (C) 2014 American Society of Civil Engineers.
Keywords
Construction Industry; Costing; Production Planning; Project Management; Reliability; Scheduling; Subcontracting; Construction Projects; Production Units; Myopic Behaviors; Project Stakeholders; Subcontractors; Production Plan; Percent Plan Completion; Scheduling Performances; Project-level Costs; Performance Measurement Tools; Construction Managers; Last Planner System; Earned Value Management System; Management-level Project Performance; Evms; Operational-level Planning Reliability; Balanced Scorecard; Lean Construction; Contractors; Indexes; Design; Model; Earned Value; Lean; Construction; Schedule Performance Index; Cost Performance Index; Percent-plan-completion; Empirical Analysis
Kim, Taehoon; Kim, Yong-woo; Cho, Hunhee. (2016). Customer Earned Value: Performance Indicator from Flow and Value Generation View. Journal Of Management In Engineering, 32(1).
View Publication
Abstract
The earned value method (EVM) is considered an advanced project control technique that provides a quantitative measure of work performance. However, the EVM is effective only under the assumption that every activity is independent. Literature shows that the EVM lacks the value generation view even working against the reliability of workflow. The goal of this research is to propose a project metric system to supplement the EVM in terms of the workflow and value generation. The researchers suggest a new metric of customer earned value (CEV), which is defined as the budgeted amount of work completed and is used by the successors on a network. Through a hypothetical case study, this research investigates how the work-in-process between trades and schedule performance in each trade behave under different uncertainties. The result suggests that the proposed metrics can provide project managers with more relevant managerial information on project progress as well as on the level of collaboration. The proposed system with the EVM would facilitate collaboration on project planning and control where variability and interdependency are involved. (C) 2015 American Society of Civil Engineers.
Keywords
Budgeting; Customer Services; Organisational Aspects; Planning; Project Management; Customer Earned Value; Project Planning; Project Managers; Trade-schedule Performance; Work-in-process; Budgeted Amount; Project Metric System; Advanced Project Control Technique; Earned Value Method; Performance Indicator; Value Generation View; Management; Project Control Metric; Collaboration
Ibrahim, Amir; El-Anwar, Omar; Marzouk, Mohamed. (2018). Socioeconomic Impact Assessment of Highly Dense-Urban Construction Projects. Automation In Construction, 92, 230 – 241.
View Publication
Abstract
Dense-urban construction is reported to affect the social and economic welfare of surrounding residents and local businesses in various ways. However, research studies and practical methodologies aimed at assessing to what extent the choice of a construction plan that reduces such effect are very limited. The objective of this paper is to present the development of an automated assessment methodology to fill this research gap. To this end, two formulations are presented; one based on multi-attributed utility functions and the other based on monetary compensations for disruptions caused by construction operations. Both formulations assess the impacts of construction plans on (1) increased travel distance; (2) residents' relocation; (3) business loss; (4) business closure; and (5) noise inconvenience. The proposed automated methodology is implemented in five sequential phases and utilizes Geographical Information Systems (GIS) and Visual Basic Application (VBA). Using the proposed implementation, the two alternative formulations are applied to an infrastructure upgrading project in Cairo, Egypt that had five possible construction scenarios. While the two formulations resulted in the same preference order for the five scenarios, they exhibited different performance in terms of their (1) assessment relative values; (2) required input data and robustness; (3) ease of results interpretation; and (4) comprehensiveness and scalability. The developed framework shows promising results in terms of identifying and sorting the major root causes of the socioeconomic disruptions caused by dense urban construction. Results show that using the proposed methodology informs decision-making and planning at the early stages of a project, which in turn helps to reduce cost overruns and schedule delays.
Keywords
Construction Projects; Socioeconomics; Social Services; Construction Project Management; Building Design & Construction; Geographic Information Systems; Infrastructure (economics); Dense-urban Construction; Gis; Socioeconomic Assessment; Decision Making; Economics; Plant Shutdowns; Tourism Industry; Automated Assessment; Construction Operations; Construction Plan; Socio-economic Assessments; Socio-economic Impact Assessment; Urban Construction; Utility Functions; Visual Basic Application; Pavement Construction; Road; Sustainability; Behavior; Industry; Highway; Models; Choice
Anderson, Anne; Dossick, Carrie Sturts; Osburn, Laura. (2020). Curriculum To Prepare AEC Students for BIM-Enabled Globally Distributed Projects. International Journal Of Construction Education & Research, 16(4), 270 – 289.
View Publication
Abstract
Globalization and the increasing adoption of BIM and other technologies in the AEC industry have changed the way we prepare graduates for the digital workplace. This paper presents curriculum design where students from five universities worked together to develop design and construction proposals. This paper describes a collaborative project executed in two parts. Part I included the University of Washington in the USA and IIT-Madras in India. Part II included Washington State University in the USA, and National Taiwan University and National Cheng Kung University in Taiwan. Students from these global universities worked on a multi-disciplinary, interdependent project where teams created 3D models and 4D construction simulations. This curriculum addresses ACCE and ABET accreditation requirements regarding multi-disciplinary teams, ethical and professional responsibilities in global, economic, environmental, and societal contexts, and effective teamwork. In this paper, we describe the course design, evaluative criteria, and lessons learned. We found that it was important to emphasize BIM Execution Planning for distributed teams given that communication and coordination can be challenging across time zones and cultural differences. Working through technical challenges of exchanging BIM data, the students learned coordination skills in a globally distributed team environment that simulated real work experiences. [ABSTRACT FROM AUTHOR]; Copyright of International Journal of Construction Education & Research is the property of Routledge and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Keywords
College Curriculum; Project Management; Digital Technology; Work Environment; Globalization; Bim; Building Information Modeling; Digital Literacy; Distributed Teams; Global Collaboration
Choi, Kunhee; Bae, Junseo; Yin, Yangtian; Lee, Hyun Woo. (2021). Act(2): Time Cost Tradeoffs from Alternative Contracting Methods. Journal Of Management In Engineering, 37(1).
View Publication
Abstract
Incentive/disincentive (I/D) and cost-plus-time (A+B) are two of the most widely used alternative contracting methods (ACMs) for accelerating the construction of highway infrastructure improvement projects. However, little is known about the effects of trade-offs in terms of project schedule and cost performance. This study addresses this problem by creating and testing a stochastic decision support model called accelerated alternative contracting cost-time trade-off (ACT(2)). This model was developed by a second-order polynomial regression analysis and validated by the predicted error sum of square statistic and paired comparison tests. The results of a descriptive trend analysis based on a rich set of high-confidence project data show that I/D is effective at reducing project duration but results in higher cost compared to pure A+B and conventional methods. This cost-time trade-off effect was confirmed by the ACT(2) model, which determines the level of cost-time trade-off for different ACMs. This study will help state transportation agencies promote more effective application of ACMs by providing data-driven performance benchmarking results when evaluating competing acceleration strategies and techniques. (C) 2020 American Society of Civil Engineers.
Keywords
Highway; Construction; Model; Alternative Contracting Methods; Cost-plus-time; A Plus B; Incentive; Infrastructure Trend; Time-cost Trade-off