I know interstates have to be designed to AASHTO standards but what about ramps at interchanges? Is there a grey area along the ramp where the standard changes from AASHTO to the state design manual?
Generally invert changes at sanitary manholes of 2' or greater are done with inside or outside drop manholes but I never really understood what the purpose is. If it's for hydraulic reasons, why not use them for storm manholes as well?
In the Hydraflow Storm Sewers manual, it says HGL calculations are based on energy-based standard step method. But it notes that it does not compute supercritical flow profiles and that when the energy equation cannot balance, it assumes critical depth. Why would the energy equation not balance...
There is a common rule that contour lines cannot branch or split. However if there is a v-shaped valley where the bottom is at elev 10, for example, then the 10 contour will be a straight line and then split once the elevation of the bottom of the valley changes. So is this rule just an...
Where should the invert elevation of the pipe into a basin be set at? If its low, as the basin fills up, so will the pipe. Does this matter? Usually pipes are designed to flow full so I'm not saying the pipe can be used as additional storage but what are the considerations when determing the...
