Traditional braced frames are an efficient and economic means of resisting seismic demands. However, braced frames are prone to story mechanisms, which can result in concentrations of demands and damage during seismic events. Including steel strongbacks in conjunction with traditional braced frames can mitigate story mechanisms. The SBF results in...
This work analyzes the numerical curvature of buckling braces. An existing brace modeling learning tool, which in its current state allows users to change the inputs within a simulated model of a braced element, was modified to display the curvature diagram. The curvature diagram was verified through comparison to existing...
Transportation infrastructure provides a vital service for the functionality of a
city. The efficient design of road networks poses an interesting topic in computer
science for digital content developers. For civil engineers, the visualization of
analysis results on infrastructure both efficiently and intuitively is crucial. The
following contributions are made...
The characterization of the seismic performance of structures relies on numerical simulations. However, estimates of seismic response are subject to various sources of uncertainty, including modeling uncertainty. This research estimated the response of two full-scale structural specimens composed of a moment resisting frame, elastic spines, and force-limiting connections (FLC), which...
While real-time hybrid simulation has been utilized for structures subjected to seismic events for decades, its use in fluid-structure interaction problems is still a novel endeavor. Gathering data for cascading seismic and tsunami events is difficult due to space constraints in existing experimental facilities, complications regarding the application of scaling...
Cross-laminated timber (CLT) is an attractive building material because it is renewable, promotes fast installation, and possesses a high strength-to-weight ratio. The use of CLT in seismic applications has become increasingly common with the development of post-tensioned CLT rocking wall lateral force resisting systems (LFRS). The CLT pier-and-spandrel system designed,...
Unlike other industries, overall efficiency of construction projects has been growing minimally which directly causes cost overruns of projects. Though reducing idle time and increasing operational efficiency of construction equipment could result in significant cost saving, there is lack of practical knowledge of adjusting operational efficiency and integrating cost and...
Steel Slit Panel Frames (SSPFs) are an innovative and resilient lateral force resisting system. Steel Slit Panels (SSPs) are bolted to the beams and act as replaceable seismic fuses, dissipating energy through flexural yielding in links between vertical rows of slits. SSPFs have shown promise as a lateral force resisting...
The Steel Plate Shear Wall (SPSW) system, is an innovative seismic lateral force resistant system, which has experienced increased use over the last three decades. The SPSW system is composed of boundary elements which anchor web plates that develop diagonal tension fields. A number of SPSW buildings have been built...
This study computationally and experimentally examines the mechanisms of crack penetration, deflection and the transition between penetration and deflection. The finite element analysis based computational modeling work used strength-and-energy based cohesive-zone approach to study the effect of dimensionless parameters (e.g., interfacial incident angle, fracture-length scale, and normalized toughness) on penetration/deflection...
The Pacific Northwest is at risk for significant seismic and tsunami events, which are capable of severely damaging lifeline transportation infrastructure, particularly bridges. As the bridges in the United States age and begin to show signs of fatigue, the risk for severe damage increases. Proper monitoring and inspection of bridges...
The fluid impact forces on a bridge superstructure in horizontal and vertical directions due to tsunamis represented by solitary waves are investigated through a large-scale laboratory experiment and numerical simulations. The experiment is conducted in a two-dimensional wave basin using a 1:5 scaled reinforced concrete bridge deck model tested under...
During the 2011 Great East Japan Earthquake and Tsunami, numerous bridge structures were damage or destroyed. The damage to bridge systems was caused by long duration strong ground shaking, tsunami inundation forces, or both. Long duration strong ground shaking from subduction zone earthquakes and the multi-hazard scenario of combined earthquake...
In this work we consider a model for pattern-producing vegetation in semi-arid regions of the world proposed by Klausmeier. It is a coupled nonlinear diffusion-advection evolutionary PDE system describing the vegetation density and water amount. The model was studied extensively by J.Sherratt who took into consideration the field data for...
The steel diagrid structural system is a recent load bearing and lateral resisting structural system for tall building structures that is relatively unexplored in the western United States. One possible reason for the little use of diagrid systems in earthquake prone regions is the lack of guidelines and application examples...
Current bridge design codes do not account for the effects of duration of mega-thrust subduction zone earthquakes. Furthermore, codes and even recent performance-based design methodologies only make use of the peak response quantities (forces, displacements, and ductility demands) and do not account for the increased number of inelastic cycles that...
Open grid steel bridge decks have been in use for nearly a century. These open grid decks provide an economical and lightweight alternative to traditional reinforced concrete decks. As the transportation infrastructure continues to deteriorate, open grid decks can be used as a cost effective way to rehabilitate structurally deficient...
During the past several decades, earthquakes have caused extensive damage to
buildings, including wood-frame, single-family dwellings, in the United States. In
order to mitigate future losses, existing buildings in earthquake prone areas should be
evaluated for their seismic safety. This is also an important issue for buildings in
Oregon due...
The collapse of the I-35W Bridge in Minneapolis, MN on August 1, 2007 brought into question the design and inspection of gusset plates in steel truss bridges. The experimental tests performed in this research study the sway-buckling strength and behavior of large-scale steel gusset plates in an isolated truss connection....
In the past ten years, renewed research interest has shown the benefits of internal curing by incorporating saturated lightweight fine aggregate (LWFA) in high performance concrete (HPC). As a result, the technology of internal curing has steadily progressed from laboratory studies to field applications. To determine the optimum LWFA content,...
Large numbers of vintage reinforced concrete deck-girder bridges remain in the national bridge inventory. Many of these exhibit diagonal cracking and other distress. Due to the design practices of the time, it is common to observe cracks at locations where flexural reinforcing steel is terminated along the span. The presence...
Large numbers of reinforced concrete deck girder bridges that were constructed during the
interstate system expansion of the 1950s have developed diagonal cracking in the stems.
Compared to the present AASHTO-LRFD standards, the provisions of the 1950s allowed
for higher shear stress in the concrete, thus reducing the amount of...
In wireless sensor network applications, low-power operation of the wireless receiver is critical. To address this need an ultra-low power Binary Frequency Shift Keying (BFSK) receiver using the super-regenerative architecture is developed.
A prototype receiver is built and tested for operation in the 900 MHz ISM band. Lab measurements show...
Automatic painterly rendering systems have been proposed but they opted for selecting a single style to generate paintings from images, which lacks the ability of creatively using multiple styles to focus important objects and deemphasize unimportant part of the scenes. We provide a multi-style painting framework to
address this issue...
A basic tradeoff to consider when designing a distributed data-mining framework is the need for a compromise between the cost of communication and computation resources and the accuracy of the mining results. This is essentially a decision of whether it is more efficient to communicate all of the data to...
Popular applications such as P2P file sharing, multiplayer gaming, videoconferencing, etc. rely on the efficiency of content distribution from a single source to multiple receivers. Most users of these applications are on the widely prevalent source constraint networks such as the Digital Subscriber Line (DSL) and wireless networks. Overlay multicast...
Since the collapse of World Trade Center building number seven (WTC7), significant research has been done to understand the behavior of steel structures in fire and enable engineers to account for the behavior of steel framing systems exposed to fire during design. Despite these efforts, there are still significant barriers...
Pile caps are structural elements used to transfer loads from columns to a group of piles, which transfer them to stronger soil layers. Pile cap with horizontal distance between the column and piles less than twice its effective depth is categorized as "deep," where significant nonlinear strain distribution occurs through...
N-ary relationships, which relate N entities where N is not necessarily two, are omnipresent in real life. In this thesis, we develop a visualization technique for N-ary relationships.
First, we propose a visual metaphor that utilizes vertices and polygons to represent entities and N-ary relationships. Based on this visual metaphor,...
This dissertation studies the development of the design procedures for Steel Slit Panel Frame (SSPF). The (SSPF) system is a seismic force-resisting system (SFRS) with ductile behavior and good energy dissipation up to 5\% to 7\% lateral drift that acting as seismic fuses. The current design guidelines provided valuable information...
Coastal multi-hazards, i.e., earthquakes followed by tsunamis, induce severe damage to coastal infrastructure. The multi-hazards can cause soil liquefaction, which is one of the major concerns for evaluating sediments transport potential and structure failure mechanisms. The objectives for this work is threefold. First, to build and validate a soil numerical...
The constitutive behavior of high-performance fiber-reinforced cementitious composites (HPFRCCs) under mechanical loading is characterized by significant tensile properties that play an essential role in the structural response of several applications in structural engineering. The significance of tensile properties of HPFRCCs in structural engineering is the focus of three manuscripts presented...
Steel moment-resisting frames (MRFs) are widely used in the United States to resist seismic forces. MRFs have many advantages, including architectural versatility, vetted member and connection detailing requirements, and high ductility for special MRFs (SMRF). However, MRFs require large members to meet story drift criteria. Moreover, strong-column-weak-beam requirements can result...
The impact of tsunamis on coastal structures gained great a new impetus following the 2004 Indian Ocean Tsunami and the 2011 Tohoku earthquake and tsunami. While several experimental programs have been performed to gain a fundamental understanding, numerical models are needed to study additional features that cannot all be tested...
Connections in mass timber structural systems dissipate energy and transfer lateral forces from mass timber elements such as shear walls and diaphragms, providing critical load paths. Cross-laminated timber (CLT) is a prominent mass timber material used to manufacture wall and floor assemblies. Fire performance research of CLT walls and floors...
For mid-rise and high rise buildings, slender reinforced concrete (RC) structural walls are commonly used as the main structural elements to resist lateral applied loads in high seismically areas around the globe. These RC structural walls can provide substantial deformation capacity, stiffness, and lateral strength through the contribution of their...
The role of ground motion duration on the seismic performance of civil engineering structures remains unclear. Thus, the role of earthquake strong ground motion duration is assessed in a three manuscript thesis, which includes: (1) assessment of the effects of ground motion duration on the seismic performance of a model...
Damage estimates to the built environment from tsunamis are important for disaster mitigation, including planning emergency response and recovery. This dissertation evaluates the damage states of buildings in a small urban coastal city, Seaside, Oregon, from tsunami hazards generated by a Cascadia Subduction Zone (CSZ) event. This study is separated...
Fluid-structure interaction (FSI) is a very interesting and challenging multi-disciplinary field involving interaction of a movable or deformable structure with an internal or surrounding fluid flow. FSI has several practical engineering applications such as the determination of the hydrodynamic forces on a structure or the dynamics of motion of bodies...
The collapse of the I-35W Bridge in Minneapolis, MN in 2007 prompted an investigation into the design and inspection of the steel truss bridges. Further investigation into the collapse revealed that a gusset plate experienced sway buckling, causing the bridge failure. This bridge failure motivated research into the analysis and...
In this study, a coupled potential flow-viscous flow model is used for numerical wave tank simulation. The solver satisfies all the requirements for such a simulation environment. The coupling scheme is based on a non-overlapping heterogeneous domain decomposition method. In this method, the flow domain consists of two subdomains. In...
There are about 80 million single-family dwellings (SFD) in the United States, predominantly of wood-frame construction. Of these, 68% are owner occupied. A home is typically the largest single investment of a family, and is often not covered by earthquake insurance, even where it is available. Of all SFD in...
Protein-protein interactions underlie all biological processes and are a field of study that has wide implications throughout many other fields including medicine, genetics, biology, and ecology. Proteins are the building blocks and primary actors of life. They work together to accomplish virtually every task within a cell, including, metabolism, signal...
The response of adjacent structural systems to earthquake motions is investigated using the finite element framework OpenSees. Results of sensitivity analyses demonstrate that structural response quantities can increase in either or both of the adjacent structures for specific configurations. The structural models used include steel moment-resisting frames and rigid shear...
The Astoria-Megler Bridge is a 6.6 kilometer (4.1 mile) long bridge, connecting Oregon and Washington on US 101, with a continuous steel truss main span of 376 m (1232 ft). It is the second longest main span bridge of this type in the world. Due to vortex shedding, some of...
A numerical model for the simulation of fully-coupled fluid-structure
interaction is developed in this study. In modeling the fluid, the Reynolds
Averaged Navier-Stokes equations are solved for an incompressible viscous
fluid field and a k-ε model is employed for turbulence computations.
Hydrodynamic forces obtained by the integration of the fluid...
Corrosion of reinforcement is recognized as the predominant factor that limits the service life of reinforced concrete (RC) structures exposed to aggressive environments. This corrosion deterioration can lead to damage resulting in capacity loss or even failure. For structures exposed to coastal marine environments or deicing or anti-icing applications, this...
During the interstate expansion of the 1950s, many conventionally reinforced concrete
deck girder bridges were built throughout the country. These now vintage bridges
commonly exhibit diagonal cracking and rate inadequately for shear, thus they are
candidates for shear strengthening to extend their useful life. Near-surface mounted
(NSM) retrofitting is a...
Fluid-structure interaction (FSI) is an interesting and challenging interdisciplinary area comprised of fields such as engineering- fluids/structures/solids, computational science, and mathematics. FSI has several practical engineering applications such as the design of coastal infrastructure (such as bridges, levees) subjected to harsh environments from natural forces such as tsunamis, storm surges,...
Due to age, original design that is deficient by modern standards, inadequate maintenance, environmental conditions, and increasing loads, large numbers of bridges in United States and elsewhere are classified as deficient and in need of rehabilitation or replacement. According to a national bridge inventory established by the Federal Highway Administration,...
Ponding of water on roof systems leading to collapse causes expensive damage and jeopardizes the life safety of building occupants. Current building codes and design specifications for flat roof systems offer minimal guidance in designing for ponding loads. The present research investigated ponding load effects on a long span, lightweight...
Many conventionally reinforced concrete deck girder bridges (RCDG) and their intermediate supporting bent caps were designed during the Eisenhower interstate era of the 1950’s with the AASHO design equations at the time, which subsequently place higher demand on the concrete. The referenced components may exhibit diagonal cracking due to the...
An experiment on solitary wave impact on a vertical cylinder was conducted in the three-dimensional wave basin at the Oregon State University Hinsdale Wave Research Laboratory. The cylinder was designed using mechanic principles and finite element analysis techniques to enable accurate measurement of horizontal force and overturning moment. Video data...
A methodology was developed to permit rectification and metrification of digital images of steel truss gusset plate connections. The approach will enable rapid and accurate collection of field measurements as compared to traditional methods to enable structural evaluation of gusset plate connections. The program enables the operator to quickly create...
Long-term durability of surface-bonded carbon fiber-reinforced polymer (CFRP) U-wraps for shear strengthening of reinforced concrete (RC) bridge members remains uncertain due to the limited field experience with these materials. This paper provides experimental results from the testing of full-scale RC bridge girder specimens after exposure to prolonged freeze-thaw cycling. CFRP...
Identification and population counts of soil mesofauna can be an
important tool for soil ecologists to determine the soil biodiversity. Information
provided from population counts can give insight to soil ecologists about the
effects of human land use, monitoring soil and water health, benefits of soil
biodiversity in agriculture, and...
Current ACI design provisions for shear in reinforced concrete (RC) beams strengthened
with externally bonded carbon fiber-reinforced polymer (CFRP) U-wraps may not adequately account for the effect of scale. This paper describes tests of 6 geometrically scaled beams to identify possible scale effects of such beams. Results indicated that effective...
Article 1: Behavior of Epoxy Injected Diagonally Cracked Full-Scale CRC Deck-Girders.
Many cast-in place reinforced concrete deck-girder bridges (RCDG) remain in the national inventory and exhibit diagonal cracking. Epoxy injection has been in use for several decades as a method for sealing diagonal cracks, but the effects on girder behavior...
This dissertation presents a dual-path 2-0 MASH (Multi-stAge-noise -SHaping) ADC with two verified digital corrections of DAC mismatch error and quantization noise leakage. By using these two techniques, the requirements for the analog circuits are greatly relaxed. The dual-path structure generates two outputs, one only composed of conversion errors, the...
A need exists to develop a non-destructive testing technique that can identify
the formation and propagation of diagonal tension cracks in conventionally
steel reinforced concrete deck girder (RCDG) highway bridges in the State of
Oregon. Such a technique could be included into a structural health
monitoring (SHM) system installed on...
This dissertation examines tsunami and hurricane wave loads on bridge superstructures. Tsunamis have caused significant damage to coastal communities in recent years. For example, the 2011 Great East Japan Earthquake and resulting Tohoku Tsunami destroyed infrastructure along the east coast of Japan including bridge superstructures. Recent hurricanes have also caused...
Fluid-structure interaction (FSI) has been of significant research interest worldwide over the past several decades because of its variety of applications in both offshore and coastal engineering. Researchers analyzing FSI systems rely heavily on experimental tests in model scale in laboratories or large-scale sea trials. However, these tests are often...
Catastrophic earthquake and tsunami events that resulted in significant loss of life and property over the past two decades have raised the global awareness regarding the need to understand the response of communities and their built environment to multi-hazard extreme events. In recognition to this impending threat to the coastal...
Discrete columns, such as stone and soil-cement columns, are often used to improve the liquefaction resistance of loose sandy ground. In particular, stone columns are considered to increase resistance potential by densification, drainage, and reinforcement mechanisms. For silty soil, the shear stress reduction resulting from the reinforcing effect of stiffer...
We show that Pappus Curves, introduced by R. Schwartz to study his dynamical system in the real projective plane generated by iterated applications of the classical Pappus Theorem, are algebraic exactly in the linear case. Our approach is to use properties of projective curves such as singular points, genus, number...
This dissertation presents the results of a research effort conducted to better understand the stress-strain, volume change, shear band formation, and strength characteristics of normally consolidated anisotropic clay under fully three-dimensional stress states. A series of consolidated drained true triaxial tests with a constant mean effective stress and constant Lode...
While there are many ways to evaluate a user interface design, the user's mental workload and situation awareness (SA) are particularly important considerations in the supervisory control of safety-critical systems. Typically, operators of these systems must monitor high-volume, time-sensitive status information. Interface design for this domain can be challenging and...
Non-destructive testing methods and applications have become of increasing interest due to the worldwide aging and deteriorating infrastructure network. In the field of Civil Engineering, bridges and bridge components as well as non-structural elements such as roadway pavements for example, are affected. In particular, the Acoustic Emission (AE) technique offers...
Ever since composite laminate technology was introduced into the aerospace and automotive industry, there has been a need to fully understand the damage progression experienced by composite laminated plates in the presence of a notch. While numerous research studies have been conducted on this matter when subjected to in-plane loads,...
Many conventionally reinforced concrete deck girder (RCDG) bridges were built in the US during the 1950s, throughout the expansion of the Interstate System. Designs followed the AASHO standard of the time, which permitted higher shear stress in concrete and reduced detailing requirements than permitted by current specifications. Many of these...
In recent years confinement requirements for concrete columns have increased in seismic regions. Steel jackets are one way to confine reinforced concrete columns. The increased confinement provides additional strength and ductility for the columns during seismic events. For reinforced concrete columns with steel jackets, there are different section properties in...
Multiple-input multiple-output (MIMO) antenna technology is promising
for high-speed wireless communications without increasing the transmission band-
width. Space time coding (STC) is a scheme that employs multiple antennas to
increase transmission rate or to improve transmission quality. STC is used widely
in mobile cellular networks, wireless local area networks (WLAN)...
Heavy timber framing relies primarily on bracing to withstand lateral loads due to earthquakes and wind events. Bracing configurations in heavy timber framed buildings vary widely and include cross bracing, knee bracing, and other geometries. Many heavy timber frames constructed during colonial American times are still standing, exceeding the expected...
Speckled dace (Rhinichthys osculus) is a small cyprinid that is geographically widespread throughout western North America, and the most frequently occurring sh in Oregon. Because of the genetic and morphological variation in this species across its range, it has been referred to as a "species complex" and no revision to...
Evacuation strategies have been established for most user groups in tsunami inundation zones; however, surprisingly little information is available for a growing visitor group - surfers. For near-shore tsunami events, Oregon surfers, who recreate in the nearshore region, must make life or death choices when deciding what to do in...
Most benthic marine organisms have a bipartite life with an early pelagic stage that enables dispersal of offspring, connecting spatially separated populations, and a late stage where individuals reside in a benthic habitat. Settlement of pelagic offspring to bottom associated substrates is the process that connects the two life history...
At a time of rapid global change, a socio-ecological system (SES) approach can provide a framework through which to quantify and communicate the risks and uncertainties of coupled human-natural systems. Islands, and tropical coral reef islands in particular, can be excellent models for SES research since they may be considered...
Community colleges are experiencing a decline in state allocated funding. Traditionally, college administrators look for ways to cut expenditures and raise tuition and fees to make up for the shortfall. Using available land resources to generate a revenue stream may provide revenue for community colleges.
The purpose of this study...