There are many existing bridges around the world that were designed without consideration for seismic effects. Many of these bridges were designed before modern earthquake engineering design standards and practices existed and thus are expected to perform poorly during strong ground shaking. Common structural deficiencies are found in their reinforced...
Carbon fiber reinforced polymer (CFRP) materials are emerging as an effective means of strengthening and rehabilitating bridges. Near surface mounting (NSM) is a newer technique for application of CFRP for retrofitting of bridge members that provides advantages over conventional strengthening techniques. The technique is still new and uncertainties remain regarding...
Recent research in the UK has found that the wheat cultivar grown in the first year can have a significant impact on the amount of take-all that develops in the second year, regardless of the cultivar planted in year two. ‘Einstein’ is one such cultivar that reduces take-all disease (reduced...
Silviculture systems that involve commercial thinning may provide higher quality wildlife habitat than traditional clearcut systems, yet such systems have not been vigorously tested. This prospective study examined forest floor animal abundance and habitat relationships under three different silviculture conditions: clearcuts, commercial thins, and uncuts. Eighteen stands, six per treatment,...
In the interest of meeting multiple forest management goals that include maintenance of wildlife, particularly cavity-nesting birds, uneven-aged silvicultural treatments are used increasingly in the Pacific Northwest. However, questions remain regarding the responses of cavity-nesting birds and residual green trees to different harvest intensities and patterns. To study these issues,...
Downed wood and antelope bitterbrush (Purshia tridentata) are often managed on federal ponderosa pine (Pinus ponderosa) forests in central Oregon to prevent catastrophic wildfires and provide wildlife habitat. However, although much is known regarding the roles of downed wood and bitterbrush in wildfire behavior, little is known regarding the relationships...
Scour is the main cause of bridge failures in the United States. Bridge failures raise a hazard to the safety of the traveling public as well as the massive economic consequences due to the high cost of constructing a new or a replacement bridge. The Oregon Department of Transportation (ODOT)...
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...
As ecoroofs have become more widespread throughout the U.S., it has become increasingly important to understand their structural behavior. The purpose of this research was to investigate the load effects exerted on a roof structure with an ecoroof during rain events and the subsequent drainage period, with the intention of...
Pin and hanger assemblies are a common type of connection used in past engineering practice for steel girder bridges. The connection consists of pins, hanger plates, and girder ends. The connection detail was used widely between 1930 and 1980. The connections are considered fracture critical and nonredundant because connection failure...
