Engineering Commons^™

Impact Of Anthropogenic Activities On Hydro-Climatological Variables, Kuk Hyun Ahn

Open Access Dissertations

The natural environment has been significantly affected by anthropogenic activities. Between 1700s and 2000s, agricultural land area had quintupled and the extent of natural vegetation was globally reduced by half. Furthermore many scientists argue that the recent rise in CO2 levels in the atmosphere is mainly due to anthropogenic activities. Anthropogenic activities may also play a crucial role in the change of the hydro-climatologic variables. In this study, impact of anthropogenic activities on two representative hydro-climatologic variables, temperature and streamflow, is investigated. The variations in temperature occur over larger spatial and time scale, and hence the United States is adopted …

Integrating Pro-Environmental Behavior With Transportation Network Modeling: User And System Level Strategies, Implementation, And Evaluation, Husain M. Abdul Aziz

Open Access Dissertations

Personal transport is a leading contributor to fossil fuel consumption and greenhouse (GHG) emissions in the U.S. The U.S. Energy Information Administration (EIA) reports that light-duty vehicles (LDV) are responsible for 61\% of all transportation related energy consumption in 2012, which is equivalent to 8.4 million barrels of oil (fossil fuel) per day. The carbon content in fossil fuels is the primary source of GHG emissions that links to the challenge associated with climate change. Evidently, it is high time to develop actionable and innovative strategies to reduce fuel consumption and GHG emissions from the road transportation networks. This dissertation …

Nano-Modification For High Performance Cement Composites With Cellulose Nanocrystals And Carbon Nanotubes, Yizheng Cao

Open Access Dissertations

One of the new engineering frontiers is the exploration of infrastructure materials with novel combinations of properties that break traditional paradigms. The goal of this study is to utilize two different nano-fibers, cellulose nanocrystals (CNCs) and carbon nanotubes (CNTs) to modify the nanoscale structures of cement composites and thereby improve the performance at the macro-level. This study also evaluates the mechanism behind the modification, since fiber bridging, the most common reinforcing mechanism for fiber-reinforced composites, cannot be simply applied because CNCs are too short to bridge cracks in cement composites. ^ The mechanical tests show an increase in the flexural …

Strategies For The Replacement Of Historic Bridge Guardrails, Adam J. Clauss

Open Access Theses

Bridges that are designated historic present a special challenge to bridge engineers whenever rehabilitation work or improvements are made to the bridges. Federal and state laws protect historically significant bridges, and railings on these bridges can be subject to protection because of the role they play in aesthetics. Unfortunately, original railings on historic bridges do not typically meet current crash-test requirements and typically do not meet current standards for railing height and size of permitted openings. The objective of this study is to develop strategies that can be used to address existing railings on historic bridges and to develop solutions …

Heavy Vehicle Rollover Propensity At Roundabouts On Highspeed Roads, Thomas M. Hall

Open Access Theses

There is a recent trend of building roundabouts on high-speed roads, often with significant heavy vehicle traffic. With the increased presence of trucks on roundabouts, the issue of rollover has become a concern. Geometric features that allow excessive speed on the approach and entry have been connected to rollover, as well as sudden changes in crossfall and radius. However, the effect on the rollover threshold of changing the roundabout's circulatory superelevation is not fully understood. The impact of aggressive driving behaviors, as displayed by high driver speed far from the roundabout, as well as errors that are manifested by the …

A Nonlinear Interface Formulation For Frictional Contact, Layla K Amaireh

Open Access Dissertations

Finite element simulations of contact problems often involve modeling the interaction of multiple bodies across a non-confirming interface. Non-Confirming Meshes (NCM) are typically associated with large sliding or adaptive refinement on one side of the interface to capture localized nonlinear behavior due to large deformations, damage and inelasticity. The use of NCMs, however, presents a number of numerical issues; the main challenge with such discretizations is to ensure compatibility of the kinematic and traction fields along the non-conforming interface. ^ The Enriched Discontinuous Galerkin Approach (EDGA) (Haikal and Hjelmstad,2010)addresses this challenge by implementing a local enrichment along with an interface …

A Stochastic Multi-Criteria Assessment Of Security Of Transportation Assets, Michelle Sophie Dojutrek

Open Access Dissertations

Transportation project evaluation and prioritization use traditional performance measures including travel time, safety, user costs, economic efficiency, and environmental quality. The project impacts in terms of enhancing the infrastructure resilience or mitigating the consequences of infrastructure damage in the event of disaster occurrence are rarely considered in project evaluation. This dissertation presents a methodology to address this issue so that in evaluating and prioritizing investments, infrastructure with low security can receive the attention they deserve. Secondly, the methodology can be used for evaluating and prioritizing candidate investments dedicated specifically to security enhancement. In defining security as a function of threat …

Experimental Database, Analysis And Design Of Noncompact And Slender Concrete-Filled Steel Tube (Cft) Members, Zhichao Lai

Open Access Dissertations

Concrete-filled steel tube beam-columns are categorized as compact, noncompact or slender depending on the governing tube slenderness ratio. AISC 360-10 specifies the provisions for designing noncompact and slender rectangular and circular CFT members under axial compression, flexure, and combined axial and flexural loading. This research presents the development and evaluation of these design provisions. Available experimental databases of CFT members are reviewed, and a new experimental database of tests conducted on noncompact and slender CFT members is compiled. Detailed 3D finite element method (FEM) models are developed for noncompact and slender CFT members, and benchmarked using experimental results. The AISC …

Effects Of Web Reinforcement Discontinuities On The Seismic Response Of Structural Walls, Ying Wang

Open Access Dissertations

Field evidence was interpreted to suggest that discontinuities in the longitudinal web reinforcement caused severe damage in structural walls during strong ground motion. To test this hypothesis, six small-scale reinforced concrete structural walls were tested under lateral displacement reversals. Test variables included the presence of web longitudinal reinforcement discontinuities and number of loading cycles. The test results indicated that unit tensile strains in longitudinal reinforcing bars in boundary elements were approximately 50% higher in structural walls with web longitudinal reinforcement cutoffs relative to walls without reinforcement cutoffs. Higher unit tensile strains caused an increase in permanent strain accumulation, increasing the …

Capacity-Related Driver Behavior On Modern Roundabouts Built On High-Speed Roads, Shaikh Ahmad

Open Access Theses

The objective of this thesis was to investigate the factors that affect capacity-related driver behavior on modern roundabouts built on high-speed roads. The capacity of roundabouts is strongly affected by the behavior of drivers as represented by critical headway (critical gap) and follow-up headway (follow-up time). The effects of heavy vehicles (single-unit truck, bus, and semi-trailer) and area type (rural or urban) on roundabout capacity were investigated by comparing the critical headways for roundabouts located on high-speed and low-speed roads. The effects of nighttime conditions (in the presence of street lighting) were also considered. Data were collected using the Purdue …

Evaluation Of Collapse Indicators For Seismically Vulnerable Reinforced Concrete Buildings, Nicholas R. Skok

Open Access Theses

Older reinforced concrete buildings can be prone to column shear and compression failures during earthquakes because of inadequate transverse reinforcement. Cities in seismic areas still have large inventories of older and potentially deficient buildings. To analyze every building and estimate its vulnerability in detail is costly. A simple method to rank quickly older buildings according to their seismic vulnerability is needed to help engineers prioritize the use of resources for rehabilitating the most vulnerable buildings.

Four indicators of building damage or collapse were evaluated using numerical analysis and prior data from building surveys: column index (Hassan & Sozen, 1997), R …

Fire Behavior Of Bolted Connections, Qiaqia Zhu

Open Access Theses

Bolted connection failures have been observed in building fires and large-scale structural fire tests. Limited information is available on plate bearing behavior at elevated temperatures. The failure mode of a shear-tab connection could change from plate bearing failure to bolt shear failure between 400 (degree Celsius) °C to 600°C. Component-based models have been used to predict the behavior of bolted connections. Earlier researchers have developed simple mathematical models to represent the force-displacement relationships of bolt shear and plate bearing components of bolted connections. However, these models need to be verified experimentally for US building construction and materials. Therefore, eleven single-bolted …

Evaluation Of Methods For Estimating Prestress Losses In High-Strength Structural Concrete, Mayren Yelitza Mata Carrillo

Open Access Theses

The purpose of this study was to evaluate the applicability of several current approaches used to estimate losses in prestressed concrete members with compressive strengths greater than 15ksi. The scope of the study focused on time-dependent losses for normal weight concrete bonded applications. The approaches evaluated were the PCI Design Handbook (2010) method, the AASHTO Specifications (2012) refined method, the PCI Bridge Design Manual (2003) time-dependent analysis using both the AASHTO (2012) and the PCI-BDM (2003) creep and shrinkage models, and a time-step method developed by Swartz (2010). The methods were compared to existing data on prestress losses from twenty-two …

Scour In Regions Of Flow Separation With Free-Surface Effects, John Frederick Newton

Open Access Dissertations

Downstream of essentially all overflow and drop structures two distinct flow regimes are possible, one associated with a plunging flow, the other dominated by a flow that rides along the surface. Predicting the flow regime is important because diving-jet scouring rates are substantially faster than surface flow scouring rates, and diving-jet scour holes form nearer to the structure. A bi-stable region exists in which either flow is possible with the same upstream and downstream flow conditions. Bi-stable regime boundaries were delineated for a wide variety of fixed bed structures, based on both new experiments and reanalysis of others' experiments with …

Development, Numerical Demonstration And Experimental Verification Of A Method For Model Updating Of Boundary Conditions, Christian Eduardo Silva Salazar

Open Access Theses

The study of vibrations in beams has been largely addressed by authors and researchers. However, relatively few researchers have considered the case of unknown boundary conditions, as usually it is reasonable to assume the classical cases such as simply supported, clamped or free. Indeed, there are a wide variety of boundary-condition configurations, each one representing a whole different problem with its own modal characteristics. ^ A method for updating experimental beam models to specifically address the issue of unknown boundary conditions is proposed. This methodology takes advantage of vector comparison techniques such as the modal assurance criterion and the dot …

Tracking Dynamic Construction Objects ---A Key Node Modeling Approach Using Color-Depth Cameras, Chenxi Yuan

Open Access Theses

A construction site presents a dynamic scenario. Locations of multiple objects are continuously changing and a lot of objects enter and exit the site in high frequencies. Meanwhile a construction activity consists of a large amount of stochastic operations, many uncertainties occur when making decisions. Believing that detecting, locating and tracking dynamic construction objects in real time improve construction productivity and enhance construction safety, a large number of studies have applied a variety of sensing technologies to construction sites. Hybrid image-point cloud sensing technologies, such as color-depth cameras, have a great potential in achieving real time object recognition and tracking …

Evaluation Of Asphalt Pavement Interface, Hyung Jun Ahn

Open Access Theses

This paper presents the development process of modified pull-off test for measurement of in-situ pavement interface bonding strength. The modified test method was validated using two case studies (i.e., delaminated vs. non-delaminated pavements on I-65 and intelligent compacted vs. non-intelligent compacted pavements on US-52) and used for developing a correlation model for estimating a probability of delamination failure at a given pull-off bonding strength. In addition, methodologies for probabilistic interpretations with pull-off test results were explored.

The results demonstrated that the modified pull-off test showed its applicability in measurement of interface bonding condition with both weak and strong conditions. Additionally, …

Systematic Analysis Of Drainage Events In Free Draining And Managed Subsurface Drainage Systems, Guy Bou Lahdou

Open Access Theses

Understanding the hydrologic controls that regulate outflow from free and managed subsurface drainage systems during drainage events can offer improved insight on the overall functioning and effectiveness of the systems so that they can be better managed or retrofitted to increase their environmental benefits. This study used drainage, precipitation, water table, and soil moisture data from a monitoring site located in east central Indiana to investigate the event hydrology of 22 drainage events in free and managed subsurface drainage systems. Relationships between event drainage volume, drain flow hydrograph metrics, column soil moisture, water table depth, and precipitation characteristics were explored …

A Framework Of Effective Debris Management For A Resilient Community, Jooho Kim

Open Access Theses

Natural disasters have an enormous physical impact on communities and generate a huge volume of debris. The amount of debris is almost five to ten times higher than the annual solid waste volume in a community, and slow debris removal can hinder both emergency response and proceeding with the tasks of recovery. The cost of debris management also can reach more than 27% of the total disaster recovery costs. Therefore, debris management teams have considerable challenges in removing disaster debris. ^ This thesis introduces a framework for an effective debris management plan based on the interrelationship between critical infrastructure systems …

Quality Assurance And Quality Control Correlations For The Dynamic Cone Penetrometer, Eshan Ganju

Open Access Theses

The Dynamic Cone Penetrometer (DCP) is a device that is used for the estimation of in situ compaction quality of constructed subgrades and embankments. It is a relatively inexpensive, light-weight and easy to use device that measures the dynamic penetration resistance of the compacted soil, from which an estimate of soil strength and stiffness characteristics can be made. Owing to its ease of use, many DOTs in the U.S. have employed the DCP in their compaction quality control procedures, and over the past few decades, extensive research has been carried out on the development of correlations between the results of …

Detailed Finite Element Analysis And Preliminary Study Of The Effects Of Friction And Fastener Pre-Tension On The Mechanical Behavior Of Fastened Built-Up Members, Francisco Javier Bonachera Martin

Open Access Theses

The characterization of fatigue resistance is one of the main concerns in structural engineering, a concern that is particularly important in the evaluation of existing bridge members designed or erected before the development of fatigue design provisions. The ability of a structural member to develop alternate load paths after the failure of a component is known as member-level or internal redundancy. In fastened built-up members, these alternate load paths are affected by the combination of fastener pre-tension and friction between the structural member components in contact. In this study, a finite element methodology to model and analyze riveted and bolted …

Small Strain Stiffness Of A Carbonatic Fine Grained Soil, Sulaiman Dawood

Open Access Theses

The work presented in this thesis is part of a broad effort aimed at the characterization of the engineering properties, microstructure and mineralogy of soft fine-grained carbonatic soil deposit in Southwestern Indiana (Daviess Co.). The specific focus of this thesis is the characterization, through both field and laboratory measurements, of the small strain behavior of this soil, commonly referred to as a "marl."

Index tests indicate that the 3.5 m marl layer present at the site is characterized by two soil types alternating in small sublayers: a high plasticity silt (soil M) with wn ∼60% and CaCO3 ∼60%, mostly in …

Graphical Performance Measures For Practitioners To Identify Split Failures, Richard Scott Freije

Open Access Theses

Detector occupancy is commonly used to measure traffic signal performance. Despite improvements in controller computational power, there have been relatively few innovations in occupancy-based performance measures or integration with other data. This thesis introduces and demonstrates the use of graphical performance measures based on detector occupancy ratios to verify potential split failures and other signal timing shortcomings reported to practitioners by the public. The proposed performance measures combine detector occupancy during the green interval, detector occupancy during the first five seconds of the red interval, and phase termination cause (gap out or force off). These are summarized by time of …

Excessive Delays In Closeouts Can Be Removed With The Adaptation Of Better Practices, Vasudha Kaul

Open Access Theses

Until recent times, closeout was not given its due diligence simply because the damage it created was not appreciated. Literature, thought-provoking discussions and thoughtful deliberations have punctuated the absolute need for a project closeout planning at the very beginning of a project. Many experienced project managers fail to plan the closeout of a job and concentrate solely on completing the contractual scope of work without paying much heed to the final percent of construction projects, the one percent that is an extremely time-consuming and expensive process if not catered for well in advance. The closeout stage is given its due …

The Hong Kong-Zhu Hai-Macau Bridge: Impacts On The Greater Pearl River Delta, Jun He

Open Access Theses

This research looks at the impacts of megaprojects on their host regions through a case study of the Hong Kong-Zhu Hai-Macau Bridge (HZMB). The purpose of this study is to analyze the potential economic impact of the HZMB on the region through existing data and stakeholder interviews. The research will specifically focus on megaprojects' impacts on tourism industry and economic development in general. The research results are aimed to address the four research objectives of the study, which are similarities and differences between the HZBM and other megaprojects, common issues involved in developing megaprojects, the future impacts of the HZMB …

Risk-Based Bridge Inspection Practices, Rebecca Reising

Open Access Theses

Improving bridge safety, reliability, and the allocation of bridge inspection resources are the goals of the proposed risk based bridge inspection practices. Currently, most bridges in the United States are inspected at a fixed calendar interval of 24 months, without regard to the condition of the bridge. Newer bridges with little or no damage are inspected with the same frequency as older, more deteriorated bridges thus creating inefficiency in the allocation of inspection resources. Because of limited resources, it is not possible to spend the necessary time examining bridges that are in poor condition and require extra attention since equal …

Floodplain Mapping Using Soil Survey Geographic (Ssurgo) Database, Nikhil Sangwan

Open Access Theses

Floods are the most damaging of all natural disasters, adversely affecting millions of lives and causing financial losses worth billions of dollars every year across the globe. Flood inundation maps play a key role in assessment and mitigation of the potential flood hazards. However, there are several communities in the United States for which the flood risk maps have not been published yet, as the current flood inundation mapping methods are typically very expensive and time consuming. The objective of this study is to develop and examine an economical alternative approach to floodplain mapping using widely available soil survey data. …

Investigating The Role Of Dem Resolution And Accuracy On Flood Inundation Mapping, Siddharth Saksena

Open Access Theses

Saksena, Siddharth. M.S.C.E., Purdue University, May 2014. Investigating the Role of DEM Resolution and Accuracy on Flood Inundation Mapping. Major Professor: Venkatesh Merwade. Topography plays an important role in determining the accuracy of flood inundation maps. A lot of the current flood inundation maps are created using topographic information derived from Light Detection and Ranging (LiDAR) data. Although LiDAR data is very accurate, it is expensive, computationally time consuming and not available in several areas across the United States and around the world. As a result, coarser resolution DEMs which are easily available but less accurate are used for flood …

Signalized Corridor Assessment, William Benjamin Smith

Open Access Theses

Traffic engineers are often required to investigate the operation of a corridor and determine if there are any areas for improvement. Typical performance measures used to aid in the analysis are volume-to-capacity ratio and average delays based on the Highway Capacity Manual method. Signal timing software might also be used to adjust the split timings in effort to improve the corridor. This thesis discusses procedure to implement split timing optimization and delay analysis to enhance the current process of corridor assessment.

This study examined the newly opened US-231 bypass corridor outside of West Lafayette, IN. Initially, all intersections were operating …

Rheological Properties Of Laponite And Chemically Modified Laponite Suspensions, Meng Shen

Open Access Theses

This research investigates the rheological properties of concentrated laponite RD suspensions modified through the addition of laponite RDS and sodium pyrophosphate (SPP). The work is aimed at establishing the possible suitability of these materials for treating liquefaction susceptible sands. This application requires that a laponite suspension initially exhibits liquid like behavior and low viscosity that allow its delivery into the pore space of a sand, but that over time the suspension develop a gel structure with solid like behavior that can serve to restrict sand particle mobility during earthquake shaking.

The experimental program made use of a Physica MCR 301 …