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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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,...
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...
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 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 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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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,...
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...
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...
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...
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...
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...
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...