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.