Engineering Commons^™

Preferred Sensor Selection For Damage Estimation In Civil Structures, Matthew Styckiewicz

Masters Theses 1911 - February 2014

Detecting structural damage in civil structures through non-destructive means is a growing field in civil engineering. There are many viable methods, but they can often be time consuming and costly; requiring large amounts of data to be collected. By determining which data are the most optimal at detecting damage and which are not the methods can be better optimized. The objective of this thesis was to adapt an existing method of data optimization, used for damage detection in mechanical engineering applications, for use with civil structures. The existing method creates Parameter Signatures based on characteristics from the system being analyzed, …

Evaluating At-Grade Rail Crossing Safety Along The Knowledge Corridor In Massachusetts, Timothy P. Horan

Masters Theses 1911 - February 2014

Highway-rail grade crossings are safer than ever, but collisions between motor vehicles and trains persist. Some collisions could be prevented by actively maintaining such grade crossings, yet many at-grade rail crossings are only evaluated following collisions. Those crossings that experience no collisions may go decades without being inspected. In recent years, the Congress has allocated funds for a national High-Speed Intercity Passenger Rail program, and it is in the public’s interest for state road/highway agencies to inspect all highway-rail crossings in high-speed rail corridors to ensure that the warning systems in place are commensurate with the crossings’ needs. The objectives …

The Effect Of Roadside Elements On Driver Behavior And Run-Off-The-Road Crash Severity, Cole D. Fitzpatrick

Masters Theses 1911 - February 2014

Roadside vegetation provides numerous environmental and psychological benefits to drivers. Previous studies have shown that natural landscapes can effectively lower crash rates and cause less stress and frustration to the driver. However, run-off-the-road crashes resulting in a collision with a tree are twice as likely to result in a fatality, thus reinforcing the need to examine the placement of vegetation within the clear zone. This study explores the relationship between the size of the clear zone and the presence of roadside vegetation on selected driver attributes, including both driver speed and lateral positioning. To evaluate the effect on the driver …

Operational And Safety-Based Analyses Of Varied Toll Lane Configurations, Ian A. Mckinnon

Masters Theses 1911 - February 2014

Toll plaza operation is a critical component of roadway operations throughout the United States, as tolls provide both revenue for expansion and opportunity for demand management. Originally cash or physical currency based, tolling has morphed to meet the twentieth century demand in terms of throughput and efficiency in the form of electronic toll collection. Electronic tolling has introduced a new form of driver decision making at toll plazas due to the additional payment choice. Despite the user convenience these facilities provide to consumers, this form of collection has not come without safety and operational concerns. Confusion at the toll plaza, …

Multi Rotor Wind Turbine Design And Cost Scaling, Preeti Verma

Masters Theses 1911 - February 2014

The current generation wind turbines are upscaled into multi megawatt range in terms of output power. However, the energy benefit from the turbine is offset by the increased mass and cost. Twenty MW wind turbines are now feasible with rotor diameters up to 200 m, according to a new report from the EU-funded UpWind project in 2011. The question is, how much bigger can wind turbines get realistically? One concept worth considering, and the one that is the subject of this thesis, is to have more than one rotor on a single support structure. Such turbines could have a greater …

Load Reduction Of Floating Wind Turbines Using Tuned Mass Dampers, Gordon M. Stewart

Masters Theses 1911 - February 2014

Offshore wind turbines have the potential to be an important part of the United States' energy production profile in the coming years. In order to accomplish this wind integration, offshore wind turbines need to be made more reliable and cost efficient to be competitive with other sources of energy. To capitalize on high speed and high quality winds over deep water, floating platforms for offshore wind turbines have been developed, but they suffer from greatly increased loading. One method to reduce loads in offshore wind turbines is the application of structural control techniques usually used in skyscrapers and bridges. Tuned …

A Quantitative Analysis Of The Impacts From Selected Climate Variables Upon Traffic Safety In Massachusetts, Katrina M. Hecimovic

Masters Theses 1911 - February 2014

Current literature predicts that climate change may increase both the occurrence and severity of heavy rainfall events and winter precipitation in the Northeast United States. A potential increase in intense precipitation events related to climate change would theoretically also cause an increase in weather-related delays, increase in overall traffic disruptions, a substantive shift in travel behavior, and presumably a negative effect on safety and maintenance operations of highways. This current research study examines the existing impacts from both an operational and behavioral perspective of how weather events currently impact overall safety along routes in Massachusetts. A secondary objective of the …

Vehicle Miles Traveled (Vmt) Fee Financing Alternatives: Lessons Learned And Future Opportunities, Ashley L. Costa

Masters Theses 1911 - February 2014

State Departments of Transportation (DOTs) today are seeking financing alternatives so that transportation infrastructure investments can become less dependent on the amount of fuel U.S. drivers consume. Because the fuel tax is no longer viewed as a sustainable and stable option, other financing alternatives are being considered. One such alternative includes the vehicle miles traveled (VMT) fee. Examples of such VMT fee alternatives include: 1) collection using an onboard diagnostic system (OBD), 2) collection at the fuel pump using an OBD in conjunction with GPS technology, and 3) collection at a vehicle inspection station using the OBD.

This proposed research …

Interfacial Strength Between Prestressed Hollow Core Slabs And Cast-In-Place Concrete Toppings, Ryan M. Mones

Masters Theses 1911 - February 2014

The horizontal shear strength of the interface between prestressed concrete hollow core slabs and cast-in-place concrete topping slabs was evaluated through a set of 24 push-off experiments. The push-off test specimens featured segments of dry-mix and wet-mix hollow core slabs with a variety of surface treatments including machine finished, sandblasted, broom roughened, rake roughened and grouted. A cast-in-place slab was poured on top of the hollow core specimens to form a 15 inch by 15 inch interface between the two materials. Results indicate the average horizontal shear strength of the push-off specimens was 227 psi. Higher shear strength and slip …

Development Of A Cost Minimizing Strategy To Mitigate Bird Mortalities In A Wind Farm, Karamvir Singh

Masters Theses 1911 - February 2014

Wind is the second largest renewable energy source after solar. It is one of the fastest growing sources of electricity in the world and currently of wind energy is installed in the United States and an additional is under construction (Office of Energy and Environment Affairs, 2011). For the growth of wind electricity, one of the most prominent environmental concerns relates to the death of birds, bats and other avian species resulting from collision with turbine blades.

This thesis develops a model that provides the optimal strategy of turning the turbines off in a wind farm for certain periods to …

Driver Dynamics And The Longitudinal Control Model, Gabriel G. Leiner

Masters Theses 1911 - February 2014

Driver psychology is one of the most difficult phenomena to model in the realm of traffic flow theory because mathematics often cannot capture the human factors involved with driving a car. Over the past several decades, many models have attempted to model driver aggressiveness with varied results. The recently proposed Longitudinal Control Model (LCM) makes such an attempt, and this paper offers evidence of the LCM's usefulness in modeling road dynamics by analyzing deceleration rates that are commonly associated with various levels of aggression displayed by drivers. The paper is roughly divided into three sections, one outlining the LCM's ability …

New Technologies In Short Span Bridges: A Study Of Three Innovative Systems, Andrew Lahovich

Masters Theses 1911 - February 2014

Short span bridges are commonly used throughout the United States to span small waterways and highway overpasses. New technologies in the civil engineering industry have aided in the creation of many unique designs of these short span highway bridges in efforts to decrease construction cost, decrease maintenance costs, increase efficiency, increase constructability, and increase safety. Three innovative systems, the Integral Abutment Bridge, “Bridge-in-a-Backpack”, and the Folded Plate Girder bridge will be analyzed to study how the bridges behave under various types of loading.

Detailed finite element models were created for integral abutment bridges of varying geometry. These models are used …

Evaluation Of Live-Load Distribution Factors (Lldfs) Of Next Beam Bridges, Abhijeet Kumar Singh

Masters Theses 1911 - February 2014

A new precast-prestressed cross section was recently developed by a consortium of engineers from the six New England states, New York and members of the northeast region of PCI. The northeast extreme Tee (NEXT) beam is efficient for medium Bridge spans (50 to 80 ft long). Field formwork savings are introduced by having a flange cast integrally during fabrication of the beams at the precasting plant. Job safety is increased because a working platform is created. The flange width of the NEXT Beams can be adjusted during fabrication to accommodate roadways of different widths and skew angles. Because the section …

Material Characterization And Computational Simulation Of Steel Foam For Use In Structural Applications, Brooks H. Smith

Masters Theses 1911 - February 2014

Cellular metals made from aluminum, titanium, or other metals are becoming increasingly popular for use in structural components of automobiles, aircraft, and orthopaedic implants. Civil engineering applications remain largely absent, primarily due to poor understanding of the material and its structural properties. However, the material features a high stiffness to weight ratio, excellent energy dissipation, and low thermal conductivity, suggesting that it could become a highly valuable new material in structural engineering. Previous attempts to characterize the mechanical properties of steel foam have focused almost exclusively upon uniaxial compression tests, both in experimental research and in computational simulations. Further, computational …

User Equilibrium In A Disrupted Network With Real-Time Information And Heterogeneous Risk Attitude, Ryan J. Pothering

Masters Theses 1911 - February 2014

The traffic network is subject to random disruptions, such as incidents, bad weather, or other drivers’ random behavior. A traveler’s route choice behavior in such a network is thus affected by the probabilities of such disruptions, his/her attitude towards risk, and real-time information on revealed traffic conditions that could potentially reduce the level of uncertainty due to the disruptions. As the road network’s performance is de-termined collectively by all travelers’ choices, it is also affected by these factors. This thesis features the development of a multi-class user equilibrium model based on hetero-geneous risk attitude distributions and a user equilibrium model …

Probabilistic Analysis Of Offshore Wind Turbine Soil-Structure Interaction, Wystan Carswell

Masters Theses 1911 - February 2014

A literature review of current design and analysis methods for offshore wind turbine (OWT) foundations is presented, focusing primarily on the monopile foundation. Laterally loaded monopile foundations are typically designed using the American Petroleum Institute (API) p-y method for offshore oil platforms, which presents several issues when extended to OWTs, mostly with respect to the large pile diameters required and the effect of cyclic loading from wind and waves. Although remedies have been proposed, none have been incorporated into current design standards. Foundations must be uniquely designed for each wind farm due to extreme dependence on site characteristics. The uncertainty …

Evaluating And Modeling Traveler Response To Real-Time Information In The Pioneer Valley, Tyler De Ruiter

Masters Theses 1911 - February 2014

This study used focus groups and surveys to provide a comprehensive evaluation of the Regional Traveler Information Center (RTIC) at UMass Amherst. The evaluation was completed by obtaining the awareness, usage, and perceived effectiveness of RTIC’s information by residents in the Pioneer Valley. It was found that awareness of RTIC is limited due to its lack of advertisement. Usage is focused primarily on its webcams and advisory information. Surveys showed that participants perceive RTIC to be useful, even though they may never have seen the information before (the survey provided a chance for them to become familiar with the service). …

Vibration Reduction Of Offshore Wind Turbines Using Tuned Liquid Column Dampers, Colin Roderick

Masters Theses 1911 - February 2014

Offshore wind turbines (OWTs) are becoming an accepted method for generating electricity. The environmental conditions of offshore locations often impose high wind and wave forces on OWTs making them susceptible to intense loading and undesirable vibrations. One method to reduce system vibrations is through the use of structural control devices typically utilized in civil structures. Tuned liquid column dampers (TLCDs) show great promise in the application to OWTs due to their high performance and low cost. This thesis examines the use of TLCDs in OWTs.

Equations of motion for limited degree-of-freedom TLCD-turbine models are presented. A baseline analysis of each …

Spatial And Temporal Correlations Of Freeway Link Speeds: An Empirical Study, Piotr J. Rachtan

Masters Theses 1911 - February 2014

Congestion on roadways and high level of uncertainty of traffic conditions are major considerations for trip planning. The purpose of this research is to investigate the characteristics and patterns of spatial and temporal correlations and also to detect other variables that affect correlation in a freeway setting. 5-minute speed aggregates from the Performance Measurement System (PeMS) database are obtained for two directions of an urban freeway – I-10 between Santa Monica and Los Angeles, California. Observations are for all non-holiday weekdays between January 1st and June 30th, 2010. Other variables include traffic flow, ramp locations, number of lanes and the …

Bioretention: Evaluating Their Effectiveness For Improving Water Quality In New England Urban Environments, Mary Dehais

Masters Theses 1911 - February 2014

Nonpoint source (NPS) pollution is one of the leading causes of water quality problems in the United States. Bioretention has become one of the more frequently used stormwater management practices for addressing NPS pollution in urbanized watersheds in New England. Yet despite increased acceptance, bioretention is not widely practiced. This study explores and evaluates the efficacy of bioretention for protecting urban water quality.

This research found that numerous monitoring methods are used by researchers and industry experts to assess the effectiveness of stormwater best management practices (BMPs) and low impact development (LID) practices that include bioretention. The two most common …

An Application Of Spatially Based Crash Analyses And Road Safety Investigations To Increase Older Driver Safety, Deanna A. Peabody

Masters Theses 1911 - February 2014

Arguably the greatest issue facing the transportation profession is the ability to provide social equity with regards to both safety and mobility given the aging population. Given the overall dominance of the automobile within the transportation system, the ability to provide feasible alternatives is daunting. This fact, when coupled with the well-documented challenges of older drivers, underscores the need for improved safety features and system-wide safety approaches with a focus on the older driver. This paper describes an application of spatial crash analysis and road safety investigations that were employed in Massachusetts with a direct focus on the older driver. …

Automated Detection And Counting Of Pedestrians On An Urban Roadside, Gayatri D. Prabhu

Masters Theses 1911 - February 2014

This thesis implements an automated system that counts pedestrians with 85% accuracy. Two approaches have been considered and evaluated in terms of count accuracy, cost and ease of deployment. The first approach employs the Autoscope Solo Terra, a traffic camera which is widely used to monitor vehicular traffic. The Solo Terra supports an image processing-based detector that counts the number of objects crossing user-defined areas in the captured image. The count is updated based on the amount of movement across the selected regions. Therefore, a second approach has been considered that uses a histogram of oriented gradients (HoG), an advanced …

Development Of Anchorage System For Frp Strengthening Applications Using Integrated Frp Composite Anchors, Geoffrey N. Mcguirk

Masters Theses 1911 - February 2014

Over the past three decades the use of externally bonded fiber reinforced polymer (FRP) materials for structural strengthening applications has become an accepted and widely used method. A primary concern of FRP structural strengthening systems is that the FRP often debonds from the concrete well before the load capacity of the FRP material is reached. In addition, debonding failures are often brittle and occur with little warning. Past research concluded that fastening FRP sheets with FRP anchors is an effective method for delaying or preventing debonding failures. However, there is a clear lack of research pertaining to fastening FRP sheets …

Evaluating Alternative Toll-Based Financing Approaches: A Case Study Of The Boston Metropolitan Area, Rosaria M. Berliner

Masters Theses 1911 - February 2014

The current condition of the nation’s transportation system is of great concern to State Departments of Transportation. Currently, funds in many state transportation budgets are depleting. Nowadays, State DOT officials together with researchers are exploring various transportation financing approaches and they are considering the utility, merits, challenges, and impacts of these approaches.

A major financing approach being considered relies on the collection of tolls on existing toll roads and on roads on which tolls are not presently collected. Recent technology advancements in Open Road Tolling and All-Electronic Tolling have provided State DOTs with the opportunity to consider expanding the use …

Safety And Operational Assessment Of Gap Acceptance Through Large-Scale Field Evaluation, Steven Maxwell Tupper

Masters Theses 1911 - February 2014

Given that “driver error” is cited as a contributing factor in 93 percent of all crashes, understanding driver behavior is an essential element in mitigating the crash problem. Among the more dangerous roadway elements are unsignalized intersections where drivers’ gap acceptance behavior is strongly correlated to the operational and safety performance of the intersection. While a basic understanding of drivers’ gap acceptance behavior exists, several unanswered questions remain.

Previous work has attempted to address some of these questions, however to date the research has been somewhat limited in scope and scale due to the challenges of collecting high fidelity gap …

Route Choice Behavior In Risky Networks With Real-Time Information, Michael D. Razo

Masters Theses 1911 - February 2014

This research investigates route choice behavior in networks with risky travel times and real-time information. A stated preference survey is conducted in which subjects use a PC-based interactive maps to choose routes link-by-link in various scenarios. The scenarios include two types of maps: the first presenting a choice between one stochastic route and one deterministic route, and the second with real-time information and an available detour. The first type measures the basic risk attitude of the subject. The second type allows for strategic planning, and measures the effect of this opportunity on subjects' choice behavior.

Results from each subject are …

A Quantitative Analysis Of The Impacts From Selected Variables Upon Safety Belt Usage In Massachusetts, Samuel W. Gregorio

Masters Theses 1911 - February 2014

Safety belts are the most effective safety device in vehicles in terms of preventing injuries (1). Every year, safety belt usage data across the nation is collected by the individual states, the District of Columbia, and U.S. territories in a probability-based observational survey. Using this survey, Massachusetts, a secondary seat belt law state, ranked last in safety belt usage in 2008. This percentage was approximately a 2 percent decrease from 2007. This value was not an aberration as within the recent past, Massachusetts, a secondary safety belt law state, has consistently ranked at or near the bottom of the 50 …

Historic Bridge Evaluation Using Finite Element Techniques, Helena M. Charron

Masters Theses 1911 - February 2014

The present study examined the application of modern, computer-based analysis methods to two existing historic bridges in Massachusetts. The first bridge featured in this study is the Woronoco Bridge, a reinforced concrete open spandrel arch bridge that was constructed in 1923. It was hoped that a computer-based, parametric study of this bridge would prove it to be deck-stiffened, similar to select bridges of Swiss engineer Robert Maillart. However, the results do not support that there was any intent to reduce bending in the arch as a result of increasing the stiffness of the bridge deck. Instead, the Woronoco Bridge appears …

Investigation Of The Behavior Of Open Cell Aluminum Foam, Patrick J. Veale

Masters Theses 1911 - February 2014

The study investigates the behavior open cell aluminum foam in scenarios applicable to potential use in structural applications. Behavior was examined through mechanical testing, computer modeling and analytic expressions. Existing assumptions about the foam characteristics that define the elastic properties were expanded to include contributions of axial and shear deformations in addition to bending and were rewritten in terms of the axial and bending stiffness ratios of ligaments. Compressive and tensile tests were performed to gain a measure of the elastic properties of the foam as well as the behavior and failure mechanisms in both loading conditions. The materials used …

Material Characterization And Structural Response Of Historic Truss Bridges, Sean L. Kelton

Masters Theses 1911 - February 2014

Historic truss bridges are examined in this thesis through material characterization of wrought iron and structural evaluation of an early 20th century pony truss bridge. The mechanical properties of wrought iron from six 19th century truss bridges were evaluated through mechanical testing that includes hardness and tension tests. The main findings of this work are: 1) That hardness is a poor predictor of yield and ultimate stress but has some ability in screening iron for iron with low ductility, 2) there is a statistically significant difference in the distribution of yield and ultimate stresses between material samples from different bridges, …