Feasibility of Seismic Retrofit Techniques for Bridges Subjected to Scour
Open Access
- Author:
- Kukoda, Bryan Jeffrey
- Area of Honors:
- Civil Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Dr. Swagata Banerjee Basu, Thesis Supervisor
Eric Todd Donnell, Thesis Honors Advisor - Keywords:
- seismic retrofit techniques
bridge design
earthquakes
flooding
local scour - Abstract:
- The combination of seismic activity and flood-induced scour on bridge piers poses a serious risk for bridge failure in areas of the United States that are both seismically active and prone to flooding. Sacramento County, CA, one such that is highly susceptible to earthquakes and floods, was chosen as the study region. Flood-induced scour erodes the soil around bridge piers; this loss of lateral support significantly decreases the strength of the bridge piers and increases the risk of bridge failure under seismic loading. Thus, in the presence of scour, existing bridge seismic retrofit techniques may not work properly. The purpose of this study is to investigate the effectiveness of three bridge seismic retrofit techniques used by State Departments of Transportation (hereby referred to as DOTs) in the presence of flood-induced scour for two different bridge models. In order to perform the feasibility analysis, a finite element bridge model is created in SAP 2000 and modified to represent the different scour depths at the bridge piers and the different seismic retrofits for the bridge at each scour depth. The seismic activity is modeled through sixty different ground motion time histories that were generated for the study region. The effectiveness of each retrofit technique is determined by measuring the maximum bridge deck deflections due to each ground motion for each bridge model. The comparison of bridge seismic performance in the presence and absence of scour will also demonstrate the amplified vulnerability of the sample bridges in the presence of scour.