8,255
edits
Changes
Jump to navigation
Jump to search
mLine 1:
Line 1: − + Line 26:
Line 26: − + Line 43:
Line 43: − + − + Line 59:
Line 59: − +
no edit summary
<poem>
<poem>
Curb cuts are a form of BMP [[Inlets|inlet]].
Curb cuts are a form of LID/BMP [[Inlets|inlet]].
They are well suited to retrofit scenarios and to collect runoff from catchments with relatively gentle longitudinal slope, and/or a greater cross slope. This might be the local topography of a parking lot or a piece of parkland?
They are well suited to retrofit scenarios and to collect runoff from catchments with relatively gentle longitudinal slope, and/or a greater cross slope. This might be the local topography of a parking lot or a piece of parkland?
As this inlet width is directly proportional to longitudinal slope; the required curb cut width increases rapidly on steeper roads.
As this inlet width is directly proportional to longitudinal slope; the required curb cut width increases rapidly on steeper roads.
{{#widget:WolframAlpha|id=664012476f5d9635d57cd58920e763e6}}</div>
{{#widget:WolframAlpha|id=664012476f5d9635d57cd58920e763e6}}</div>
To completely capture linear flow travelling along a gutter perpendicular to a curb inlet, the inlet must be of width::
To completely capture linear flow travelling along a gutter perpendicular to a curb inlet, the inlet must be of width<ref>U.S. Department of Transportation, Federal Highways Administration. 2013. “URBAN DRAINAGE DESIGN MANUAL.” https://www.fhwa.dot.gov/engineering/hydraulics/pubs/10009/10009.pdf.[[File:USFHWA 2009.pdf|view here]]</ref>::
<math>W_T=0.817Q^{0.42}S_{0}^{0.3}\left (\frac{1}{nS_{x}}\right)^{0.6}</math>
<math>W_T=0.817Q^{0.42}S_{0}^{0.3}\left (\frac{1}{nS_{x}}\right)^{0.6}</math>
*''W'' is the available curb cut width (m)}}
*''W'' is the available curb cut width (m)}}
Where the curb cut width is constrained and a greater flow into the BMP is desired, the effective cross slope may be increased by adding a depressed apron.
Where the curb cut width is constrained and a greater flow into the BMP is desired, the effective cross slope may be increased by adding a depressed apron.
==Example==
==Example==
A curb cut of 3 m is proposed as an inlet for an offline [[Bioretention|bioretention cell]] receiving runoff from an adjacent roadway. The gutter and the curb are made from smooth concrete with Manning's 'n' = 0.013. The x-slope is 3% and the longitudinal slope of the road is 2%. The design storm produces flow of 0.08 m<sup>3</sup>/s.
A curb cut of 3 m is proposed as an inlet for an offline [[Bioretention|bioretention cell]] receiving runoff from an adjacent roadway. The gutter and the curb are made from smooth concrete with Manning's 'n' = 0.013. The x-slope is 3% and the longitudinal slope of the road is 2%. The 1 in 25 year design storm produces a peak flow of 0.08 m<sup>3</sup>/s.
The width of inlet to capture 100% of this flow is::
The width of inlet to capture 100% of this flow is::
{{:Curb cuts: Gallery}}
{{:Curb cuts: Gallery}}
----
----
[[category: modeling]]
[[category: Calculations]]