Intern PPT Presentation

SADOGA ROAD BRIDGE OVER BURRINGTON BROOK

Heath, MA (Bridge# H-14-009)SADOGA ROAD BRIDGE OVER BURRINGTON BROOK

Sadoga Road Bridge Over Burrington BrookHeath, MA (Bridge# H-14-009)

BackgroundThe bridge currently in place over Burrington Brook was built in 1940 and is now in disrepair.

Project Scope of Work1) Replacement of the superstructure

Project Scope of Work2) Repair of eroded foundations

My Job 1) Gather DATAStream Length Source: Massachusetts Stream Stats Main Channel Slope Source: HEC-RASDrainage Area Source: Massachusetts Stream Stats Mean Annual PrecipitationSource: Massachusetts Stream Stats

Heath, MA

Drainage Area = 1.03 Sq. milesStream Length = 1.29 MilesAnn. Precipitation = 51.56 inches

Main Channel SlopeDetermine Channel SlopeChannel ElevationDistance TraveledMain-Channel Slope(feet)(miles)(feet / mile)11414.1110.12721548.6321.083134.5210.956140.786

My Job 2) Estimate Peak Flow Magnitudes

My Job 2) Estimate Peak Flow Magnitudes

My Job 3) Determine Cross-Sectional Areas Primary PurposeWater flow (Q) depends on Water Velocity (v) and Channel Cross-Sectional Area (A)Cross-Sectional Area changes a great deal in a riverDepending upon the rivers area (at any one point), we can determine the water surface elevationThis is important for determining the appropriate height for the bridgeSoftware: Watershed Modeling System (WMS)

My Job 3) Determine Cross-Sectional Areas

My Job 3) Determine Cross-Sectional Areas

My Job 4) Determine Channel Profile

Software: HEC-RAS

My Job 5) Determine Scour DepthWhat is Scour?Definition: Erosion caused by swiftly moving water on the abutments of a bridge, which could eventually threaten the bridges structural integrity 3 Types of Scour: Contraction, Pier and AbutmentFor this particular bridge, the bridge was short enough to not require piers in its design. Further, the bridge opening is appropriately sized for the brook and there is therefore no contraction scour (the water does not have to squeeze inside a small opening to pass under the bridge).

My Job 6) Determine Scour DepthAccording to the LRFD Bridge Manual (Given that Sadoga Road is Local and Rural): i)Scour Design Flood Frequency = 25 Years ii)Scour Check Flood Return Frequency = 50 Years

My Job 5) Determine Scour Depth

My Job 6) Make RecommendationsRecommendation #1: Hydraulic Design Flood Return Frequency = 10 Years

My Job 6) Make RecommendationsRecommendation #2: Peak Water Surface Elevation Directly Upstream of Bridge (10 Year Design) = 1402.02 feet

My Job 6) Make Recommendations

Scour DepthBelow Channel FloorRecommendation #3: Scour Depth

Hydraulic Report OutlineExecutive Summary Summarize the scope and significant results of the studyProject Description Define the context of existing structure within the local and regional built and natural environment. Five sections:Existing BridgeCrossed waterway Highway conveyedLand uses in the vicinity of the bridgeSpecial site considerationsData Collection Summarize the results of the hydraulic studys data collection Engineering Methods Identify Analytical MethodsHydrologic AnalysesHydraulic AnalysesScour Safety/Stability AnalysesConclusions and Recommendations Appendices

Burrington Brook 10, 25, 50, 100 & 500 peak flows

Any Questions?

Any Questions?