Civil and Environmental Engineering Commons^™

Perceived Value Of Building Information Modeling In Facilities Operations And Maintenance, Francisco Forns-Samso

Civil Engineering ETDs

Conventional practices and inefficiencies in accessing relevant operation and maintenance (O&M) information are major issues to maintain facilities for their intended purpose. The need to have access to accurate information efficiently is critical to operate and maintain a facility. Building Information Models are databases able to store, organize and exchange structured information. Their use has proven to be successful in the design and construction phase. However, the benefits have not transcended to the O&M phase. Reluctance to process change, lack of knowledge and lack of documented metrics has prevented owners from adopting BIM to support the O&M phase. The purpose …

The Development Of A Modified Biaxial Composite Test Specimen, Anthony Torres

Civil Engineering ETDs

Bi-axial testing of composite structures has been an important topic in the research community for some years now. Bi-axial test specimens in the past have typically been cruciform specimens with a tapered thickness gage section. This ensures that the specimen will fail under bi-axial loading rather than uni-axial loading due to high stress concentrations at the intersecting loading arms. To reduce the stress concentration in the loading arms the intersection points are rounded and curved inward toward the center of the specimen. By having the curvature of the intersecting arms come closer into the specimen it reduces the amount of …

Lateral Outflow From Supercritical Channels, Nelson Bernardo

Civil Engineering ETDs

Stormwater pollutants caused by urban runoff are a major concern for the Albuquerque Metropolitan Arroyo Flood Control Authority (AMAFCA), and other flood control authorities, as stormwater channels eventually are discharged into natural waterways. One method of improving stormwater quality is diverting frequent storms or the first flush of less frequent storms to a structural debris filter and/or a constructed wetland prior to reentrance into the channel. The focus of this study was to develop a procedure to allow determination of laterally diverted flows of stormwater from a supercritical channel for treatment. A range of design flows were tested and evaluated …

Effect Of Air On Vibration Of Structures, Tong Xia

Civil Engineering ETDs

This research primarily studies the effect of air on vibration of structures. Theoretical solutions based on various physics are derived and compared with experimental results to determine how air modifies the vibrational behavior of structures. This work may help in determining the characteristics of structural vibrations — from acoustic behavior to earthquake response - in practical buildings. The work consists of several primary components: derivation of theories that predict the effect of air on structural vibrations and vice-versa, design of experiments, and determination of the importance of air in structural vibrations and the applicability of different physics under various vibrational …

Structural Assesment Of Joints In Satellites Using Guided Waves, Angela Montoya

Civil Engineering ETDs

The intention of the Air Forces Responsive Space Initiative Project is to develop procedures and technologies necessary to produce a satellite within six days from the initial order. Modular satellite designs have been proposed to help streamline the process of preparing a satellite for deployment. These designs would save time by allowing panels with common functions to be manufactured and tested long before a new satellite is needed. Prior to launch, the integrity of the panel-to-panel connections would need to be tested for quality in order to show that the craft is flight worthy. The experimental test method presented in …

Establishing A Collaborative Environment Between Transportation Agencies And Tribal Communities, Rebecca Martinez

Civil Engineering ETDs

Historically, transportation systems have overcome physical and geographical barriers to provide a flow of people and commodities across nations. While geographical barriers have been overcome, political and institutional barriers still exist when multiple government stakeholders are involved in the transportation planning process. Such is the case on transportation projects affecting or of concern to tribal communities. Many states across the nation have taken initiative in implementing programs to aid in the creation of a collaborative environment among transportation agencies and tribal communities. One such effort has been the establishment of intergovernmental networks within states that create a working group of …

Validation Of Geographically Based Surface Interpolation Methods For Adjusting Construction Cost Estimates By Project Location, Su Zhang

Civil Engineering ETDs

In the construction industry, cost estimates are fundamental to the success of a construction project. Location factors are commonly used to adjust cost estimates by project location. However, not all locations have corresponding factors. Nowadays, the construction industry has employed a simple, proximity-based location factor interpolation method which is widely accepted and used. Under this method, for a location without adjustment factor, the factor of the geographically “nearest neighbor” will be selected. Although this approach was statistically substantiated by former research, it was still not sufficiently supported, considering that only one year’s RSMeans City Cost Index (CCI) dataset was tested. …

A Framework For Assessing And Improving Quality Of Data From Visual Evaluation Of Asset Conditions, Arturo Adrian Cordova

Civil Engineering ETDs

Investments in transportation infrastructure assets are among the largest investments made by governmental agencies. Besides requiring a large investment for design and construction, transportation infrastructure also requires a significant amount of resources and effort for performing maintenance and/or rehabilitation activities. Along with other considerations, data on asset conditions are used to make decisions regarding the timing of maintenance activities, the type of treatment, and the resources employed. Some parameters under assessment, however, are evaluated through visual — or manual — assessments performed by evaluators on the site due to a lack of reliable, inexpensive automated methods to collect the data. …

Hydraulic Properties Of Asphalt Concrete, Ronald Eric Pease

Civil Engineering ETDs

This research has applied standard unsaturated flow models and laboratory methods common to soil analysis, to characterize the hydraulic properties of asphalt concrete. Wetting and drying water characteristic curves were measured for six asphalt concrete cores. From the water characteristic curves, it is proposed that asphalt concrete may require bi-modal sigmoid curves to represent drying. It is also proposed that asphalt concrete is a hydrophobic material during wetting and a hydrophilic material during drying. The wetting curves developed for the asphalt concrete were fit with power functions, while the drying curves follow a sigmoid curve as expected for a wettable …

Evaluation Of Fwd Software And Deflection Basin For Airport Pavements, Mesbah Uddin Ahmed

Civil Engineering ETDs

Falling Weight Deflectometer (FWD) test data are processed by backcalculation software to obtain modulus of layer materials of airport pavements. Currently, several backcalculation software are available. However it is not known which software produces accurate and consistence modulus values. In this study three backcalculation software; namely, BAKFAA, EVERCALC, and MODULUS are evaluated for consistency and accuracy. To examine accuracy, software predicted modulus values are compared to the laboratory tested modulus values of soils, aggregate, and asphalts. Consistency is examined by statistical analysis using three sets of FWD deflection data produced by three loads with magnitudes of 9, 12, and 16 …

Metrology Of Optical Telescope Components, Ran Fu

Civil Engineering ETDs

Precision astronomic structures such as telescopes often require structural materials that possess ultra low coefficient of thermal expansion (CTE) and coefficient of moisture expansion (CME) so that strict dimensional stability requirements can be met. Composite materials such as carbon fiber reinforced epoxy (CFRE) composites can meet those requirements because of their nearly-zero CTE and potentially low CME. To employ these composite materials for telescope structural design, it is necessary to first develop practical and economical methods to determine their CTE and CME. Although many previous studies have discussed CTE and CME measurements of various materials, none of them suitably serve …

Macro And Nanocreep Of Self-Consolidating Concrete, Aaron Reinhardt

Civil Engineering ETDs

Self-consolidating concrete (SCC) is a concrete that can flow under its own weight, easily filling forms with highly congested reinforcement. Due to its fresh properties, there has been growing interest in using SCC in precast and prestressed applications. These applications are known to be sensitive to time-dependent phenomena such as creep and shrinkage. Therefore, it is important to understand the creep and shrinkage behavior of SCC compared with other types of concrete. This research presents macro and nanoscale creep experiments used for a multiscale characterization of creep of SCC. Macrocreep experiments placed different SCC and normal vibrated concrete (NVC) mixes …

Validation Of Methods For Adjusting Construction Cost Estimates By Project Location, Adam Martinez

Civil Engineering ETDs

Location factors are used to adjust conceptual cost estimates by project location. Presently, the construction industry has adopted a simple, proximity-based interpolation method which uses the “nearest neighbor” location factor to estimate unknown location factors. Although this approach is widely accepted, its validity has not been statistically substantiated. This study assessed the current method of adjusting conceptual cost estimates by project location. An evaluation of 14 alternative spatial estimation methods was also conducted. These methods were based on different approaches for combining 4 criteria: proximity, state boundary, home value, and income. This study used the 2006 RSMeans city cost index …

Relationship Between Procurement Duration And Project Performance In Design-Build Water/Wastewater Projects, Ruoyu Jin

Civil Engineering ETDs

The design-build (DB) project delivery system (PDS) has been widely applied and studied in the construction industry. Its advantages include shortened project duration, lowered risk to the owner, improved project performance, and possibly reduced cost. Researchers have also studied the factors related to the improved performance in DB projects, especially in the building and transportation industries. Compared to the building and highway industries, the application of DB in water/wastewater (WW) projects has been rarely studied before. One of the potential factors that may influence project performance is procurement duration (PD). By focusing on DB applied to WW projects, this study …

Ozone And Biofiltration As An Alternative To Reverse Osmosis For Removing Ppcps And Edcs From Wastewater, Carson Odell Lee

Civil Engineering ETDs

A lot of attention has been paid to trace amounts of pharmaceuticals and personal care products (PPCPs) and endocrine disrupting compounds (EDCs) in drinking water supplies. Current water and wastewater treatment techniques, such as coagulation, flocculation, and sedimentation for water treatment and the conventional activated sludge process for wastewater treatment, have shown only limited success in their removal. Although there is a lack of evidence linking these emerging microconstituents to adverse human health effects, not a lot is known about the effects of long term exposure to these compounds and more research is still needed. This study examined advanced wastewater …

Evaluation Of Selected Airport Pavements In New Mexico, Raju Bisht

Civil Engineering ETDs

Rehabilitation of poor conditioned airport pavements can be very expensive compared to the rehabilitation of relatively good conditioned airport pavements. Determining the conditions of airport pavements is a first step to determine appropriate rehabilitation method and timing. In this study, the conditions of 10 airport pavements in New Mexico are evaluated. Those airports include a total of 19 runway pavements. The major goal is to rank these airport pavements based on their functional and structural conditions. The functional conditions of the pavements are evaluated based on the field collected surface distress data and skid resistance. Field collected distress data such …

Effect Of Solids Retention Time In Membrane Bioreactors On Reverse Osmosis Membrane Fouling, Elizabeth Field

Civil Engineering ETDs

As sources of clean fresh water diminish, there is an increasing interest in water reuse. Membrane bioreactors (MBRs) are commonly used in wastewater treatment plants, though reuse of treated wastewater for potable purposes requires more advanced treatment. Reverse osmosis (RO), a water treatment process commonly used for drinking water, provides near complete removal of all inorganic and organic constituents from water. While much research has been conducted on both treatment processes, little research has been done on how the combined processes work together in treating wastewater to high enough standards for potable water reuse. The MBR-RO treatment process was studied …

Hydrogeological Engineering Approaches To Investigate And Characterize Heterogeneous Aquifers, Dylan Harp

Civil Engineering ETDs

This dissertation presents a compilation of five stand-alone manuscripts (Chapters 2 through 5 and Appendix A). Chapters 2 through 5 present hydrogeological analysis approaches, while Appendix A is utilized within the dissertation introduction as an example of a non-physically based modeling approach, albeit demonstrated on a non-hydrogeologically based application. Chapter 2 presents an inverse approach to decompose pumping influences from water-level fluctuations observed at a monitoring location. Chapter 3 presents an inferencing approach to identify effective aquifer properties at the interwell scale that can be applied to highly transient datasets. Chapter 4 introduces the use of a Markov-chain model of …

Optimal Sensor Placement In Structural Health Monitoring (Shm) With A Field Application On A Rc Bridge, Mohammad Azarbayejani

Civil Engineering ETDs

Structural health monitoring (SHM) is a research field that targets detecting and locating damage in structures. The main objective of SHM is to detect damage at its onset and inform authorities about the type, nature and location of the damage in the structure. Successful SHM requires deploying optimal sensor networks. We present a probabilistic approach to identify optimal location of sensors based on a priori knowledge on damage locations while considering the need for redundancy in sensor networks. The optimal number of sensors is identified using a multi-objective optimization approach incorporating information entropy and cost of the sensor network. As …

Temporal Biomass Density And Filamentous Bacteria Effects On Secondary Settling, Patricia A. Jones

Civil Engineering ETDs

The activated sludge wastewater treatment process is the most common technology used today and solids separation is a critical and often problematic component of this technology. This leads to requirements for larger clarifiers, increased pumping costs of the diluted settled solids stream, and increased costs for solids treatment. For the past thirty years, the majority of the research in secondary settling problems has focused on the role of filamentous bacteria, and also factors such as floc size and shape. The effects of variable biomass density on settleability of biosolids produced in full scale activated sludge wastewater treatment systems has been …

Decision Process For Energy Efficient Building Retrofits : The Owner's Perspective, Christian Birk Jones

Civil Engineering ETDs

Energy consumption and conservation is an important consideration for commercial building owners. The commercial building sector consumes a great deal of energy. Energy reduction for commercial buildings can result in operations cost savings and reduction in environmentally harmful emissions. The decision process employed by owners to determine the energy conservation measures for an existing building retrofit requires a repeatable standard. This research investigates decision steps that are currently used. Then it determines what decision steps should be followed, and important aspects and considerations that will improve the process. The research used literature review and case study interviews to collect and …

The Relationship Between Procurment Duration And Design-Build Success In Transportation Projects, Ao Chen

Civil Engineering ETDs

State Departments of Transportation (DOTs)are increasingly interested in developing new strategies for the design and construction of transportation projects. As a result, they are adopting more integrated process. Projects that previously used separate steps and parties may now be included in a single Design-Build system. When making a decision between a traditional Design-Bid-Build delivery system or a more integrated project delivery system like Design-Build, the DOTs consider potential more cost savings, time savings, and quality improvement. In order to maximize success in Design-Build project delivery, state DOTs need to pay attention to the initial steps, like procurement. DOTs should prepare …

Modeling Riparian Groundwater Depth As A Function Of River Flow For The Rio Grande At Albuquerque, Nm, Kelly Isaacson

Civil Engineering ETDs

Riparian corridor ecological health is strongly tied to river streamflow. As climate change threatens to significantly reduce monthly streamflows in semi-arid regions, riparian groundwater will be similarly reduced, impacting native and non-native flora. This paper presents a geographic information system (GIS) based approach for creating comprehensive riparian water surfaces from point surface water and groundwater measurements. These water surfaces are used to calculate depth to groundwater as a function of river discharge for the study reach in Albuquerque, NM, USA. A one dimensional hydraulic model, calibrated with USGS streamflow data, was used to interpolate streamflow measurements throughout the study reach …

Laboratory Evaluation Of Cracking In Asphalt Concrete, Evan Michael Casey Kias

Civil Engineering ETDs

Cracking is one of the major distresses in asphalt concrete leading to high maintenance and rehabilitation costs throughout the nations pavement infrastructure. Asphalt concrete is a three phase, heterogeneous composite consisting of aggregate, mastic, and air voids. Crack initiation, crack path and propagation are not well understood in asphalt concrete. This thesis work presents testing and analysis of cracking in semi-circular notched asphalt concrete samples in three point bending. Load and crack width data at different locations of the sample were captured in real time using Linear Variable Differential Transformers (LVDTs). Crack initiation, path, and velocity are examined with varying …

Evaluation Of Subgrade Strength And Flexible Pavement Designs For Reliability, Nayan Saha

Civil Engineering ETDs

Reliability is an important factor in flexible pavement design to consider the variability associated with the design inputs. In this study, subgrade strength variability and flexible pavement designs are evaluated for reliability. The effects of weak subgrade on pavement design and performance prediction are evaluated through a case study using Mechanistic-Empirical Pavement Design Guide (MEPDG). Permanent deformation or rutting is very sensitive to subgrade strength. International roughness index (IRI) is sensitive to the subgrade strength. Six existing pavement sections' design data are studied to examine the effect of variability associated with subgrade strength and selection criteria of subgrade strength for …

Hydraulic Modeling Study To Determine Diversion Structure Impacts - Rio Grande At Albuquerque, New Mexico -, Jungseok Ho

Civil Engineering ETDs

The primary objective of this study is to develop and use physical and numerical modeling techniques to predict the hydraulic impact on the Rio Grande induced by the Albuquerque diversion structure and its operation. A 1:24 scale distorted movable bed model, constructed and tested to investigate the hydraulic performance of the diversion structure, provided measurements for validating the numerical models developed in this study. Crushed coal was substituted for the prototype sediment particles and a 6.5 times steeper channel bed slope were employed to obtain sediment transport model similitude.

The diversion structure consists of an overshot gate system that can …

Numerical Study Of Granular Soil Behavior Using Random Arrays Of Elastic Ellipsoids, Xiaoshan Lin

Civil Engineering ETDs

For the purpose of improving computer simulation of granular materials in the framework of the Discrete Element Method (DEM), 2-D and 3-D discrete element models using random arrays of elastic ellipsoids have been developed.

Development Of High-Pressure Liquid Chromatography Techniques For The Analysis Of Wastewater Effluent, Glenn Douglas Pierce

Civil Engineering ETDs

This investigation characterized a biological secondary wastewater effluent by conventional wastewater analysis parameters, evaluated the capabilities of activated carbon and macroreticular resin for recover­ing residual organics from the effluent, correlated conventional para­meters with carbon recoveries, developed high-pressure liquid chroma­tographic techniques for separation of organics in the recovered mixtures and identified a selected extract fraction. The Organics-Carbon Adsorbable Standard Method was adapted for use with a low turbidity effluent and a mass balance based on non-volatile total organic carbon was developed, demonstrating that the sorptive capacity of the system was not exceeded by a 60-1 sample. Ten individual carbon chloroform extracts …

The Effect Of Earth Media On Seismic Motion And Structure Response, Joseph John Fedock

Civil Engineering ETDs

An analysis is performed to determine the influence of the choice of a constitutive model for the earth medium upon the response of a rigid structure to seismic waves. A finite element method is employed to analyze the motions of an embedded structure in which the surrounding earth medium is represented by three different constitutive models. Linear elastic, linear viscoelastic, and elastic-plastic models of soil behavior are utilized in one- and two-dimensional analyses. The seismic disturbance is characterized by a pressure wave for the one-dimensional case while a system of horizontally propagating Rayleigh waves is used in the two-dimensional analysis. …

Buckling Of Stiffened Plates And Shells, William De La Garza

Civil Engineering ETDs

The emphasis in this dissertation is the determination of buckling loads on many types of structures. The available solutions are usually written in a complex form that requires large amounts of time in order to find the buckling loads. For stiffened structures the use of finite difference calculus will provide a vehicle for obtaining solutions that are not as complex. In addition, the use of a reasonable approximation for the stiffener behavior allows the solution to be written in closed from. Direct substitution of the elastic and geometric properties of the stiffeners gives the buckling loads. The application of finite …