Definition - What does Ramp Manhole mean?
A ramp manhole is defined as a slope provided at a bend where two pipes carrying flowing liquid like storm water or sewage meet to carry the liquid forward. This ramp, or transition, prevents the accumulation of heavier particles present in the flowing liquid at bends and at right angles.
Ramp manholes are also known as Backdrop manholes.
Trenchlesspedia explains Ramp Manhole
A ramp manhole is used where the level difference between drains are greater than 600 mm. A gradual slope is provided for for smooth transition. In cases where the ground slopes steeply, ramps are designed for sewer pipes laid to control the velocity and depths of construction. The ramp is formed in the end of the upper sewer with a rodding eye for a level difference of 1800 mm at an angle of 45 degrees. For larger sewers, cascade ramps consisting of steps are used to break the flow.