Engineering Commons^™

Use Of Harsh-Braking Data From Connected Vehicles As A Surrogate Safety Measure, Nathaniel Patrick Edelmann

Boise State University Theses and Dissertations

Traffic safety may be analyzed with the use of surrogate safety measures, measures of safety that do not incorporate collision data but rather rely on the concept of traffic conflicts. Use of these measures provides several benefits over use of more traditional analysis methods with historical crash data. Surrogate measures eliminate the need to wait for crashes to occur to conduct a safety analysis. The amount of time required for enough crash data to accumulate can be significant, delaying safety analyses. Similarly, these measures allow for safety analysis to be conducted prior to crashes occurring, potentially calling attention to hazardous …

Using Differential Shear Strain Measurements To Monitor Crosstie Support Conditions In Railroad Tracks, D. Kody Johnson

Boise State University Theses and Dissertations

This thesis details a comprehensive numerical analysis of load determination, and crosstie support assessment and monitoring using strain gauges to measure differential rail shear strain in ballasted railroad tracks due to applied railcar wheel loads. These differential shear strain measurements can be related to applied wheel loading and crosstie support reactions through the geometric and constitutive properties of a given rail section. The basic theory behind the measurement technique was reviewed and investigated using finite element models of varying complexity. The impact of field conditions such as differential ballast and subgrade support, track stiffness, crosstie spacing, gauge installation location, and …

Quantifying The Effects Of Climate Change On Pavement Performance Prediction Using Aashtoware Pavement Me Design, Md Shahjalal Chowdhury

Boise State University Theses and Dissertations

Climate change is one of the most concerning global issues and has the potential to influence every aspect of human life. Like different components of society, it can impose significant adverse impacts on pavement infrastructure. Although several research efforts have focused on studying the effects of climate change on natural and built systems, its impact on pavement performance has not been studied as extensively. The primary objectives of this thesis research was to quantify the effect of temperature changes on flexible pavement response and performance prediction using the AASHTOWare Pavement ME Design (PMED), and quantify the effects of Local Calibration …

Effect Of Subgrade Conditions On Pavement Analysis And Performance Prediction: A Study For Idaho Conditions, Md Jibon

Boise State University Theses and Dissertations

The Mechanistic-Empirical (M-E) pavement design approach detailed in the Mechanistic-Empirical Pavement Design Guide (MEPDG), and subsequently implemented through AASHTOWare^® Pavement ME Design relies extensively on detailed material properties that ultimately govern the analysis and performance prediction results. For unbound materials like soils and aggregates, Resilient Modulus (M_R) is the most critical input parameter affecting layer response under vehicular and environmental loading. Representing a material’s ability to ‘recover’ after loading, resilient modulus is determined in the laboratory through repeated load triaxial testing. Although the original test protocol to measure the resilient modulus value of a soil or aggregate …

Exploring The Use Of Data From Newer Technologies In Road Design, Mahamudul Hasan

Boise State University Theses and Dissertations

The use of Light Detection and Ranging (Lidar) is widespread currently all over the world including the United States. Though on-the-ground surveying and photogrammetric surveying are the more common methods to acquire terrain information, Lidar data is being increasingly used for this purpose due to its various advantages. Various research indicates that the accuracy of Lidar data has increased enough to make its use suitable for diverse applications. One potential application that is explored in this research is the use of terrain models generated from Lidar data in road design. To make such use possible we need to be assured …

Effect Of Particle Breakage On Ballast Permanent Deformation — A Study Using The Discrete Element Method, Beema Dahal

Boise State University Theses and Dissertations

The ballast layer comprises relatively large (often as large as 63 mm) angular particles that mainly function to dissipate train-induced stresses from crossties to the underlying subgrade soils and to provide rapid drainage for surface water. Moreover, the ballast layer is also critical towards ensuring a smooth riding track profile, dampening dynamic loads, as well as providing lateral, longitudinal and vertical resistance against excessive track deformations. Under train loading and during track maintenance processes like tamping, individual ballast particles can undergo significant breakage leading to fouling of the ballast layer. The fouling mechanism leads to gradual deterioration in ballast shear …

Effect Of Subsurface Conditions On Flexible Pavement Behavior: Non-Destructive Testing And Mechanistic Analysis, Md. Fazle Rabbi

Boise State University Theses and Dissertations

The behavior of flexible pavements under traffic and environmental loading can be significantly affected by subsurface conditions. Inadequate support conditions under the surface can lead to excessive pavement deformations, often leading to structural and functional failure. This research effort focused on assessing the effects of base/subbase and subgrade layer conditions on flexible pavement behavior. The results of this study are presented in the form of two journal manuscripts.

The first manuscript focuses on utilizing pavement structural and functional evaluation data in making pavement rehabilitation decisions. Visual distress surveys and Falling Weight Deflectometer (FWD) testing are often carried out by agencies …

Feasibility Of Aerial Tramway At Boise State University, Majed Alsaqyani

Boise State University Theses and Dissertations

The use of aerial tramways is becoming common in cities as a way to provide reliable, safe, sustainable, and cost-effective mass transportation. The aerial tramway is especially effective in the most congested areas of major cities. The growth of Boise State University (BSU) and downtown Boise makes this location especially attractive for a tramway. Moreover, based on data collected for this analysis, it is clear that the BSU community is open to using the tramway instead of more traditional modes of transportation.

The viability of the tramway is further enhanced because the computer science department has moved to City Center …

Evaluating The Effectiveness Of A Hybrid Geosynthetic Reinforcement System To Mitigate Differential Heave On Flexible Pavement Due To Expansive Subgrades, Mir Md. Tamim

Boise State University Theses and Dissertations

Transportation industries encounter substantial challenges with respect to ride quality and serviceability when they deal with expansive soils underneath roadway structures. These soils exhibit swell-shrink behavior with moisture variations, which cause surficial heaving on the pavement structure and cost billions of dollars for the maintenance of pavements. For the past four decades, a particular stretch of US-95 (Oregon line to Elephant Butte) exhibited recurrent swelling distresses due to the underlying expansive soils. Despite remedial measures that exhibited satisfactory results for most of the sections, recurrent damage still continued in few sections. Further research indicated that the problematic soils were located …

Subsurface Characterization Of Flexible Pavements Constructed Over Expansive Soil Subgrades And Selection Of Suitable Rehabilitation Alternatives, Kazi Moinul Islam

Boise State University Theses and Dissertations

Expansive soils present significant engineering challenges, with annual costs associated with repairing structures constructed over expansive soils estimated to run into several billion dollars. Volume changes in expansive soil deposits induced by fluctuations in the moisture content can result in severe damage to overlying structures. A flexible pavement section near the Western Border of Idaho has experienced recurrent damage due to volume changes in the underlying expansive soil layer; traditional stabilization methods have provided partial success over the years. The main objective of this research effort was to characterize the problematic soil layer contributing to the recurrent pavement damage and …

Effect Of Particle Size Distribution And Packing Characteristics On Railroad Ballast Shear Strength: A Numerical Study Using The Discrete Element Method, S. M. Naziur Mahmud

Boise State University Theses and Dissertations

Railroad infrastructure plays a significant role in sustaining the economy of a country, and facilitates fast, safe and reliable transportation of passengers as well as commodities. Significant capital investments are required for the construction and maintenance of a railroad network that is structurally and functionally adequate. The ballast layer is one of the main structural components of a conventional rail track system, and comprises coarse-grained unbound particles, often as large as in size. The ballast as a load-bearing layer resists train-induced stresses through particle-particle interaction. Accordingly, particle-size distribution and packing characteristics are important factors that govern the mechanical behavior of …

Evaluating The Effects Of Major Assumptions In Layered Elastic Theory On Railroad Track Response Prediction Through The Development Of An Improved Track Analysis Software, Sadichchha Sharma

Boise State University Theses and Dissertations

Railway transportation has been recently gaining popularity due to its efficiency and environmental-friendly technology which has led to its increased usage for both passenger and freight transport. For railway transport to be a sustainable component of the transportation infrastructure in the United States, adequate structural and functional design of track components is essential. This is primarily dependent on thorough understanding of track mechanics and track structural response under loading, and can be accomplished through mechanistic analysis of railway track structure response under loading. Considering the need for a mechanistic track analysis program that can serve as a link between the …