Civil Engineering Commons^™

Evaluating The Appropriateness Of Project Delivery Systems For Different Trenchless Methods, Ali Mostafavi, Tom Iseley, Dulcy Abraham

Infrastructure System-of-Systems (I-SoS ) Research Group

Trenchless methods have been considered to be a viable solution for pipeline projects in urban areas. Their applicability in pipeline projects is expected to increase with the rapid advancements in technology and emerging concerns regarding social costs related to trenching methods. Selecting appropriate project delivery system (PDS) is a key to the success of trenchless projects. To ensure success of the project, the selected project delivery should be tailored to trenchless project specific characteristics and owner needs, since the effectiveness of project delivery systems differs based on different project characteristics and owners requirements. Since different trenchless methods have specific characteristics …

Eulerian-Lagrangian Two Phase Debris Flow Model, Cora E. Martinez

FIU Electronic Theses and Dissertations

The main objective of this work is to develop a quasi three-dimensional numerical model to simulate stony debris flows, considering a continuum fluid phase, composed by water and fine sediments, and a non-continuum phase including large particles, such as pebbles and boulders. Large particles are treated in a Lagrangian frame of reference using the Discrete Element Method, the fluid phase is based on the Eulerian approach, using the Finite Element Method to solve the depth-averaged Navier–Stokes equations in two horizontal dimensions. The particle’s equations of motion are in three dimensions. The model simulates particle-particle collisions and wall-particle collisions, taking into …

A Methodological Framework For Modeling Pavement Maintenance Costs For Projects With Performance-Based Contracts, Kamalesh Panthi

FIU Electronic Theses and Dissertations

Performance-based maintenance contracts differ significantly from material and method-based contracts that have been traditionally used to maintain roads. Road agencies around the world have moved towards a performance-based contract approach because it offers several advantages like cost saving, better budgeting certainty, better customer satisfaction with better road services and conditions. Payments for the maintenance of road are explicitly linked to the contractor successfully meeting certain clearly defined minimum performance indicators in these contracts. Quantitative evaluation of the cost of performance-based contracts has several difficulties due to the complexity of the pavement deterioration process. Based on a probabilistic analysis of failures …

Development Of A Hurricane-Resistant Roof-To-Wall Connection Using High-Performance Fiber Composites, Cetin Canbek

FIU Electronic Theses and Dissertations

Significant portion of losses in hurricanes occur due to a discontinuous load path and weak connections. The purpose of this study was to develop an innovative, efficient and non-intrusive roof-to-wall connection for wood-frame structures using high-performance fiber reinforced polymer (FRP) composite materials.

The development of new connections was carried out at the component level tests. Initially the bond strength between FRP and wood interface was investigated. Subsequently, a progressive FRP tie development test was conducted and several alternatives were tested and the most feasible one was chosen.

The new FRP tie was then tested in a full-scale wood-frame structure to …

Integrated Surface-Ground Water Modeling In Wetlands With Improved Methods To Simulate Vegetative Resistance To Flow, Mauro Nalesso

FIU Electronic Theses and Dissertations

This dissertation focused on developing an integrated surface – subsurface hydrologic simulation numerical model by programming and testing the coupling of the USGS MODFLOW-2005 Groundwater Flow Process (GWF) package (USGS, 2005) with the 2D surface water routing model: FLO-2D (O’Brien et al., 1993). The coupling included the necessary procedures to numerically integrate and verify both models as a single computational software system that will heretofore be referred to as WHIMFLO-2D (Wetlands Hydrology Integrated Model). An improved physical formulation of flow resistance through vegetation in shallow waters based on the concept of drag force was also implemented for the simulations of …

Mechanical Properties Of Self-Consolidating Concrete With Pozzolanic Materials, Indra Prasad Chapagain

FIU Electronic Theses and Dissertations

Self-consolidating concrete has been described as the most revolutionary development in concrete technology in several decades with the ability to flow freely through closely spaced reinforcements, expel entrapped air and self compact without vibration. Since it was first developed in Japan in the early 1980's, major development in the chemical admixture technology has made SCC more viable.

An experimental study was conducted to identify the mechanical properties of SCC by optimizing the use of pozzolanic materials and local aggregates with some proposed statistical models. The research was focused to investigate compressive strength, splitting tensile strength, modulus of elasticity and drying …

Predicting Delay Reductions From Freeway Traffic Diversion For Incident Management, Jie Bian

FIU Electronic Theses and Dissertations

Traffic incidents are a major source of traffic congestion on freeways. Freeway traffic diversion using pre-planned alternate routes has been used as a strategy to reduce traffic delays due to major traffic incidents. However, it is not always beneficial to divert traffic when an incident occurs. Route diversion may adversely impact traffic on the alternate routes and may not result in an overall benefit.

This dissertation research attempts to apply Artificial Neural Network (ANN) and Support Vector Regression (SVR) techniques to predict the percent of delay reduction from route diversion to help determine whether traffic should be diverted under given …

Investigating The Origin Of Pm2.5 In Baltimore Using Highly Time-Resolved Organic Molecular Markers Measured During The Baltimore Pm-Supersite, Anna R. Bernardo-Bricker

FIU Electronic Theses and Dissertations

The detailed organic composition of atmospheric fine particles with an aerodynamic diameter smaller than or equal to 2.5 micrometers (PM 2.5) is an integral part of the knowledge needed in order to fully characterize its sources and transformation in the environment. For the study presented here, samples were collected at 3-hour intervals. This high time resolution allows gaining unique insights on the influence of short- and long-range transport phenomena, and dynamic atmospheric processes. A specially designed sequential sampler was deployed at the 2002-2003 Baltimore PM Supersite to collect PM2.5 samples at a 3-hourly resolution for extended periods of consecutive days, …

Mitigation Of Roof Uplift Through Vortex Suppresion Techniques, Collette Marguerite Blessing

FIU Electronic Theses and Dissertations

The objective of this study was to assess the effectiveness of modified roof edge geometry in the reduction of high suction pressures at roof corner and edge regions through full-scale testing approach. Utilizing the RenaissanceRe 6-fan Wall of Wind (WOW) testing apparatus, a test structure instrumented with pressure transducers was equipped with six different modified roof edge geometries and subjected to hurricane force winds. A series of seven tests, six for the different roof geometries and one to determine the standard pressure distribution without any modifications, were conducted and pressure data from all seven tests were compared. Results indicated that …

Optimization Of Transit Transfer Times : A System-Wide Approach, Fabian Cevallos

FIU Electronic Theses and Dissertations

This dissertation presents a system-wide approach, based on genetic algorithms, for the optimization of transfer times for an entire bus transit system. Optimization of transfer times in a transit system is a complicated problem because of the large set of binary and discrete values involved. The combinatorial nature of the problem imposes a computational burden and makes it difficult to solve by classical mathematical programming methods.

The genetic algorithm proposed in this research attempts to find an optimal solution for the transfer time optimization problem by searching for a combination of adjustments to the timetable for all the routes in …

A Study Of Hydraulic Properties Of High Level Waste Simulant, Sudhakar N. Chodavarapu

FIU Electronic Theses and Dissertations

The purpose of this study was to determine the unsaturated hydraulic properties of High Level Waste simulant by applying inverse modeling and parameter estimation methods and data obtained by experiments.

Saltcake simulant was placed in column equipped with tensiometers and flow meters. Variable pressure boundary conditions ranging from 100 to 500 cm were applied along the column, outflow and the pressure head were measured with respect to time. The experimental data was analyzed using an inverse modeling software and the van Genuchten's hydraulic parameters for unsaturated porous media were determined. In addition, the unsaturated hydraulic conductivities were obtained as a …

Lumps And Balls In High-Slump Concrete: Reasons And Remedy, Ivan R. Canino-Vazquez

FIU Electronic Theses and Dissertations

The objective of this research was to investigate the reason lumps occur in high-slump concrete and develop adequate batching procedures for a lumps-free high-slump ready-mix concrete mix used by the Florida Department of Transportation. Cement balls are round lumps of cement, sand, and coarse aggregate, typically about the size of a baseball that frequently occur in high-slump concrete. Such lumps or balls jeopardize the structural integrity of structural members.

Experiments were conducted at the CSR Rinker concrete plant in Miami, Florida, based on a protocol developed by a team of Florida Department of Transportation (FDOT) concrete engineers, Rinker personnel, and …

A Computer Simulation Model For Single-Lane Roundabouts, Hesham Roshdy Elbadrawi

FIU Electronic Theses and Dissertations

During the past three decades, the use of roundabouts has increased throughout the world due to their greater benefits in comparison with intersections controlled by traditional means. Roundabouts are often chosen because they are widely associated with low accident rates, lower construction and operating costs, and reasonable capacities and delay.

In the planning and design of roundabouts, special attention should be given to the movement of pedestrians and bicycles. As a result, there are several guidelines for the design of pedestrian and bicycle treatments at roundabouts that increase the safety of both pedestrians and bicyclists at existing and proposed roundabout …

Trip Generation Study Of Gasoline Stations With Convenience Market, Quick Service Restaurant, And Car Wash In Miami-Dade County, Elio Roberto Espino

FIU Electronic Theses and Dissertations

The objectives of the thesis are twofold: (a) validation of trip generation rates for land use 846 (LU-846) published in ITE's Trip Generation Manual, and (b) the generation of trip generation models for a newly introduced land use, the gasoline station with convenience market, quick service restaurant and car wash. Data was collected at five sites representative of the new land use and the number of trips produced by the sites were compared with estimates made using the ITE rates for LU-846. The ITE rates were found to underestimate trip generation by 50% to 400%. Additionally, Multiple regression was performed …

Mode Choice Modeling With Neural Network : Boston Area Case Study, Soon Chung

FIU Electronic Theses and Dissertations

Demand forecasting is an essential element in the analysis of transportation systems. It is concerned with the behavior of consumers of transportation services and facilities. We choose geographic, demographic, and socioeconomic characteristics of consumers that may affect the travel demand of each selected. We use an artificial neural network to predict travel demand with characteristics selected from three different database sources: Census Summary Tape files, TIGER/Line files, and Federal Transit Administration's National Transit GIS database.

A neural network is an information processing system that is intensely parallel and neural networks are capable of learning how to classify and associate input/output …

Traffic Signal Control - A Neural Network Approach, Gerard Nivard Cadet

FIU Electronic Theses and Dissertations

Artificial Neural Networks (ANNs) have been proven to be an important development in a variety of problem solving areas. Increasing research activity in ANN applications has been accompanied by equally rapid growth in the commercial mainstream use of ANNs. However, there is relatively little research of practical application of ANNs taking place in the field of transportation engineering. The central idea of this thesis is to use Artificial Neural Network Software Autonet in connection with Highway Capacity Software to estimate delay. Currently existing signal control system are briefly discussed and their short coming presented. As a relative new mathematical model, …

Temporal Gis Applications In Public Transit Planning And Management, Hesham R. Elbadrawi

FIU Electronic Theses and Dissertations

Geographic Information Systems (GISs) provide a powerful framework for various tasks of transit management such as planning, performance evaluation, and marketing. GIS may be used to solve complex planning problems, assist in operations planning, and meet other management and operational needs. However, due to the changing nature of transit planning and operational data, transit planners and operators need to analyze the data over time, which requires a temporal GIS that is capable of storing, manipulating, and analyzing changes with respect to both time and space.

Temporal GIS will allow planners and transit operators to analyze data within a certain time …

Flexible Pavement Layer Moduli Determination : An Adaptive Artificial Neural Network Approach, Michael A. Adeife

FIU Electronic Theses and Dissertations

The estimation of pavement layer moduli through the use of an artificial neural network is a new concept which provides a less strenuous strategy for backcalculation procedures. Artificial Neural Networks are biologically inspired models of the human nervous system. They are specifically designed to carry out a mapping characteristic. This study demonstrates how an artificial neural network uses non-destructive pavement test data in determining flexible pavement layer moduli. The input parameters include plate loadings, corresponding sensor deflections, temperature of pavement surface, pavement layer thicknesses and independently deduced pavement layer moduli.

Evaluating The Effectiveness Of A Delineated Wellhead Protection Area : The North West Wellfield In Dade County, Florida, Jose H. Olivo Jr.

FIU Electronic Theses and Dissertations

Methods for the evaluation of the effectiveness of the Wellhead Protection Program (WHPP) in the North West Wellfield, Dade County, Florida are presented. This is done through application of two computer programs developed by the Environmental Protection Agency: WHPA (Version 2.2), a Modular Semi-Analytical Model for the Delineation of Wellhead Protection Areas, and WHAEM, the Wellhead Analytical Element Model. In addition the Calculated Fixed Radius Method for capture zone delineation is also used. Wellhead delineation results from the afore mentioned three methods are obtained for both present and future water demands, based on population predictions done for the years 2010, …

Computer Program For The Analysis Of Non-Prismatic Beams, Roberto Antonio Alas

FIU Electronic Theses and Dissertations

One of the major problems in the analysis of beams with Moment of Inertia varying along their length, is to find the Fixed End Moments, Stiffness, and Carry-Over Factors.

In order to determine Fixed End Moments, it is necessary to consider the non-prismatic member as integrated by a large number of small sections with constant Moment of Inertia, and to find the M/EI values for each individual section. This process takes a lot of time from Designers and Structural Engineers.

The object of this thesis is to design a computer program to simplify this repetitive process, obtaining rapidly and effectively …