This research explores some of the issues, challenges and dilemmas of existing research found in the construction workforce, it starts with past research that can be found on the current problems in the industry and how it has developed. It covers the distinguishing factors that influence a construction company's success and how it has affected depending on the characteristics of the company. It was to examine the effectiveness of the recruitment and selection practices of entrants in the construction industry workforce and pathways to improve those practices.

The semiconductor manufacturing business model provides unique challenges for the design and construction of supporting fabrication facilities. To accommodate the latest semiconductor processes and technologies, manufacturing facilities are constantly re-tooled and upgraded. Common to this sector of construction is the retrofit project environment. This type of construction project introduces a multitude of existing conditions constraints and functions entirely differently than traditional new-build projects. This facility conversion process is further constrained by owner needs for continuous manufacturing operations and a compressed design/construction schedule to meet first-to-market milestones.

To better control the variables within this project environment, Building Information Modeling (BIM) workflows are being explored and introduced into this project typology. The construction supply-chain has also increased their focus on offsite construction techniques to prefabricate components in a controlled environment. The goal is to overlap construction timelines and improve the productivity of workers to meet the increasingly demanding schedules and to reduce on-site congestion. Limited studies exist with regards to the manufacturing retrofit construction environment, particularly when focusing on the effectiveness of BIM and prefabrication workflows. This study fills the gap by studying labor time utilization rates for Building Information Modeling workflows for prefabrication of MEP (mechanical/electrical/plumbing) and process piping equipment in a retrofit construction environment.

A semiconductor manufacturing facility serves as a case-study for this research in which the current state process for utilizing BIM for prefabrication is mapped and analyzed. Labor time utilization is studied through direct observation in relation to the current state modeling process. Qualitative analysis of workflows and quantitative analysis of labor time utilization rates provide workflow interventions which are implemented and compared against the current state modeling process.

This research utilizes a mixed-method approach to explore the hypothesis that reliable/trusted geometry is the most important component for successful implementation of a BIM for prefabrication workflow in a retrofit environment. The end product of this research is the development of a prefaBIM framework for the introduction of a dynamic modeling process for retrofit prefabrication which forms the basis for a model-based delivery system for retrofit prefabrication.

Public Private Partnerships (PPP) have been in use for years in the United Kingdom, Europe, Australia and for a shorter time here in the United States. Typical PPP infrastructure projects include a multi-year term of operation in addition to constructing the structural features to be used. Early studies are proving PPP delivery methods to be effective at construction cost containment. An examination of the key elements that constitute the early stage negotiation reveal that there is room for negotiation created by the governing documentation while maintaining a competitive environment that brings the best value available to the Public entity. This paper will examine why PPP's are effective during this critical construction period of the facilities life cycle. It is the intent of this study to examine why the features and outcomes of more or less negotiation and the degree of rigor associated with it.

Public-Private Partnerships (P3) in North America have become a trend in the past two decades and are gaining attention in the transportation industry with some large scale projects being delivered by this approach. This is due to the need for alternative funding sources for public projects and for improved efficiency of these projects in order to save time and money. Several research studies have been done, including mature markets in Europe and Australia, on the cost and schedule performance of transportation projects but no similar study has been conducted in North America. This study focuses on cost and schedule performance of twelve P3 transportation projects during their construction phase, costing over $100 million each, consisting of roads and bridges only with no signature tunnels. The P3 approach applied in this study is the Design-Build-Finance-Operate-Maintain (DBFOM) model and the results obtained are compared with similar research studies on North American Design-Build (DB) and Design-Bid-Build (DBB) projects. The schedule performance for P3 projects in this study was found to be -0.23 percent versus estimated as compared to the 4.34 percent for the DBB projects and 11.04 percent for the DB projects in the Shrestha study, indicating P3 projects are completed in less time than other methods. The cost performance in this study was 0.81 percent for the P3 projects while in the Shrestha study the average cost increase for the four DB projects was found to be 1.49 percent while for the DBB projects it was 12.71 percent, again indicating P3 projects reduce cost compared to other delivery approaches. The limited number of projects available for this study does not allow us to draw an explicit conclusion on the performance of P3s in North America but paves the way for future studies to explore more data as it becomes available. However, the results in this study show that P3 projects have good cost and schedule adherence to the contract requirements. This study gives us an initial comparison of P3 performance with the more traditional approach and shows us the empirical benefits and limitations of the P3 approach in the highway construction industry.

Nowadays there is a pronounced interest in the need for sustainable and reliable infrastructure systems to address the challenges of the future infrastructure development. This dissertation presents the research associated with understanding various sustainable and reliable design alternatives for water distribution systems. Although design of water distribution networks (WDN) is a thoroughly studied area, most researchers seem to focus on developing algorithms to solve the non-linear hard kind of optimization problems associated with WDN design. Cost has been the objective in most of the previous studies with few models considering reliability as a constraint, and even fewer models accounting for the environmental impact of WDN. The research presented in this dissertation combines all these important objectives into a multi-objective optimization framework. The model used in this research is an integration of a genetic algorithm optimization tool with a water network solver, EPANET. The objectives considered for the optimization are Life Cycle Costs (LCC) and Life Cycle Carbon Dioxide (CO2) Emissions (LCE) whereby the system reliability is made a constraint. Three popularly used resilience metrics were investigated in this research for their efficiency in aiding the design of WDNs that are able to handle external natural and man-made shocks. The best performing resilience metric is incorporated into the optimization model as an additional objective. Various scenarios were developed for the design analysis in order to understand the trade-offs between different critical parameters considered in this research. An approach is proposed and illustrated to identify the most sustainable and resilient design alternatives from the solution set obtained by the model employed in this research. The model is demonstrated by using various benchmark networks that were studied previously. The size of the networks ranges from a simple 8-pipe system to a relatively large 2467-pipe one. The results from this research indicate that LCE can be reduced at a reasonable cost when a better design is chosen. Similarly, resilience could also be improved at an additional cost. The model used in this research is more suitable for water distribution networks. However, the methodology could be adapted to other infrastructure systems as well.

Trenchless technologies have emerged as a viable alternative to traditional open trench methods for installing underground pipelines and conduits. Pilot Tube Microtunneling, also referred to as the pilot tube system of microtunneling, guided auger boring, or guided boring method, is a recent addition to the family of trenchless installation methods. Pilot tube microtunneling originated in Japan and Europe, and was introduced to the United States in the year 1995 (Boschert 2007). Since then this methodology has seen increased utilization across North America particularity in municipal markets for the installation of gravity sewers. The primary reason contributing to the growth of pilot tube microtunneling is the technology's capability of installing pipes at high precision in terms of line and grade, in a wide range of ground conditions using relatively inexpensive equipment. The means and methods, applicability, capabilities and limitations of pilot tube microtunneling are well documented in published literature through many project specific case studies. However, there is little information on the macroscopic level regarding the technology and industry as a whole. With the increasing popularity of pilot tube microtunneling, there is an emerging need to address the above issues. This research effort surveyed 22 pilot tube microtunneling contractors across North America to determine the current industry state of practice with the technology. The survey examined various topics including contractor profile and experience; equipment, methods, and pipe materials utilized; and issues pertaining to project planning and construction risks associated with the pilot tube method. The findings of this research are based on a total of 450 projects completed with pilot tube microtunneling between 2006 and 2010. The respondents were diverse in terms of their experience with PTMT, ranging from two to 11 years. A majority of the respondents have traditionally provided services with other trenchless technologies. As revealed by the survey responses, PTMT projects grew by 110% between the years 2006 and 2010. It was found that almost 72% of the 450 PTMT projects completed between 2006 and 2010 by the respondents were for sanitary sewers. Installation in cobbles and boulders was rated as the highest risk by the contractors.