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Description
The thesis examines how high density polyethylene (HDPE) pipe installed by horizontal directional drilling (HDD) and traditional open trench (OT) construction techniques behave differently in saturated soil conditions typical of river crossings. Design fundamentals for depth of cover are analogous between HDD and OT; however, how the product pipe is situated in the soil medium is vastly different. This distinction in pipe bedding can produce significant differences in the post installation phase. The research was inspired by several incidents involving plastic pipe installed beneath rivers by HDD where the pipeline penetrated the overburden soil and floated to the surface after installation. It was hypothesized that pipes installed by HDD have a larger effective volume due to the presence of low permeability bentonite based drilling fluids in the annular space on completion of the installation. This increased effective volume of the pipe increases the buoyant force of the pipe compared to the same product diameter installed by OT methods, especially in situations where the pipe is installed below the ground water table. To simulate these conditions, a real-scale experiment was constructed to model the behavior of buried pipelines submerged in saturated silty soils. A full factorial design was developed to analyze scenarios with pipe diameters of 50, 75, and 100 mm installed at varying depths in a silty soil simulating an alluvial deposition. Contrary to the experimental hypothesis, pipes installed by OT required a greater depth of cover to prevent pipe floatation than similarly sized pipe installed by HDD. The results suggested that pipes installed by HDD are better suited to survive changing depths of cover. In addition, finite element method (FEM) modeling was conducted to understand soil stress patterns in the soil overburden post-installation. Maximum soil stresses occurring in the soil overburden between post-OT and HDD installation scenarios were compared to understand the pattern of total soil stress incurred by the two construction methods. The results of the analysis showed that OT installation methods triggered a greater total soil stress than HDD installation methods. The annular space in HDD resulted in less soil stress occurring in the soil overburden. Furthermore, the diameter of the HDD annular space influenced the soil stress that occurred in the soil overburden, while the density of drilling fluids did not vastly affect soil stress variations. Thus, the diameter of the annular space could impact soil stress patterns in HDD installations post-construction. With these findings engineers and designers may plan, design, and construct more efficient river-crossing projects.
ContributorsCho, Chin-sŏng (Author) / Ariaratnam, Samuel (Thesis advisor) / Lueke, Jason (Thesis advisor) / Arizona State University (Publisher)
Created2012
Description
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.
ContributorsHatfield, Whitney (Author) / Ariaratnam, Samuel (Thesis advisor) / Chasey, Allan (Committee member) / Bearup, Wylie (Committee member) / Arizona State University (Publisher)
Created2017
Description
The Phoenix-Metro area currently has problems with its transportation systems. Over-crowded and congested freeways have slowed travel times within the area. Express bus transportation and the existence of "High Occupancy" lanes have failed to solve the congestion problem. The light rail system is limited to those within a certain distance from the line, and even the light rail is either too slow or too infrequent for a commuter to utilize it effectively. To add to the issue, Phoenix is continuing to expand outward instead of increasing population density within the city, therefore increasing the time it takes to travel to downtown Phoenix, which is the center of economic activity. The people of Phoenix and its surrounding areas are finding that driving themselves to work is just as cost-effective and less time consuming than taking public transportation. Phoenix needs a cost-effective solution to work in co- existence with improvements in local public transportation that will allow citizens to travel to their destination in just as much time, or less time, than travelling by personal vehicle.
ContributorsSerfilippi, Jon (Author) / Ariaratnam, Samuel (Thesis director) / Pendyala, Ram (Committee member) / Pembroke, Jim (Committee member) / Barrett, The Honors College (Contributor) / Ira A. Fulton School of Engineering (Contributor)
Created2012-12
Description
The fact that the lean construction approach, a project-based production management approach, is considered as a best practice in the construction industry and a key solution to alleviate the implications of various forms of waste on the construction projects performance in general, and the Lebanese ones in particular, motivates the author to conduct a study to evaluate it as a strategic option. For that to happen, a bibliographic analysis has been developed to serve the key project objective. The bibliographic analysis is expected to help construction professionals to deepen their knowledge in Lean philosophy and its applications in the construction industry. After developing a solid background of understanding of Lean Construction, a survey to collect information from construction companies within the Lebanese territory has been conducted, followed by analysis and interpretations of the findings to examine lean construction inside the Lebanese construction Industry; that has been achieved in terms of understanding and analyzing the suitability, acceptability, and applicability of lean construction principles, tools, and techniques by Lebanese construction firms. Performed Revision has been crowned with a detailed explanation of the lean construction approach accompanied with an applicable lean construction implementation guideline. Besides that, survey results showed a wide acceptance of most lean construction principles (namely, waste elimination and continuous improvement) by Lebanese construction professionals. It has been shown as well, that lean construction tools and techniques are applied by a major portion of the Lebanese construction firms due to the significant impact these tools and techniques have on the project quality, schedule, and cost. However, all analyzed results confirm one main conclusion, that a significant portion of the Lebanese construction industry lack that adequate knowledge and understanding of lean construction philosophy, which necessitates the development of “Lean Construction Education Programs” as a principal enabler for successful lean construction adoption. This paper has been developed mainly to guide Lebanese construction professionals, especially project and construction managers, towards understanding and adopting lean construction as a mean to deliver projects of value and to inform Lebanese construction industry leaders about the current state of lean construction inside the Lebanese construction Industry.
ContributorsMetlej, Kamal (Author) / Grau Torrent, David (Thesis advisor) / Ariaratnam, Samuel (Committee member) / Czerniawski, Thomas (Committee member) / Arizona State University (Publisher)
Created2021
Description
As the construction industry in Saudi Arabia was on its way to thriving again. Their growth was due to the unprecedented volume of planned projects such as large-scale and unique projects. Suddenly, the world was faced with one of the most disrupting events in the last century which had a devastating impact on the construction industry specifically. This paper explores mainly the impact of the COVID-19 pandemic on construction projects in Saudi Arabia. Particularly, this paper explores how the pandemic and its related events contributed to the projects' schedule disturbances. This is because most of the projects rely on manpower and supply chains which were heavily disrupted due to the protective measures. For that, a study was conducted to evaluate the impact on the construction projects in Saudi Arabia, to what extent the schedule projects were affected, and what were the main reasons for the schedule delays. The research relied on a field survey and schedule analysis for 12 projects which resulted in identifying several causes of delays and the delayed durations that the projects in Saudi Arabia were facing. This research allows those in construction fields to identify the main causes of delays in order to avoid or minimize the impact of these issues on future projects.
ContributorsObeid, Muhammad Hasan Hani (Author) / Ariaratnam, Samuel (Thesis advisor) / El Asmar, Mounir (Committee member) / Chong, Oswald (Committee member) / Arizona State University (Publisher)
Created2021
Description
Dubai has emerged as an important center for international business attracting significant inflows of the foreign workforce. Dubai’s population is unique as nationals represent only 15% of the total population, with 200 other nationalities comprising the other 85%. Thus, Cultural Diversity is unavoidable. Cultural Diversity refers to cultural heterogeneity such as differences in race, ethnicity, language, nationality, and religion. As it is a characteristic of Culturally Heterogeneous Workgroups (CHWs), cultural diversity affects how they interact with each other. Since the core concepts of leadership are dealing, inspiring, and motivating teams, the team member’s diversity directly connects with the leadership concept.While many researchers argue whether (CHWs) suffer or benefit from cultural diversity, it is agreed that such diversity has its challenges. Diverse workgroups have been shown to suffer from poor cohesion and social integration. People who are different from their co-worker’s report feeling uneasy and having less organizational commitment. Miscommunication, the development of obstacles, and improper adaptation behaviors are all possible negative impacts.
In the absence of local studies on how cultural diversity is related to leadership, this thesis questioned the connection between cultural diversity and leadership level through a quantitative research approach. This would help understand how different leaders at different levels perceive cultural diversity challenges, which would help focus on specific level(s) in future and research practical ways to address cultural diversity issues of cultural diversity. Measurement scales for leadership levels and cultural diversity challenges were developed. A survey was used to collect data from skilled workers in the construction industry in Dubai, and non-parametric statistical methods were used to analyze the collected data and answer the research question. Whereas a strong correlation was initially expected between work experience, whether in total or within UAE, and leadership level, this was not the case. Most importantly, no significant evidence was found to support a relationship between cultural diversity challenges and both participants’ leadership level and their UAE work experience.
ContributorsSalama, Anas (Author) / Ariaratnam, Samuel (Thesis advisor) / El Asmar, Mounir (Committee member) / Czerniawski, Thomas (Committee member) / Arizona State University (Publisher)
Created2022