Civil Engineering Commons^™

Site Specific Modelling Of Traffic Loading On Highway Bridges, Bernard Enright, Eugene J. Obrien

Conference papers

Accurate traffic loading models based on measured weigh-in-motion (WIM) data are essential for the accurate assessment of existing bridges. Much work has been published on the Monte Carlo simulation of single lanes of heavy vehicle traffic, and this can easily be extended to model the loading on bridges with two streams of traffic in opposing directions. However, a typical highway bridge will have multiple lanes in the same direction, and various types of correlation are evident in measured traffic, such as groups of very heavy vehicles travelling together and heavy vehicles being overtaken by lighter ones. These traffic patterns affect …

Integrating Seasonal Climate Forecasts Into Institutional Decision-Making Processes, David Watkins

All ECSTATIC Materials

It is often challenging to integrate climate forecast use into actual decision-making processes, even when modeling demonstrates significant benefits from its use. Decision-making processes are guided by both formal policy frameworks, and the particular institutional structures under which decision-makers must operate. In addition, water is shared across multiple stakeholders, who are often represented by specific government or private sector agencies. These agencies face different costs depending upon the outcome of a forecast, and different preferences for risk. Depending upon the institutional and political arrangements for how decisions are made, these stakeholder interests may figure more or less strongly in water …

Estimation Of The Water Balance Using Observed Soil Water In The Nebraska Sandhills, Venkataramana Sridhar, K. G. Hubbard

Civil Engineering Faculty Publications and Presentations

Analyzing the dynamic hydrologic conditions of the Sandhills is critical for water and range management, sustainability of the Sandhills ecosystem as well as for dune stability. There are complex models available to quantify both surface and subsurface hydrological processes. However, we present in this study an application of a relatively simple model to arrive at best estimates of the water balance components. Using the Thornthwaite-Mather (TM) model, water balance components were estimated for 4 Automated Weather Data Network (AWDN) weather monitoring stations. Estimated averages of the water balance components suggested that mean annual precipitation of these four sites was only …

Examination Of Factors Affecting The Frequency, Response Time, And Clearance Time Of Incidents On Freeways, Indrajit Ghosh

Wayne State University Dissertations

Traffic incidents are the primary cause of non-recurrent congestion in urban areas, resulting in reductions in roadway capacity and significant safety hazards to other motorists, as well as first responders. Many communities have initiated incident management programs that detect and respond to incidents and restore freeways to full capacity by clearing the incident scene as soon as possible. In the Detroit metro area, the Michigan Department of Transportation (MDOT) operates a Freeway Courtesy Patrol (FCP) program as part of its larger freeway incident management program from the Michigan Intelligent Transportation Systems (MITS) Center in downtown Detroit. The MITS Center maintains …

Flexible Pavement Rut Depth Modeling For Different Climate Zones, Asmaiel Kodan Naiel

Wayne State University Dissertations

Pavement rutting is one of the most important types of pavement distress that affect road safety and ride quality. Therefore, the primary objective of this study was to develop pavement rutting empirical models for different climate zones to predict pavement rutting on granular base based on LTPP data. Flexible pavements with granular base course were considered for this study. These models lead to better understanding of rutting phenomena and the factors that may have affect in pavement rutting. In addition, these models will help state and local transportation agencies make accurate decisions for maintenance, rehabilitation and reconstruction of pavement.

To …

Skewed Bridge Behaviors: Experimental, Analytical, And Numerical Analysis, Bang-Jo Chun

Wayne State University Dissertations

In the US, nearly 33.5% of highway bridges are skewed. In the past, these skewed bridges have been analyzed as straight bridges. Nevertheless, there exists an extensive literature indicating the mechanical behavior of skewed bridges being quite different from their straight counterparts. In this thesis, to better understand the behavior of skewed bridges, experimental, numerical, and analytical researches have been conducted. The analytical method proposed here is the first of its kind in the skewed bridge research, and is expected to aid the bridge engineers with their design.

First, a three dimensional finite element analysis (FEA) model was developed and …

Bottom Flange Reinforcement In Nu I-Girders, George Morcous Ph.D., Kromel Hanna Ph.D., Maher K. Tadros Ph.D., P.E.

Mid-America Transportation Center: Final Reports and Technical Briefs

The 1996 edition of AASHTO Standard Specifications for Highway Bridges stated that nominal confinement reinforcement be placed to enclose prestressing steel in the bottom flange of bridge girders from girder ends to at least a distance equal to the girder’s height. The 2004 edition of AASHTO LRFD Bridge Design Specifications changed the distance over which the confinement reinforcement was to be distributed from 1.0h to 1.5h, and gave minimum requirements for the amount of steel to be used, No.3 bars, and their maximum spacing, not to exceed 6.” Research was undertaken to study what impact, if any, confinement reinforcement had …

Load Rating Of Complex Bridges, George Morcous Ph.D., Kromel Hanna Ph.D., Maher K. Tadros Ph.D., P.E.

Mid-America Transportation Center: Final Reports and Technical Briefs

The National Bridge Inspection Standards require highway departments to inspect, evaluate, and determine load ratings for structures defined as bridges located on all public roads. Load rating of bridges is performed to determine the live load that structures can safely carry at a given structural condition. Bridges are rated for three types of loads, design loads, legal loads, and permit loads, which is a laborious and time-consuming task as it requires the analysis of the structure under different load patterns. Several tools are currently available to assist bridge engineers to perform bridge rating in a consistent and timely manner. However, …

Study Of Rf Propagation Characteristics For Wireless Sensor Networks In Railroad Environments, Hamid Sharif, Michael Hempel

Mid-America Transportation Center: Final Reports and Technical Briefs

The freight railroad industry in North America is exerting efforts to leverage Wireless Sensor Networks to monitor systems and components on railcars. This allows fault detection and accident prevention even while a train is moving. Railcars, constructed mostly of ferrous materials such as steel, are expected to severely impact signal propagation. To better understand this effect we first evaluated the signal characteristics when sensor nodes are placed in various locations around railcars. We used EM-Field modeling and evaluation techniques to obtain these results and found that node placement selection is critical for the node’s communication distance. As a second research …

Performance Measures Of Warm Asphalt Mixtures For Safe And Reliable Freight Transportation, Hosin "David" Lee Ph.D., P.E., Yongjoo "Thomas" Kim

Mid-America Transportation Center: Final Reports and Technical Briefs

Warm mix asphalt (WMA) is an emerging technology that can allow asphalt to flow at a lower temperature for mixing, placing and compaction. The advantages of WMA include reduced fuel consumption, less carbon dioxide emission, longer paving season, longer hauling distance, reduced oxidation of asphalt, early opening to traffic and a better working environment in the field. In the United States, WMA has become popular in recent years. However, to provide a safe and reliable highway for heavier truck traffic with a high tire pressure, WMA mixtures must meet requirements for strength, stiffness, rutting, and moisture resistance.

WMA mixtures with …

Extending Asphalt Pavement Life Using Thin Whitetopping, Mustaque Hossain, Sharmin Sultana

Mid-America Transportation Center: Final Reports and Technical Briefs

Due to budget constraints, many highway agencies are becoming interested in pavement preservation or rehabilitation rather than reconstruction to ensure pavement is in serviceable condition. Thin whitetopping (TWT) is the process of rehabilitating distressed asphalt concrete (AC) pavements by using a concrete overlay. This study was done to develop a design catalog for existing AC pavements to be overlaid with TWT. The finite element (FE) analysis was performed with SolidWorks, which is the 3-D FE software program used to develop this design catalog. The design considered different TWT thicknesses, existing AC layer thickness and modulus, the bonding condition between TWT …

Assessing The Damage Potential In Pretensioned Bridges, Caused By Increased Truck Loads Due To Freight Movements (Phase I), Robert J. Peterman, Steven Hammerschmidt

Mid-America Transportation Center: Final Reports and Technical Briefs

When evaluating the condition of existing bridges determining in situ stresses in the members provides valuable information about the condition of the structures. In this study, a method of surface strain relief was investigated whereby the change in strain at the surface of concrete members is used to determine the in situ stress. The method involved mounting a linear electrical-resistance strain gage along the axis of maximum stress, coring around the gage, and then relating the change in strain to the corresponding stress in the member. Members were fabricated and varying stresses were applied in order to determine the accuracy …

Characteristics And Contributory Causes Related To Large Truck Crashes (Phase I) -Fatal Crashes, Sundanda Dissanayake Ph.D., P.E.

Mid-America Transportation Center: Final Reports and Technical Briefs

One-ninth of all traffic fatalities in the United States have involved large trucks in the past five years, although large trucks contributed to only 3% of registered vehicles and 7% of vehicle miles travelled. This contrasting proportion indicates that truck crashes in general tend to be more severe than other crashes though they constitute a smaller sector of vehicles on the road. To study this issue, fatal crash data from the FARS was used to analyze characteristics and factors contributing to truck-involved crashes. Driver, vehicle, and crash-related contributory causes were identified, and as an extension the likelihood of occurrence of …

Improving Freight Fire Safety: Assessment Of The Effectiveness Of Mist-Controlling Additives In Mitigating Crash-Induced Diesel Fires, Albert Ratner Ph.D.

Mid-America Transportation Center: Final Reports and Technical Briefs

Adding long chained polymers to diesel has been proposed as a method to prevent crash fires by arresting the break-up of diesel fuel into a fine mist in transportation related accidents. The effect of such additives on the flow properties of diesel was investigated by studying the impact of poly-butadiene and diesel blend drops on a solid surface using high speed imaging. The addition of the polymer imparted shear-thinning behavior to diesel, and the base viscosities increased rapidly with polymer concentration. Four concentrations of the polymer were tested at three different impact speeds under atmospheric pressure. Maximum spread factors and …

Modeling The Effect Of Moisture On Resilient Modulus Of Untreated Reclaimed Asphalt Pavement, Mohamed Attia, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The use of reclaimed asphalt pavement (RAP) as a base layer is increasing as quality aggregate becomes scarcer and more expensive. Moisture content is known to have a great impact on the resilient modulus (M_R) of granular materials, and several researchers have devoted effort to develop and verify analytical models to describe that impact. Limited work has been done to quantify the effect of moisture content on RAP as a base layer. It has not been determined whether the existence of aged binder will allow designers to use the same analytical models developed for granular materials. This study …

Influence Of Shear Key Performance On The Fatigue Life Of Adjacent Beam Bridges, Sara Roberts

All Theses

Adjacent beam bridges, such as box beams and hollow core bridges have been one of the most popular forms of precast prestressed bridges in the past. Recently, an awareness of major durability problems has led owners to make improvements to the old standards or move away from the system completely. These issues usually stem from the breakdown of the shear key which provides continuity between adjacent members. This research focuses on determining the best improvements that will reduce durability issues and increase the bridge's service life.
A review of previous research performed on adjacent beam bridges is performed, focusing on …

The Effects Of Behavioral, Geometric And Heavy Vehicle Traffic Flow Characteristics On Capacity And Emissions At Roundabouts, Cho Honest Sone

Civil Engineering Theses - Archive

Modern roundabouts, first constructed in England in the early 1960s, are becoming increasingly popular replacements for signalized and stop controlled intersections in the United States. Roundabouts were introduced to replace traditional traffic circles and rotaries. With the characteristics of entering traffic that yield to circulating traffic and geometric constraints that slow entering vehicles, roundabouts have proven to be more efficient than traffic circles and in some cases than signalized and stop-controlled intersections. Roundabouts often require drivers to decelerate from, and reaccelerate to, highway speeds, and can involve one or multiple stops. One concern about congested roundabouts is that vehicle emissions …

Testing & Design Life Modeling Of Polyurea Liners For Potable Water Pipes, Mustafa Z. Kanchwala

Civil Engineering Theses - Archive

Currently, there are various renewal methods available for different applications, among which coatings and linings are most commonly used for the renewal of water pipes. Polyurea is a lining material applied to the interior surface of the deteriorated host pipe using spray technique. It is applied to enhance the structural ability of the pipeline. This thesis presents the preliminary results of an ongoing laboratory testing program designed to investigate the renewal of potable water pipes using polyurea spray lining. This research focuses on predicting the long-term behavior of polyurea composite. The goal of this test was to establish a relationship …

Experimental Studies On Shrinkage Induced Pressure Measurements Of Four Expansive Soils, Varagorn Puljan

Civil Engineering Theses - Archive

Civil structures were damaged by expansive soils due to its large volumetric changes caused by moisture fluctuations. During wet and dry season, the ground heaves up and also shrinks noticeably. The significant amount of curling pressure which is induced by soil shrinkage could cause severe damages to the infrastructure. Especially in the eastern and central Texas, pavements encounter severe cracking and premature loss of serviceability. The maintenance costs, in some cases, are greater than the initial construction costs. Residential dwell structures built on problematic expansive soils often become distressed due to volume changes associated with seasonal moisture content variations. This …

Comprehensive Studies On Deep Soil Mixing And Lightweight Aggregates Applications To Mitigate Approach Slab Settlements, Ekarut Archeewa

Civil Engineering Dissertations - Archive

Bridge approach settlement is a common problem to the Transportation Departments nationwide. This uneven transition causes inconvenience to passengers and increases the cost of maintenance and repair of the distressed approach slabs. The Texas Department of Transportation spends millions of dollars annually to mitigate this problem across the state. The potential causes for this problem are numerous and purely site specific. Hence this problem may not have a unique solution. In this research, two methods were selected to mitigate the approach slab settlements. The first one is an improvement of ground foundation technique by using Deep Soil Mixing (DSM) columns …