Timothy R. B. Taylor

NIGHTTIME CONSTRUCTION ISSUES

The findings of the Kentucky Transportation Cabinet study, Nighttime Construction Issues, are summarized. The current state of nighttime construction was examined through a survey of nighttime construction practitioners. To determine the feasibility of performing a project at night, the factors that affect night operations are discussed as well as a nighttime project evaluation form. Because lighting is a crucial element of any night project, a new form of lighting technology is briefly discussed. An idea that is slowly gaining favor with transportation departments is outlined—the contractor-supplied work plan. Finally, ideas for improvements in public relations and recommendations for overall nighttime project improvement are discussed.

Isolation and characterization of the 32.5 kDa protein from the venom of an endoparasitic wasp

The major venom proteins from the endoparasitic wasp were analyzed for distribution in the venom gland. A 32.5 kDa protein was purified from the venom gland of the Chelonus near curvimaculatus wasp. The protein accounts for about 25% of the total protein content of the venom and each gland contains 3-6 pmol of this component. The protein is acidic in nature and anion-exchange chromatography facilitated the purification of the protein to apparent homogeneity. On testing the purified protein by in vivo bioassay, it was found to elicit an effect comparable with the complete venom. The protein does not appear to have any disulfide bonds of major structural importance exposed under SDS-denaturing conditions. Products of chemical partial digest of the purified protein at the methionyl residues by cyanogen bromide were analyzed by SDS-PAGE. The 27.6 kDa fragment retained an epitope to an antibody raised against total Chelonus venom proteins, whereas no epitopes were detected for 4.9 and 0.6 kDa fragments.

Modeling the Impact of Design Rework on Transportation Infrastructure Construction Project Performance

Rework in construction development projects can significantly degrade project cost and schedule performance. Previous research has shown that in a typical construction development project, rework in the construction phase could increase construction cost by up to 12.4% of the contract price. In large, complex projects, undiscovered rework in the design phase can induce rework in the construction phase, thus increasing project cost. The time when rework is discovered during the project development process affects the magnitude of the impact of rework on overall project performance. However, available knowledge is not always successful in improving project managers’ understanding of the feedback mechanisms that drive undiscovered rework impacts on project performance, specifically the interaction between different phases during the developing process. The current work uses a system dynamics model of a two-phase project development cycle to identify high leverage points for minimizing the impacts of rework and ripple effects on project development performance. The work contributes to the existing body of knowledge by providing a structured feedback description of how design undiscovered rework combines with ripple effects to impact project performance in both the design and construction phases, as well as evaluating possible solutions to the problem. Model analysis suggests that failing to discover rework near its creation in the project development process can magnify the impact of rework on project performance.

Cognitive Workload Demands Using 2D and 3D Spatial Engineering Information Formats

AbstractConstruction project performance is significantly reliant on the effective communication of the project’s design to the end construction worker. Spatial design is frequently represented in two-dimensional (2D) drawings of various views. These views must be combined and decoded by the end user to effectively understand all orientations of a building element and can lead to errors. Advances in three-dimensional computer-aided design (3D CAD) and 3D printing have provided promising advancements in the presentation of spatial engineering information. This research investigates cognitive-workload demands of each information format. Cognitive workload is the amount of mental resources required to complete a task from the total available mental resources. Asking subjects to complete a reconstructing task of a simple structure using 2D drawings, a 3D CAD interface, and a 3D printed model introduces the individuals to alternative forms of information presentation. After completing the task, the subjects we...

Impact of Public Policy and Societal Risk Perception on U.S. Civilian Nuclear Power Plant Construction

AbstractDue to the increasing demand for energy in the United States, the Nuclear Regulatory Commission is currently reviewing permit applications for 26 new nuclear power reactors. However, the previous generation of U.S. civilian nuclear plant construction experienced significant cost and schedule overruns. Previous research identified “regulatory ratcheting” (continuous, retroactive change in nuclear plant regulations) as one of the primary causes of this poor performance. Regulatory ratcheting was enabled by the nuclear industry’s two-step permitting and licensing process for civilian power plant construction, which allowed society’s perception of the risks associated with nuclear plant operation to impact nuclear plant construction. How will public policy and societal risk perception affect the next generation of U.S. civilian nuclear plant construction? This question is investigated using a dynamic simulation model of the public policy and social feedback processes that impact U.S. nuclear plant con...

Quantitative analysis of the impact of craft worker availability on construction project safety performance

Purpose This paper aims to quantify the impact of craft worker shortage on construction project safety performance. Design/methodology/approach A database of 50 North American construction projects completed between 2001 and 2014 was compiled by taking information from a research project survey and the Construction Industry Institute Benchmarking and Metrics Database. The t-test and Mann-Whitney test were used to determine whether there was a significant difference in construction project safety performance on projects with craft worker recruiting difficulty. Poisson regression analysis was then used to examine the relationship between craft worker recruiting difficulty and Occupational Safety and Health Administration Total Number of Recordable Incident Cases per 200,000 Actual Direct Work Hours (TRIR) on construction projects. Findings The result showed that the TRIR distribution of a group of projects that reported craft worker recruiting difficulty tended to be higher than the TRIR distribution of a group of projects with no craft worker recruiting difficulty (p-value = 0.004). Moreover, the average TRIR of the projects that reported craft worker recruiting difficulty was more than two times the average TRIR of projects that experienced no craft recruiting difficulty (p-value = 0.035). Furthermore, the Poisson regression analysis demonstrated that there was a positive exponential relationship between craft worker recruiting difficulty and TRIR in construction projects (p-value = 0.004). Research limitations/implications The projects used to construct the database are heavily weighted towards industrial construction. Practical implications There have been significant long-term gains in construction safety within the USA. However, if recent craft shortages continue, the quantitative analyses presented herein indicate a strong possibility that more safety incidents will occur unless the shortages are reversed. Innovative construction means and methods should be developed and adopted to work in a safe manner with a less qualified workforce. Originality/value The Poisson regression model is the first model that quantifiably links project craft worker availability to construction project safety performance.

Demographic influences on construction craft shortages in the U. S. and Canada

The United States and Canadian construction markets are facing a shortfall of skilled craft workers in the face of increasing labor demands. There are initial indications that the shortages are already having a significant impact on project performance in the industrial construction sectors. While there are many demographic aspects of the shortage, the authors focus on the shift in aging of the United States and Canadian construction workforce and the effects this is having on the availability of craft workers, especially on highly skilled craft trades such as pipefitters and electricians. Also, the authors examine immigration policy and its influence on the qualifications of the construction workforce. The authors use multiple US and Canadian data sources to examine the trends on both sides of the border, including the US Bureau of Labor Statistics’ Current Population Survey, Statistic Canada, and the Build Force Canada datasets. The findings show that while both the US and Canadian construction markets are experiencing an aging workforce, the aging of the US workforce is occurring at a much faster rate.

Forecasting Highway Construction Staffing Requirements

Adequate construction staffing is critical for performance of highway construction projects. The variable nature of these projects, however, can make it difficult to estimate construction staff requirements for both the short and long term. This study gathered information on the methods being used at highway transportation agencies to forecast staffing requirements. These methods are diverse and range from simple heuristics based on generic project types to multi-variate regression models developed from historical project data.

Project Scoping Process Model Development to Achieve On-Time and On-Budget Delivery of Highway Projects

Transportation agencies have significantly improved many aspects of project delivery, yet they continue to be challenged by cost increases and time delays that occur after a project is programmed and funded. An increase or a change in the scope of a project to improve facility performance is a common source of such cost increases and schedule delays. Therefore, this study focused on improvement in the project scoping process (PSP) to achieve on-time and on-budget delivery of highway projects. The thrust of this research was to develop a framework that could help transportation agencies improve their scope development processes and practices. A key effort in this study was to assess current project scoping practices. After a literature review, the research team developed a survey protocol, distributed questionnaires, collected survey data, and performed data analysis. Forty responses were received that represented 23 state transportation agencies (STAs). On the basis of the survey responses, six STAs were selected for face-to-face interviews. The intent of the interviews was to confirm survey results and delve into topics not covered in the survey. As a result of these tasks, the research team identified considerable variation in scope development processes across the agencies with respect to the definition of a PSP, formality of the process, timing of the PSP, and project maturity when a project is programmed. On the basis of what was learned from the literature review, surveys, and follow-up interviews, the research team developed a PSP definition and framework. This PSP framework contains three major actions, namely, to select the project, to analyze the project, and to advance the preferred alternative.

Analysis of the impact of craft labour availability on North American construction project productivity and schedule performance

Abstract The North American construction industry has experienced periods of craft shortages for decades. While this problem has received significant attention from researchers, less attention has been given to quantifying the impact of availability of craft labour on project performance. The primary contribution of the current work to the body of knowledge is the quantification of the relationship between craft labour availability and project performance, as measured by project productivity and schedule. Data from 97 construction projects completed in the U.S. and Canada between 2001 and 2014 were collected from two industry databases. The primary analysis shows that projects that experienced craft shortages underwent substantial and statistically lower productivity compared to projects that did not. The analysis also shows a significant growth in schedule overrun due to the craft labour shortages among the same population of projects. Further exploration by means of several regression analyses shows a statistically significant correlation between increased craft recruiting difficulty and lower project productivity and also higher schedule overruns in both project databases. The results are confirmed across both databases and serve as informative models that provide valuable insight for project management teams to perceive the risk that lack of skills poses on project productivity and time performance. Understanding the level of impact that craft shortages are having through robust statistical analyses is a first step in developing the motivation for industry leaders, communities and construction stakeholders to address this challenge.