Segmented cylindrical reinforced plastic manhole structure

A molded reinforced plastic segment for use in a manhole structure of the type comprising a body cylindrical about a vertical axis, made up of at least one tier of said segments and surmounted by a transition element having an access opening and supporting a conventional manhole cover and frame assembly, said segment comprising a thin-walled cylindrical segment curved about a vertical axis with vertical side edges and horizontal top and bottom edges, the exterior surface of said segment wall is substantially smooth and uninterrupted, the interior surface of said segment wall is provided with a plurality of evenly spaced, inwardly extending horizontal ribs, the uppermost one of said ribs being located along said top edge of said segment, the lowermost one of said ribs being spaced upwardly from said bottom edge of said segment such that when said body comprises more than one tier, the ribs of segments located one above the other will be evenly spaced throughout the height of said body, said ribs of said segment extending substantially from one vertical edge of said segment to the other whereby, when said segment is joined to another to form a tier, said interior ribs of said segments will form substantially continuous annular ribs, each of said vertical side edges of said segment being configured to provide an interlocking vertical joint between it and the vertical edge of an adjacent one of said segments in a tier thereof, each of said horizontal top and bottom edges of said segment being configured to provide an interlocking horizontal joint between it and the horizontal edge of an adjacent segment of adjacent tiers thereabove and therebelow when said manhole body comprises more than one tier, said segment being nestable with another identical segment.

A segmented manhole structure comprising a hollow body surmounted by a transition element, said body being cylindrical about a vertical axis with upper and lower ends, said body comprising at least one tier of curved nestable reinforced plastic segments, at least two segments being required for each tier, each of said segments having vertical side edges configured to provide an interlocking vertical joint between it and an adjacent one of said segments in said at least one tier each of said segments having horizontal top and bottom edges configured to provide an interlocking horizontal joint between it and adjacent segments of adjacent tiers thereabove and therebelow when said body comprises more than one tier, said segments of said body being joined together by an adhesive sealant at said vertical and horizontal interlocking joints rendering said joints fluid tight, each of said segments having a substantially smooth and uninterrupted exterior surface and inwardly extending horizontal ribs on its interior surface so that said manhole structure body has a substantially smooth and uninterrupted exterior surface and an interior surface with inwardly extending horizontal, substantially continuous, annular ribs, said transition element being supported on said upper end of said body, means for forming a fluid-tight seal between said transition element and said upper end of said body, said transition element having an access opening therein.