Discipline: Technology and Engineering
Subcategory: Civil/Mechanical/Manufacturing Engineering
Session: 2
Room: Exhibit Hall A
Christian Moreira - University of Maryland College Park
Co-Author(s): Janasia Cuney, Prairie View A&M University, Prairie View, Texas
Hydraulic failure occurs when drainage infrastructure such as culverts and bridges no longer meet the recommended performance standards. Examples range from an inability handle increasing flow rates due to urban development to catastrophic structural failures (e.g., bridge collapse or culvert washout). The purpose of this study is to develop a methodology using publicly-available information (PAI) to rapidly assess the failure potential of hydraulic infrastructure in a given region. The ability to utilize PAI could provide stakeholders and communities with planning information which could be used to inform more detailed traditional modeling-based master plan-type evaluations and drainage mitigation/rehabilitation plans. Information was collected from the 1999 and 2018 Flood Insurance Study (FIS) completed by FEMA. The FIS has a flow rates table for various drainage structures across the parish, which includes cross sections for each structure. FIS includes flood profiles of drainage structures in Lafayette, where the headwater and tailwater can be collected. Differential Head can then be calculated with the change in headwater and tailwater. The 10 and 50 year flow rates, headwater, and tailwater were transferred into excel. QGIS was used to analyze and map the data onto Lafayette. Latitudes and longitudes were found for each structure by finding where the coulee and street intersected in QGIS. Once found flow rates and differential head were plotted in QGIS. Structures were then considered passing if they met or exceeded the design criteria set by DOTD. The criteria set by the Department of Transportation (DOTD) is the differential head is less than 0.5 feet. A structure was considered to be overtopping if the road elevation minus the differential head is greater than negative four inches.Our findings show over time the amount of drainage structures meeting the DOTD standards increased from 1999 to 2018. In the 10 year flood there was an increase of 32% and in the 50 year flood there was a 57% increase. However, in the 10 year flood 37% of drainage structures were found to be overtopping and in the 50 year was even larger being 58%. This could imply infrastructure is generally improving over time but may be not be designed for higher flooding events. The FIS can provide a quick way to assess the performance of a county’s drainage infrastructure compared to detailed modeling studies. The FIS provides a way to check if structures are overtopping during a range of design flood scenarios. Future research involves development of ways to incorporate municipal maintenance, repair, or upgrade records to provide a comprehensive assessment of the failure potential of regional drainage infrastructure. References: District 61 Staff. ‘Flood of August 2016.’ LADOTD, 2016. ‘Flood Insurance Study.’ Federal Emergency Management Agency, 1999. ‘Flood Insurance Study.’ Federal Emergency Management Agency, 2018. LADOTD. 2011 Hydraulics Manual. LADOTD, 2011.
Funder Acknowledgement(s): This study was supported, in part, by a grant from NSF awarded to Robert L. Miller, PhD, PE, Assistant Director for Louisiana Watershed Flood Center, University of Louisiana at Lafayette, Lafayette, LA. This material is based upon work supported by the National Science Foundation under Grant :REU Site: Research Experience for Undergraduates in Advanced Infrastructural Materials (award Number: 1757786).
Faculty Advisor: Robert L. Miller, PhD, PE, robert.miller@louisiana.edu
Role: I completed the data collection from the flow rates table and the flood profile from the 2018 Flood Insurance study done by Federal Emergency Management Agency. I also completed a map analysis with the information collected using QGIS. The analysis included looking at how well drainage structures were performing in conjunction with department of transportation standards set. More specifically how close or far the differential head was to passing by the DOTD standard.