ADA Standards and Definitions Flashcards
_____ are used to convert concentrated stormwater flow into low-velocity sheet flow. As flow is discharged from a pipe, headwall, swale, or other conveyance, it is detained and spread horizontally along a contour by a low, level, non erodible barrier such as concrete
wall.
Level Spreader
Clear width of walking surfaces
36”
Where the accessible route makes a 180 degree turn:
Clear width at approaching turn
42” (1066 mm)
Where the accessible route makes a 180 degree turn:
Clear width at the turn
48” (1220 mm)
Where the accessible route makes a 180 degree turn:
Clear width leaving the turn
42” (1066mm)
Clear width of a ramp where handrails are provided
36” (915mm)
Max rise of ramp
30” (762mm)
Max length of ramp
30’ (9116mm)
Min landing width of ramp turning 90 degrees
60” x 60” (1525x1525mm)
Min and max of handrail heights
34-38” (865-965mm)
Grading:
Best suited for lineal construction such as roads paths and utility trenching
Average End Area Method
Grading:
Appropriate for large, relatively uncomplicated grading plans and may also be used to calculate volumes of water in ponds and lakes
Contour Area Method
Grading:
Appropriate for complex grading projects and urban conditions
Borrow Pit Method or Grid Method
Optimum range for 2R+T
24-26”
Min Width for Disabled Parking
9’
