v2 new feature - Culvert
A variety of barrel cross-sections can be selected including:
- pipes,
- rectangular box sections,
- horizontal or vertical elliptical sections of pipe arch
sections.
Multiple barrels can be defined but all barrels will have the same
attributes.
If the inflow is described by a hydrograph completion of the design
for the peak flow causes the [Route] command button to be enabled. The
available storage upstream of the embankment through which the culvert
passes is defined by the slope of the flood plains on either side of
the channel and the slope and geometry of the channel leading to the
culvert. A table is constructed with the stage, discharge and volume
storage upstream of the culvert assuming that the upstream water
surface is approximately horizontal. This allows the inflow hydrograph
to be routed through the ponded reach with the result that the peak
flow through the culvert is less than the peak of the inflow
hydrograph. The design can then be updated for the reduced flow or
left unchanged.
The results are displayed both graphically and in tabular form as in
other flood routing commands.
If the culvert is surcharged either by a high flow rate or by a high
tail-water depth it may happen that the flow is split into two
components – through the culvert and over the weir formed by the
embankment. In this case the weir flow is reported separately and the
depth over the crest of the embankment is shown.
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