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dc.contributor.advisorBriaud, Jean-Louisen_US
dc.creatorV Govindasamy, Ananden_US
dc.date.accessioned2010-07-15T00:11:51Zen_US
dc.date.accessioned2010-07-23T21:43:26Z
dc.date.available2010-07-15T00:11:51Zen_US
dc.date.available2010-07-23T21:43:26Z
dc.date.created2009-05en_US
dc.date.issued2010-07-14en_US
dc.date.submittedMay 2009en_US
dc.identifier.urihttp://hdl.handle.net/1969.1/ETD-TAMU-2009-05-422en_US
dc.description.abstractBridge scour is the term which describes the erosion of soil surrounding a bridge foundation due to water. Bridge scour can cause the reduction of the load carrying capacity of bridge foundations, excessive foundation settlements, and damage to bridge abutments. Bridges with foundations that are unstable for calculated and/or observed scour conditions are termed scour critical bridges. Approximately 25,000 bridges in the United States are classified as scour critical and about 600 of them are in Texas. This designation comes in part from the use of over-conservative methods that predict excessive scour depths in erosion resistant materials. Other methods have been developed to eliminate this over-conservatism but are uneconomical because they require site-specific erosion testing. The major contribution of this dissertation is a new method to assess a bridge for scour and erosion classification charts which categorizes the erodibility of geomaterials according to conventional engineering properties. The new method is a three level Bridge Scour Assessment (BSA) procedure which is relatively simple and economical. It does not require site-specific erosion testing and eliminates the over-conservatism in current methods. The first level, BSA 1, uses charts that extrapolate the maximum scour depth recorded during the life of the bridge to obtain the scour depth corresponding to a specified future flood event. The second level, BSA 2, determines the maximum scour depth and is carried out if BSA 1 does not conclude with a specific plan of action for the bridge. The third level, BSA 3, determines the time dependent scour depth and is carried out if BSA 2 does not conclude with a specific plan of action. The scour vulnerability depends on the comparison between the predicted and allowable scour depths. The 11 case histories used to validate the new method showed good agreement between predicted values and field measurements. BSA 1 was then applied to 16 bridges. In this process, 6 out of 10 bridges classified as scour critical by current methods were found to be stable. These results show that the new method allows for more realistic evaluation of bridges for scour while not requiring site-specific erosion testing.en_US
dc.format.mimetypeapplication/pdfen_US
dc.language.isoengen_US
dc.subjectBridge scouren_US
dc.subjectsoil erosionen_US
dc.subjecterodibilityen_US
dc.subjectscour critical bridgesen_US
dc.subjectbridge scour assessmenten_US
dc.titleSimplified Method for Estimating Future Scour Depth at Existing Bridgesen_US
dc.typeBooken
dc.typeThesisen
thesis.degree.departmentCivil Engineeringen_US
thesis.degree.disciplineCivil Engineeringen_US
thesis.degree.grantorTexas A&M Universityen_US
thesis.degree.nameDoctor of Philosophyen_US
thesis.degree.levelDoctoralen_US
dc.contributor.committeeMemberChen, Hamn-Chingen_US
dc.contributor.committeeMemberOlivera, Franciscoen_US
dc.contributor.committeeMemberMathewson, Christopheren_US
dc.type.genreElectronic Dissertationen_US
dc.type.materialtexten_US


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