Complex oscillations including chaotic motions have been identified in off-shore and submerged mooring systems characterized by nonlinear fluid-structure interactions and restoring forces. In this paper, a means of controlling these nonlinear oscillations is addressed. When applied, the controller is able to drive the system to periodic oscillations of arbitrary periodicity....
An analysis method for moving loads computes the internal demand history in a structural member at integration points of force-based finite elements as opposed to the end forces of a refined displacement-based finite element mesh. The force-based formulation satisfies strong equilibrium of internal section forces with the element end forces...
The behavior of stirrups engaged by diagonal cracks and under service loads is
largely unknown. Full-size laboratory specimens were loaded to induce diagonal
cracks and subjected to high-cycle fatigue loading to represent a service life of 50
years. Tests indicated little change in the average stirrup stress range and mean...
Reverse osmosis (RO) is being increasingly used in treatment of domestic
wastewater secondary effluent for potable and non-potable reuse. Among other
foulants, dissolved biopolymers, i.e., proteins and polysaccharides, can lead to
severe fouling of RO membranes. In this study, the roles of RO membrane surface
properties in membrane fouling by...
The LRFR Manual, within commentary Article C6.4.4.2.3, contains provisions for development of site-specific live load factors. In Oregon, truck Weigh-in-Motion (WIM) data were used to develop live load factors for use on state-owned bridges. The factors were calibrated using the same statistical methods that were used in the original development...
This research focused on the enhanced reductive dechlorination of trichloroethene (TCE) and its surrogate, trichlorofluoroethene (TCFE), using two bioremediation methods in anaerobic conditions. Two anaerobic bioremediation studies were conducted to investigate the effects of microbial communities in the presence of different electron acceptors and donors during anaerobic reductive dechlorination of...
This work furthers the understanding of processes occurring in catchments that affect stream nitrate concentrations using two different approaches: a temporally intensive case study of three headwater catchments with varying land use (through storm event monitoring) and a spatially intensive study on the regional scale (through statistical modeling) of 1st-4th...
The main objective of this research study is to incorporate construction worker safety and health into sustainable design and construction practices. This can be fulfilled by the development of an innovative construction worker safety and health planning tool, called Sustainable Construction Safety and Health (SCSH) Rating System that will:
•...
Hyporheic Exchange Flow (HEF) is driven by head gradients defined by the hydro-topography of the stream surface, which is controlled by the particular geomorphology of the stream. We quantified the impact of large wood, which typically exerts a strong control on stream morphology, on HEF in a second order, low...
Light-frame construction practices and materials have changed greatly
over the past 100 years. Contemporary research has focused on modern construction; thus, we know a great deal about the behavior of modern lightframe buildings under lateral forces. However, there are many light-frame buildings that were built prior to the introduction of...
