Matching Items (26)
Filtering by
- All Subjects: Civil Engineering
- Genre: Doctoral Dissertation
- Creators: El Asmar, Mounir
- Creators: Zapata, Claudia
Description
Unsaturated soil mechanics is becoming a part of geotechnical engineering practice, particularly in applications to moisture sensitive soils such as expansive and collapsible soils and in geoenvironmental applications. The soil water characteristic curve, which describes the amount of water in a soil versus soil suction, is perhaps the most important soil property function for application of unsaturated soil mechanics. The soil water characteristic curve has been used extensively for estimating unsaturated soil properties, and a number of fitting equations for development of soil water characteristic curves from laboratory data have been proposed by researchers. Although not always mentioned, the underlying assumption of soil water characteristic curve fitting equations is that the soil is sufficiently stiff so that there is no change in total volume of the soil while measuring the soil water characteristic curve in the laboratory, and researchers rarely take volume change of soils into account when generating or using the soil water characteristic curve. Further, there has been little attention to the applied net normal stress during laboratory soil water characteristic curve measurement, and often zero to only token net normal stress is applied. The applied net normal stress also affects the volume change of the specimen during soil suction change. When a soil changes volume in response to suction change, failure to consider the volume change of the soil leads to errors in the estimated air-entry value and the slope of the soil water characteristic curve between the air-entry value and the residual moisture state. Inaccuracies in the soil water characteristic curve may lead to inaccuracies in estimated soil property functions such as unsaturated hydraulic conductivity. A number of researchers have recently recognized the importance of considering soil volume change in soil water characteristic curves. The study of correct methods of soil water characteristic curve measurement and determination considering soil volume change, and impacts on the unsaturated hydraulic conductivity function was of the primary focus of this study. Emphasis was placed upon study of the effect of volume change consideration on soil water characteristic curves, for expansive clays and other high volume change soils. The research involved extensive literature review and laboratory soil water characteristic curve testing on expansive soils. The effect of the initial state of the specimen (i.e. slurry versus compacted) on soil water characteristic curves, with regard to volume change effects, and effect of net normal stress on volume change for determination of these curves, was studied for expansive clays. Hysteresis effects were included in laboratory measurements of soil water characteristic curves as both wetting and drying paths were used. Impacts of soil water characteristic curve volume change considerations on fluid flow computations and associated suction-change induced soil deformations were studied through numerical simulations. The study includes both coupled and uncoupled flow and stress-deformation analyses, demonstrating that the impact of volume change consideration on the soil water characteristic curve and the estimated unsaturated hydraulic conductivity function can be quite substantial for high volume change soils.
ContributorsBani Hashem, Elham (Author) / Houston, Sandra L. (Thesis advisor) / Kavazanjian, Edward (Committee member) / Zapata, Claudia (Committee member) / Arizona State University (Publisher)
Created2013
Description
Alternative Project Delivery Methods (APDMs), namely Design Build (DB) and Construction Manager at Risk (CMAR), grew out of the need to find a more efficient project delivery approach than the traditional Design Bid Build (DBB) form of delivery. After decades of extensive APDM use, there have been many studies focused on the use of APDMs and project outcomes. Few of these studies have reached a level of statistical significance to make conclusive observations about APDMs. This research effort completes a comprehensive study for use in the horizontal transportation construction market, providing a better basis for decisions on project delivery method selection, improving understanding of best practices for APDM use, and reporting outcomes from the largest collection of APDM project data to date. The study is the result of an online survey of project owners and design teams from 17 states representing 83 projects nationally. Project data collected represents almost six billion US dollars. The study performs an analysis of the transportation APDM market and answers questions dealing with national APDM usage, motivators for APDM selection, the relation of APDM to pre-construction services, and the use of industry best practices. Top motivators for delivery method selection: the project schedule or the urgency of the project, the ability to predict and control cost, and finding the best method to allocate risk, as well as other factors were identified and analyzed. Analysis of project data was used to compare to commonly held assumptions about the project delivery methods, confirming some assumptions and refuting others. Project data showed that APDM projects had the lowest overall cost growth. DB projects had higher schedule growth. CMAR projects had low design schedule growth but high construction schedule growth. DBB showed very little schedule growth and the highest cost growth of the delivery methods studied. Best practices in project delivery were studied: team alignment, front end planning, and risk assessment were identified as practices most critical to project success. The study contributes and improves on existing research on APDM project selection and outcomes and fills many of the gaps in research identified by previous research efforts and industry leaders.
ContributorsBingham, Evan Dale (Author) / Gibson Jr., G. Edward (Thesis advisor) / El Asmar, Mounir (Thesis advisor) / Bearup, Wylie (Committee member) / Arizona State University (Publisher)
Created2014
Description
A method for evaluating the integrity of geosynthetic elements of a waste containment system subject to seismic loading is developed using a large strain finite difference numerical computer program. The method accounts for the effect of interaction between the geosynthetic elements and the overlying waste on seismic response and allows for explicit calculation of forces and strains in the geosynthetic elements. Based upon comparison of numerical results to experimental data, an elastic-perfectly plastic interface model is demonstrated to adequately reproduce the cyclic behavior of typical geomembrane-geotextile and geomembrane-geomembrane interfaces provided the appropriate interface properties are used. New constitutive models are developed for the in-plane cyclic shear behavior of textured geomembrane/geosynthetic clay liner (GMX/GCL) interfaces and GCLs. The GMX/GCL model is an empirical model and the GCL model is a kinematic hardening, isotropic softening multi yield surface plasticity model. Both new models allows for degradation in the cyclic shear resistance from a peak to a large displacement shear strength. The ability of the finite difference model to predict forces and strains in a geosynthetic element modeled as a beam element with zero moment of inertia sandwiched between two interface elements is demonstrated using hypothetical models of a heap leach pad and two typical landfill configurations. The numerical model is then used to conduct back analyses of the performance of two lined municipal solid waste (MSW) landfills subjected to strong ground motions in the Northridge earthquake. The modulus reduction "backbone curve" employed with the Masing criterion and 2% Rayleigh damping to model the cyclic behavior of MSW was established by back-analysis of the response of the Operating Industries Inc. landfill to five different earthquakes, three small magnitude nearby events and two larger magnitude distant events. The numerical back analysis was able to predict the tears observed in the Chiquita Canyon Landfill liner system after the earthquake if strain concentrations due to seams and scratches in the geomembrane are taken into account. The apparent good performance of the Lopez Canyon landfill geomembrane and the observed tension in the overlying geotextile after the Northridge event was also successfully predicted using the numerical model.
ContributorsArab, Mohamed G (Author) / Kavazanjian, Edward (Thesis advisor) / Zapata, Claudia (Committee member) / Houston, Sandra (Committee member) / Arizona State University (Publisher)
Created2011
Description
It is estimated that wind induced soil transports more than 500 x 106 metric tons of fugitive dust annually. Soil erosion has negative effects on human health, the productivity of farms, and the quality of surface waters. A variety of different polymer stabilizers are available on the market for fugitive dust control. Most of these polymer stabilizers are expensive synthetic polymer products. Their adverse effects and expense usually limits their use. Biopolymers provide a potential alternative to synthetic polymers. They can provide dust abatement by encapsulating soil particles and creating a binding network throughout the treated area. This research into the effectiveness of biopolymers for fugitive dust control involved three phases. Phase I included proof of concept tests. Phase II included carrying out the tests in a wind tunnel. Phase III consisted of conducting the experiments in the field. Proof of concept tests showed that biopolymers have the potential to reduce soil erosion and fugitive dust transport. Wind tunnel tests on two candidate biopolymers, xanthan and chitosan, showed that there is a proportional relationship between biopolymer application rates and threshold wind velocities. The wind tunnel tests also showed that xanthan gum is more successful in the field than chitosan. The field tests showed that xanthan gum was effective at controlling soil erosion. However, the chitosan field data was inconsistent with the xanthan data and field data on bare soil.
ContributorsAlsanad, Abdullah (Author) / Kavazanjian, Edward (Thesis advisor) / Edwards, David (Committee member) / Zapata, Claudia (Committee member) / Arizona State University (Publisher)
Created2011
Description
Laterally-loaded short rigid drilled shaft foundations are the primary foundation used within the electric power transmission line industry. Performance of these laterally loaded foundations is dependent on modulus of the subsurface, which is directly measured by the Pressuremeter (PMT). The PMT test provides the lateral shear modulus at intermediate strains, an equivalent elastic modulus for lateral loading, which mimics the reaction of transmission line foundations within the elastic range of motion. The PMT test, however, is expensive to conduct and rarely performed. Correlations of PMT to blow counts and other index properties have been developed but these correlations have high variability and may result in unconservative foundation design. Variability in correlations is due, in part, because difference of the direction of the applied load and strain level between the correlated properties and the PMT. The geophysical shear wave velocity (S-wave velocity) as measured through refraction microtremor (ReMi) methods can be used as a measure of the small strain, shear modulus in the lateral direction. In theory, the intermediate strain modulus of the PMT is proportional to the small strain modulus of S-wave velocity. A correlation between intermediate strain and low strain moduli is developed here, based on geophysical surveys conducted at fourteen previous PMT testing locations throughout the Sonoran Desert of central Arizona. Additionally, seasonal variability in S-wave velocity of unsaturated soils is explored and impacts are identified for the use of the PMT correlation in transmission line foundation design.
ContributorsEvans, Ashley Elizabeth (Author) / Houston, Sandra (Thesis advisor) / Zapata, Claudia (Thesis advisor) / van Paassen, Leon (Committee member) / Arizona State University (Publisher)
Created2018
Description
The demand for new highway infrastructure, the need to repair aging infrastructure, and the drive to optimize public expenditures on infrastructure have led transportation agencies toward alternative contracting methods (ACMs) such as design-build (DB) and construction manager/general contractor (CM/GC). U.S. transportation agencies have substantial experience with traditional design-bid-build delivery. To promote ACMs, the Federal Highway Administration and the National Cooperative Highway Research Program (NCRHP) have published ACM guidance documents. However, the published material and research tend to focus on pre-award activities. The need for guidance on ACM post-award activities is confirmed in NCHRP’s request for a guidebook focusing on ACM contract administration (NCHRP 2016).
This dissertation fills the crucial knowledge gap in contract administration functions and tools for DB and CM/GC highway project delivery. First, this research identifies and models contract administration functions in DBB, CM/GC, and DB using integrated definition modeling (IDEF0). Second, this research identifies and analyzes DB and CM/GC tools for contract administration by conducting 30 ACM project case studies involving over 90 ACM practitioners. Recommendations on appropriate use regarding project phase, complexity, and size were gathered from 16 ACM practitioners. Third, the alternative technical concepts tool was studied. Data from 30 DB projects was analyzed to explore the timing of DB procurement and DB initial award performance in relation to the project influence curve. Types of innovations derived from ATCs are discussed. Considerable industry input at multiple stages grounds this research in professional practice.
Results indicate that the involvement of the contractor during the design phase for both DB and CM/GC delivery creates unique contract administration functions that need unique tools. Thirty-six DB and CM/GC tools for contract administration are identified with recommendations for effective implementation. While strong initial award performance is achievable in DB projects, initial award performance in this sample of projects is only loosely tied to the level of percent base design at procurement. Cost savings typically come from multiple ATCs, and innovations tend to be incremental rather than systemic, disruptive, or radical. Opportunity for innovation on DB highway projects is influenced by project characteristics and engaging the DB entity after pre-project planning.
This dissertation fills the crucial knowledge gap in contract administration functions and tools for DB and CM/GC highway project delivery. First, this research identifies and models contract administration functions in DBB, CM/GC, and DB using integrated definition modeling (IDEF0). Second, this research identifies and analyzes DB and CM/GC tools for contract administration by conducting 30 ACM project case studies involving over 90 ACM practitioners. Recommendations on appropriate use regarding project phase, complexity, and size were gathered from 16 ACM practitioners. Third, the alternative technical concepts tool was studied. Data from 30 DB projects was analyzed to explore the timing of DB procurement and DB initial award performance in relation to the project influence curve. Types of innovations derived from ATCs are discussed. Considerable industry input at multiple stages grounds this research in professional practice.
Results indicate that the involvement of the contractor during the design phase for both DB and CM/GC delivery creates unique contract administration functions that need unique tools. Thirty-six DB and CM/GC tools for contract administration are identified with recommendations for effective implementation. While strong initial award performance is achievable in DB projects, initial award performance in this sample of projects is only loosely tied to the level of percent base design at procurement. Cost savings typically come from multiple ATCs, and innovations tend to be incremental rather than systemic, disruptive, or radical. Opportunity for innovation on DB highway projects is influenced by project characteristics and engaging the DB entity after pre-project planning.
ContributorsPapajohn, Dean (Author) / El Asmar, Mounir (Thesis advisor) / Gibson, G. Edward (Committee member) / Bearup, Wylie (Committee member) / Molenaar, Keith R. (Committee member) / Arizona State University (Publisher)
Created2019
Description
Planning efforts conducted during the early stages of a construction project, known
as front end planning (FEP), have a large impact on project success and significant
influence on the configuration of the final project. As a key component of FEP, front end
engineering design (FEED) plays an essential role in the overall success of large industrial
projects. The primary objective of this dissertation focuses on FEED maturity and accuracy
and its impact on project performance. The author was a member of the Construction
Industry Institute (CII) Research Team (RT) 331, which was tasked to develop the FEED
Maturity and Accuracy Total Rating System (FEED MATRS), pronounced “feed matters.”
This dissertation provides the motivation, methodology, data analysis, research findings
(which include significant correlations between the maturity and accuracy of FEED and
project performance), applicability and contributions to academia and industry. A scientific
research methodology was employed in this dissertation that included a literature review,
focus groups, an industry survey, data collection workshops, in-progress projects testing,
and statistical analysis of project performance. The results presented in this dissertation are
based on input from 128 experts in 57 organizations and a data sample of 33 completed
and 11 on-going large industrial projects representing over $13.9 billion of total installed
cost. The contributions of this work include: (1) developing a tested FEED definition for
the large industrial projects sector, (2) determining the industry’s state of practice for
measuring FEED deliverables, (3) developing an objective and scalable two-dimensional
method to measure FEED maturity and accuracy, and (4) quantifying that projects with
high FEED maturity and accuracy outperformed projects with low FEED maturity and
accuracy by 24 percent in terms of cost growth, in relation to the approved budget.
as front end planning (FEP), have a large impact on project success and significant
influence on the configuration of the final project. As a key component of FEP, front end
engineering design (FEED) plays an essential role in the overall success of large industrial
projects. The primary objective of this dissertation focuses on FEED maturity and accuracy
and its impact on project performance. The author was a member of the Construction
Industry Institute (CII) Research Team (RT) 331, which was tasked to develop the FEED
Maturity and Accuracy Total Rating System (FEED MATRS), pronounced “feed matters.”
This dissertation provides the motivation, methodology, data analysis, research findings
(which include significant correlations between the maturity and accuracy of FEED and
project performance), applicability and contributions to academia and industry. A scientific
research methodology was employed in this dissertation that included a literature review,
focus groups, an industry survey, data collection workshops, in-progress projects testing,
and statistical analysis of project performance. The results presented in this dissertation are
based on input from 128 experts in 57 organizations and a data sample of 33 completed
and 11 on-going large industrial projects representing over $13.9 billion of total installed
cost. The contributions of this work include: (1) developing a tested FEED definition for
the large industrial projects sector, (2) determining the industry’s state of practice for
measuring FEED deliverables, (3) developing an objective and scalable two-dimensional
method to measure FEED maturity and accuracy, and (4) quantifying that projects with
high FEED maturity and accuracy outperformed projects with low FEED maturity and
accuracy by 24 percent in terms of cost growth, in relation to the approved budget.
ContributorsYussef, Abdulrahman (Author) / Gibson, Jr., G. Edward (Thesis advisor) / El Asmar, Mounir (Thesis advisor) / Bearup, Wylie (Committee member) / Wiezel, Avi (Committee member) / Arizona State University (Publisher)
Created2019
Description
Transportation systems in the U.S. are in a poor state of disrepair. A significant investment is needed to replace or rehabilitate current transportation infrastructure. Currently, transportation investments are lackluster with the recession of 2008 heavily impacting transportation spending, inciting deficits and budgetary cuts at state and federal government levels. As a result, policy makers and public officials are increasingly looking for innovative financing and alternative delivery methods to supplement traditional financing and delivery for transportation projects. Subsequently, the number of public-private partnerships (PPP or P3) has increased substantially over the last two decades.
There is a growing need to quantify the project performance and financial benefits of PPP. This dissertation fills this gap in knowledge by performing a comprehensive quantitative analysis of PPP project performance and financial sources for transportation projects in the U.S. This study’s specific research objectives are:
(1) Develop a solid baseline for comparison, comprised of non-PPP projects;
(2) Quantify PPP project cost and schedule performance; and
(3) Quantify private versus public financing sources of PPP.
A thorough literature review led to the development of a structured data collection process for PPP and comparable non-PPP projects. Financing data was collected and verified for a total of 133 ongoing and completed projects; while performance data was verified for a subset of 81 completed projects. Data analysis included regression analysis, descriptive statistics, inferential statistics and non-parametric statistical tests.
The results provide benchmarks for PPP project performance and financing sources. For the performance results, non-PPP projects have an average cost change of 8.46 percent and an average schedule change of -0.22 percent. PPP projects have an average cost change of 3.04 percent and average schedule change of 1.38 percent. Statistical analysis showed cost change for PPP projects were superior to that of non-PPP; however, schedule change differences were not significant. For the financing results, private financing totaled 44.5 percent while public financing totaled 55.5 percent. This result shows private financing can be used to leverage public financing with close to a one-to-one ratio and that PPP has the potential to double the amount of infrastructure delivered to the public.
There is a growing need to quantify the project performance and financial benefits of PPP. This dissertation fills this gap in knowledge by performing a comprehensive quantitative analysis of PPP project performance and financial sources for transportation projects in the U.S. This study’s specific research objectives are:
(1) Develop a solid baseline for comparison, comprised of non-PPP projects;
(2) Quantify PPP project cost and schedule performance; and
(3) Quantify private versus public financing sources of PPP.
A thorough literature review led to the development of a structured data collection process for PPP and comparable non-PPP projects. Financing data was collected and verified for a total of 133 ongoing and completed projects; while performance data was verified for a subset of 81 completed projects. Data analysis included regression analysis, descriptive statistics, inferential statistics and non-parametric statistical tests.
The results provide benchmarks for PPP project performance and financing sources. For the performance results, non-PPP projects have an average cost change of 8.46 percent and an average schedule change of -0.22 percent. PPP projects have an average cost change of 3.04 percent and average schedule change of 1.38 percent. Statistical analysis showed cost change for PPP projects were superior to that of non-PPP; however, schedule change differences were not significant. For the financing results, private financing totaled 44.5 percent while public financing totaled 55.5 percent. This result shows private financing can be used to leverage public financing with close to a one-to-one ratio and that PPP has the potential to double the amount of infrastructure delivered to the public.
ContributorsRamsey, David Wayne (Author) / El Asmar, Mounir (Thesis advisor) / Kaloush, Kamil (Committee member) / Gibson, Jr., G. Edward (Committee member) / Arizona State University (Publisher)
Created2016
Description
Entering a new market in the construction industry is a complex task. Although many contractors have experienced the benefits of expanding their market offerings, many more have had unsuccessful experiences causing hardship for the entire organization. Standardized decision-making processes can help to increase the likelihood of success, but few specialty contractors have taken the time to develop a formal procedure. According to this research, only 6 percent of survey respondents and 7 percent of case study participants from the sheet metal industry have a formal decision process. Five sources of data (existing literature, industry survey, semi-structured interviews, factor prioritization workshops, and expert panel discussions) are consulted to understand the current market entry decision-making practices and needs of the sheet metal industry. The data help to accomplish three study objectives: (1) determine the current processes and best practices used for market entry decision-making in the sheet metal industry, (2) identify motivations leading to market entry by sheet metal contractors, and (3) develop a standardized decision process that improves market entry decision outcomes. Grounded in a firm understanding of industry practices, a three-phased decision-making framework is created to provide a structured approach to guide contractors to an informed decision. Four industry leaders with over 175 years of experience in construction reviewed and applied every step of the framework to ensure it is practical and easy to use for contractors.
ContributorsSullivan, Jera J (Author) / El Asmar, Mounir (Thesis advisor) / Gibson, G Edward (Committee member) / Sullivan, Kenneth (Committee member) / Arizona State University (Publisher)
Created2016
Description
Despite advancements in construction and construction-related technology, capital project performance deviations, typically overruns, remain endemic within the capital projects industry. Currently, management is generally unaware of the current status of their projects, and thus monitoring and control of projects are not achieved effectively. In an ever-increasing competitive industry landscape, the need to deliver projects within technical, budgetary, and schedule requirements becomes imperative to sustain a healthy return on investment for the project stakeholders. The fact that information lags within the capital projects industry has motivated this research to find practices and solutions that facilitate Instantaneous Project Controls (IPC).
The author hypothesized that there are specific practices that, if properly implemented, can lead to instantaneous controls of capital projects. It is also hypothesized that instantaneous project controls pose benefits to project performance. This research aims to find practices and identify benefits and barriers to achieving a real-time mode of control. To achieve these objectives, several lines of inquiry had to be pursued. A panel of 13 industry professionals and three academics collaborated on this research project. Two surveys were completed to map the current state of project control practices and to identify state-of-the-art or ideal processes. Ten case studies were conducted within and outside of the capital projects industry to identify practices for achieving real-time project controls. Also, statistical analyses were completed on retrospective data for completed capital projects in order to quantify the benefits of IPC. In conclusion, this research presents a framework for implementing IPC across the capital projects industry. The ultimate output from this research is procedures and recommendations that improve project controls processes.
The author hypothesized that there are specific practices that, if properly implemented, can lead to instantaneous controls of capital projects. It is also hypothesized that instantaneous project controls pose benefits to project performance. This research aims to find practices and identify benefits and barriers to achieving a real-time mode of control. To achieve these objectives, several lines of inquiry had to be pursued. A panel of 13 industry professionals and three academics collaborated on this research project. Two surveys were completed to map the current state of project control practices and to identify state-of-the-art or ideal processes. Ten case studies were conducted within and outside of the capital projects industry to identify practices for achieving real-time project controls. Also, statistical analyses were completed on retrospective data for completed capital projects in order to quantify the benefits of IPC. In conclusion, this research presents a framework for implementing IPC across the capital projects industry. The ultimate output from this research is procedures and recommendations that improve project controls processes.
ContributorsAbbaszadegan, Amin (Author) / Grau Torrent, David (Thesis advisor) / El Asmar, Mounir (Committee member) / Gibson, Jr., G. Edward (Committee member) / Arizona State University (Publisher)
Created2016