Urban Storm Drain Design: Junction box standards

Junction box standards Highlight various parts of Manhole Type M standards and specification sheet. Identify “things” that may confuse Feel free to mark on the sheet in your participant manual.

Junction box standards Similar to inlet considerations, rebar important. Sometimes can join boxes to maintain orientation If box over 6 feet wide -- special case, call BRG.

Junction box standards Riser does not have to be different dimension than the box

Junction box standards Make as many elements as possible identical Enhance constructability Min/max dimensions: maximum is structural limitation, if must exceed call BRG for guidance. D+1 ft. becomes limiting with box structures – they can get wide

Junction box standards Try to make elements identical and repeatable 1 set inlet, 1 set laterals, 1 junction

Junction box standards Offsets are not a constraint. Can have multiple offsets. Can have multiple penetrations on a side.

Junction box standards When have high topographic relief, use drops in junction boxes to control energy and velocity. Try to keep time of travel in system similar to pre- development conditions. d/D, Q, and V tells us where we need to change D as move through the system.