GIS Database Development - Levee Geotechnical Evaluation Project
BACKGROUND:
FUGRO, is a prime subconsultant working on a team under a $35 million contract to DWR, to evaluate 350 miles of Northern California levees that protect urban communities. The study employs state-of-the-art methods for collecting data that include airborne, hydrographic, land surveys, and conventional geotechnical exploration. Data are used to support the geotechnical analyses that evaluate the integrity and safety of the levee systems.
FUGRO’S ROLE IN GIS DATABASE DEVELOPEMENT:
A project-wide GIS database is being developed to aide geotechnical evaluations. Fugro is directing the work of three site areas: Reclamation District 17; Reclamation District 404; and Natomas. The database is being built with data gathered from:
• Site reconnaissance
• Review of historic levee performance
• Aerial data collection of FLI-MAP® and Fugro Helicopter Electro-Magnetics (HEM) systems
• Drilling and sampling of exploratory borings and cone penetration tests
• Field tests and observations; installation of open standpipe piezometers
• Laboratory tests performed on retrieved soil samples for data processing and compilation in gINT and GIS
Data describing the subsurface and surficial characteristics of the levees is being collected, integrated, and managed in GIS to support engineering analyses and preliminary design and estimate construction costs for upgrading levees to FEMA certification standards. The GIS group managed and mapped Helicopter Electromagnetic (HEM) data, Magnetometer data, and high density topographic data obtained with Fugro's FLI-MAP® system. Using that data, specialized GIS cross sections were developed to display levee geometry and local geology, as well as, evaluate seepage, rapid drawdown, slope stability, and seismic vulnerability of the levees.
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