Earthquakes a . tsunamis pose significant threats to port and harbor
communities in the Pacific Northwest. Developing effective mitigation and
preparedness plans requires a comprehensive understanding of community
vulnerability. Research presented here focuses on the vulnerability of ports and
harbors to earthquake and tsunami hazards and includes a regional study...
The seismic performance of port structures has been well documented following
recent earthquakes, and indicates that port structures are highly susceptible to earthquake-induced
damages. These damages are primarily due to soil liquefaction and the associated
ground failures. Sheet pile bulkheads provide vital intermodal and lifeline transportation
links between water-side and...
This dissertation presents the results of a research effort conducted to better understand the seismic performance and analysis of pile-supported wharves. Given the limited number of well-documented field case histories, the seismic performance of pile-supported wharves has been poorly quantified, and the analysis methods commonly employed in engineering practice have...
The pesticide carbaryl is applied annually to tidelands in Willapa Bay and Grays
Harbor, WA to control populations of burrowing shrimp which modify sediments making
the habitat unsuitable for oyster culture. Fish trapped on sprayed mudflats are often killed,
but little is known about effects on fish present in subtidal...
Earthquake engineering analyses are often performed using shallow, crustal earthquake motions (e.g., 1940 El Centro). However, large areas of the world are subject to subduction zone earthquake motions (e.g., the Pacific Northwest). A subduction zone earthquake motion is characterized by its long duration (e.g., strong shaking lasts for more than...
Base isolation is an alternative seismic design strategy in which the primary structures
and their internal components are uncoupled from the potentially damaging horizontal
components of an earthquake by base isolators which attenuate the transmission of
horizontal acceleration into the system. Rotating machines are among the key internal
components of...
Large numbers of reinforced concrete (RC) bridges were built in the past that are now considered seismically deficient. The structural members most likely to be considered deficient are the supporting columns. Typical deficient columns contain inadequate transverse reinforcement and poorly detailed lap splice lengths above the foundation. Insufficient lap splice...
The research presented in this thesis assessed the use of high strength steel (HSS) reinforcement for use in reinforced concrete (RC) bridge columns. HSS is not currently allowed in reinforced concrete bridge columns due to a lack of information on the material characteristics and performance information when used in RC...
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...
The Cascadia Subduction Zone has recently been identified as a source for an impending great earthquake. The potential of a large earthquake has created widespread interest into the resiliency of lifelines within the potentially affected areas. One critical lifeline is the electrical distribution and transmission systems which relies on legacy...
Recently, the concept of performance based design has become popular for many types of structures, including port facilities under seismic loading. For the case of pile-supported wharves, the level of performance is generally estimated using the displacement capacity of the structure. Therefore, understanding soil-pile interaction is one of the most...
The response of lightweight equipment in structures supported on
resilient-friction-base isolators (R-FBI) subjected to harmonic ground motion and various
earthquake ground motions is examined. The equipment-structure base system is modeled
as a three degree-of-freedom discrete system (SDOF subsystems). An efficient
semi-analytical numerical solution procedure for the determination of equipment response...
Performance-based design has gained interest in recent years among structural designers and researchers. Performance-based design includes selection of appropriate building sites, structural systems and configurations, as well as analytical procedures used in the design process, to confirm that the structure has adequate strength, stiffness and energy dissipation capacity to respond...
The overall goal of this project was to design a wood frame shear wall that could withstand greater displacement before damage occurred to the Gypsum Wall Board (GWB). More specifically, the objectives of the study were: (1) to evaluate damage to the GWB in alternative shear wall designs at 1%,...
This PhD dissertation describes and evaluates a geographical analysis of candidate areas for siting nuclear plants utilizing a wet cooling tower in the Columbia River Basin (CRB). It focuses on the analysis of water availability for cooling and how it may be limited by climate change effects on river streamflow....
The Horsetail Creek (HC) bridge is an example of an Oregon bridge that was classified as structurally deficient and was not designed to withstand earthquake (EQ) excitations. A fiber-reinforced polymer (FRP) rehabilitation was performed on the HC bridge to increase flexural and shear capacities for traffic loads. However, a seismic...
Engineering analysis of heavy timber structures under dynamic loads
is generally lacking. Some literature suggests that heavy timber structures
are stiffer than expected, but popular engineering opinion is to the contrary.
In addition, prior research has shown that passive friction dampers can be
used in timber structures for the intended...
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 overarching objective of this study is to examine and compare the vulnerabilities of bridges combining effects of earthquake-induced ground shaking, ground failure (e.g., landslides and lateral spreading), and tsunami inundation. A parametric study is performed to understand the sensitivity of economic loss and traffic capacity with respect to the...
There are many links between exposure to environmental pollution and risks to human health. While advances in the fields of toxicology, exposure science, and environmental chemistry have shown light on many of these links, many more research challenges remain. One major challenge is how to accurately characterize the toxicity of...