Structural Engineering Commons^™

Multi-Physics Modeling Of Geomechanical Systems With Coupled Hydromechanical Behaviors, Ahmad Mohamed

Electronic Theses and Dissertations

Geotechnical structures under realistic field conditions are usually influenced with complex interactions of coupled hydromechanical behavior of porous materials. In many geotechnical applications, however, these important coupled interactions are ignored in their constitutive models. Under coupled hydromechanical behavior, stress in porous materials causes volumetric change in strain, which causes fluid diffusion; consequently, pore pressure dissipates through the pores that results in the consolidation of porous material. The objective of this research wasto demonstrate the advantages of using hydromechanical models to estimate deformation and pore water pressure of porous materials by comparing with mechanical-only models. Firstly, extensive literature survey was conducted …

Evaluating The Use Of Recycled Concrete Aggregate In French Drain Applications, Zachary Behring

Electronic Theses and Dissertations

Recycled concrete aggregate (RCA) is often used as a replacement of virgin aggregate in road foundations (base course), embankments, hot-mix asphalt, and Portland cement concrete. However, the use of RCA in exfiltration drainage systems, such as French drains, is currently prohibited in many states of the U.S. The French drain system collects water runoff from the road pavement and transfers to slotted pipes underground and then filters through coarse aggregate and geotextile. The primary concerns with using RCA as a drainage media are the fines content and the precipitation of calcium carbonate to cause a reducing in filter fabric permittivity. …

Non-Destructive Evaluation Of Concrete Structures Using High Resolution Digital Image And Infrared Thermography Technology, Azusa Watase

Electronic Theses and Dissertations

As existing bridge structures age, they are susceptible to the effects of deterioration, damage and other deleterious processes. These effects hamper the capacity and efficiency of transportation networks and adversely impact local, regional and national economic growth. As a result, bridge authorities and other professionals have become more sensitive to maintenance issues related to this aging infrastructure. While highway bridge condition have been monitored by visual inspection, non-destructive evaluation (NDE) technologies have also been developing and they are expected to be utilized for effective management of highway bridges or other civil infrastructure systems. Efficient use of these technologies saves time …

Wind Loading On Trees Integrated With A Building Envelope, Aly Mousaad Aly, Alberto Zasso, Girma Bitsuamlak, Alberto Nicola Longarini, Arindam Gam Chowdhury

Faculty Publications

With the sustainability movement, vegetated building envelopes are gaining more popularity. This requires special wind effect investigations, both from sustainability and resiliency perspectives. The current paper focuses on wind load estimation on small- and full-scale trees used as part of green roofs and balconies. Small-scale wind load assessment was carried out using wind tunnel testing in a global-effect study to understand the interference effects from surrounding structures. Full-scale trees were investigated at a large open-jet facility in a local-effect study to investigate the wind-tree interaction. The effect of Reynolds number combined with shape change on the overall loads measured at …

Effect Of Support Compliance On The Resonant Behavior Of Microcantilever-Based Sensors In Viscous Fluids, Rabin Maharjan

Dissertations (1934 -)

Resonant microcantilevers are often considered for use in chemical sensing and biosensing applications. However, when excited in the conventional transverse flexural mode, their performance in liquids is severely compromised. Theoretical and experimental studies have shown that the detrimental effects of the liquid may be mitigated by operating the microcantilever in lateral flexure, especially for microbeams having smaller length-to-width (L/b) ratios. However, for these most promising geometries the predictions of existing models tend to diverge from experimental data for resonant frequency (f_res) and quality factor (Q). A likely reason for these discrepancies is support compliance, which has been neglected …

Episodic Adaptations And Trade-Offs: Examples From The Victorian Construction Industry, Manikam Pillay, David Borys

Research outputs 2013

A central facet of resilience engineering involves adaptation which involves making temporal adjustments by responding, monitoring, anticipation and learning from disturbances continuous stressors. This ability to adapt is inherent in the actions which manifest as behaviors in individuals and teams. In the main, the response is generally in response is to regular and irregular threats such that work continues to operate as normal. Invariably, these adaptations also require trade-offs and sacrifices being made at a number of levels. However, there is little published research that seeks to explain how such adaptations actually occur in construction works. It has been suggested …

Effects Of Openings On The Analysis And Design Of Precast Prestressed Hollow Core Slabs, Eoghan Lodge

Theses

Precast prestressed hollow core floors are a widely used structural element which offers increased speed of construction, reduced self-weight and many other advantages. Due to the relatively low span-to-depth ratio and the speed of construction hollow core slabs are utilised in a large number of commercial buildings. In order to carry the services to the upper floors an opening must be made within the prestressed slab. Cutting an opening in a prestressed slab has significant effects on the structural behaviour of the slab and can considerably reduce the ultimate capacity of the slab.

This paper outlines the limited available guidance …

Reinforced Concrete Deterioration Of A 100 Year Old Structure In A Marine Environment, Ross O'Donovan

Theses

The current study investigates the deterioration of a 100 year old bridge located in a harsh marine environment. Constructed in 1908 - 1909 the Mizen Head Footbridge was one of the oldest reinforced concrete bridges in Ireland. The demolition of the bridge in 2009 provided a unique opportunity to examine its service life and to extract samples for analysis and investigation. A review of the construction of the bridge, and its maintenance history are presented, with a view to analysing their influence on the behaviour of the concrete.

Reinforcement corrosion due to chloride attack was identified. A focused study indicates …

Application Of Multi-Hazard Seismic-Blast Detailing For Highway Bridges, Dominique Morton Torres

Dissertations and Theses

The increase of worldwide terrorist attacks on public transportation has heightened our concerns of protecting the nation’s transportation infrastructure. Highway bridges are an attractive target for terrorist attacks due to ease of accessibility and their overall importance to society. The primary objective of this research is to investigate multi-hazard seismic-blast correlations of blast-induced bridge components through numerical simulations of a high-precision finite element model of a typical highway bridge in New York. Seismic-detailing for blast loading on bridges has been investigated to study the correlations between seismic design for blast load effects. High-precision 3D Finite Element models of bridges detailed …

Design, Construction And Load Testing Of The Pat Daly Road Bridge In Washington County, Mo, With Internal Glass Fiber Reinforced Polymers Reinforcement, Zhibin Lin, Mostafa Fakharifar, Chenglin Wu, Genda Chen, Wesley James Bevans, Arun Vijay Kumar Gunasekaran, Sahra Sedigh

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The overarching goal of this project is to deploy and assess an innovative corrosion-free bridge construction technology for long-term performance of new and existing bridges. The research objective of this project is to conduct a comprehensive study (instrumentation, construction, both laboratory and field evaluation) of a rapidly constructed and durable, three-span bridge with cast-in-place cladding steel reinforced concrete substructure and precast concrete decks/girders reinforced with glass fiber reinforced polymers (GFRP). The bridge has one conventional concrete-girder span, one conventional steel-girder span, and one innovative concrete box-girder span. The conventional concrete and steel girders were used to demonstrate the effective use …

Microsimulation Evaluation Of Eurocode Load Model For American Long-Span Bridges, Bernard Enright, Colm Carey, Colin Caprani

Articles

The ability to accurately predict traffic loading is essential for cost-effective bridge maintenance and repair programs. The traffic load model currently used in the United States for the design of long-span bridges was developed over three decades ago. In the meantime vehicle characteristics and traffic patterns have changed. The Eurocode for traffic loading is more recent, but was calibrated only for bridges up to 200 m long. In this work, Weigh-In-Motion traffic records from 11 different sites across Alabama are used to establish congested traffic loading. Traffic microsimulation is used to generate the congestion, based on the real traffic data. …

Elastic–Plastic Analysis And Strength Evaluation Of Adhesive Joints In Wind Turbine Blades, Yi Hua, Ananth Ram Mahanth Kasavajhala, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

The objective of this paper is to investigate the performance of adhesive joints of carbon/epoxy wind turbine blade subjected to combined bending and tension loadings through finite element method. The influence of adhesive material properties and geometrical details including fillet and imperfections was examined in terms of interlaminar stresses in the adhesive layer. The variation of stress intensity with change in adhesive shear modulus has also been investigated, while contour integral method was used for evaluating the stress intensity factors (SIF) at the imperfection tip. Furthermore, the strength of the joint was assessed through the crack initiation and propagation analysis. …

Aggregate Shape Characterization Using Digital Image Processing, Norbert H. Maerz, David Newton Richardson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Aggregates must meet certain specifications to be acceptable in asphalt and concrete applications. Among these are specifications that deal with the various aspects of aggregate shape, including flatness and elongation and aggregate angularity. The current practice for ensuring those specifications is the use of manual-mechanical tests. These tests are time consuming, labor intensive and subjective. In addition, tests such as the compacted or uncompacted voids tests (Figure 1), are taken to be a shape (angularity) indicator, even thought the measured quantify is the void ratio. This report describes a prototype of an automated digital video image analysis system that measures …

Effect Of High-Volume Fly Ash On Shear Strength Of Concrete Beams, Mahdi Arezoumandi, Jeffery Volz, John Myers

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Every year concrete production exceeds 6.5 billion tons worldwide, nearly 1 ton for every man, woman, and child on the planet. In fact, concrete is used 10 times more than any other building material in the world, primarily because of its incredible versatility, availability, and relatively low cost. Unfortunately, the production of Portland cement - the key ingredient in concrete - generates approximately a pound of carbon dioxide for every pound of cement produced. One method of reducing concrete's carbon footprint is to replace a significant amount of the cement with fly ash, a by-product of coal-burning thermal power stations. …

Multi Geophysical Parameters For Earthquake Forecasting, Ramesh P. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

This article focuses on the importance of keeping the public aware of earthquake forecasting. This article also encourages proper seismic codes to design buildings in the seismic-prone regions because such practice can save lives and property associated with an earthquake.

An Experimental Study On Bond Strength Of Reinforcing Steel In High-Volume Fly-Ash Concrete, Trevor J. Looney, Mahdi Arezoumandi, Jeffery S. Volz, John J. Myers

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The production of Portland cement-the key ingredient in concrete-generates a significant amount of carbon dioxide. However, because of its incredible versatility, availability, and relatively low cost, concrete is the most consumed manmade material on the planet. One method of reducing concrete's contribution to greenhouse gas emissions is the use of fly ash to replace a significant amount of the cement. an experimental investigation was conducted to compare the bond strength of reinforcing steel in high-volume fly-ash concrete (HVFAC)-concrete with at least 50 % of the cement replaced with fly ash-with conventional concrete (CC). This study investigated two HVFAC mixes [with …

Dynamic Vulnerability Assessment Of Highway And Railway Bridges, Mehdi Mohseni

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Dynamic loads can cause severe damage to bridges, and lead to malfunction of transportation networks. A comprehensive understanding of the nature of the dynamic loads and the structural response of bridges can prevent undesired failures while keeping the cost-safety balance. Dissimilar to the static behavior, the dynamic response of bridges depends on several structural parameters such as material properties, damping and mode shapes. Furthermore, dynamic load characteristics can significantly change the structural response. In most cases, complexity and involvement of numerous parameters require the designer to investigate the bridge response via a massive numerical study.

This dissertation targets three main …

Investigation Of Out-Of-Plane Properties Of Interlocking Compressed Earth Block Walls, Nicholas Anthony Herskedal

Master's Theses

Interlocking compressed earth blocks (ICEBs) are cement stabilized soil blocks that allow for dry stacked construction. The incomplete understanding of the inelastic performance of ICEB building systems limits widespread acceptance of this structural system in earthquake prone areas. This thesis presents results from an experimental program designed to explore the behavior of ICEB walls, built according to current design practice in Indonesia and Thailand, and subjected to out-of-plane loading. A total of five reinforced and grouted ICEB walls were constructed and tested.

Results from experimentation show the current masonry design code, ACI 530, adequately predicts the yield strength of these …

Development Of Mems-Based Corrosion Sensor, Feng Pan

Graduate Theses and Dissertations

This research is to develop a MEMS-based corrosion sensor, which is used for monitoring uniform, galvanic corrosion occurring in infrastructures such as buildings, bridges. The corrosion sensor is made up of the composite of micro/nano metal particles with elastomers. The mechanism of corrosion sensor is based on the mass transport of corrosive species through the sensor matrix. When the metal particles in the matrix corrode, the electrical resistivity of the material increases due to increasing particle resistances or reduction of conducting pathways. The corrosion rate can be monitored by detecting the resistivity change in sensing elements. The life span of …

The Effect Of Mortar Strength On The Standard Test For Strand Bond, Cameron Murray

Civil Engineering Undergraduate Honors Theses

The prestressed industry is moving towards adopting the Standard Test for Strand Bond (STSB) to quantify the bond capacity of prestressing strand. In the test, strand is pulled through an 18 in. cylindrical casing filled with mortar. The force corresponding to the dead end displacement of 0.1 in. is recorded and this value is used to quantify strand bond. One of the concerns of the test is the requirement of a mean mortar strength of 4,500 to 5,000 psi during testing. There is concern that this 500 psi range may be too difficult to achieve. A study was conducted to …