Abstract: A turndown pad (20) having a deck panel sub-assembly (22) that is connected to side-wall sub-assemblies (24) by corner pultrusion members (26) and that is supported by a mounting pultrusion member (98). The deck panel sub-assembly (22) and the side-wall sub-assemblies (24) are constructed of lateral arrays of panel members (34). Selected side-wall sub-assemblies (24) are constructed of parallel lateral arrays of panel members (34) and pad (20 can also further include a portal trim member (110). In alternative embodiments, pad (20) can cooperate with an extension (120) and a platform anchor (124).

Abstract: A manhole insert wherein gusset (58,60) and (62,64) or offset sections (142,144) and (146,148) anchor pins (94,96) or (158,160) that can be grappled with tools (not shown) to remove the insert. The bottom of the insert includes a conical frustum (40) and an inverted cone (48) or a panel that has a convex inner surface.