Civil Engineering Commons^™

Improving Analysis Of Heavy To Extreme Precipitation Using Conditional Bias-Penalized Optimal Estimation, Ridwan Siddique

Civil Engineering Theses - Archive

Precipitation estimation is a very important topic from the societal perspective as heavy precipitation can cause flooding from which loss of lives and damage to properties can occur. In current practice, a number of spatial interpolation techniques are used for precipitation estimation using rain gauge data. Most of them are based on minimizing error variance but none of them consider Type-II conditional bias. As such, the existing techniques work well in the mid ranges of the precipitation distribution but tend to under- and overestimate large and small precipitation amounts, respectively. Conditional bias- penalized kriging (CBPK) adds a penalty term for …

Staged Construction Modeling Of Large Diameter Steel Pipes Using 3-D Nonlinear Finite Element Analysis, Mojtaba Salehi Dezfooli

Civil Engineering Dissertations - Archive

This study investigates the performance of large diameter steel pipes during stage construction. Using this study, metal pipes are designed utilizing existing native soil for embedment around the pipe rather than imported materials. This indeed, translates into a considerable amount of cost saving and advances in designing pipeline. This model is used for peer review/ designing of a 242 km (150 miles) pipeline project, Integrated Pipeline (IPL), that transports approximately hundreds of millions of gallons from Lake Palestine, 137 km (85 miles) southeast of Dallas, to Lake Benbrook, Tarrant County, Texas. The IPL project supplies water to more than1.8 million …

A Comparative Study Of Carbon Nanotubes And Granular Activated Carbon: Physicochemical Properties And Adsorption Capacities, Roja Haritha Gangupomu

Civil Engineering Dissertations - Archive

Adsorption technologies with activated carbon have proven their prominence in wide variety of industrial applications for the removal of pollutants from gaseous streams for generations. Nanoadsorbents due to their unique structure and the presence of high-energy binding sites can enhance adsorption of pollutants, particularly for hazardous pollutants difficult to control using conventional sorbents like activated carbon and can help industries in their struggle for greener technologies. The objective of this study was to characterize raw and purified CNTs and compare their physical and chemical properties to commercially available granular activated carbon (GAC). The CNT purification process was done in two …

Stabilization Of High Sulfate Soils, Nagasreenivasu Talluri

Civil Engineering Dissertations - Archive

Stabilization of expansive soils using lime and cement has been a favorite technique for practitioners over the years. However, recent heaving and premature pavement failures in lime and cement treated subgrades containing sulfates led to question the validity of calcium based stabilization. When expansive soils containing sulfates are treated with calcium based stabilizers, calcium from stabilizer reacts with soil sulfate and clay alumina to form expansive mineral Ettringite. Formation and growth of the mineral Ettringite was reported as the cause of severe heaving in several pavement failures. Under favorable environmental conditions Ettringite transforms in to another expansive mineral Thaumasite. This …

Development Of A Model For Estimation Of Buried Large Diameter Thin-Walled Steel Pipe Deflection Due To External Loads, Jwala Raj Sharma

Civil Engineering Dissertations - Archive

Design of buried pipeline systems involves solution of geotechnical and structural problems in addition to the hydraulics and mechanical issues. Just like any buried structure, it is of utmost importance to understand how the pipe interacts with the soil when subjected to external and internal loads. Based on the mode of withstanding loads, pipes are classified into two major categories, which are rigid and flexible pipes. Pipe material is the major factor governing the classification of a pipe being rigid or flexible. Rigid pipe is a pipe which is designed to withstand external dead and live loads and internal pressure …

Assessment Of Stress/Volume-Controlled Soil-Water Retention Properties Of Unsaturated Sandy Soils., Hailu Ayalew

Civil Engineering Theses - Archive

The main objectives of this work are to determine the effect of net normal stress and volume change on the soil-water retention properties of silty sand and clayey sand soils under stressed/volume-controlled conditions; to model soil-water retention parameters under stress/volume-controlled conditions; and to model the effect of higher net normal stress state on the soil-water retention characteristics of these two test soils based on the experimental test results. In order to investigate the effect of stress/volume change on the soil-water retention characteristics of these two test soils, two test methods were followed: the stress/volume-controlled soil-water characteristic test (Tempe pressure cell …

Physical, Mechanical And Chemical Aging Of Polyurea Nanocomposites, Ghanshyam Pal

Electronic Theses and Dissertations

Two component polyurea systems, on one hand, are gaining popularity as corrosion and abrasion resistant coatings and linings while on the other hand there are a few polyurea compositions being used as barrier against blast and ballistic threats to protect nation's critical infrastructure. Physical properties of polymer composites can be tailored with appropriate choice of type, size and amount of reinforcement. In general, nano-sized reinforcements provide better reinforcing over conventional reinforcements due to higher surface to volume ratio. In this dissertation, the first aim is to study effect of nanoreinforcement addition on the overall character (mechanical, chemical and microstructural) of …

Gap Acceptance Parameters For Hcm 2010 Roundabout Capacity Model Applications In Italy, A. Gazzarri, Michael T. Martello, Antonio Pratelli, Reginald R. Souleyrette

Civil Engineering Faculty Publications

This paper deals with the field data observation and successive application of estimation procedures in order to estimate follow-up headway and critical headway at roundabouts. Average follow-up headway and average critical headway are two key parameters in the new roundabout capacity model presented in the 2010 edition of the Highway Capacity Manual (HCM). The HCM 2010 capacity model was developed as an exponential regression model with parameter estimates based on gap acceptance theory. Gap acceptance models are strongly affected by driver behaviour and local habits. Follow-up headways can be field measured, while critical headway cannot be obtained directly. The paper …

Analysis Of Fatal And Nonfatal Accidents Involving Earthmoving Equipment Operators And On-Foot Workers, Esref Emrah Kazan

Wayne State University Dissertations

In view of the limitations of univariate statistics for studying construction accidents, a multivariate approach was undertaken using crosstabulation analysis and logistic regression.

Heavy construction equipment accidents related data for four type of equipment; backhoe, bulldozer, excavator and scraper were incorporated in the study using categorical variables. Degree of injury indicating the severity of accident outcome (fatal vs. nonfatal) was selected as the dependent variable, and a variety of factors potentially affecting the outcome comprised the independent variables. Cross tabulation results enabled the understanding and evaluation of associations between the research variables, while logistic regression yielded predictive models that helped …

Evaluation Of Surface Transportation Funding Alternatives Using Criteria System Established Through A Delphi Survey Of Texas Transportation Experts, Sasanka Bhushan Pulipati

Civil Engineering Dissertations - Archive

For more than a decade, transportation officials have been concerned that, at current levels, the fuel tax, the primary funding source of surface transportation in the United States, would not provide enough revenue to satisfy the ever rising transportation needs. Recent studies have evaluated alternative funding strategies at the national and state levels. In this dissertation, the author improves this evaluation procedure by developing a multi-criteria evaluation of different funding options for implementation in Texas using a technique called PROMETHEE. This evaluation uses a new criteria system established through his Delphi survey of Texas-based experts who are experienced in transportation …

Improving Productivity Of Tunnel Boring Machines, Nicholas Jencopale

Civil Engineering Theses - Archive

Tunneling with tunnel boring machines (TBMs) is one of the most mechanized and sophisticated processes within the construction industry. However, there are risks when venturing down several hundred feet where the conditions cannot be accurately determined in advance. Months and years of planning, engineering, profiling, researching, and scheduling go into a typical tunneling project before any ground breaking event. This thesis will discuss in detail the growing technologies of the tunneling process using tunnel boring machines (TBM). First, some background information on tunneling and the use of a TBM will be provided to introduce the process and the industry being …

Corrosion Potentials Of Lightweight Concrete Wrapped With Fiber Reinforced Polymers (Frp), Eric Goucher

Civil Engineering Theses - Archive

The purpose of this research was to investigate the effects of Fiber Reinforced Polymer wraps on corrosion protection of lightweight concrete. Many studies have been undertaken for normal density concrete, but there are very few studies regarding lightweight concrete and externally bonded FRP wraps. This experiment involved the use of an accelerated corrosion test to determine the corrosion protection that FRP would afford lightweight concrete, while making a comparison with a similarly proportioned normalweight mix. 42 cylinders were subject to a constant 12 V power from a DC Power Supply while being immersed in a 5% NaCl for a period …

Structural And Material Performance Of Rubberized And Hybrid Concrete Pipes, Mohammad Mohammadagha

Civil Engineering Theses - Archive

This study investigates how the combination of steel fiber, crumb rubber, synthetic fiber, and conventional steel cage will improve the ductility of regular concrete pipes and thin-walled semi-rigid concrete pipes. In this study, pipes with four different concrete mixtures were produced and tested: (1) Steel Bar Reinforced Concrete Pipe (SBRCP), (2) Crumb Rubber Reinforced Concrete Pipe (CRRCP), (3) Steel Fiber Reinforced Concrete Pipe (SFRCP), and (4) Synthetic Fiber Reinforced Concrete Pipe (SNFRCP). This study investigates how the variation of the fiber volume fraction and crumb rubber content in concrete mix affects the behavior of pipes with diameters ranging from 24in. …

Ensemble Streamflow Forecasting For The Upper Trinity River Basin In Texas, Manabendra Saharia

Civil Engineering Theses - Archive

By allowing for routine use of longer-lead quantitative precipitation forecast (QPF) in hydrologic prediction, ensemble forecasting offers hope for extending the lead time for short-range streamflow forecasting. In this work, this potential is assessed by comparatively evaluating ensemble streamflow hindcasts forced by Day 1-3 QPF with those forced by Day 1 QPF for five headwater basins in the Upper Trinity River Basin in North Texas. The hindcasts are generated for a 7-year period of 2004 to 2010 using the Hydrologic Ensemble Forecast Service (HEFS), which operates on the Community Hydrologic Prediction System (CHPS) of the National Weather Service (NWS). HEFS …

The Relation Between Freeway Average Speed And Speed Noise, Bahar Zarin

Civil Engineering Theses - Archive

A significant amount of energy could be saved by applying traffic management policies. Many factors affect the fuel consumption rate, and the most important traffic-related ones include variables such as speed, number of stops, the speed noise, and the acceleration noise. Fuel consumption models for both urban and highway traffic are used to evaluate the effect of these factors. Previous literature shows the speed and the acceleration of the individual vehicles as well as the aero-dynamic effects are the most considered parameters in highway fuel consumption models. However, the existing models are based on the average or cruising speed and …

Characterization Of Impact Damage And Fiber Reinforced Polymer Repair Systems For Metallic Utility Poles, Cara Johnson

Electronic Theses and Dissertations

Previous studies have demonstrated that the behavior of fiber reinforced polymers (FRPs) bonded to metallic utility poles are governed by the following failure modes; yielding of the metallic substrate, FRP tensile rupture, FRP compressive buckling, and debonding of FRP from the substrate. Therefore, an in situ method can be devised for the repair of utility poles, light poles, and mast arms that returns the poles to their original service strength. This thesis investigates the effect of damage due to vehicular impact on metallic poles, and the effectiveness of externally-bonded FRP repair systems in restoring their capacity. Damage is simulated experimentally …

Experimental And Numerical Investigations On Bond Durability Of Cfrp Strengthened Concrete Members Subjected To Environmental Exposure, Haider Al-Jelawy

Electronic Theses and Dissertations

Fiber reinforced polymer (FRP) composites have become an attractive alternative to conventional methods for external-strengthening of civil infrastructure, particularly as applied to flexural strengthening of reinforced concrete (RC) members. However, durability of the bond between FRP composite and concrete has shown degradation under some aggressive environments. Although numerous studies have been conducted on concrete members strengthened with FRP composites, most of those studies have focused on the degradation of FRP material itself, relatively few on bond behavior under repeated mechanical and environmental loading. This thesis investigates bond durability under accelerated environmental conditioning of two FRP systems commonly employed in civil …

Monitoring For Underdetermined Underground Structures During Excavation Using Limited Sensor Data, Nader Mehdawi

Electronic Theses and Dissertations

A realistic field monitoring application to evaluate close proximity tunneling effects of a new tunnel on an existing tunnel is presented. A blind source separation (BSS)-based monitoring framework was developed using sensor data collected from the existing tunnel while the new tunnel was excavated. The developed monitoring framework is particularly useful to analyze underdetermined systems due to insufficient sensor data for explicit input force-output deformation relations. The analysis results show that the eigen-parameters obtained from the correlation matrix of raw sensor data can be used as excellent indicators to assess the tunnel structural behaviors during the excavation with powerful visualization …

A Real-Time Crane Service Scheduling Decision Support System (Css-Dss) For Construction Tower Cranes, Amir Tork

Electronic Theses and Dissertations

The success of construction projects depends on proper use of construction equipment and machinery to a great extent. Thus, appropriate planning and control of the activities that rely on construction equipment could have significant effects on improving the efficiency of project operations. Cranes are the largest and most conspicuous construction equipment, widely used in typical construction sites. They play a major role in relocation of materials in horizontal and vertical directions on construction sites. Given the nature of activities relying on construction cranes in various stages of a project, cranes normally have control over the critical path of the project …

Real-Time Traffic Safety Evaluation Models And Their Application For Variable Speed Limits, Rongjie Yu

Electronic Theses and Dissertations

Traffic safety has become the first concern in the transportation area. Crashes have cause extensive human and economic losses. With the objective of reducing crash occurrence and alleviating crash injury severity, major efforts have been dedicated to reveal the hazardous factors that affect crash occurrence at both the aggregate (targeting crash frequency per segment, intersection, etc.,) and disaggregate levels (analyzing each crash event). The aggregate traffic safety studies, mainly developing safety performance functions (SPFs), are being conducted for the purpose of unveiling crash contributing factors for the interest locations. Results of the aggregate traffic safety studies can be used to …