The behavior of mass timber beam-to-column connections under seismic loading is not yet well understood. Mass timber beam-to-column connections must have the ability to maintain load-carrying capacity despite the deformations that will be imposed on all components of the building during seismic events. This behavior is called deformation compatibility. The...
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...
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,...
Cross-laminated timber (CLT) panels have been gaining popularity as diaphragm elements in mid- to high-rise construction projects. In addition, CLT-concrete composite (CCC) diaphragms have been implemented to expand the use of CLT diaphragms. To understand the behavior of CLT and CCC diaphragms, this research effort sought to characterize the cyclic,...
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...
In this thesis, the effectiveness of the 100 percent + XX percent seismic response directional combination rule available in codes and standards is evaluated using simulated nonlinear seismic response of two existing multi-story reinforced concrete plan-irregular buildings. The 5-story and 8-story buildings were designed according to the 1975 seismic codes...
Tsunamis have the potential to inflict severe damage and loss of life in coastal communities. Structures known as vertical evacuation buildings provide an alternative evacuation site for communities living in relatively flat, coastal regions with inadequate sources of high ground for evacuation. Design of these structures balances risk and economy,...
Engineered wood composites are used in many structural applications and are intended for dry use. However, these materials may encounter significant amounts of wetting while in service, which can lead to structural failures. This study combined aspects of wood science, mechanics, structural engineering, and mycology to assess changes in material...
The dissertation uses state-of-the-art structural engineering theories, in parallel with the modern and still-developing control theory of electrical engineering to mitigate the vibratory responses of a double-stayed bridge subjected to strong earthquake ground motions.
First, a nonlinear finite element model of the double-stayed bridge subjected to non-uniform (multi-support) earthquake excitations...
The nonlinear response of an ocean system subjected to random excitations can exhibit very complex dynamic behaviors including jump phenomena and coexistence of attractors. In this study, the stochastic system response behavior of a simple (Duffing) oscillator under narrow-band random excitations is first examined in the subharmonic resonance region. A...
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...
In a homogenous and isotropic material, the location of the neutral axis coincides with the location of the centroid of the beam. Wood is anisotropic, meaning that it has different properties in different directions. It is also non-homogenous, meaning that the beam exhibits different properties at different locations throughout its...
Infrastructures along the Oregon Coast are vulnerable to seismic events in the Cascadia Subduction Zone that could generate large tsunamis. Bridges along the coast are an important part of the transportation and lifeline system in the area. The major damages on these bridges due to earthquake and/or tsunami would result...
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...
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...
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...
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...
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...
Capacity of transverse 1950's vintage reinforced concrete deck girder bridge bent caps with large straight bar anchorages were investigated and evaluated. Eleven subassemblage column specimens were examined with different anchorage lengths, bar groupings, amount of transverse steel, and externally applied axial force. Test results showed an increase in anchorage capacity...
