Bridge Scour Evaluations, NH, MA and ME, NH, MA, ME

Services:

HYDROLOGIC AND HYDRAULIC EVALUATIONS
SCOUR COUNTERMEASURES
QUALITATIVE SUMMARY REPORTS
HYDRAULIC ANALYSIS
PLAN OF ACTION (POA) REPORTS
HYDRAULIC MODELING
 

NH, MA, ME

Nobis was on the design team for contracts to conduct hydrologic and hydraulic evaluations of 37 MaineDOT bridges, 35 NHDOT bridges, and 64 MassDOT bridges. The work involved managing field evaluations of the 136 bridges, preparing Qualitative Summary Reports, performing hydraulic analyses, and preparing Plan of Action (POA) reports for each bridge.

Hydrologic information for the contributing areas was collected from available sources including flood studies, existing USACE HEC-RAS models, existing U.S. Department of Transportation (USDOT) Federal Highway Administration (FHA) WSPRO models, soils maps, and Flood Insurance Rate Maps.  This information was used to determine representative flows for the 10-, 50- and 100-year storms, which were incorporated into a hydraulic analysis of each bridge to model the probable effects the river flood-flows would have on the existing bridge structures.

The hydraulics were modeled using USACE HEC-RAS computer software program, regression analysis and/or continuity equations for selected bridges.  These models allowed Nobis to estimate water surface elevations, flood velocities, and scour depths at bridge piers and abutments.
 

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